From: Jack Lau <jacklau1222gm@gmail.com>
To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
Subject: Re: [FFmpeg-devel] [PATCH v3] avformat/whip: Add WHIP muxer support for subsecond latency streaming
Date: Wed, 4 Jun 2025 11:38:53 +0800
Message-ID: <8AAF27DC-32AE-4EAD-A464-F13C68A97AE6@gmail.com> (raw)
In-Reply-To: <CADxeRw=5o1NvZTvjr3buZ6fN0n-4i_QdAg41-Ne=MShEhA7XfQ@mail.gmail.com>
> On Jun 4, 2025, at 11:21, Steven Liu <lingjiujianke@gmail.com> wrote:
>
> Jack Lau via ffmpeg-devel <ffmpeg-devel@ffmpeg.org> 于2025年5月17日周六 17:25写道：
>>
>> 0. WHIP Version 3.
>> 1. The WHIP muxer has been renamed and refined, with improved logging context and error messages for SSL, DTLS, and RTC.
>> 2. Magic numbers have been replaced with macros and extracted to functions, and log levels have been altered for better clarity.
>> 3. DTLS curve list has been updated, and SRTP profile names have been refined for FFmpeg and OpenSSL.
>> 4. ICE STUN magic number has been refined, and RTP payload types have been updated based on Chrome's definition.
>> 5. Fixed frame size has been refined to rtc->audio_par->frame_size, and h264_mp4toannexb is now used to convert MP4/ISOM to annexb.
>> 6. OPUS timestamp issue has been addressed, and marker setting has been corrected after utilizing BSF.
>> 7. DTLS handshake and ICE handling have been optimized for improved performance, with a single handshake timeout and server role to prevent ARQ.
>> 8. Consolidated ICE request/response handling and DTLS handshake into a single function, and fixed OpenSSL build errors to work with Pion.
>> 9. Merge TLS & DTLS implementation, shared BIO callbacks, read, write, print_ssl_error, openssl_init_ca_key_cert, init_bio_method function and shared same data structure
>> 10. Modify configure that whip is enabled only dtls is enabled(just support openssl for now) to fix build error
>>
>> Co-authored-by: winlin <winlinvip@gmail.com>
>> Co-authored-by: yangrtc <yangrtc@aliyun.com>
>> Co-authored-by: cloudwebrtc <duanweiwei1982@gmail.com>
>> Co-authored-by: Haibo Chen <495810242@qq.com>
>> Co-authored-by: Steven Liu <lq@chinaffmpeg.org>
>> Co-authored-by: Jun Zhao <barryjzhao@tencent.com>
>> Signed-off-by: Jack Lau <jacklau1222@qq.com>
>> ---
>> configure | 12 +
>> doc/muxers.texi | 47 +
>> libavformat/Makefile | 1 +
>> libavformat/allformats.c | 1 +
>> libavformat/avio.c | 5 +-
>> libavformat/http.c | 6 +
>> libavformat/http.h | 2 +
>> libavformat/protocols.c | 1 +
>> libavformat/srtp.h | 4 +-
>> libavformat/tls.c | 70 +-
>> libavformat/tls.h | 58 +-
>> libavformat/tls_openssl.c | 857 ++++++++++++++++-
>> libavformat/whip.c | 1917 +++++++++++++++++++++++++++++++++++++
>> 13 files changed, 2925 insertions(+), 56 deletions(-)
>> create mode 100644 libavformat/whip.c
>>
>> diff --git a/configure b/configure
>> index 0609dac4ab..2a3166962a 100755
>> --- a/configure
>> +++ b/configure
>> @@ -3747,6 +3747,7 @@ wav_demuxer_select="riffdec"
>> wav_muxer_select="riffenc"
>> webm_chunk_muxer_select="webm_muxer"
>> webm_dash_manifest_demuxer_select="matroska_demuxer"
>> +whip_muxer_deps_any="dtls_protocol"
>> wtv_demuxer_select="mpegts_demuxer riffdec"
>> wtv_muxer_select="mpegts_muxer riffenc"
>> xmv_demuxer_select="riffdec"
>> @@ -3845,6 +3846,9 @@ srtp_protocol_select="rtp_protocol srtp"
>> tcp_protocol_select="network"
>> tls_protocol_deps_any="gnutls openssl schannel securetransport libtls mbedtls"
>> tls_protocol_select="tcp_protocol"
>> +# TODO: Support libtls, mbedtls, and gnutls.
>> +dtls_protocol_deps_any="openssl"
>> +dtls_protocol_select="udp_protocol"
>> udp_protocol_select="network"
>> udplite_protocol_select="network"
>> unix_protocol_deps="sys_un_h"
>> @@ -7192,6 +7196,14 @@ enabled rkmpp && { require_pkg_config rkmpp rockchip_mpp rockchip/r
>> }
>> enabled vapoursynth && require_headers "vapoursynth/VSScript4.h vapoursynth/VapourSynth4.h"
>>
>> +enabled openssl && {
>> + enabled whip_muxer && {
>> + $pkg_config --exists --print-errors "openssl >= 1.0.1k" ||
>> + require_pkg_config openssl "openssl >= 1.0.1k" openssl/ssl.h SSL_library_init ||
>> + require_pkg_config openssl "openssl >= 1.0.1k" openssl/ssl.h OPENSSL_init_ssl
>> + }
>> +}
>> +
>>
>> if enabled gcrypt; then
>> GCRYPT_CONFIG="${cross_prefix}libgcrypt-config"
>> diff --git a/doc/muxers.texi b/doc/muxers.texi
>> index 04b7f20b7e..30c95c3d34 100644
>> --- a/doc/muxers.texi
>> +++ b/doc/muxers.texi
>> @@ -3879,4 +3879,51 @@ ffmpeg -f webm_dash_manifest -i video1.webm \
>> manifest.xml
>> @end example
>>
>> +@anchor{whip}
>> +@section whip
>> +
>> +WebRTC (Real-Time Communication) muxer that supports sub-second latency streaming according to
>> +the WHIP (WebRTC-HTTP ingestion protocol) specification.
>> +
>> +It uses HTTP as a signaling protocol to exchange SDP capabilities and ICE lite candidates. Then,
>> +it uses STUN binding requests and responses to establish a session over UDP. Subsequently, it
>> +initiates a DTLS handshake to exchange the SRTP encryption keys. Lastly, it splits video and
>> +audio frames into RTP packets and encrypts them using SRTP.
>> +
>> +Ensure that you use H.264 without B frames and Opus for the audio codec. For example, to convert
>> +an input file with @command{ffmpeg} to WebRTC:
>> +@example
>> +ffmpeg -re -i input.mp4 -acodec libopus -ar 48000 -ac 2 \
>> + -vcodec libx264 -profile:v baseline -tune zerolatency -threads 1 -bf 0 \
>> + -f whip "http://localhost:1985/rtc/v1/whip/?app=live&stream=livestream"
>> +@end example
>> +
>> +For this example, we have employed low latency options, resulting in an end-to-end latency of
>> +approximately 150ms.
>> +
>> +@subsection Options
>> +
>> +This muxer supports the following options:
>> +
>> +@table @option
>> +
>> +@item handshake_timeout @var{integer}
>> +Set the timeout in milliseconds for ICE and DTLS handshake.
>> +Default value is 5000.
>> +
>> +@item pkt_size @var{integer}
>> +Set the maximum size, in bytes, of RTP packets that send out.
>> +Default value is 1500.
>> +
>> +@item authorization @var{string}
>> +The optional Bearer token for WHIP Authorization.
>> +
>> +@item cert_file @var{string}
>> +The optional certificate file path for DTLS.
>> +
>> +@item key_file @var{string}
>> +The optional private key file path for DTLS.
>> +
>> +@end table
>> +
>> @c man end MUXERS
>> diff --git a/libavformat/Makefile b/libavformat/Makefile
>> index 6c9992adab..96a6430158 100644
>> --- a/libavformat/Makefile
>> +++ b/libavformat/Makefile
>> @@ -637,6 +637,7 @@ OBJS-$(CONFIG_WEBM_CHUNK_MUXER) += webm_chunk.o
>> OBJS-$(CONFIG_WEBP_MUXER) += webpenc.o
>> OBJS-$(CONFIG_WEBVTT_DEMUXER) += webvttdec.o subtitles.o
>> OBJS-$(CONFIG_WEBVTT_MUXER) += webvttenc.o
>> +OBJS-$(CONFIG_WHIP_MUXER) += whip.o avc.o http.o srtp.o tls_openssl.o
>> OBJS-$(CONFIG_WSAUD_DEMUXER) += westwood_aud.o
>> OBJS-$(CONFIG_WSAUD_MUXER) += westwood_audenc.o
>> OBJS-$(CONFIG_WSD_DEMUXER) += wsddec.o rawdec.o
>> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
>> index b5a23f9c17..3e5f127dc1 100644
>> --- a/libavformat/allformats.c
>> +++ b/libavformat/allformats.c
>> @@ -517,6 +517,7 @@ extern const FFOutputFormat ff_webp_muxer;
>> extern const FFInputFormat ff_webvtt_demuxer;
>> extern const FFOutputFormat ff_webvtt_muxer;
>> extern const FFInputFormat ff_wsaud_demuxer;
>> +extern const FFOutputFormat ff_whip_muxer;
>> extern const FFOutputFormat ff_wsaud_muxer;
>> extern const FFInputFormat ff_wsd_demuxer;
>> extern const FFInputFormat ff_wsvqa_demuxer;
>> diff --git a/libavformat/avio.c b/libavformat/avio.c
>> index d109f3adff..b146ac9f19 100644
>> --- a/libavformat/avio.c
>> +++ b/libavformat/avio.c
>> @@ -339,8 +339,9 @@ static const struct URLProtocol *url_find_protocol(const char *filename)
>> }
>> }
>> av_freep(&protocols);
>> - if (av_strstart(filename, "https:", NULL) || av_strstart(filename, "tls:", NULL))
>> - av_log(NULL, AV_LOG_WARNING, "https protocol not found, recompile FFmpeg with "
>> + if (av_strstart(filename, "https:", NULL) || av_strstart(filename, "tls:", NULL) ||
>> + av_strstart(filename, "dtls:", NULL))
>> + av_log(NULL, AV_LOG_WARNING, "https or dtls protocol not found, recompile FFmpeg with "
>> "openssl, gnutls or securetransport enabled.\n");
>>
>> return NULL;
>> diff --git a/libavformat/http.c b/libavformat/http.c
>> index f7b2a8a029..ff63c25969 100644
>> --- a/libavformat/http.c
>> +++ b/libavformat/http.c
>> @@ -562,6 +562,12 @@ int ff_http_averror(int status_code, int default_averror)
>> return default_averror;
>> }
>>
>> +const char* ff_http_get_new_location(URLContext *h)
>> +{
>> + HTTPContext *s = h->priv_data;
>> + return s->new_location;
>> +}
>> +
>> static int http_write_reply(URLContext* h, int status_code)
>> {
>> int ret, body = 0, reply_code, message_len;
>> diff --git a/libavformat/http.h b/libavformat/http.h
>> index 5f650ef143..d1b691826b 100644
>> --- a/libavformat/http.h
>> +++ b/libavformat/http.h
>> @@ -62,4 +62,6 @@ int ff_http_do_new_request2(URLContext *h, const char *uri, AVDictionary **optio
>>
>> int ff_http_averror(int status_code, int default_averror);
>>
>> +const char* ff_http_get_new_location(URLContext *h);
>> +
>> #endif /* AVFORMAT_HTTP_H */
>> diff --git a/libavformat/protocols.c b/libavformat/protocols.c
>> index 93a6d67261..d394454d41 100644
>> --- a/libavformat/protocols.c
>> +++ b/libavformat/protocols.c
>> @@ -62,6 +62,7 @@ extern const URLProtocol ff_subfile_protocol;
>> extern const URLProtocol ff_tee_protocol;
>> extern const URLProtocol ff_tcp_protocol;
>> extern const URLProtocol ff_tls_protocol;
>> +extern const URLProtocol ff_dtls_protocol;
>> extern const URLProtocol ff_udp_protocol;
>> extern const URLProtocol ff_udplite_protocol;
>> extern const URLProtocol ff_unix_protocol;
>> diff --git a/libavformat/srtp.h b/libavformat/srtp.h
>> index 3189f8f54b..35224cc9ba 100644
>> --- a/libavformat/srtp.h
>> +++ b/libavformat/srtp.h
>> @@ -27,7 +27,7 @@
>> struct AVAES;
>> struct AVHMAC;
>>
>> -struct SRTPContext {
>> +typedef struct SRTPContext {
>> struct AVAES *aes;
>> struct AVHMAC *hmac;
>> int rtp_hmac_size, rtcp_hmac_size;
>> @@ -40,7 +40,7 @@ struct SRTPContext {
>> uint32_t roc;
>>
>> uint32_t rtcp_index;
>> -};
>> +} SRTPContext;
>>
>> int ff_srtp_set_crypto(struct SRTPContext *s, const char *suite,
>> const char *params);
>> diff --git a/libavformat/tls.c b/libavformat/tls.c
>> index f96ff6215d..e06b7022bf 100644
>> --- a/libavformat/tls.c
>> +++ b/libavformat/tls.c
>> @@ -1,6 +1,7 @@
>> /*
>> - * TLS/SSL Protocol
>> + * TLS/DTLS/SSL Protocol
>> * Copyright (c) 2011 Martin Storsjo
>> + * Copyright (c) 2025 Jack Lau
>> *
>> * This file is part of FFmpeg.
>> *
>> @@ -20,6 +21,7 @@
>> */
>>
>> #include "avformat.h"
>> +#include "internal.h"
>> #include "network.h"
>> #include "os_support.h"
>> #include "url.h"
>> @@ -93,7 +95,7 @@ int ff_tls_open_underlying(TLSShared *c, URLContext *parent, const char *uri, AV
>> c->listen = 1;
>> }
>>
>> - ff_url_join(buf, sizeof(buf), "tcp", NULL, c->underlying_host, port, "%s", p);
>> + ff_url_join(buf, sizeof(buf), c->is_dtls ? "udp" : "tcp", NULL, c->underlying_host, port, "%s", p);
>>
>> hints.ai_flags = AI_NUMERICHOST;
>> if (!getaddrinfo(c->underlying_host, NULL, &hints, &ai)) {
>> @@ -124,7 +126,65 @@ int ff_tls_open_underlying(TLSShared *c, URLContext *parent, const char *uri, AV
>> }
>>
>> freeenv_utf8(env_http_proxy);
>> - return ffurl_open_whitelist(&c->tcp, buf, AVIO_FLAG_READ_WRITE,
>> - &parent->interrupt_callback, options,
>> - parent->protocol_whitelist, parent->protocol_blacklist, parent);
>> + if (c->is_dtls) {
>> + av_dict_set_int(options, "connect", 1, 0);
>> + av_dict_set_int(options, "fifo_size", 0, 0);
>> + /* Set the max packet size to the buffer size. */
>> + av_dict_set_int(options, "pkt_size", c->mtu, 0);
>> + }
>> + ret = ffurl_open_whitelist(c->is_dtls ? &c->udp : &c->tcp, buf, AVIO_FLAG_READ_WRITE,
>> + &parent->interrupt_callback, options,
>> + parent->protocol_whitelist, parent->protocol_blacklist, parent);
>> + if (c->is_dtls) {
>> + if (ret < 0) {
>> + av_log(c, AV_LOG_ERROR, "WHIP: Failed to connect udp://%s:%d\n", c->underlying_host, port);
>> + return ret;
>> + }
>> + /* Make the socket non-blocking, set to READ and WRITE mode after connected */
>> + ff_socket_nonblock(ffurl_get_file_handle(c->udp), 1);
>> + c->udp->flags |= AVIO_FLAG_READ | AVIO_FLAG_NONBLOCK;
>> + }
>> + return ret;
>> }
>> +
>> +/**
>> + * Read all data from the given URL url and store it in the given buffer bp.
>> + */
>> +int ff_url_read_all(const char *url, AVBPrint *bp)
>> +{
>> + int ret = 0;
>> + AVDictionary *opts = NULL;
>> + URLContext *uc = NULL;
>> + char buf[MAX_URL_SIZE];
>> +
>> + ret = ffurl_open_whitelist(&uc, url, AVIO_FLAG_READ, NULL, &opts, NULL, NULL, NULL);
>> + if (ret < 0) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to open url %s\n", url);
>> + goto end;
>> + }
>> +
>> + while (1) {
>> + ret = ffurl_read(uc, buf, sizeof(buf));
>> + if (ret == AVERROR_EOF) {
>> + /* Reset the error because we read all response as answer util EOF. */
>> + ret = 0;
>> + break;
>> + }
>> + if (ret <= 0) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to read from url=%s, key is %s\n", url, bp->str);
>> + goto end;
>> + }
>> +
>> + av_bprintf(bp, "%.*s", ret, buf);
>> + if (!av_bprint_is_complete(bp)) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Exceed max size %.*s, %s\n", ret, buf, bp->str);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> + }
>> +
>> +end:
>> + ffurl_closep(&uc);
>> + av_dict_free(&opts);
>> + return ret;
>> +}
>> \ No newline at end of file
>> diff --git a/libavformat/tls.h b/libavformat/tls.h
>> index 6c6aa01a9a..cb626f1977 100644
>> --- a/libavformat/tls.h
>> +++ b/libavformat/tls.h
>> @@ -1,6 +1,7 @@
>> /*
>> - * TLS/SSL Protocol
>> + * TLS/DTLS/SSL Protocol
>> * Copyright (c) 2011 Martin Storsjo
>> + * Copyright (c) 2025 Jack Lau
>> *
>> * This file is part of FFmpeg.
>> *
>> @@ -22,10 +23,27 @@
>> #ifndef AVFORMAT_TLS_H
>> #define AVFORMAT_TLS_H
>>
>> +#include "libavutil/bprint.h"
>> #include "libavutil/opt.h"
>>
>> #include "url.h"
>>
>> +/**
>> + * Maximum size limit of a certificate and private key size.
>> + */
>> +#define MAX_CERTIFICATE_SIZE 8192
>> +
>> +enum DTLSState {
>> + DTLS_STATE_NONE,
>> +
>> + /* Whether DTLS handshake is finished. */
>> + DTLS_STATE_FINISHED,
>> + /* Whether DTLS session is closed. */
>> + DTLS_STATE_CLOSED,
>> + /* Whether DTLS handshake is failed. */
>> + DTLS_STATE_FAILED,
>> +};
>> +
>> typedef struct TLSShared {
>> char *ca_file;
>> int verify;
>> @@ -40,6 +58,25 @@ typedef struct TLSShared {
>> int numerichost;
>>
>> URLContext *tcp;
>> +
>> + int is_dtls;
>> +
>> + enum DTLSState state;
>> +
>> + int use_external_udp;
>> + URLContext *udp;
>> +
>> + /* The fingerprint of certificate, used in SDP offer. */
>> + char *fingerprint;
>> +
>> + /* The certificate and private key content used for DTLS handshake */
>> + char* cert_buf;
>> + char* key_buf;
>> + /**
>> + * The size of RTP packet, should generally be set to MTU.
>> + * Note that pion requires a smaller value, for example, 1200.
>> + */
>> + int mtu;
>> } TLSShared;
>>
>> #define TLS_OPTFL (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_ENCODING_PARAM)
>> @@ -51,10 +88,27 @@ typedef struct TLSShared {
>> {"key_file", "Private key file", offsetof(pstruct, options_field . key_file), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }, \
>> {"listen", "Listen for incoming connections", offsetof(pstruct, options_field . listen), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, .flags = TLS_OPTFL }, \
>> {"verifyhost", "Verify against a specific hostname", offsetof(pstruct, options_field . host), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }, \
>> - {"http_proxy", "Set proxy to tunnel through", offsetof(pstruct, options_field . http_proxy), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }
>> + {"http_proxy", "Set proxy to tunnel through", offsetof(pstruct, options_field . http_proxy), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }, \
>> + {"use_external_udp", "Use external UDP from muxer or demuxer", offsetof(pstruct, options_field . use_external_udp), AV_OPT_TYPE_INT, { .i64 = 0}, 0, 1, .flags = TLS_OPTFL }, \
>> + {"mtu", "Maximum Transmission Unit", offsetof(pstruct, options_field . mtu), AV_OPT_TYPE_INT, { .i64 = 0}, INT64_MIN, INT64_MAX, .flags = TLS_OPTFL}, \
>> + {"fingerprint", "The optional fingerprint for DTLS", offsetof(pstruct, options_field . fingerprint), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL}, \
>> + {"cert_buf", "The optional certificate buffer for DTLS", offsetof(pstruct, options_field . cert_buf), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL}, \
>> + {"key_buf", "The optional private key buffer for DTLS", offsetof(pstruct, options_field . key_buf), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL}
>>
>> int ff_tls_open_underlying(TLSShared *c, URLContext *parent, const char *uri, AVDictionary **options);
>>
>> +int ff_url_read_all(const char *url, AVBPrint *bp);
>> +
>> +int ff_dtls_set_udp(URLContext *h, URLContext *udp);
>> +
>> +int ff_dtls_export_materials(URLContext *h, char *dtls_srtp_materials, size_t materials_sz);
>> +
>> +int ff_dtls_state(URLContext *h);
>> +
>> +int ff_ssl_read_key_cert(char *key_url, char *cert_url, char *key_buf, size_t key_sz, char *cert_buf, size_t cert_sz, char **fingerprint);
>> +
>> +int ff_ssl_gen_key_cert(char *key_buf, size_t key_sz, char *cert_buf, size_t cert_sz, char **fingerprint);
>> +
>> void ff_gnutls_init(void);
>> void ff_gnutls_deinit(void);
>>
>> diff --git a/libavformat/tls_openssl.c b/libavformat/tls_openssl.c
>> index 8b0cf9efb2..b589d5d90a 100644
>> --- a/libavformat/tls_openssl.c
>> +++ b/libavformat/tls_openssl.c
>> @@ -1,6 +1,7 @@
>> /*
>> - * TLS/SSL Protocol
>> + * TLS/DTLS/SSL Protocol
>> * Copyright (c) 2011 Martin Storsjo
>> + * Copyright (c) 2025 Jack Lau
>> *
>> * This file is part of FFmpeg.
>> *
>> @@ -19,8 +20,10 @@
>> * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>> */
>>
>> +#include "libavutil/mem.h"
>> #include "network.h"
>> #include "os_support.h"
>> +#include "libavutil/random_seed.h"
>> #include "url.h"
>> #include "tls.h"
>> #include "libavutil/opt.h"
>> @@ -29,6 +32,436 @@
>> #include <openssl/ssl.h>
>> #include <openssl/err.h>
>>
>> +/**
>> + * Returns a heap‐allocated null‐terminated string containing
>> + * the PEM‐encoded public key. Caller must free.
>> + */
>> +static char *pkey_to_pem_string(EVP_PKEY *pkey) {
>> + BIO *mem = NULL;
>> + BUF_MEM *bptr = NULL;
>> + char *pem_str = NULL;
>> +
>> + // Create a memory BIO
>> + if (!(mem = BIO_new(BIO_s_mem())))
>> + goto err;
>> +
>> + // Write public key in PEM form
>> + if (!PEM_write_bio_PrivateKey(mem, pkey, NULL, NULL, 0, NULL, NULL))
>> + goto err;
>> +
>> + // Extract pointer/length
>> + BIO_get_mem_ptr(mem, &bptr);
>> + if (!bptr || !bptr->length)
>> + goto err;
>> +
>> + // Allocate string (+1 for NUL)
>> + pem_str = av_malloc(bptr->length + 1);
>> + if (!pem_str)
>> + goto err;
>> +
>> + // Copy data & NUL‐terminate
>> + memcpy(pem_str, bptr->data, bptr->length);
>> + pem_str[bptr->length] = '\0';
>> +
>> +cleanup:
>> + BIO_free(mem);
>> + return pem_str;
>> +
>> +err:
>> + // error path: free and return NULL
>> + free(pem_str);
>> + pem_str = NULL;
>> + goto cleanup;
>> +}
>> +
>> +/**
>> + * Serialize an X509 certificate to a av_malloc’d PEM string.
>> + * Caller must free the returned pointer.
>> + */
>> +static char *cert_to_pem_string(X509 *cert)
>> +{
>> + BIO *mem = BIO_new(BIO_s_mem());
>> + BUF_MEM *bptr = NULL;
>> + char *out = NULL;
>> +
>> + if (!mem) goto err;
>> +
>> + /* Write the PEM certificate */
>> + if (!PEM_write_bio_X509(mem, cert))
>> + goto err;
>> +
>> + BIO_get_mem_ptr(mem, &bptr);
>> + if (!bptr || !bptr->length) goto err;
>> +
>> + out = av_malloc(bptr->length + 1);
>> + if (!out) goto err;
>> +
>> + memcpy(out, bptr->data, bptr->length);
>> + out[bptr->length] = '\0';
>> +
>> +cleanup:
>> + BIO_free(mem);
>> + return out;
>> +
>> +err:
>> + free(out);
>> + out = NULL;
>> + goto cleanup;
>> +}
>> +
>> +
>> +/**
>> + * Generate a SHA-256 fingerprint of an X.509 certificate.
>> + *
>> + * @param ctx AVFormatContext for logging (can be NULL)
>> + * @param cert X509 certificate to fingerprint
>> + * @return Newly allocated fingerprint string in "AA:BB:CC:…" format,
>> + * or NULL on error (logs via av_log if ctx is not NULL).
>> + * Caller must free() the returned string.
>> + */
>> +static char *generate_fingerprint(X509 *cert)
>> +{
>> + unsigned char md[EVP_MAX_MD_SIZE];
>> + int n = 0;
>> + AVBPrint fingerprint;
>> + char *result = NULL;
>> + int i;
>> +
>> + /* To prevent a crash during cleanup, always initialize it. */
>> + av_bprint_init(&fingerprint, 0, AV_BPRINT_SIZE_UNLIMITED);
>> +
>> + if (X509_digest(cert, EVP_sha256(), md, &n) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to generate fingerprint, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto end;
>> + }
>> +
>> + for (i = 0; i < n; i++) {
>> + av_bprintf(&fingerprint, "%02X", md[i]);
>> + if (i + 1 < n)
>> + av_bprintf(&fingerprint, ":");
>> + }
>> +
>> + if (!fingerprint.str || !strlen(fingerprint.str)) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Fingerprint is empty\n");
>> + goto end;
>> + }
>> +
>> + result = av_strdup(fingerprint.str);
>> + if (!result) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Out of memory generating fingerprint\n");
>> + }
>> +
>> +end:
>> + av_bprint_finalize(&fingerprint, NULL);
>> + return result;
>> +}
>> +
>> +int ff_ssl_read_key_cert(char *key_url, char *cert_url, char *key_buf, size_t key_sz, char *cert_buf, size_t cert_sz, char **fingerprint)
>> +{
>> + int ret = 0;
>> + BIO *key_b = NULL, *cert_b = NULL;
>> + AVBPrint key_bp, cert_bp;
>> + EVP_PKEY *pkey;
>> + X509 *cert;
>> + char *key_tem = NULL, *cert_tem = NULL;
>> +
>> + /* To prevent a crash during cleanup, always initialize it. */
>> + av_bprint_init(&key_bp, 1, MAX_CERTIFICATE_SIZE);
>> + av_bprint_init(&cert_bp, 1, MAX_CERTIFICATE_SIZE);
>> +
>> + /* Read key file. */
>> + ret = ff_url_read_all(key_url, &key_bp);
>> + if (ret < 0) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to open key file %s\n", key_url);
>> + goto end;
>> + }
>> +
>> + if (!(key_b = BIO_new(BIO_s_mem()))) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> +
>> + BIO_write(key_b, key_bp.str, key_bp.len);
>> + pkey = PEM_read_bio_PrivateKey(key_b, NULL, NULL, NULL);
>> + if (!pkey) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to read private key from %s\n", key_url);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> + /* Read certificate. */
>> + ret = ff_url_read_all(cert_url, &cert_bp);
>> + if (ret < 0) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to open cert file %s\n", cert_url);
>> + goto end;
>> + }
>> +
>> + if (!(cert_b = BIO_new(BIO_s_mem()))) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> +
>> + BIO_write(cert_b, cert_bp.str, cert_bp.len);
>> + cert = PEM_read_bio_X509(cert_b, NULL, NULL, NULL);
>> + if (!cert) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to read certificate from %s\n", cert_url);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> + key_tem = pkey_to_pem_string(pkey);
>> + cert_tem = cert_to_pem_string(cert);
>> +
>> + snprintf(key_buf, key_sz, "%s", key_tem);
>> + snprintf(cert_buf, cert_sz, "%s", cert_tem);
>> +
>> + /* Generate fingerprint. */
>> + *fingerprint = generate_fingerprint(cert);
>> + if (!*fingerprint) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to generate fingerprint from %s\n", cert_url);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> +end:
>> + BIO_free(key_b);
>> + av_bprint_finalize(&key_bp, NULL);
>> + BIO_free(cert_b);
>> + av_bprint_finalize(&cert_bp, NULL);
>> + if (key_tem) av_free(key_tem);
>> + if (cert_tem) av_free(cert_tem);
>> + return ret;
>> +}
>> +
>> +static int openssl_gen_private_key(EVP_PKEY **pkey, EC_KEY **eckey)
>> +{
>> + int ret = 0;
>> +
>> + /**
>> + * Note that secp256r1 in openssl is called NID_X9_62_prime256v1 or prime256v1 in string,
>> + * not NID_secp256k1 or secp256k1 in string.
>> + *
>> + * TODO: Should choose the curves in ClientHello.supported_groups, for example:
>> + * Supported Group: x25519 (0x001d)
>> + * Supported Group: secp256r1 (0x0017)
>> + * Supported Group: secp384r1 (0x0018)
>> + */
>> +#if OPENSSL_VERSION_NUMBER < 0x30000000L /* OpenSSL 3.0 */
>> + EC_GROUP *ecgroup = NULL;
>> + int curve = NID_X9_62_prime256v1;
>> +#else
>> + const char *curve = SN_X9_62_prime256v1;
>> +#endif
>> +
>> +#if OPENSSL_VERSION_NUMBER < 0x30000000L /* OpenSSL 3.0 */
>> + *pkey = EVP_PKEY_new();
>> + *eckey = EC_KEY_new();
>> + ecgroup = EC_GROUP_new_by_curve_name(curve);
>> + if (!ecgroup) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Create EC group by curve=%d failed, %s", curve, ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> +#if OPENSSL_VERSION_NUMBER < 0x10100000L // v1.1.x
>> + /* For openssl 1.0, we must set the group parameters, so that cert is ok. */
>> + EC_GROUP_set_asn1_flag(ecgroup, OPENSSL_EC_NAMED_CURVE);
>> +#endif
>> +
>> + if (EC_KEY_set_group(*eckey, ecgroup) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Generate private key, EC_KEY_set_group failed, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + if (EC_KEY_generate_key(*eckey) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Generate private key, EC_KEY_generate_key failed, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + if (EVP_PKEY_set1_EC_KEY(*pkey, *eckey) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Generate private key, EVP_PKEY_set1_EC_KEY failed, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +#else
>> + *pkey = EVP_EC_gen(curve);
>> + if (!*pkey) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Generate private key, EVP_EC_gen curve=%s failed, %s\n", curve, ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +#endif
>> + goto end;
>> +
>> +einval_end:
>> + ret = AVERROR(EINVAL);
>> +end:
>> +#if OPENSSL_VERSION_NUMBER < 0x30000000L /* OpenSSL 3.0 */
>> + EC_GROUP_free(ecgroup);
>> +#endif
>> + return ret;
>> +}
>> +
>> +static int openssl_gen_certificate(EVP_PKEY *pkey, X509 **cert, char **fingerprint)
>> +{
>> + int ret = 0, serial, expire_day;
>> + const char *aor = "lavf";
>> + X509_NAME* subject = NULL;
>> +
>> + *cert= X509_new();
>> + if (!*cert) {
>> + goto enomem_end;
>> + }
>> +
>> + // TODO: Support non-self-signed certificate, for example, load from a file.
>> + subject = X509_NAME_new();
>> + if (!subject) {
>> + goto enomem_end;
>> + }
>> +
>> + serial = (int)av_get_random_seed();
>> + if (ASN1_INTEGER_set(X509_get_serialNumber(*cert), serial) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to set serial, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + if (X509_NAME_add_entry_by_txt(subject, "CN", MBSTRING_ASC, aor, strlen(aor), -1, 0) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to set CN, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + if (X509_set_issuer_name(*cert, subject) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to set issuer, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> + if (X509_set_subject_name(*cert, subject) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to set subject name, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + expire_day = 365;
>> + if (!X509_gmtime_adj(X509_get_notBefore(*cert), 0)) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to set notBefore, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> + if (!X509_gmtime_adj(X509_get_notAfter(*cert), 60*60*24*expire_day)) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to set notAfter, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + if (X509_set_version(*cert, 2) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to set version, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + if (X509_set_pubkey(*cert, pkey) != 1) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to set public key, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + if (!X509_sign(*cert, pkey, EVP_sha1())) {
>> + av_log(NULL, AV_LOG_ERROR, "TLS: Failed to sign certificate, %s\n", ERR_error_string(ERR_get_error(), NULL));
>> + goto einval_end;
>> + }
>> +
>> + *fingerprint = generate_fingerprint(*cert);
>> + if (!*fingerprint) {
>> + goto enomem_end;
>> + }
>> +
>> + goto end;
>> +enomem_end:
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> +einval_end:
>> + ret = AVERROR(EINVAL);
>> +end:
>> + X509_NAME_free(subject);
>> + //av_bprint_finalize(&fingerprint, NULL);
>> + return ret;
>> +}
>> +
>> +int ff_ssl_gen_key_cert(char *key_buf, size_t key_sz, char *cert_buf, size_t cert_sz, char **fingerprint)
>> +{
>> + int ret = 0;
>> + EVP_PKEY *pkey = NULL;
>> + EC_KEY *ec_key = NULL;
>> + X509 *cert = NULL;
>> + char *key_tem = NULL, *cert_tem = NULL;
>> +
>> + ret = openssl_gen_private_key(&pkey, &ec_key);
>> + if (ret < 0) goto error;
>> +
>> + ret = openssl_gen_certificate(pkey, &cert, fingerprint);
>> + if (ret < 0) goto error;
>> +
>> + key_tem = pkey_to_pem_string(pkey);
>> + cert_tem = cert_to_pem_string(cert);
>> +
>> + snprintf(key_buf, key_sz, "%s", key_tem);
>> + snprintf(cert_buf, cert_sz, "%s", cert_tem);
>> +
>> + if (key_tem) av_free(key_tem);
>> + if (cert_tem) av_free(cert_tem);
>> +error:
>> + return ret;
>> +}
>> +
>> +
>> +/**
>> + * Deserialize a PEM‐encoded private or public key from a NUL-terminated C string.
>> + *
>> + * @param pem_str The PEM text, e.g.
>> + * "-----BEGIN PRIVATE KEY-----\n…\n-----END PRIVATE KEY-----\n"
>> + * @param is_priv If non-zero, parse as a PRIVATE key; otherwise, parse as a PUBLIC key.
>> + * @return EVP_PKEY* on success (must EVP_PKEY_free()), or NULL on error.
>> + */
>> +static EVP_PKEY *pkey_from_pem_string(const char *pem_str, int is_priv)
>> +{
>> + BIO *mem = BIO_new_mem_buf(pem_str, -1);
>> + if (!mem) {
>> + av_log(NULL, AV_LOG_ERROR, "BIO_new_mem_buf failed\n");
>> + return NULL;
>> + }
>> +
>> + EVP_PKEY *pkey = NULL;
>> + if (is_priv) {
>> + pkey = PEM_read_bio_PrivateKey(mem, NULL, NULL, NULL);
>> + } else {
>> + pkey = PEM_read_bio_PUBKEY(mem, NULL, NULL, NULL);
>> + }
>> +
>> + if (!pkey)
>> + av_log(NULL, AV_LOG_ERROR, "Failed to parse %s key from string\n",
>> + is_priv ? "private" : "public");
>> +
>> + BIO_free(mem);
>> + return pkey;
>> +}
>> +
>> +/**
>> + * Deserialize a PEM‐encoded certificate from a NUL-terminated C string.
>> + *
>> + * @param pem_str The PEM text, e.g.
>> + * "-----BEGIN CERTIFICATE-----\n…\n-----END CERTIFICATE-----\n"
>> + * @return X509* on success (must X509_free()), or NULL on error.
>> + */
>> +static X509 *cert_from_pem_string(const char *pem_str)
>> +{
>> + BIO *mem = BIO_new_mem_buf(pem_str, -1);
>> + if (!mem) {
>> + av_log(NULL, AV_LOG_ERROR, "BIO_new_mem_buf failed\n");
>> + return NULL;
>> + }
>> +
>> + X509 *cert = PEM_read_bio_X509(mem, NULL, NULL, NULL);
>> + if (!cert) {
>> + av_log(NULL, AV_LOG_ERROR, "Failed to parse certificate from string\n");
>> + return NULL;
>> + }
>> +
>> + BIO_free(mem);
>> + return cert;
>> +}
>> +
>> +
>> typedef struct TLSContext {
>> const AVClass *class;
>> TLSShared tls_shared;
>> @@ -38,8 +471,56 @@ typedef struct TLSContext {
>> BIO_METHOD* url_bio_method;
>> #endif
>> int io_err;
>> + char error_message[256];
>> } TLSContext;
>>
>> +/**
>> + * Retrieves the error message for the latest OpenSSL error.
>> + *
>> + * This function retrieves the error code from the thread's error queue, converts it
>> + * to a human-readable string, and stores it in the TLSContext's error_message field.
>> + * The error queue is then cleared using ERR_clear_error().
>> + */
>> +static const char* openssl_get_error(TLSContext *ctx)
>> +{
>> + int r2 = ERR_get_error();
>> + if (r2) {
>> + ERR_error_string_n(r2, ctx->error_message, sizeof(ctx->error_message));
>> + } else
>> + ctx->error_message[0] = '\0';
>> +
>> + ERR_clear_error();
>> + return ctx->error_message;
>> +}
>> +
>> +int ff_dtls_set_udp(URLContext *h, URLContext *udp)
>> +{
>> + TLSContext *c = h->priv_data;
>> + c->tls_shared.udp = udp;
>> + return 0;
>> +}
>> +
>> +int ff_dtls_export_materials(URLContext *h, char *dtls_srtp_materials, size_t materials_sz)
>> +{
>> + int ret = 0;
>> + const char* dst = "EXTRACTOR-dtls_srtp";
>> + TLSContext *c = h->priv_data;
>> +
>> + ret = SSL_export_keying_material(c->ssl, dtls_srtp_materials, materials_sz,
>> + dst, strlen(dst), NULL, 0, 0);
>> + if (!ret) {
>> + av_log(c, AV_LOG_ERROR, "TLS: Failed to export SRTP material, %s\n", openssl_get_error(c));
>> + return -1;
>> + }
>> + return 0;
>> +}
>> +
>> +int ff_dtls_state(URLContext *h)
>> +{
>> + TLSContext *c = h->priv_data;
>> + return c->tls_shared.state;
>> +}
>> +
>> /* OpenSSL 1.0.2 or below, then you would use SSL_library_init. If you are
>> * using OpenSSL 1.1.0 or above, then the library will initialize
>> * itself automatically.
>> @@ -121,7 +602,7 @@ void ff_openssl_deinit(void)
>> }
>> #endif
>>
>> -static int print_tls_error(URLContext *h, int ret)
>> +static int print_ssl_error(URLContext *h, int ret)
>> {
>> TLSContext *c = h->priv_data;
>> int printed = 0, e, averr = AVERROR(EIO);
>> @@ -193,7 +674,7 @@ static int url_bio_destroy(BIO *b)
>> static int url_bio_bread(BIO *b, char *buf, int len)
>> {
>> TLSContext *c = GET_BIO_DATA(b);
>> - int ret = ffurl_read(c->tls_shared.tcp, buf, len);
>> + int ret = ffurl_read(c->tls_shared.is_dtls ? c->tls_shared.udp : c->tls_shared.tcp, buf, len);
>> if (ret >= 0)
>> return ret;
>> BIO_clear_retry_flags(b);
>> @@ -209,7 +690,7 @@ static int url_bio_bread(BIO *b, char *buf, int len)
>> static int url_bio_bwrite(BIO *b, const char *buf, int len)
>> {
>> TLSContext *c = GET_BIO_DATA(b);
>> - int ret = ffurl_write(c->tls_shared.tcp, buf, len);
>> + int ret = ffurl_write(c->tls_shared.is_dtls ? c->tls_shared.udp : c->tls_shared.tcp, buf, len);
>> if (ret >= 0)
>> return ret;
>> BIO_clear_retry_flags(b);
>> @@ -250,11 +731,300 @@ static BIO_METHOD url_bio_method = {
>> };
>> #endif
>>
>> +static av_cold void init_bio_method(URLContext *h)
>> +{
>> + TLSContext *p = h->priv_data;
>> + BIO *bio;
>> +#if OPENSSL_VERSION_NUMBER >= 0x1010000fL
>> + p->url_bio_method = BIO_meth_new(BIO_TYPE_SOURCE_SINK, "urlprotocol bio");
>> + BIO_meth_set_write(p->url_bio_method, url_bio_bwrite);
>> + BIO_meth_set_read(p->url_bio_method, url_bio_bread);
>> + BIO_meth_set_puts(p->url_bio_method, url_bio_bputs);
>> + BIO_meth_set_ctrl(p->url_bio_method, url_bio_ctrl);
>> + BIO_meth_set_create(p->url_bio_method, url_bio_create);
>> + BIO_meth_set_destroy(p->url_bio_method, url_bio_destroy);
>> + bio = BIO_new(p->url_bio_method);
>> + BIO_set_data(bio, p);
>> +#else
>> + bio = BIO_new(&url_bio_method);
>> + bio->ptr = p;
>> +#endif
>> + SSL_set_bio(p->ssl, bio, bio);
>> +}
>> +
>> +static void openssl_info_callback(const SSL *ssl, int where, int ret) {
>> + const char *method = "undefined";
>> + TLSContext *ctx = (TLSContext*)SSL_get_ex_data(ssl, 0);
>> +
>> + if (where & SSL_ST_CONNECT) {
>> + method = "SSL_connect";
>> + } else if (where & SSL_ST_ACCEPT)
>> + method = "SSL_accept";
>> +
>> + if (where & SSL_CB_LOOP) {
>> + av_log(ctx, AV_LOG_DEBUG, "Info method=%s state=%s(%s), where=%d, ret=%d\n",
>> + method, SSL_state_string(ssl), SSL_state_string_long(ssl), where, ret);
>> + } else if (where & SSL_CB_ALERT) {
>> + method = (where & SSL_CB_READ) ? "read":"write";
>> + av_log(ctx, AV_LOG_DEBUG, "Alert method=%s state=%s(%s), where=%d, ret=%d\n",
>> + method, SSL_state_string(ssl), SSL_state_string_long(ssl), where, ret);
>> + }
>> +}
>> +
>> +/**
>> + * Always return 1 to accept any certificate. This is because we allow the peer to
>> + * use a temporary self-signed certificate for DTLS.
>> + */
>> +static int openssl_dtls_verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
>> +{
>> + return 1;
>> +}
>> +
>> +static int dtls_handshake(URLContext *h)
>> +{
>> + int ret = 0, r0, r1;
>> + TLSContext *p = h->priv_data;
>> +
>> + r0 = SSL_do_handshake(p->ssl);
>> + r1 = SSL_get_error(p->ssl, r0);
>> + if (r0 <= 0) {
>> + if (r1 != SSL_ERROR_WANT_READ && r1 != SSL_ERROR_WANT_WRITE && r1 != SSL_ERROR_ZERO_RETURN) {
>> + av_log(p, AV_LOG_ERROR, "TLS: Read failed, r0=%d, r1=%d %s\n", r0, r1, openssl_get_error(p));
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> + } else {
>> + av_log(p, AV_LOG_TRACE, "TLS: Read %d bytes, r0=%d, r1=%d\n", r0, r0, r1);
>> + }
>> +
>> + /* Check whether the DTLS is completed. */
>> + if (SSL_is_init_finished(p->ssl) != 1)
>> + goto end;
>> +
>> + p->tls_shared.state = DTLS_STATE_FINISHED;
>> +end:
>> + return ret;
>> +}
>> +
>> +static av_cold int openssl_init_ca_key_cert(URLContext *h)
>> +{
>> + int ret;
>> + TLSContext *p = h->priv_data;
>> + TLSShared *c = &p->tls_shared;
>> + EVP_PKEY *pkey = NULL;
>> + X509 *cert = NULL;
>> + /* setup ca, private key, certificate */
>> + if (c->ca_file) {
>> + if (!SSL_CTX_load_verify_locations(p->ctx, c->ca_file, NULL))
>> + av_log(h, AV_LOG_ERROR, "SSL_CTX_load_verify_locations %s\n", openssl_get_error(p));
>> + }
>> +
>> + if (c->cert_file) {
>> + ret = SSL_CTX_use_certificate_chain_file(p->ctx, c->cert_file);
>> + if (ret <= 0) {
>> + av_log(h, AV_LOG_ERROR, "Unable to load cert file %s: %s\n",
>> + c->cert_file, openssl_get_error(p));
>> + ret = AVERROR(EIO);
>> + goto fail;
>> + }
>> + } else if (p->tls_shared.cert_buf) {
>> + cert = cert_from_pem_string(p->tls_shared.cert_buf);
>> + if (SSL_CTX_use_certificate(p->ctx, cert) != 1) {
>> + av_log(p, AV_LOG_ERROR, "SSL: Init SSL_CTX_use_certificate failed, %s\n", openssl_get_error(p));
>> + ret = AVERROR(EINVAL);
>> + return ret;
>> + }
>> + } else if (p->tls_shared.is_dtls){
>> + av_log(p, AV_LOG_ERROR, "TLS: Init cert failed, %s\n", openssl_get_error(p));
>> + ret = AVERROR(EINVAL);
>> + goto fail;
>> + }
>> +
>> + if (c->key_file) {
>> + ret = SSL_CTX_use_PrivateKey_file(p->ctx, c->key_file, SSL_FILETYPE_PEM);
>> + if (ret <= 0) {
>> + av_log(h, AV_LOG_ERROR, "Unable to load key file %s: %s\n",
>> + c->key_file, openssl_get_error(p));
>> + ret = AVERROR(EIO);
>> + goto fail;
>> + }
>> + } else if (p->tls_shared.key_buf) {
>> + pkey = pkey_from_pem_string(p->tls_shared.key_buf, 1);
>> + if (SSL_CTX_use_PrivateKey(p->ctx, pkey) != 1) {
>> + av_log(p, AV_LOG_ERROR, "TLS: Init SSL_CTX_use_PrivateKey failed, %s\n", openssl_get_error(p));
>> + ret = AVERROR(EINVAL);
>> + return ret;
>> + }
>> + } else if (p->tls_shared.is_dtls){
>> + av_log(p, AV_LOG_ERROR, "TLS: Init pkey failed, %s\n", openssl_get_error(p));
>> + ret = AVERROR(EINVAL);
>> + goto fail;
>> + }
>> + ret = 0;
>> +fail:
>> + return ret;
>> +}
>> +
>> +/**
>> + * Once the DTLS role has been negotiated - active for the DTLS client or passive for the
>> + * DTLS server - we proceed to set up the DTLS state and initiate the handshake.
>> + */
>> +static int dtls_start(URLContext *h, const char *url, int flags, AVDictionary **options)
>> +{
>> + TLSContext *p = h->priv_data;
>> + TLSShared *c = &p->tls_shared;
>> + int ret = 0;
>> + c->is_dtls = 1;
>> + const char* ciphers = "ALL";
>> + /**
>> + * The profile for OpenSSL's SRTP is SRTP_AES128_CM_SHA1_80, see ssl/d1_srtp.c.
>> + * The profile for FFmpeg's SRTP is SRTP_AES128_CM_HMAC_SHA1_80, see libavformat/srtp.c.
>> + */
>> + const char* profiles = "SRTP_AES128_CM_SHA1_80";
>> + /* Refer to the test cases regarding these curves in the WebRTC code. */
>> +#if OPENSSL_VERSION_NUMBER >= 0x10100000L /* OpenSSL 1.1.0 */
>> + const char* curves = "X25519:P-256:P-384:P-521";
>> +#elif OPENSSL_VERSION_NUMBER >= 0x10002000L /* OpenSSL 1.0.2 */
>> + const char* curves = "P-256:P-384:P-521";
>> +#endif
>> +
>> +#if OPENSSL_VERSION_NUMBER < 0x10002000L /* OpenSSL v1.0.2 */
>> + p->ctx = SSL_CTX_new(DTLSv1_method());
>> +#else
>> + p->ctx = SSL_CTX_new(DTLS_method());
>> +#endif
>> + if (!p->ctx) {
>> + ret = AVERROR(ENOMEM);
>> + goto fail;
>> + }
>> +
>> +#if OPENSSL_VERSION_NUMBER >= 0x10002000L /* OpenSSL 1.0.2 */
>> + /* For ECDSA, we could set the curves list. */
>> + if (SSL_CTX_set1_curves_list(p->ctx, curves) != 1) {
>> + av_log(p, AV_LOG_ERROR, "TLS: Init SSL_CTX_set1_curves_list failed, curves=%s, %s\n",
>> + curves, openssl_get_error(p));
>> + ret = AVERROR(EINVAL);
>> + return ret;
>> + }
>> +#endif
>> +
>> +#if OPENSSL_VERSION_NUMBER < 0x10100000L // v1.1.x
>> +#if OPENSSL_VERSION_NUMBER < 0x10002000L // v1.0.2
>> + if (ctx->dtls_eckey)
>> + SSL_CTX_set_tmp_ecdh(p->ctx, p->dtls_eckey);
>> +#else
>> + SSL_CTX_set_ecdh_auto(p->ctx, 1);
>> +#endif
>> +#endif
>> +
>> + /**
>> + * We activate "ALL" cipher suites to align with the peer's capabilities,
>> + * ensuring maximum compatibility.
>> + */
>> + if (SSL_CTX_set_cipher_list(p->ctx, ciphers) != 1) {
>> + av_log(p, AV_LOG_ERROR, "TLS: Init SSL_CTX_set_cipher_list failed, ciphers=%s, %s\n",
>> + ciphers, openssl_get_error(p));
>> + ret = AVERROR(EINVAL);
>> + return ret;
>> + }
>> + ret = openssl_init_ca_key_cert(h);
>> + if (ret < 0) goto fail;
>> +
>> + /* Server will send Certificate Request. */
>> + SSL_CTX_set_verify(p->ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, openssl_dtls_verify_callback);
>> + /* The depth count is "level 0:peer certificate", "level 1: CA certificate",
>> + * "level 2: higher level CA certificate", and so on. */
>> + SSL_CTX_set_verify_depth(p->ctx, 4);
>> + /* Whether we should read as many input bytes as possible (for non-blocking reads) or not. */
>> + SSL_CTX_set_read_ahead(p->ctx, 1);
>> + /* Setup the SRTP context */
>> + if (SSL_CTX_set_tlsext_use_srtp(p->ctx, profiles)) {
>> + av_log(p, AV_LOG_ERROR, "TLS: Init SSL_CTX_set_tlsext_use_srtp failed, profiles=%s, %s\n",
>> + profiles, openssl_get_error(p));
>> + ret = AVERROR(EINVAL);
>> + return ret;
>> + }
>> +
>> + /* The ssl should not be created unless the ctx has been initialized. */
>> + p->ssl = SSL_new(p->ctx);
>> + if (!p->ssl) {
>> + ret = AVERROR(ENOMEM);
>> + goto fail;
>> + }
>> +
>> + /* Setup the callback for logging. */
>> + SSL_set_ex_data(p->ssl, 0, p);
>> + SSL_set_info_callback(p->ssl, openssl_info_callback);
>> + /**
>> + * We have set the MTU to fragment the DTLS packet. It is important to note that the
>> + * packet is split to ensure that each handshake packet is smaller than the MTU.
>> + */
>> + SSL_set_options(p->ssl, SSL_OP_NO_QUERY_MTU);
>> + SSL_set_mtu(p->ssl, p->tls_shared.mtu);
>> +#if OPENSSL_VERSION_NUMBER >= 0x100010b0L /* OpenSSL 1.0.1k */
>> + DTLS_set_link_mtu(p->ssl, p->tls_shared.mtu);
>> +#endif
>> + init_bio_method(h);
>> +
>> + if (p->tls_shared.use_external_udp != 1) {
>> + if ((ret = ff_tls_open_underlying(&p->tls_shared, h, url, options)) < 0) {
>> + av_log(p, AV_LOG_ERROR, "Failed to connect %s\n", url);
>> + return ret;
>> + }
>> + }
>> +
>> + /* Setup DTLS as passive, which is server role. */
>> + c->listen ? SSL_set_accept_state(p->ssl) : SSL_set_connect_state(p->ssl);
>> +
>> + /**
>> + * During initialization, we only need to call SSL_do_handshake once because SSL_read consumes
>> + * the handshake message if the handshake is incomplete.
>> + * To simplify maintenance, we initiate the handshake for both the DTLS server and client after
>> + * sending out the ICE response in the start_active_handshake function. It's worth noting that
>> + * although the DTLS server may receive the ClientHello immediately after sending out the ICE
>> + * response, this shouldn't be an issue as the handshake function is called before any DTLS
>> + * packets are received.
>> + *
>> + * The SSL_do_handshake can't be called if DTLS hasn't prepare for udp.
>> + */
>> + if (p->tls_shared.use_external_udp != 1) {
>> + ret = dtls_handshake(h);
>> + // Fatal SSL error, for example, no available suite when peer is DTLS 1.0 while we are DTLS 1.2.
>> + if (ret < 0) {
>> + av_log(p, AV_LOG_ERROR, "TLS: Failed to drive SSL context, ret=%d\n", ret);
>> + return AVERROR(EIO);
>> + }
>> + }
>> +
>> + av_log(p, AV_LOG_VERBOSE, "TLS: Setup ok, MTU=%d, fingerprint %s\n",
>> + p->tls_shared.mtu, p->tls_shared.fingerprint);
>> +
>> + ret = 0;
>> +fail:
>> + return ret;
>> +}
>> +
>> +/**
>> + * Cleanup the DTLS context.
>> + */
>> +static av_cold int dtls_close(URLContext *h)
>> +{
>> + TLSContext *ctx = h->priv_data;
>> + SSL_free(ctx->ssl);
>> + SSL_CTX_free(ctx->ctx);
>> + av_freep(&ctx->tls_shared.fingerprint);
>> + av_freep(&ctx->tls_shared.cert_buf);
>> + av_freep(&ctx->tls_shared.key_buf);
>> +#if OPENSSL_VERSION_NUMBER < 0x30000000L /* OpenSSL 3.0 */
>> + EC_KEY_free(ctx->dtls_eckey);
>> +#endif
>> + return 0;
>> +}
>> +
>> static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
>> {
>> TLSContext *p = h->priv_data;
>> TLSShared *c = &p->tls_shared;
>> - BIO *bio;
>> int ret;
>>
>> #if OPENSSL_VERSION_NUMBER < 0x10100000L
>> @@ -271,52 +1041,26 @@ static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **op
>> // support for the old protocols immediately after creating the context.
>> p->ctx = SSL_CTX_new(c->listen ? SSLv23_server_method() : SSLv23_client_method());
>> if (!p->ctx) {
>> - av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
>> + av_log(h, AV_LOG_ERROR, "%s\n", openssl_get_error(p));
>> ret = AVERROR(EIO);
>> goto fail;
>> }
>> SSL_CTX_set_options(p->ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
>> - if (c->ca_file) {
>> - if (!SSL_CTX_load_verify_locations(p->ctx, c->ca_file, NULL))
>> - av_log(h, AV_LOG_ERROR, "SSL_CTX_load_verify_locations %s\n", ERR_error_string(ERR_get_error(), NULL));
>> - }
>> - if (c->cert_file && !SSL_CTX_use_certificate_chain_file(p->ctx, c->cert_file)) {
>> - av_log(h, AV_LOG_ERROR, "Unable to load cert file %s: %s\n",
>> - c->cert_file, ERR_error_string(ERR_get_error(), NULL));
>> - ret = AVERROR(EIO);
>> - goto fail;
>> - }
>> - if (c->key_file && !SSL_CTX_use_PrivateKey_file(p->ctx, c->key_file, SSL_FILETYPE_PEM)) {
>> - av_log(h, AV_LOG_ERROR, "Unable to load key file %s: %s\n",
>> - c->key_file, ERR_error_string(ERR_get_error(), NULL));
>> - ret = AVERROR(EIO);
>> - goto fail;
>> - }
>> + ret = openssl_init_ca_key_cert(h);
>> + if (ret < 0) goto fail;
>> // Note, this doesn't check that the peer certificate actually matches
>> // the requested hostname.
>> if (c->verify)
>> SSL_CTX_set_verify(p->ctx, SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);
>> p->ssl = SSL_new(p->ctx);
>> if (!p->ssl) {
>> - av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
>> + av_log(h, AV_LOG_ERROR, "%s\n", openssl_get_error(p));
>> ret = AVERROR(EIO);
>> goto fail;
>> }
>> -#if OPENSSL_VERSION_NUMBER >= 0x1010000fL
>> - p->url_bio_method = BIO_meth_new(BIO_TYPE_SOURCE_SINK, "urlprotocol bio");
>> - BIO_meth_set_write(p->url_bio_method, url_bio_bwrite);
>> - BIO_meth_set_read(p->url_bio_method, url_bio_bread);
>> - BIO_meth_set_puts(p->url_bio_method, url_bio_bputs);
>> - BIO_meth_set_ctrl(p->url_bio_method, url_bio_ctrl);
>> - BIO_meth_set_create(p->url_bio_method, url_bio_create);
>> - BIO_meth_set_destroy(p->url_bio_method, url_bio_destroy);
>> - bio = BIO_new(p->url_bio_method);
>> - BIO_set_data(bio, p);
>> -#else
>> - bio = BIO_new(&url_bio_method);
>> - bio->ptr = p;
>> -#endif
>> - SSL_set_bio(p->ssl, bio, bio);
>> + SSL_set_ex_data(p->ssl, 0, p);
>> + SSL_CTX_set_info_callback(p->ctx, openssl_info_callback);
>> + init_bio_method(h);
>> if (!c->listen && !c->numerichost)
>> SSL_set_tlsext_host_name(p->ssl, c->host);
>> ret = c->listen ? SSL_accept(p->ssl) : SSL_connect(p->ssl);
>> @@ -325,7 +1069,7 @@ static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **op
>> ret = AVERROR(EIO);
>> goto fail;
>> } else if (ret < 0) {
>> - ret = print_tls_error(h, ret);
>> + ret = print_ssl_error(h, ret);
>> goto fail;
>> }
>>
>> @@ -338,31 +1082,35 @@ fail:
>> static int tls_read(URLContext *h, uint8_t *buf, int size)
>> {
>> TLSContext *c = h->priv_data;
>> + URLContext *uc = c->tls_shared.is_dtls ? c->tls_shared.udp
>> + : c->tls_shared.tcp;
>> int ret;
>> // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
>> - c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
>> - c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
>> + uc->flags &= ~AVIO_FLAG_NONBLOCK;
>> + uc->flags |= h->flags & AVIO_FLAG_NONBLOCK;
>> ret = SSL_read(c->ssl, buf, size);
>> if (ret > 0)
>> return ret;
>> if (ret == 0)
>> return AVERROR_EOF;
>> - return print_tls_error(h, ret);
>> + return print_ssl_error(h, ret);
>> }
>>
>> static int tls_write(URLContext *h, const uint8_t *buf, int size)
>> {
>> TLSContext *c = h->priv_data;
>> + URLContext *uc = c->tls_shared.is_dtls ? c->tls_shared.udp
>> + : c->tls_shared.tcp;
>> int ret;
>> // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
>> - c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
>> - c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
>> + uc->flags &= ~AVIO_FLAG_NONBLOCK;
>> + uc->flags |= h->flags & AVIO_FLAG_NONBLOCK;
>> ret = SSL_write(c->ssl, buf, size);
>> if (ret > 0)
>> return ret;
>> if (ret == 0)
>> return AVERROR_EOF;
>> - return print_tls_error(h, ret);
>> + return print_ssl_error(h, ret);
>> }
>>
>> static int tls_get_file_handle(URLContext *h)
>> @@ -401,3 +1149,22 @@ const URLProtocol ff_tls_protocol = {
>> .flags = URL_PROTOCOL_FLAG_NETWORK,
>> .priv_data_class = &tls_class,
>> };
>> +
>> +static const AVClass dtls_class = {
>> + .class_name = "dtls",
>> + .item_name = av_default_item_name,
>> + .option = options,
>> + .version = LIBAVUTIL_VERSION_INT,
>> +};
>> +
>> +const URLProtocol ff_dtls_protocol = {
>> + .name = "dtls",
>> + .url_open2 = dtls_start,
>> + .url_handshake = dtls_handshake,
>> + .url_close = dtls_close,
>> + .url_read = tls_read,
>> + .url_write = tls_write,
>> + .priv_data_size = sizeof(TLSContext),
>> + .flags = URL_PROTOCOL_FLAG_NETWORK,
>> + .priv_data_class = &dtls_class,
>> +};
>> diff --git a/libavformat/whip.c b/libavformat/whip.c
>> new file mode 100644
>> index 0000000000..0671e23635
>> --- /dev/null
>> +++ b/libavformat/whip.c
>> @@ -0,0 +1,1917 @@
>> +/*
>> + * WebRTC-HTTP ingestion protocol (WHIP) muxer
>> + * Copyright (c) 2023 The FFmpeg Project
>> + *
>> + * This file is part of FFmpeg.
>> + *
>> + * FFmpeg is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU Lesser General Public
>> + * License as published by the Free Software Foundation; either
>> + * version 2.1 of the License, or (at your option) any later version.
>> + *
>> + * FFmpeg is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> + * Lesser General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU Lesser General Public
>> + * License along with FFmpeg; if not, write to the Free Software
>> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>> + */
>> +
>> +#include "libavcodec/avcodec.h"
>> +#include "libavcodec/codec_desc.h"
>> +#include "libavcodec/h264.h"
>> +#include "libavcodec/startcode.h"
>> +#include "libavutil/base64.h"
>> +#include "libavutil/bprint.h"
>> +#include "libavutil/crc.h"
>> +#include "libavutil/hmac.h"
>> +#include "libavutil/intreadwrite.h"
>> +#include "libavutil/lfg.h"
>> +#include "libavutil/opt.h"
>> +#include "libavutil/mem.h"
>> +#include "libavutil/random_seed.h"
>> +#include "libavutil/time.h"
>> +#include "avc.h"
>> +#include "nal.h"
>> +#include "avio_internal.h"
>> +#include "http.h"
>> +#include "internal.h"
>> +#include "mux.h"
>> +#include "network.h"
>> +#include "srtp.h"
>> +#include "tls.h"
>> +
>> +/**
>> + * Maximum size limit of a Session Description Protocol (SDP),
>> + * be it an offer or answer.
>> + */
>> +#define MAX_SDP_SIZE 8192
>> +
>> +/**
>> + * The size of the Secure Real-time Transport Protocol (SRTP) master key material
>> + * that is exported by Secure Sockets Layer (SSL) after a successful Datagram
>> + * Transport Layer Security (DTLS) handshake. This material consists of a key
>> + * of 16 bytes and a salt of 14 bytes.
>> + */
>> +#define DTLS_SRTP_KEY_LEN 16
>> +#define DTLS_SRTP_SALT_LEN 14
>> +
>> +/**
>> + * The maximum size of the Secure Real-time Transport Protocol (SRTP) HMAC checksum
>> + * and padding that is appended to the end of the packet. To calculate the maximum
>> + * size of the User Datagram Protocol (UDP) packet that can be sent out, subtract
>> + * this size from the `pkt_size`.
>> + */
>> +#define DTLS_SRTP_CHECKSUM_LEN 16
>> +
>> +/**
>> + * When sending ICE or DTLS messages, responses are received via UDP. However, the peer
>> + * may not be ready and return EAGAIN, in which case we should wait for a short duration
>> + * and retry reading.
>> + * For instance, if we try to read from UDP and get EAGAIN, we sleep for 5ms and retry.
>> + * This macro is used to limit the total duration in milliseconds (e.g., 50ms), so we
>> + * will try at most 5 times.
>> + * Keep in mind that this macro should have a minimum duration of 5 ms.
>> + */
>> +#define ICE_DTLS_READ_INTERVAL 50
>> +
>> +/* The magic cookie for Session Traversal Utilities for NAT (STUN) messages. */
>> +#define STUN_MAGIC_COOKIE 0x2112A442
>> +
>> +/**
>> + * The DTLS content type.
>> + * See https://tools.ietf.org/html/rfc2246#section-6.2.1
>> + * change_cipher_spec(20), alert(21), handshake(22), application_data(23)
>> + */
>> +#define DTLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC 20
>> +
>> +/**
>> + * The DTLS record layer header has a total size of 13 bytes, consisting of
>> + * ContentType (1 byte), ProtocolVersion (2 bytes), Epoch (2 bytes),
>> + * SequenceNumber (6 bytes), and Length (2 bytes).
>> + * See https://datatracker.ietf.org/doc/html/rfc9147#section-4
>> + */
>> +#define DTLS_RECORD_LAYER_HEADER_LEN 13
>> +
>> +/**
>> + * The DTLS version number, which is 0xfeff for DTLS 1.0, or 0xfefd for DTLS 1.2.
>> + * See https://datatracker.ietf.org/doc/html/rfc9147#name-the-dtls-record-layer
>> + */
>> +#define DTLS_VERSION_10 0xfeff
>> +#define DTLS_VERSION_12 0xfefd
>> +
>> +/**
>> + * Maximum size of the buffer for sending and receiving UDP packets.
>> + * Please note that this size does not limit the size of the UDP packet that can be sent.
>> + * To set the limit for packet size, modify the `pkt_size` parameter.
>> + * For instance, it is possible to set the UDP buffer to 4096 to send or receive packets,
>> + * but please keep in mind that the `pkt_size` option limits the packet size to 1400.
>> + */
>> +#define MAX_UDP_BUFFER_SIZE 4096
>> +
>> +/* Referring to Chrome's definition of RTP payload types. */
>> +#define WHIP_RTP_PAYLOAD_TYPE_H264 106
>> +#define WHIP_RTP_PAYLOAD_TYPE_OPUS 111
>> +
>> +/**
>> + * The STUN message header, which is 20 bytes long, comprises the
>> + * STUNMessageType (1B), MessageLength (2B), MagicCookie (4B),
>> + * and TransactionID (12B).
>> + * See https://datatracker.ietf.org/doc/html/rfc5389#section-6
>> + */
>> +#define ICE_STUN_HEADER_SIZE 20
>> +
>> +/**
>> + * The RTP header is 12 bytes long, comprising the Version(1B), PT(1B),
>> + * SequenceNumber(2B), Timestamp(4B), and SSRC(4B).
>> + * See https://www.rfc-editor.org/rfc/rfc3550#section-5.1
>> + */
>> +#define WHIP_RTP_HEADER_SIZE 12
>> +
>> +/**
>> + * For RTCP, PT is [128, 223] (or without marker [0, 95]). Literally, RTCP starts
>> + * from 64 not 0, so PT is [192, 223] (or without marker [64, 95]), see "RTCP Control
>> + * Packet Types (PT)" at
>> + * https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml#rtp-parameters-4
>> + *
>> + * For RTP, the PT is [96, 127], or [224, 255] with marker. See "RTP Payload Types (PT)
>> + * for standard audio and video encodings" at
>> + * https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml#rtp-parameters-1
>> + */
>> +#define WHIP_RTCP_PT_START 192
>> +#define WHIP_RTCP_PT_END 223
>> +
>> +/**
>> + * In the case of ICE-LITE, these fields are not used; instead, they are defined
>> + * as constant values.
>> + */
>> +#define WHIP_SDP_SESSION_ID "4489045141692799359"
>> +#define WHIP_SDP_CREATOR_IP "127.0.0.1"
>> +
>> +/* Calculate the elapsed time from starttime to endtime in milliseconds. */
>> +#define ELAPSED(starttime, endtime) ((int)(endtime - starttime) / 1000)
>> +
>> +/* STUN Attribute, comprehension-required range (0x0000-0x7FFF) */
>> +enum STUNAttr {
>> + STUN_ATTR_USERNAME = 0x0006, /// shared secret response/bind request
>> + STUN_ATTR_USE_CANDIDATE = 0x0025, /// bind request
>> + STUN_ATTR_MESSAGE_INTEGRITY = 0x0008, /// bind request/response
>> + STUN_ATTR_FINGERPRINT = 0x8028, /// rfc5389
>> +};
>> +
>> +enum WHIPState {
>> + WHIP_STATE_NONE,
>> +
>> + /* The initial state. */
>> + WHIP_STATE_INIT,
>> + /* The muxer has sent the offer to the peer. */
>> + WHIP_STATE_OFFER,
>> + /* The muxer has received the answer from the peer. */
>> + WHIP_STATE_ANSWER,
>> + /**
>> + * After parsing the answer received from the peer, the muxer negotiates the abilities
>> + * in the offer that it generated.
>> + */
>> + WHIP_STATE_NEGOTIATED,
>> + /* The muxer has connected to the peer via UDP. */
>> + WHIP_STATE_UDP_CONNECTED,
>> + /* The muxer has sent the ICE request to the peer. */
>> + WHIP_STATE_ICE_CONNECTING,
>> + /* The muxer has received the ICE response from the peer. */
>> + WHIP_STATE_ICE_CONNECTED,
>> + /* The muxer starts attempting the DTLS handshake. */
>> + WHIP_STATE_DTLS_CONNECTING,
>> + /* The muxer has finished the DTLS handshake with the peer. */
>> + WHIP_STATE_DTLS_FINISHED,
>> + /* The muxer has finished the SRTP setup. */
>> + WHIP_STATE_SRTP_FINISHED,
>> + /* The muxer is ready to send/receive media frames. */
>> + WHIP_STATE_READY,
>> + /* The muxer is failed. */
>> + WHIP_STATE_FAILED,
>> +};
>> +
>> +typedef struct WHIPContext {
>> + AVClass *av_class;
>> +
>> + /* The state of the RTC connection. */
>> + enum WHIPState state;
>> + /* The callback return value for DTLS. */
>> + int dtls_ret;
>> + int dtls_closed;
>> +
>> + /* Parameters for the input audio and video codecs. */
>> + AVCodecParameters *audio_par;
>> + AVCodecParameters *video_par;
>> +
>> + /**
>> + * The h264_mp4toannexb Bitstream Filter (BSF) bypasses the AnnexB packet;
>> + * therefore, it is essential to insert the SPS and PPS before each IDR frame
>> + * in such cases.
>> + */
>> + int h264_annexb_insert_sps_pps;
>> +
>> + /* The random number generator. */
>> + AVLFG rnd;
>> +
>> + /* The ICE username and pwd fragment generated by the muxer. */
>> + char ice_ufrag_local[9];
>> + char ice_pwd_local[33];
>> + /* The SSRC of the audio and video stream, generated by the muxer. */
>> + uint32_t audio_ssrc;
>> + uint32_t video_ssrc;
>> + /* The PT(Payload Type) of stream, generated by the muxer. */
>> + uint8_t audio_payload_type;
>> + uint8_t video_payload_type;
>> + /**
>> + * This is the SDP offer generated by the muxer based on the codec parameters,
>> + * DTLS, and ICE information.
>> + */
>> + char *sdp_offer;
>> +
>> + /* The ICE username and pwd from remote server. */
>> + char *ice_ufrag_remote;
>> + char *ice_pwd_remote;
>> + /**
>> + * This represents the ICE candidate protocol, priority, host and port.
>> + * Currently, we only support one candidate and choose the first UDP candidate.
>> + * However, we plan to support multiple candidates in the future.
>> + */
>> + char *ice_protocol;
>> + char *ice_host;
>> + int ice_port;
>> +
>> + /* The SDP answer received from the WebRTC server. */
>> + char *sdp_answer;
>> + /* The resource URL returned in the Location header of WHIP HTTP response. */
>> + char *whip_resource_url;
>> +
>> + /* These variables represent timestamps used for calculating and tracking the cost. */
>> + int64_t whip_starttime;
>> + int64_t whip_init_time;
>> + int64_t whip_offer_time;
>> + int64_t whip_answer_time;
>> + int64_t whip_udp_time;
>> + int64_t whip_ice_time;
>> + int64_t whip_dtls_time;
>> + int64_t whip_srtp_time;
>> +
>> + /* The certificate and private key content used for DTLS hanshake */
>> + char cert_buf[MAX_CERTIFICATE_SIZE];
>> + char key_buf[MAX_CERTIFICATE_SIZE];
>> + /* The fingerprint of certificate, used in SDP offer. */
>> + char *dtls_fingerprint;
>> + /**
>> + * This represents the material used to build the SRTP master key. It is
>> + * generated by DTLS and has the following layout:
>> + * 16B 16B 14B 14B
>> + * client_key | server_key | client_salt | server_salt
>> + */
>> + uint8_t dtls_srtp_materials[(DTLS_SRTP_KEY_LEN + DTLS_SRTP_SALT_LEN) * 2];
>> +
>> + char ssl_error_message[256];
>> +
>> + /* TODO: Use AVIOContext instead of URLContext */
>> + URLContext *dtls_uc;
>> +
>> + /* The SRTP send context, to encrypt outgoing packets. */
>> + SRTPContext srtp_audio_send;
>> + SRTPContext srtp_video_send;
>> + SRTPContext srtp_rtcp_send;
>> + /* The SRTP receive context, to decrypt incoming packets. */
>> + SRTPContext srtp_recv;
>> +
>> + /* The UDP transport is used for delivering ICE, DTLS and SRTP packets. */
>> + URLContext *udp;
>> + /* The buffer for UDP transmission. */
>> + char buf[MAX_UDP_BUFFER_SIZE];
>> +
>> + /* The timeout in milliseconds for ICE and DTLS handshake. */
>> + int handshake_timeout;
>> + /**
>> + * The size of RTP packet, should generally be set to MTU.
>> + * Note that pion requires a smaller value, for example, 1200.
>> + */
>> + int pkt_size;
>> + /**
>> + * The optional Bearer token for WHIP Authorization.
>> + * See https://www.ietf.org/archive/id/draft-ietf-wish-whip-08.html#name-authentication-and-authoriz
>> + */
>> + char* authorization;
>> + /* The certificate and private key used for DTLS handshake. */
>> + char* cert_file;
>> + char* key_file;
>> +} WHIPContext;
>> +
>> +/**
>> + * Whether the packet is a DTLS packet.
>> + */
>> +static int is_dtls_packet(uint8_t *b, int size) {
>> + uint16_t version = AV_RB16(&b[1]);
>> + return size > DTLS_RECORD_LAYER_HEADER_LEN &&
>> + b[0] >= DTLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC &&
>> + (version == DTLS_VERSION_10 || version == DTLS_VERSION_12);
>> +}
>> +
>> +
>> +/**
>> + * Get or Generate a self-signed certificate and private key for DTLS,
>> + * fingerprint for SDP
>> + */
>> +static av_cold int certificate_key_init(AVFormatContext *s)
>> +{
>> + int ret = 0;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + if (whip->cert_file && whip->key_file) {
>> + /* Read the private key and certificate from the file. */
>> + if ((ret = ff_ssl_read_key_cert(whip->key_file, whip->cert_file,
>> + whip->key_buf, sizeof(whip->key_buf),
>> + whip->cert_buf, sizeof(whip->cert_buf),
>> + &whip->dtls_fingerprint)) < 0) {
>> + av_log(s, AV_LOG_ERROR, "DTLS: Failed to read DTLS certificate from cert=%s, key=%s\n",
>> + whip->cert_file, whip->key_file);
>> + return ret;
>> + }
>> + } else {
>> + /* Generate a private key to ctx->dtls_pkey and self-signed certificate. */
>> + if ((ret = ff_ssl_gen_key_cert(whip->key_buf, sizeof(whip->key_buf),
>> + whip->cert_buf, sizeof(whip->cert_buf),
>> + &whip->dtls_fingerprint)) < 0) {
>> + av_log(s, AV_LOG_ERROR, "DTLS: Failed to generate DTLS private key and certificate\n");
>> + return ret;
>> + }
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +/**
>> + * When DTLS state change.
>> + */
>> +static int dtls_context_on_state(AVFormatContext *s, const char* type, const char* desc)
>> +{
>> + int ret = 0;
>> + WHIPContext *whip = s->priv_data;
>> + int state = ff_dtls_state(whip->dtls_uc);
>> +
>> + if (state == DTLS_STATE_CLOSED) {
>> + whip->dtls_closed = 1;
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: DTLS session closed, type=%s, desc=%s, elapsed=%dms\n",
>> + type ? type : "", desc ? desc : "", ELAPSED(whip->whip_starttime, av_gettime()));
>> + goto error;
>> + }
>> +
>> + if (state == DTLS_STATE_FAILED) {
>> + whip->state = WHIP_STATE_FAILED;
>> + av_log(whip, AV_LOG_ERROR, "WHIP: DTLS session failed, type=%s, desc=%s\n",
>> + type ? type : "", desc ? desc : "");
>> + whip->dtls_ret = AVERROR(EIO);
>> + goto error;
>> + }
>> +
>> + if (state == DTLS_STATE_FINISHED && whip->state < WHIP_STATE_DTLS_FINISHED) {
>> + whip->state = WHIP_STATE_DTLS_FINISHED;
>> + whip->whip_dtls_time = av_gettime();
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: DTLS handshake is done, elapsed=%dms\n",
>> + ELAPSED(whip->whip_starttime, av_gettime()));
>> + return ret;
>> + }
>> +error:
>> + return -1;
>> +}
>> +
>> +static av_cold int dtls_initialize(AVFormatContext *s)
>> +{
>> + WHIPContext *whip = s->priv_data;
>> + /* reuse the udp created by whip */
>> + ff_dtls_set_udp(whip->dtls_uc, whip->udp);
>> + return 0;
>> +}
>> +
>> +/**
>> + * Initialize and check the options for the WebRTC muxer.
>> + */
>> +static av_cold int initialize(AVFormatContext *s)
>> +{
>> + int ret, ideal_pkt_size = 532;
>> + WHIPContext *whip = s->priv_data;
>> + uint32_t seed;
>> +
>> + whip->whip_starttime = av_gettime();
>> +
>> + ret = certificate_key_init(s);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to init certificate and key\n");
>> + return ret;
>> + }
>> +
>> + /* Initialize the random number generator. */
>> + seed = av_get_random_seed();
>> + av_lfg_init(&whip->rnd, seed);
>> +
>> + if (whip->pkt_size < ideal_pkt_size)
>> + av_log(whip, AV_LOG_WARNING, "WHIP: pkt_size=%d(<%d) is too small, may cause packet loss\n",
>> + whip->pkt_size, ideal_pkt_size);
>> +
>> + if (whip->state < WHIP_STATE_INIT)
>> + whip->state = WHIP_STATE_INIT;
>> + whip->whip_init_time = av_gettime();
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: Init state=%d, handshake_timeout=%dms, pkt_size=%d, seed=%d, elapsed=%dms\n",
>> + whip->state, whip->handshake_timeout, whip->pkt_size, seed, ELAPSED(whip->whip_starttime, av_gettime()));
>> +
>> + return 0;
>> +}
>> +
>> +/**
>> + * When duplicating a stream, the demuxer has already set the extradata, profile, and
>> + * level of the par. Keep in mind that this function will not be invoked since the
>> + * profile and level are set.
>> + *
>> + * When utilizing an encoder, such as libx264, to encode a stream, the extradata in
>> + * par->extradata contains the SPS, which includes profile and level information.
>> + * However, the profile and level of par remain unspecified. Therefore, it is necessary
>> + * to extract the profile and level data from the extradata and assign it to the par's
>> + * profile and level. Keep in mind that AVFMT_GLOBALHEADER must be enabled; otherwise,
>> + * the extradata will remain empty.
>> + */
>> +static int parse_profile_level(AVFormatContext *s, AVCodecParameters *par)
>> +{
>> + int ret = 0;
>> + const uint8_t *r = par->extradata, *r1, *end = par->extradata + par->extradata_size;
>> + H264SPS seq, *const sps = &seq;
>> + uint32_t state;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + if (par->codec_id != AV_CODEC_ID_H264)
>> + return ret;
>> +
>> + if (par->profile != AV_PROFILE_UNKNOWN && par->level != AV_LEVEL_UNKNOWN)
>> + return ret;
>> +
>> + if (!par->extradata || par->extradata_size <= 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Unable to parse profile from empty extradata=%p, size=%d\n",
>> + par->extradata, par->extradata_size);
>> + return AVERROR(EINVAL);
>> + }
>> +
>> + while (1) {
>> + r = avpriv_find_start_code(r, end, &state);
>> + if (r >= end)
>> + break;
>> +
>> + r1 = ff_nal_find_startcode(r, end);
>> + if ((state & 0x1f) == H264_NAL_SPS) {
>> + ret = ff_avc_decode_sps(sps, r, r1 - r);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to decode SPS, state=%x, size=%d\n",
>> + state, (int)(r1 - r));
>> + return ret;
>> + }
>> +
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: Parse profile=%d, level=%d from SPS\n",
>> + sps->profile_idc, sps->level_idc);
>> + par->profile = sps->profile_idc;
>> + par->level = sps->level_idc;
>> + }
>> +
>> + r = r1;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +/**
>> + * Parses video SPS/PPS from the extradata of codecpar and checks the codec.
>> + * Currently only supports video(h264) and audio(opus). Note that only baseline
>> + * and constrained baseline profiles of h264 are supported.
>> + *
>> + * If the profile is less than 0, the function considers the profile as baseline.
>> + * It may need to parse the profile from SPS/PPS. This situation occurs when ingesting
>> + * desktop and transcoding.
>> + *
>> + * @param s Pointer to the AVFormatContext
>> + * @returns Returns 0 if successful or AVERROR_xxx in case of an error.
>> + *
>> + * TODO: FIXME: There is an issue with the timestamp of OPUS audio, especially when
>> + * the input is an MP4 file. The timestamp deviates from the expected value of 960,
>> + * causing Chrome to play the audio stream with noise. This problem can be replicated
>> + * by transcoding a specific file into MP4 format and publishing it using the WHIP
>> + * muxer. However, when directly transcoding and publishing through the WHIP muxer,
>> + * the issue is not present, and the audio timestamp remains consistent. The root
>> + * cause is still unknown, and this comment has been added to address this issue
>> + * in the future. Further research is needed to resolve the problem.
>> + */
>> +static int parse_codec(AVFormatContext *s)
>> +{
>> + int i, ret = 0;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + for (i = 0; i < s->nb_streams; i++) {
>> + AVCodecParameters *par = s->streams[i]->codecpar;
>> + const AVCodecDescriptor *desc = avcodec_descriptor_get(par->codec_id);
>> + switch (par->codec_type) {
>> + case AVMEDIA_TYPE_VIDEO:
>> + if (whip->video_par) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Only one video stream is supported by RTC\n");
>> + return AVERROR(EINVAL);
>> + }
>> + whip->video_par = par;
>> +
>> + if (par->codec_id != AV_CODEC_ID_H264) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Unsupported video codec %s by RTC, choose h264\n",
>> + desc ? desc->name : "unknown");
>> + return AVERROR_PATCHWELCOME;
>> + }
>> +
>> + if (par->video_delay > 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Unsupported B frames by RTC\n");
>> + return AVERROR_PATCHWELCOME;
>> + }
>> +
>> + if ((ret = parse_profile_level(s, par)) < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to parse SPS/PPS from extradata\n");
>> + return AVERROR(EINVAL);
>> + }
>> +
>> + if (par->profile == AV_PROFILE_UNKNOWN) {
>> + av_log(whip, AV_LOG_WARNING, "WHIP: No profile found in extradata, consider baseline\n");
>> + return AVERROR(EINVAL);
>> + }
>> + if (par->level == AV_LEVEL_UNKNOWN) {
>> + av_log(whip, AV_LOG_WARNING, "WHIP: No level found in extradata, consider 3.1\n");
>> + return AVERROR(EINVAL);
>> + }
>> + break;
>> + case AVMEDIA_TYPE_AUDIO:
>> + if (whip->audio_par) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Only one audio stream is supported by RTC\n");
>> + return AVERROR(EINVAL);
>> + }
>> + whip->audio_par = par;
>> +
>> + if (par->codec_id != AV_CODEC_ID_OPUS) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Unsupported audio codec %s by RTC, choose opus\n",
>> + desc ? desc->name : "unknown");
>> + return AVERROR_PATCHWELCOME;
>> + }
>> +
>> + if (par->ch_layout.nb_channels != 2) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Unsupported audio channels %d by RTC, choose stereo\n",
>> + par->ch_layout.nb_channels);
>> + return AVERROR_PATCHWELCOME;
>> + }
>> +
>> + if (par->sample_rate != 48000) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Unsupported audio sample rate %d by RTC, choose 48000\n", par->sample_rate);
>> + return AVERROR_PATCHWELCOME;
>> + }
>> + break;
>> + default:
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Codec type '%s' for stream %d is not supported by RTC\n",
>> + av_get_media_type_string(par->codec_type), i);
>> + return AVERROR_PATCHWELCOME;
>> + }
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +/**
>> + * Generate SDP offer according to the codec parameters, DTLS and ICE information.
>> + *
>> + * Note that we don't use av_sdp_create to generate SDP offer because it doesn't
>> + * support DTLS and ICE information.
>> + *
>> + * @return 0 if OK, AVERROR_xxx on error
>> + */
>> +static int generate_sdp_offer(AVFormatContext *s)
>> +{
>> + int ret = 0, profile, level, profile_iop;
>> + const char *acodec_name = NULL, *vcodec_name = NULL;
>> + AVBPrint bp;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + /* To prevent a crash during cleanup, always initialize it. */
>> + av_bprint_init(&bp, 1, MAX_SDP_SIZE);
>> +
>> + if (whip->sdp_offer) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: SDP offer is already set\n");
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + snprintf(whip->ice_ufrag_local, sizeof(whip->ice_ufrag_local), "%08x",
>> + av_lfg_get(&whip->rnd));
>> + snprintf(whip->ice_pwd_local, sizeof(whip->ice_pwd_local), "%08x%08x%08x%08x",
>> + av_lfg_get(&whip->rnd), av_lfg_get(&whip->rnd), av_lfg_get(&whip->rnd),
>> + av_lfg_get(&whip->rnd));
>> +
>> + whip->audio_ssrc = av_lfg_get(&whip->rnd);
>> + whip->video_ssrc = av_lfg_get(&whip->rnd);
>> +
>> + whip->audio_payload_type = WHIP_RTP_PAYLOAD_TYPE_OPUS;
>> + whip->video_payload_type = WHIP_RTP_PAYLOAD_TYPE_H264;
>> +
>> + av_bprintf(&bp, ""
>> + "v=0\r\n"
>> + "o=FFmpeg %s 2 IN IP4 %s\r\n"
>> + "s=FFmpegPublishSession\r\n"
>> + "t=0 0\r\n"
>> + "a=group:BUNDLE 0 1\r\n"
>> + "a=extmap-allow-mixed\r\n"
>> + "a=msid-semantic: WMS\r\n",
>> + WHIP_SDP_SESSION_ID,
>> + WHIP_SDP_CREATOR_IP);
>> +
>> + if (whip->audio_par) {
>> + if (whip->audio_par->codec_id == AV_CODEC_ID_OPUS)
>> + acodec_name = "opus";
>> +
>> + av_bprintf(&bp, ""
>> + "m=audio 9 UDP/TLS/RTP/SAVPF %u\r\n"
>> + "c=IN IP4 0.0.0.0\r\n"
>> + "a=ice-ufrag:%s\r\n"
>> + "a=ice-pwd:%s\r\n"
>> + "a=fingerprint:sha-256 %s\r\n"
>> + "a=setup:passive\r\n"
>> + "a=mid:0\r\n"
>> + "a=sendonly\r\n"
>> + "a=msid:FFmpeg audio\r\n"
>> + "a=rtcp-mux\r\n"
>> + "a=rtpmap:%u %s/%d/%d\r\n"
>> + "a=ssrc:%u cname:FFmpeg\r\n"
>> + "a=ssrc:%u msid:FFmpeg audio\r\n",
>> + whip->audio_payload_type,
>> + whip->ice_ufrag_local,
>> + whip->ice_pwd_local,
>> + whip->dtls_fingerprint,
>> + whip->audio_payload_type,
>> + acodec_name,
>> + whip->audio_par->sample_rate,
>> + whip->audio_par->ch_layout.nb_channels,
>> + whip->audio_ssrc,
>> + whip->audio_ssrc);
>> + }
>> +
>> + if (whip->video_par) {
>> + profile_iop = profile = whip->video_par->profile;
>> + level = whip->video_par->level;
>> + if (whip->video_par->codec_id == AV_CODEC_ID_H264) {
>> + vcodec_name = "H264";
>> + profile_iop &= AV_PROFILE_H264_CONSTRAINED;
>> + profile &= (~AV_PROFILE_H264_CONSTRAINED);
>> + }
>> +
>> + av_bprintf(&bp, ""
>> + "m=video 9 UDP/TLS/RTP/SAVPF %u\r\n"
>> + "c=IN IP4 0.0.0.0\r\n"
>> + "a=ice-ufrag:%s\r\n"
>> + "a=ice-pwd:%s\r\n"
>> + "a=fingerprint:sha-256 %s\r\n"
>> + "a=setup:passive\r\n"
>> + "a=mid:1\r\n"
>> + "a=sendonly\r\n"
>> + "a=msid:FFmpeg video\r\n"
>> + "a=rtcp-mux\r\n"
>> + "a=rtcp-rsize\r\n"
>> + "a=rtpmap:%u %s/90000\r\n"
>> + "a=fmtp:%u level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=%02x%02x%02x\r\n"
>> + "a=ssrc:%u cname:FFmpeg\r\n"
>> + "a=ssrc:%u msid:FFmpeg video\r\n",
>> + whip->video_payload_type,
>> + whip->ice_ufrag_local,
>> + whip->ice_pwd_local,
>> + whip->dtls_fingerprint,
>> + whip->video_payload_type,
>> + vcodec_name,
>> + whip->video_payload_type,
>> + profile,
>> + profile_iop,
>> + level,
>> + whip->video_ssrc,
>> + whip->video_ssrc);
>> + }
>> +
>> + if (!av_bprint_is_complete(&bp)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Offer exceed max %d, %s\n", MAX_SDP_SIZE, bp.str);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> + whip->sdp_offer = av_strdup(bp.str);
>> + if (!whip->sdp_offer) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> +
>> + if (whip->state < WHIP_STATE_OFFER)
>> + whip->state = WHIP_STATE_OFFER;
>> + whip->whip_offer_time = av_gettime();
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: Generated state=%d, offer: %s\n", whip->state, whip->sdp_offer);
>> +
>> +end:
>> + av_bprint_finalize(&bp, NULL);
>> + return ret;
>> +}
>> +
>> +/**
>> + * Exchange SDP offer with WebRTC peer to get the answer.
>> + *
>> + * @return 0 if OK, AVERROR_xxx on error
>> + */
>> +static int exchange_sdp(AVFormatContext *s)
>> +{
>> + int ret;
>> + char buf[MAX_URL_SIZE];
>> + AVBPrint bp;
>> + WHIPContext *whip = s->priv_data;
>> + /* The URL context is an HTTP transport layer for the WHIP protocol. */
>> + URLContext *whip_uc = NULL;
>> + AVDictionary *opts = NULL;
>> + char *hex_data = NULL;
>> +
>> + /* To prevent a crash during cleanup, always initialize it. */
>> + av_bprint_init(&bp, 1, MAX_SDP_SIZE);
>> +
>> + if (!whip->sdp_offer || !strlen(whip->sdp_offer)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: No offer to exchange\n");
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + ret = snprintf(buf, sizeof(buf), "Cache-Control: no-cache\r\nContent-Type: application/sdp\r\n");
>> + if (whip->authorization)
>> + ret += snprintf(buf + ret, sizeof(buf) - ret, "Authorization: Bearer %s\r\n", whip->authorization);
>> + if (ret <= 0 || ret >= sizeof(buf)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to generate headers, size=%d, %s\n", ret, buf);
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + av_dict_set(&opts, "headers", buf, 0);
>> + av_dict_set_int(&opts, "chunked_post", 0, 0);
>> +
>> + hex_data = av_mallocz(2 * strlen(whip->sdp_offer) + 1);
>> + if (!hex_data) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> + ff_data_to_hex(hex_data, whip->sdp_offer, strlen(whip->sdp_offer), 0);
>> + av_dict_set(&opts, "post_data", hex_data, 0);
>> +
>> + ret = ffurl_open_whitelist(&whip_uc, s->url, AVIO_FLAG_READ_WRITE, &s->interrupt_callback,
>> + &opts, s->protocol_whitelist, s->protocol_blacklist, NULL);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to request url=%s, offer: %s\n", s->url, whip->sdp_offer);
>> + goto end;
>> + }
>> +
>> + if (ff_http_get_new_location(whip_uc)) {
>> + whip->whip_resource_url = av_strdup(ff_http_get_new_location(whip_uc));
>> + if (!whip->whip_resource_url) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> + }
>> +
>> + while (1) {
>> + ret = ffurl_read(whip_uc, buf, sizeof(buf));
>> + if (ret == AVERROR_EOF) {
>> + /* Reset the error because we read all response as answer util EOF. */
>> + ret = 0;
>> + break;
>> + }
>> + if (ret <= 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to read response from url=%s, offer is %s, answer is %s\n",
>> + s->url, whip->sdp_offer, whip->sdp_answer);
>> + goto end;
>> + }
>> +
>> + av_bprintf(&bp, "%.*s", ret, buf);
>> + if (!av_bprint_is_complete(&bp)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Answer exceed max size %d, %.*s, %s\n", MAX_SDP_SIZE, ret, buf, bp.str);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> + }
>> +
>> + if (!av_strstart(bp.str, "v=", NULL)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Invalid answer: %s\n", bp.str);
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + whip->sdp_answer = av_strdup(bp.str);
>> + if (!whip->sdp_answer) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> +
>> + if (whip->state < WHIP_STATE_ANSWER)
>> + whip->state = WHIP_STATE_ANSWER;
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: Got state=%d, answer: %s\n", whip->state, whip->sdp_answer);
>> +
>> +end:
>> + ffurl_closep(&whip_uc);
>> + av_bprint_finalize(&bp, NULL);
>> + av_dict_free(&opts);
>> + av_freep(&hex_data);
>> + return ret;
>> +}
>> +
>> +/**
>> + * Parses the ICE ufrag, pwd, and candidates from the SDP answer.
>> + *
>> + * This function is used to extract the ICE ufrag, pwd, and candidates from the SDP answer.
>> + * It returns an error if any of these fields is NULL. The function only uses the first
>> + * candidate if there are multiple candidates. However, support for multiple candidates
>> + * will be added in the future.
>> + *
>> + * @param s Pointer to the AVFormatContext
>> + * @returns Returns 0 if successful or AVERROR_xxx if an error occurs.
>> + */
>> +static int parse_answer(AVFormatContext *s)
>> +{
>> + int ret = 0;
>> + AVIOContext *pb;
>> + char line[MAX_URL_SIZE];
>> + const char *ptr;
>> + int i;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + if (!whip->sdp_answer || !strlen(whip->sdp_answer)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: No answer to parse\n");
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + pb = avio_alloc_context(whip->sdp_answer, strlen(whip->sdp_answer), 0, NULL, NULL, NULL, NULL);
>> + if (!pb)
>> + return AVERROR(ENOMEM);
>> +
>> + for (i = 0; !avio_feof(pb); i++) {
>> + ff_get_chomp_line(pb, line, sizeof(line));
>> + if (av_strstart(line, "a=ice-ufrag:", &ptr) && !whip->ice_ufrag_remote) {
>> + whip->ice_ufrag_remote = av_strdup(ptr);
>> + if (!whip->ice_ufrag_remote) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> + } else if (av_strstart(line, "a=ice-pwd:", &ptr) && !whip->ice_pwd_remote) {
>> + whip->ice_pwd_remote = av_strdup(ptr);
>> + if (!whip->ice_pwd_remote) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> + } else if (av_strstart(line, "a=candidate:", &ptr) && !whip->ice_protocol) {
>> + ptr = av_stristr(ptr, "udp");
>> + if (ptr && av_stristr(ptr, "host")) {
>> + char protocol[17], host[129];
>> + int priority, port;
>> + ret = sscanf(ptr, "%16s %d %128s %d typ host", protocol, &priority, host, &port);
>> + if (ret != 4) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed %d to parse line %d %s from %s\n",
>> + ret, i, line, whip->sdp_answer);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> + if (av_strcasecmp(protocol, "udp")) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Protocol %s is not supported by RTC, choose udp, line %d %s of %s\n",
>> + protocol, i, line, whip->sdp_answer);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> + whip->ice_protocol = av_strdup(protocol);
>> + whip->ice_host = av_strdup(host);
>> + whip->ice_port = port;
>> + if (!whip->ice_protocol || !whip->ice_host) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> + }
>> + }
>> + }
>> +
>> + if (!whip->ice_pwd_remote || !strlen(whip->ice_pwd_remote)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: No remote ice pwd parsed from %s\n", whip->sdp_answer);
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + if (!whip->ice_ufrag_remote || !strlen(whip->ice_ufrag_remote)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: No remote ice ufrag parsed from %s\n", whip->sdp_answer);
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + if (!whip->ice_protocol || !whip->ice_host || !whip->ice_port) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: No ice candidate parsed from %s\n", whip->sdp_answer);
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + if (whip->state < WHIP_STATE_NEGOTIATED)
>> + whip->state = WHIP_STATE_NEGOTIATED;
>> + whip->whip_answer_time = av_gettime();
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: SDP state=%d, offer=%luB, answer=%luB, ufrag=%s, pwd=%luB, transport=%s://%s:%d, elapsed=%dms\n",
>> + whip->state, strlen(whip->sdp_offer), strlen(whip->sdp_answer), whip->ice_ufrag_remote, strlen(whip->ice_pwd_remote),
>> + whip->ice_protocol, whip->ice_host, whip->ice_port, ELAPSED(whip->whip_starttime, av_gettime()));
>> +
>> +end:
>> + avio_context_free(&pb);
>> + return ret;
>> +}
>> +
>> +/**
>> + * Creates and marshals an ICE binding request packet.
>> + *
>> + * This function creates and marshals an ICE binding request packet. The function only
>> + * generates the username attribute and does not include goog-network-info, ice-controlling,
>> + * use-candidate, and priority. However, some of these attributes may be added in the future.
>> + *
>> + * @param s Pointer to the AVFormatContext
>> + * @param buf Pointer to memory buffer to store the request packet
>> + * @param buf_size Size of the memory buffer
>> + * @param request_size Pointer to an integer that receives the size of the request packet
>> + * @return Returns 0 if successful or AVERROR_xxx if an error occurs.
>> + */
>> +static int ice_create_request(AVFormatContext *s, uint8_t *buf, int buf_size, int *request_size)
>> +{
>> + int ret, size, crc32;
>> + char username[128];
>> + AVIOContext *pb = NULL;
>> + AVHMAC *hmac = NULL;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + pb = avio_alloc_context(buf, buf_size, 1, NULL, NULL, NULL, NULL);
>> + if (!pb)
>> + return AVERROR(ENOMEM);
>> +
>> + hmac = av_hmac_alloc(AV_HMAC_SHA1);
>> + if (!hmac) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> +
>> + /* Write 20 bytes header */
>> + avio_wb16(pb, 0x0001); /* STUN binding request */
>> + avio_wb16(pb, 0); /* length */
>> + avio_wb32(pb, STUN_MAGIC_COOKIE); /* magic cookie */
>> + avio_wb32(pb, av_lfg_get(&whip->rnd)); /* transaction ID */
>> + avio_wb32(pb, av_lfg_get(&whip->rnd)); /* transaction ID */
>> + avio_wb32(pb, av_lfg_get(&whip->rnd)); /* transaction ID */
>> +
>> + /* The username is the concatenation of the two ICE ufrag */
>> + ret = snprintf(username, sizeof(username), "%s:%s", whip->ice_ufrag_remote, whip->ice_ufrag_local);
>> + if (ret <= 0 || ret >= sizeof(username)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to build username %s:%s, max=%lu, ret=%d\n",
>> + whip->ice_ufrag_remote, whip->ice_ufrag_local, sizeof(username), ret);
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> + /* Write the username attribute */
>> + avio_wb16(pb, STUN_ATTR_USERNAME); /* attribute type username */
>> + avio_wb16(pb, ret); /* size of username */
>> + avio_write(pb, username, ret); /* bytes of username */
>> + ffio_fill(pb, 0, (4 - (ret % 4)) % 4); /* padding */
>> +
>> + /* Write the use-candidate attribute */
>> + avio_wb16(pb, STUN_ATTR_USE_CANDIDATE); /* attribute type use-candidate */
>> + avio_wb16(pb, 0); /* size of use-candidate */
>> +
>> + /* Build and update message integrity */
>> + avio_wb16(pb, STUN_ATTR_MESSAGE_INTEGRITY); /* attribute type message integrity */
>> + avio_wb16(pb, 20); /* size of message integrity */
>> + ffio_fill(pb, 0, 20); /* fill with zero to directly write and skip it */
>> + size = avio_tell(pb);
>> + buf[2] = (size - 20) >> 8;
>> + buf[3] = (size - 20) & 0xFF;
>> + av_hmac_init(hmac, whip->ice_pwd_remote, strlen(whip->ice_pwd_remote));
>> + av_hmac_update(hmac, buf, size - 24);
>> + av_hmac_final(hmac, buf + size - 20, 20);
>> +
>> + /* Write the fingerprint attribute */
>> + avio_wb16(pb, STUN_ATTR_FINGERPRINT); /* attribute type fingerprint */
>> + avio_wb16(pb, 4); /* size of fingerprint */
>> + ffio_fill(pb, 0, 4); /* fill with zero to directly write and skip it */
>> + size = avio_tell(pb);
>> + buf[2] = (size - 20) >> 8;
>> + buf[3] = (size - 20) & 0xFF;
>> + /* Refer to the av_hash_alloc("CRC32"), av_hash_init and av_hash_final */
>> + crc32 = av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), 0xFFFFFFFF, buf, size - 8) ^ 0xFFFFFFFF;
>> + avio_skip(pb, -4);
>> + avio_wb32(pb, crc32 ^ 0x5354554E); /* xor with "STUN" */
>> +
>> + *request_size = size;
>> +
>> +end:
>> + avio_context_free(&pb);
>> + av_hmac_free(hmac);
>> + return ret;
>> +}
>> +
>> +/**
>> + * Create an ICE binding response.
>> + *
>> + * This function generates an ICE binding response and writes it to the provided
>> + * buffer. The response is signed using the local password for message integrity.
>> + *
>> + * @param s Pointer to the AVFormatContext structure.
>> + * @param tid Pointer to the transaction ID of the binding request. The tid_size should be 12.
>> + * @param tid_size The size of the transaction ID, should be 12.
>> + * @param buf Pointer to the buffer where the response will be written.
>> + * @param buf_size The size of the buffer provided for the response.
>> + * @param response_size Pointer to an integer that will store the size of the generated response.
>> + * @return Returns 0 if successful or AVERROR_xxx if an error occurs.
>> + */
>> +static int ice_create_response(AVFormatContext *s, char *tid, int tid_size, uint8_t *buf, int buf_size, int *response_size)
>> +{
>> + int ret = 0, size, crc32;
>> + AVIOContext *pb = NULL;
>> + AVHMAC *hmac = NULL;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + if (tid_size != 12) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Invalid transaction ID size. Expected 12, got %d\n", tid_size);
>> + return AVERROR(EINVAL);
>> + }
>> +
>> + pb = avio_alloc_context(buf, buf_size, 1, NULL, NULL, NULL, NULL);
>> + if (!pb)
>> + return AVERROR(ENOMEM);
>> +
>> + hmac = av_hmac_alloc(AV_HMAC_SHA1);
>> + if (!hmac) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> +
>> + /* Write 20 bytes header */
>> + avio_wb16(pb, 0x0101); /* STUN binding response */
>> + avio_wb16(pb, 0); /* length */
>> + avio_wb32(pb, STUN_MAGIC_COOKIE); /* magic cookie */
>> + avio_write(pb, tid, tid_size); /* transaction ID */
>> +
>> + /* Build and update message integrity */
>> + avio_wb16(pb, STUN_ATTR_MESSAGE_INTEGRITY); /* attribute type message integrity */
>> + avio_wb16(pb, 20); /* size of message integrity */
>> + ffio_fill(pb, 0, 20); /* fill with zero to directly write and skip it */
>> + size = avio_tell(pb);
>> + buf[2] = (size - 20) >> 8;
>> + buf[3] = (size - 20) & 0xFF;
>> + av_hmac_init(hmac, whip->ice_pwd_local, strlen(whip->ice_pwd_local));
>> + av_hmac_update(hmac, buf, size - 24);
>> + av_hmac_final(hmac, buf + size - 20, 20);
>> +
>> + /* Write the fingerprint attribute */
>> + avio_wb16(pb, STUN_ATTR_FINGERPRINT); /* attribute type fingerprint */
>> + avio_wb16(pb, 4); /* size of fingerprint */
>> + ffio_fill(pb, 0, 4); /* fill with zero to directly write and skip it */
>> + size = avio_tell(pb);
>> + buf[2] = (size - 20) >> 8;
>> + buf[3] = (size - 20) & 0xFF;
>> + /* Refer to the av_hash_alloc("CRC32"), av_hash_init and av_hash_final */
>> + crc32 = av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), 0xFFFFFFFF, buf, size - 8) ^ 0xFFFFFFFF;
>> + avio_skip(pb, -4);
>> + avio_wb32(pb, crc32 ^ 0x5354554E); /* xor with "STUN" */
>> +
>> + *response_size = size;
>> +
>> +end:
>> + avio_context_free(&pb);
>> + av_hmac_free(hmac);
>> + return ret;
>> +}
>> +
>> +/**
>> + * A Binding request has class=0b00 (request) and method=0b000000000001 (Binding)
>> + * and is encoded into the first 16 bits as 0x0001.
>> + * See https://datatracker.ietf.org/doc/html/rfc5389#section-6
>> + */
>> +static int ice_is_binding_request(uint8_t *b, int size)
>> +{
>> + return size >= ICE_STUN_HEADER_SIZE && AV_RB16(&b[0]) == 0x0001;
>> +}
>> +
>> +/**
>> + * A Binding response has class=0b10 (success response) and method=0b000000000001,
>> + * and is encoded into the first 16 bits as 0x0101.
>> + */
>> +static int ice_is_binding_response(uint8_t *b, int size)
>> +{
>> + return size >= ICE_STUN_HEADER_SIZE && AV_RB16(&b[0]) == 0x0101;
>> +}
>> +
>> +/**
>> + * In RTP packets, the first byte is represented as 0b10xxxxxx, where the initial
>> + * two bits (0b10) indicate the RTP version,
>> + * see https://www.rfc-editor.org/rfc/rfc3550#section-5.1
>> + * The RTCP packet header is similar to RTP,
>> + * see https://www.rfc-editor.org/rfc/rfc3550#section-6.4.1
>> + */
>> +static int media_is_rtp_rtcp(uint8_t *b, int size)
>> +{
>> + return size >= WHIP_RTP_HEADER_SIZE && (b[0] & 0xC0) == 0x80;
>> +}
>> +
>> +/* Whether the packet is RTCP. */
>> +static int media_is_rtcp(uint8_t *b, int size)
>> +{
>> + return size >= WHIP_RTP_HEADER_SIZE && b[1] >= WHIP_RTCP_PT_START && b[1] <= WHIP_RTCP_PT_END;
>> +}
>> +
>> +/**
>> + * This function handles incoming binding request messages by responding to them.
>> + * If the message is not a binding request, it will be ignored.
>> + */
>> +static int ice_handle_binding_request(AVFormatContext *s, char *buf, int buf_size)
>> +{
>> + int ret = 0, size;
>> + char tid[12];
>> + WHIPContext *whip = s->priv_data;
>> +
>> + /* Ignore if not a binding request. */
>> + if (!ice_is_binding_request(buf, buf_size))
>> + return ret;
>> +
>> + if (buf_size < ICE_STUN_HEADER_SIZE) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Invalid STUN message, expected at least %d, got %d\n",
>> + ICE_STUN_HEADER_SIZE, buf_size);
>> + return AVERROR(EINVAL);
>> + }
>> +
>> + /* Parse transaction id from binding request in buf. */
>> + memcpy(tid, buf + 8, 12);
>> +
>> + /* Build the STUN binding response. */
>> + ret = ice_create_response(s, tid, sizeof(tid), whip->buf, sizeof(whip->buf), &size);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to create STUN binding response, size=%d\n", size);
>> + return ret;
>> + }
>> +
>> + ret = ffurl_write(whip->udp, whip->buf, size);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to send STUN binding response, size=%d\n", size);
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +/**
>> + * To establish a connection with the UDP server, we utilize ICE-LITE in a Client-Server
>> + * mode. In this setup, FFmpeg acts as the UDP client, while the peer functions as the
>> + * UDP server.
>> + */
>> +static int udp_connect(AVFormatContext *s)
>> +{
>> + int ret = 0;
>> + char url[256];
>> + AVDictionary *opts = NULL;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + /* Build UDP URL and create the UDP context as transport. */
>> + ff_url_join(url, sizeof(url), "udp", NULL, whip->ice_host, whip->ice_port, NULL);
>> +
>> + av_dict_set_int(&opts, "connect", 1, 0);
>> + av_dict_set_int(&opts, "fifo_size", 0, 0);
>> + /* Set the max packet size to the buffer size. */
>> + av_dict_set_int(&opts, "pkt_size", whip->pkt_size, 0);
>> +
>> + ret = ffurl_open_whitelist(&whip->udp, url, AVIO_FLAG_WRITE, &s->interrupt_callback,
>> + &opts, s->protocol_whitelist, s->protocol_blacklist, NULL);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to connect udp://%s:%d\n", whip->ice_host, whip->ice_port);
>> + goto end;
>> + }
>> +
>> + /* Make the socket non-blocking, set to READ and WRITE mode after connected */
>> + ff_socket_nonblock(ffurl_get_file_handle(whip->udp), 1);
>> + whip->udp->flags |= AVIO_FLAG_READ | AVIO_FLAG_NONBLOCK;
>> +
>> + if (whip->state < WHIP_STATE_UDP_CONNECTED)
>> + whip->state = WHIP_STATE_UDP_CONNECTED;
>> + whip->whip_udp_time = av_gettime();
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: UDP state=%d, elapsed=%dms, connected to udp://%s:%d\n",
>> + whip->state, ELAPSED(whip->whip_starttime, av_gettime()), whip->ice_host, whip->ice_port);
>> +
>> +end:
>> + av_dict_free(&opts);
>> + return ret;
>> +}
>> +
>> +static int ice_dtls_handshake(AVFormatContext *s)
>> +{
>> + int ret = 0, size, i;
>> + int64_t starttime = av_gettime(), now;
>> + WHIPContext *whip = s->priv_data;
>> + AVDictionary *opts = NULL;
>> + char str[8];
>> + char buf[256], *cert_buf = NULL, *key_buf = NULL;
>> +
>> + if (whip->state < WHIP_STATE_UDP_CONNECTED || !whip->udp) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: UDP not connected, state=%d, udp=%p\n", whip->state, whip->udp);
>> + return AVERROR(EINVAL);
>> + }
>> +
>> + while (1) {
>> + if (whip->state <= WHIP_STATE_ICE_CONNECTING) {
>> + /* Build the STUN binding request. */
>> + ret = ice_create_request(s, whip->buf, sizeof(whip->buf), &size);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to create STUN binding request, size=%d\n", size);
>> + goto end;
>> + }
>> +
>> + ret = ffurl_write(whip->udp, whip->buf, size);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to send STUN binding request, size=%d\n", size);
>> + goto end;
>> + }
>> +
>> + if (whip->state < WHIP_STATE_ICE_CONNECTING)
>> + whip->state = WHIP_STATE_ICE_CONNECTING;
>> + }
>> +
>> +next_packet:
>> + if (whip->state >= WHIP_STATE_DTLS_FINISHED)
>> + /* DTLS handshake is done, exit the loop. */
>> + break;
>> +
>> + now = av_gettime();
>> + if (now - starttime >= whip->handshake_timeout * 1000) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: DTLS handshake timeout=%dms, cost=%dms, elapsed=%dms, state=%d\n",
>> + whip->handshake_timeout, ELAPSED(starttime, now), ELAPSED(whip->whip_starttime, now), whip->state);
>> + ret = AVERROR(ETIMEDOUT);
>> + goto end;
>> + }
>> +
>> + /* Read the STUN or DTLS messages from peer. */
>> + for (i = 0; i < ICE_DTLS_READ_INTERVAL / 5 && whip->state < WHIP_STATE_DTLS_CONNECTING; i++) {
>> + ret = ffurl_read(whip->udp, whip->buf, sizeof(whip->buf));
>> + if (ret > 0)
>> + break;
>> + if (ret == AVERROR(EAGAIN)) {
>> + av_usleep(5 * 1000);
>> + continue;
>> + }
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to read message\n");
>> + goto end;
>> + }
>> +
>> + /* Got nothing, continue to process handshake. */
>> + if (ret <= 0 && whip->state < WHIP_STATE_DTLS_CONNECTING)
>> + continue;
>> +
>> + /* Handle the ICE binding response. */
>> + if (ice_is_binding_response(whip->buf, ret)) {
>> + if (whip->state < WHIP_STATE_ICE_CONNECTED) {
>> + whip->state = WHIP_STATE_ICE_CONNECTED;
>> + whip->whip_ice_time = av_gettime();
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: ICE STUN ok, state=%d, url=udp://%s:%d, location=%s, username=%s:%s, res=%dB, elapsed=%dms\n",
>> + whip->state, whip->ice_host, whip->ice_port, whip->whip_resource_url ? whip->whip_resource_url : "",
>> + whip->ice_ufrag_remote, whip->ice_ufrag_local, ret, ELAPSED(whip->whip_starttime, av_gettime()));
>> +
>> + ff_url_join(buf, sizeof(buf), "dtls", NULL, whip->ice_host, whip->ice_port, NULL);
>> + snprintf(str, sizeof(str), "%d", whip->pkt_size);
>> + av_dict_set(&opts, "mtu", str, 0);
>> + if (whip->cert_file) {
>> + av_dict_set(&opts, "cert_file", whip->cert_file, 0);
>> + } else
>> + av_dict_set(&opts, "cert_buf", whip->cert_buf, 0);
>> +
>> + if (whip->key_file) {
>> + av_dict_set(&opts, "key_file", whip->key_file, 0);
>> + } else
>> + av_dict_set(&opts, "key_buf", whip->key_buf, 0);
>> +
>> + av_dict_set(&opts, "fingerprint", whip->dtls_fingerprint, 0);
>> + av_dict_set(&opts, "use_external_udp", "1", 0);
>> + av_dict_set(&opts, "listen", "1", 0);
>> + /* If got the first binding response, start DTLS handshake. */
>> + ret = ffurl_open_whitelist(&whip->dtls_uc, buf, AVIO_FLAG_READ_WRITE, &s->interrupt_callback,
>> + &opts, s->protocol_whitelist, s->protocol_blacklist, NULL);
>> + if (ret < 0)
>> + goto end;
>> + dtls_initialize(s);
>> + }
>> + goto next_packet;
>> + }
>> +
>> + /* When a binding request is received, it is necessary to respond immediately. */
>> + if (ice_is_binding_request(whip->buf, ret)) {
>> + if ((ret = ice_handle_binding_request(s, whip->buf, ret)) < 0)
>> + goto end;
>> + goto next_packet;
>> + }
>> +
>> + /* If got any DTLS messages, handle it. */
>> + if (is_dtls_packet(whip->buf, ret) && whip->state >= WHIP_STATE_ICE_CONNECTED || whip->state == WHIP_STATE_DTLS_CONNECTING) {
>> + whip->state = WHIP_STATE_DTLS_CONNECTING;
>> + if ((ret = ffurl_handshake(whip->dtls_uc)) < 0)
>> + goto end;
>> + dtls_context_on_state(s, NULL, NULL);
>> + goto next_packet;
>> + }
>> + }
>> +
>> +end:
>> + if (cert_buf)
>> + av_free(cert_buf);
>> + if (key_buf)
>> + av_free(key_buf);
>> + return ret;
>> +}
>> +
>> +/**
>> + * Establish the SRTP context using the keying material exported from DTLS.
>> + *
>> + * Create separate SRTP contexts for sending video and audio, as their sequences differ
>> + * and should not share a single context. Generate a single SRTP context for receiving
>> + * RTCP only.
>> + *
>> + * @return 0 if OK, AVERROR_xxx on error
>> + */
>> +static int setup_srtp(AVFormatContext *s)
>> +{
>> + int ret;
>> + char recv_key[DTLS_SRTP_KEY_LEN + DTLS_SRTP_SALT_LEN];
>> + char send_key[DTLS_SRTP_KEY_LEN + DTLS_SRTP_SALT_LEN];
>> + char buf[AV_BASE64_SIZE(DTLS_SRTP_KEY_LEN + DTLS_SRTP_SALT_LEN)];
>> + /**
>> + * The profile for OpenSSL's SRTP is SRTP_AES128_CM_SHA1_80, see ssl/d1_srtp.c.
>> + * The profile for FFmpeg's SRTP is SRTP_AES128_CM_HMAC_SHA1_80, see libavformat/srtp.c.
>> + */
>> + const char* suite = "SRTP_AES128_CM_HMAC_SHA1_80";
>> + WHIPContext *whip = s->priv_data;
>> + ret = ff_dtls_export_materials(whip->dtls_uc, whip->dtls_srtp_materials, sizeof(whip->dtls_srtp_materials));
>> + if (ret < 0)
>> + goto end;
>> + /**
>> + * This represents the material used to build the SRTP master key. It is
>> + * generated by DTLS and has the following layout:
>> + * 16B 16B 14B 14B
>> + * client_key | server_key | client_salt | server_salt
>> + */
>> + char *client_key = whip->dtls_srtp_materials;
>> + char *server_key = whip->dtls_srtp_materials + DTLS_SRTP_KEY_LEN;
>> + char *client_salt = server_key + DTLS_SRTP_KEY_LEN;
>> + char *server_salt = client_salt + DTLS_SRTP_SALT_LEN;
>> +
>> + /* As DTLS server, the recv key is client master key plus salt. */
>> + memcpy(recv_key, client_key, DTLS_SRTP_KEY_LEN);
>> + memcpy(recv_key + DTLS_SRTP_KEY_LEN, client_salt, DTLS_SRTP_SALT_LEN);
>> +
>> + /* As DTLS server, the send key is server master key plus salt. */
>> + memcpy(send_key, server_key, DTLS_SRTP_KEY_LEN);
>> + memcpy(send_key + DTLS_SRTP_KEY_LEN, server_salt, DTLS_SRTP_SALT_LEN);
>> +
>> + /* Setup SRTP context for outgoing packets */
>> + if (!av_base64_encode(buf, sizeof(buf), send_key, sizeof(send_key))) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to encode send key\n");
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> + ret = ff_srtp_set_crypto(&whip->srtp_audio_send, suite, buf);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to set crypto for audio send\n");
>> + goto end;
>> + }
>> +
>> + ret = ff_srtp_set_crypto(&whip->srtp_video_send, suite, buf);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to set crypto for video send\n");
>> + goto end;
>> + }
>> +
>> + ret = ff_srtp_set_crypto(&whip->srtp_rtcp_send, suite, buf);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "Failed to set crypto for rtcp send\n");
>> + goto end;
>> + }
>> +
>> + /* Setup SRTP context for incoming packets */
>> + if (!av_base64_encode(buf, sizeof(buf), recv_key, sizeof(recv_key))) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to encode recv key\n");
>> + ret = AVERROR(EIO);
>> + goto end;
>> + }
>> +
>> + ret = ff_srtp_set_crypto(&whip->srtp_recv, suite, buf);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to set crypto for recv\n");
>> + goto end;
>> + }
>> +
>> + if (whip->state < WHIP_STATE_SRTP_FINISHED)
>> + whip->state = WHIP_STATE_SRTP_FINISHED;
>> + whip->whip_srtp_time = av_gettime();
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: SRTP setup done, state=%d, suite=%s, key=%luB, elapsed=%dms\n",
>> + whip->state, suite, sizeof(send_key), ELAPSED(whip->whip_starttime, av_gettime()));
>> +
>> +end:
>> + return ret;
>> +}
>> +
>> +/**
>> + * Callback triggered by the RTP muxer when it creates and sends out an RTP packet.
>> + *
>> + * This function modifies the video STAP packet, removing the markers, and updating the
>> + * NRI of the first NALU. Additionally, it uses the corresponding SRTP context to encrypt
>> + * the RTP packet, where the video packet is handled by the video SRTP context.
>> + */
>> +static int on_rtp_write_packet(void *opaque, const uint8_t *buf, int buf_size)
>> +{
>> + int ret, cipher_size, is_rtcp, is_video;
>> + uint8_t payload_type;
>> + AVFormatContext *s = opaque;
>> + WHIPContext *whip = s->priv_data;
>> + SRTPContext *srtp;
>> +
>> + /* Ignore if not RTP or RTCP packet. */
>> + if (!media_is_rtp_rtcp(buf, buf_size))
>> + return 0;
>> +
>> + /* Only support audio, video and rtcp. */
>> + is_rtcp = media_is_rtcp(buf, buf_size);
>> + payload_type = buf[1] & 0x7f;
>> + is_video = payload_type == whip->video_payload_type;
>> + if (!is_rtcp && payload_type != whip->video_payload_type && payload_type != whip->audio_payload_type)
>> + return 0;
>> +
>> + /* Get the corresponding SRTP context. */
>> + srtp = is_rtcp ? &whip->srtp_rtcp_send : (is_video? &whip->srtp_video_send : &whip->srtp_audio_send);
>> +
>> + /* Encrypt by SRTP and send out. */
>> + cipher_size = ff_srtp_encrypt(srtp, buf, buf_size, whip->buf, sizeof(whip->buf));
>> + if (cipher_size <= 0 || cipher_size < buf_size) {
>> + av_log(whip, AV_LOG_WARNING, "WHIP: Failed to encrypt packet=%dB, cipher=%dB\n", buf_size, cipher_size);
>> + return 0;
>> + }
>> +
>> + ret = ffurl_write(whip->udp, whip->buf, cipher_size);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to write packet=%dB, ret=%d\n", cipher_size, ret);
>> + return ret;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +/**
>> + * Creates dedicated RTP muxers for each stream in the AVFormatContext to build RTP
>> + * packets from the encoded frames.
>> + *
>> + * The corresponding SRTP context is utilized to encrypt each stream's RTP packets. For
>> + * example, a video SRTP context is used for the video stream. Additionally, the
>> + * "on_rtp_write_packet" callback function is set as the write function for each RTP
>> + * muxer to send out encrypted RTP packets.
>> + *
>> + * @return 0 if OK, AVERROR_xxx on error
>> + */
>> +static int create_rtp_muxer(AVFormatContext *s)
>> +{
>> + int ret, i, is_video, buffer_size, max_packet_size;
>> + AVFormatContext *rtp_ctx = NULL;
>> + AVDictionary *opts = NULL;
>> + uint8_t *buffer = NULL;
>> + char buf[64];
>> + WHIPContext *whip = s->priv_data;
>> +
>> + const AVOutputFormat *rtp_format = av_guess_format("rtp", NULL, NULL);
>> + if (!rtp_format) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to guess rtp muxer\n");
>> + ret = AVERROR(ENOSYS);
>> + goto end;
>> + }
>> +
>> + /* The UDP buffer size, may greater than MTU. */
>> + buffer_size = MAX_UDP_BUFFER_SIZE;
>> + /* The RTP payload max size. Reserved some bytes for SRTP checksum and padding. */
>> + max_packet_size = whip->pkt_size - DTLS_SRTP_CHECKSUM_LEN;
>> +
>> + for (i = 0; i < s->nb_streams; i++) {
>> + rtp_ctx = avformat_alloc_context();
>> + if (!rtp_ctx) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> +
>> + rtp_ctx->oformat = rtp_format;
>> + if (!avformat_new_stream(rtp_ctx, NULL)) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> + /* Pass the interrupt callback on */
>> + rtp_ctx->interrupt_callback = s->interrupt_callback;
>> + /* Copy the max delay setting; the rtp muxer reads this. */
>> + rtp_ctx->max_delay = s->max_delay;
>> + /* Copy other stream parameters. */
>> + rtp_ctx->streams[0]->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
>> + rtp_ctx->flags |= s->flags & AVFMT_FLAG_BITEXACT;
>> + rtp_ctx->strict_std_compliance = s->strict_std_compliance;
>> +
>> + /* Set the synchronized start time. */
>> + rtp_ctx->start_time_realtime = s->start_time_realtime;
>> +
>> + avcodec_parameters_copy(rtp_ctx->streams[0]->codecpar, s->streams[i]->codecpar);
>> + rtp_ctx->streams[0]->time_base = s->streams[i]->time_base;
>> +
>> + /**
>> + * For H.264, consistently utilize the annexb format through the Bitstream Filter (BSF);
>> + * therefore, we deactivate the extradata detection for the RTP muxer.
>> + */
>> + if (s->streams[i]->codecpar->codec_id == AV_CODEC_ID_H264) {
>> + av_freep(&rtp_ctx->streams[i]->codecpar->extradata);
>> + rtp_ctx->streams[i]->codecpar->extradata_size = 0;
>> + }
>> +
>> + buffer = av_malloc(buffer_size);
>> + if (!buffer) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> +
>> + rtp_ctx->pb = avio_alloc_context(buffer, buffer_size, 1, s, NULL, on_rtp_write_packet, NULL);
>> + if (!rtp_ctx->pb) {
>> + ret = AVERROR(ENOMEM);
>> + goto end;
>> + }
>> + rtp_ctx->pb->max_packet_size = max_packet_size;
>> + rtp_ctx->pb->av_class = &ff_avio_class;
>> +
>> + is_video = s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO;
>> + snprintf(buf, sizeof(buf), "%d", is_video? whip->video_payload_type : whip->audio_payload_type);
>> + av_dict_set(&opts, "payload_type", buf, 0);
>> + snprintf(buf, sizeof(buf), "%d", is_video? whip->video_ssrc : whip->audio_ssrc);
>> + av_dict_set(&opts, "ssrc", buf, 0);
>> +
>> + ret = avformat_write_header(rtp_ctx, &opts);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to write rtp header\n");
>> + goto end;
>> + }
>> +
>> + ff_format_set_url(rtp_ctx, av_strdup(s->url));
>> + s->streams[i]->time_base = rtp_ctx->streams[0]->time_base;
>> + s->streams[i]->priv_data = rtp_ctx;
>> + rtp_ctx = NULL;
>> + }
>> +
>> + if (whip->state < WHIP_STATE_READY)
>> + whip->state = WHIP_STATE_READY;
>> + av_log(whip, AV_LOG_INFO, "WHIP: Muxer state=%d, buffer_size=%d, max_packet_size=%d, "
>> + "elapsed=%dms(init:%d,offer:%d,answer:%d,udp:%d,ice:%d,dtls:%d,srtp:%d)\n",
>> + whip->state, buffer_size, max_packet_size, ELAPSED(whip->whip_starttime, av_gettime()),
>> + ELAPSED(whip->whip_starttime, whip->whip_init_time),
>> + ELAPSED(whip->whip_init_time, whip->whip_offer_time),
>> + ELAPSED(whip->whip_offer_time, whip->whip_answer_time),
>> + ELAPSED(whip->whip_answer_time, whip->whip_udp_time),
>> + ELAPSED(whip->whip_udp_time, whip->whip_ice_time),
>> + ELAPSED(whip->whip_ice_time, whip->whip_dtls_time),
>> + ELAPSED(whip->whip_dtls_time, whip->whip_srtp_time));
>> +
>> +end:
>> + if (rtp_ctx)
>> + avio_context_free(&rtp_ctx->pb);
>> + avformat_free_context(rtp_ctx);
>> + av_dict_free(&opts);
>> + return ret;
>> +}
>> +
>> +/**
>> + * RTC is connectionless, for it's based on UDP, so it check whether sesison is
>> + * timeout. In such case, publishers can't republish the stream util the session
>> + * is timeout.
>> + * This function is called to notify the server that the stream is ended, server
>> + * should expire and close the session immediately, so that publishers can republish
>> + * the stream quickly.
>> + */
>> +static int dispose_session(AVFormatContext *s)
>> +{
>> + int ret;
>> + char buf[MAX_URL_SIZE];
>> + URLContext *whip_uc = NULL;
>> + AVDictionary *opts = NULL;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + if (!whip->whip_resource_url)
>> + return 0;
>> +
>> + ret = snprintf(buf, sizeof(buf), "Cache-Control: no-cache\r\n");
>> + if (whip->authorization)
>> + ret += snprintf(buf + ret, sizeof(buf) - ret, "Authorization: Bearer %s\r\n", whip->authorization);
>> + if (ret <= 0 || ret >= sizeof(buf)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to generate headers, size=%d, %s\n", ret, buf);
>> + ret = AVERROR(EINVAL);
>> + goto end;
>> + }
>> +
>> + av_dict_set(&opts, "headers", buf, 0);
>> + av_dict_set_int(&opts, "chunked_post", 0, 0);
>> + av_dict_set(&opts, "method", "DELETE", 0);
>> + ret = ffurl_open_whitelist(&whip_uc, whip->whip_resource_url, AVIO_FLAG_READ_WRITE, &s->interrupt_callback,
>> + &opts, s->protocol_whitelist, s->protocol_blacklist, NULL);
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to DELETE url=%s\n", whip->whip_resource_url);
>> + goto end;
>> + }
>> +
>> + while (1) {
>> + ret = ffurl_read(whip_uc, buf, sizeof(buf));
>> + if (ret == AVERROR_EOF) {
>> + ret = 0;
>> + break;
>> + }
>> + if (ret < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to read response from DELETE url=%s\n", whip->whip_resource_url);
>> + goto end;
>> + }
>> + }
>> +
>> + av_log(whip, AV_LOG_INFO, "WHIP: Dispose resource %s ok\n", whip->whip_resource_url);
>> +
>> +end:
>> + ffurl_closep(&whip_uc);
>> + av_dict_free(&opts);
>> + return ret;
>> +}
>> +
>> +/**
>> + * Since the h264_mp4toannexb filter only processes the MP4 ISOM format and bypasses
>> + * the annexb format, it is necessary to manually insert encoder metadata before each
>> + * IDR when dealing with annexb format packets. For instance, in the case of H.264,
>> + * we must insert SPS and PPS before the IDR frame.
>> + */
>> +static int h264_annexb_insert_sps_pps(AVFormatContext *s, AVPacket *pkt)
>> +{
>> + int ret = 0;
>> + AVPacket *in = NULL;
>> + AVCodecParameters *par = s->streams[pkt->stream_index]->codecpar;
>> + uint32_t nal_size = 0, out_size = par ? par->extradata_size : 0;
>> + uint8_t unit_type, sps_seen = 0, pps_seen = 0, idr_seen = 0, *out;
>> + const uint8_t *buf, *buf_end, *r1;
>> +
>> + if (!pkt || !pkt->data || pkt->size <= 0)
>> + return ret;
>> + if (!par || !par->extradata || par->extradata_size <= 0)
>> + return ret;
>> +
>> + /* Discover NALU type from packet. */
>> + buf_end = pkt->data + pkt->size;
>> + for (buf = ff_nal_find_startcode(pkt->data, buf_end); buf < buf_end; buf += nal_size) {
>> + while (!*(buf++));
>> + r1 = ff_nal_find_startcode(buf, buf_end);
>> + if ((nal_size = r1 - buf) > 0) {
>> + unit_type = *buf & 0x1f;
>> + if (unit_type == H264_NAL_SPS) {
>> + sps_seen = 1;
>> + } else if (unit_type == H264_NAL_PPS) {
>> + pps_seen = 1;
>> + } else if (unit_type == H264_NAL_IDR_SLICE) {
>> + idr_seen = 1;
>> + }
>> +
>> + out_size += 3 + nal_size;
>> + }
>> + }
>> +
>> + if (!idr_seen || (sps_seen && pps_seen))
>> + return ret;
>> +
>> + /* See av_bsf_send_packet */
>> + in = av_packet_alloc();
>> + if (!in)
>> + return AVERROR(ENOMEM);
>> +
>> + ret = av_packet_make_refcounted(pkt);
>> + if (ret < 0)
>> + goto fail;
>> +
>> + av_packet_move_ref(in, pkt);
>> +
>> + /* Create a new packet with sps/pps inserted. */
>> + ret = av_new_packet(pkt, out_size);
>> + if (ret < 0)
>> + goto fail;
>> +
>> + ret = av_packet_copy_props(pkt, in);
>> + if (ret < 0)
>> + goto fail;
>> +
>> + memcpy(pkt->data, par->extradata, par->extradata_size);
>> + out = pkt->data + par->extradata_size;
>> + buf_end = in->data + in->size;
>> + for (buf = ff_nal_find_startcode(in->data, buf_end); buf < buf_end; buf += nal_size) {
>> + while (!*(buf++));
>> + r1 = ff_nal_find_startcode(buf, buf_end);
>> + if ((nal_size = r1 - buf) > 0) {
>> + AV_WB24(out, 0x00001);
>> + memcpy(out + 3, buf, nal_size);
>> + out += 3 + nal_size;
>> + }
>> + }
>> +
>> +fail:
>> + if (ret < 0)
>> + av_packet_unref(pkt);
>> + av_packet_free(&in);
>> +
>> + return ret;
>> +}
>> +
>> +static av_cold int whip_init(AVFormatContext *s)
>> +{
>> + int ret;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + if ((ret = initialize(s)) < 0)
>> + goto end;
>> +
>> + if ((ret = parse_codec(s)) < 0)
>> + goto end;
>> +
>> + if ((ret = generate_sdp_offer(s)) < 0)
>> + goto end;
>> +
>> + if ((ret = exchange_sdp(s)) < 0)
>> + goto end;
>> +
>> + if ((ret = parse_answer(s)) < 0)
>> + goto end;
>> +
>> + if ((ret = udp_connect(s)) < 0)
>> + goto end;
>> +
>> + if ((ret = ice_dtls_handshake(s)) < 0)
>> + goto end;
>> +
>> + if ((ret = setup_srtp(s)) < 0)
>> + goto end;
>> +
>> + if ((ret = create_rtp_muxer(s)) < 0)
>> + goto end;
>> +
>> +end:
>> + if (ret < 0 && whip->state < WHIP_STATE_FAILED)
>> + whip->state = WHIP_STATE_FAILED;
>> + if (ret >= 0 && whip->state >= WHIP_STATE_FAILED && whip->dtls_ret < 0)
>> + ret = whip->dtls_ret;
>> + return ret;
>> +}
>> +
>> +static int whip_write_packet(AVFormatContext *s, AVPacket *pkt)
>> +{
>> + int ret;
>> + WHIPContext *whip = s->priv_data;
>> + AVStream *st = s->streams[pkt->stream_index];
>> + AVFormatContext *rtp_ctx = st->priv_data;
>> +
>> + /* TODO: Send binding request every 1s as WebRTC heartbeat. */
>> +
>> + /**
>> + * Receive packets from the server such as ICE binding requests, DTLS messages,
>> + * and RTCP like PLI requests, then respond to them.
>> + */
>> + ret = ffurl_read(whip->udp, whip->buf, sizeof(whip->buf));
>> + if (ret > 0) {
>> + if (is_dtls_packet(whip->buf, ret)) {
>> + if ((ret = ffurl_write(whip->dtls_uc, whip->buf, ret)) < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to handle DTLS message\n");
>> + goto end;
>> + }
>> + }
>> + } else if (ret != AVERROR(EAGAIN)) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to read from UDP socket\n");
>> + goto end;
>> + }
>> +
>> + if (whip->h264_annexb_insert_sps_pps && st->codecpar->codec_id == AV_CODEC_ID_H264) {
>> + if ((ret = h264_annexb_insert_sps_pps(s, pkt)) < 0) {
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to insert SPS/PPS before IDR\n");
>> + goto end;
>> + }
>> + }
>> +
>> + ret = ff_write_chained(rtp_ctx, 0, pkt, s, 0);
>> + if (ret < 0) {
>> + if (ret == AVERROR(EINVAL)) {
>> + av_log(whip, AV_LOG_WARNING, "WHIP: Ignore failed to write packet=%dB, ret=%d\n", pkt->size, ret);
>> + ret = 0;
>> + } else
>> + av_log(whip, AV_LOG_ERROR, "WHIP: Failed to write packet, size=%d\n", pkt->size);
>> + goto end;
>> + }
>> +
>> +end:
>> + if (ret < 0 && whip->state < WHIP_STATE_FAILED)
>> + whip->state = WHIP_STATE_FAILED;
>> + if (ret >= 0 && whip->state >= WHIP_STATE_FAILED && whip->dtls_ret < 0)
>> + ret = whip->dtls_ret;
>> + if (ret >= 0 && whip->dtls_closed)
>> + ret = AVERROR(EIO);
>> + return ret;
>> +}
>> +
>> +static av_cold void whip_deinit(AVFormatContext *s)
>> +{
>> + int i, ret;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + ret = dispose_session(s);
>> + if (ret < 0)
>> + av_log(whip, AV_LOG_WARNING, "WHIP: Failed to dispose resource, ret=%d\n", ret);
>> +
>> + for (i = 0; i < s->nb_streams; i++) {
>> + AVFormatContext* rtp_ctx = s->streams[i]->priv_data;
>> + if (!rtp_ctx)
>> + continue;
>> +
>> + av_write_trailer(rtp_ctx);
>> + /**
>> + * Keep in mind that it is necessary to free the buffer of pb since we allocate
>> + * it and pass it to pb using avio_alloc_context, while avio_context_free does
>> + * not perform this action.
>> + */
>> + av_freep(&rtp_ctx->pb->buffer);
>> + avio_context_free(&rtp_ctx->pb);
>> + avformat_free_context(rtp_ctx);
>> + s->streams[i]->priv_data = NULL;
>> + }
>> +
>> + av_freep(&whip->sdp_offer);
>> + av_freep(&whip->sdp_answer);
>> + av_freep(&whip->whip_resource_url);
>> + av_freep(&whip->ice_ufrag_remote);
>> + av_freep(&whip->ice_pwd_remote);
>> + av_freep(&whip->ice_protocol);
>> + av_freep(&whip->ice_host);
>> + av_freep(&whip->authorization);
>> + av_freep(&whip->cert_file);
>> + av_freep(&whip->key_file);
>> + ffurl_closep(&whip->udp);
>> + ff_srtp_free(&whip->srtp_audio_send);
>> + ff_srtp_free(&whip->srtp_video_send);
>> + ff_srtp_free(&whip->srtp_rtcp_send);
>> + ff_srtp_free(&whip->srtp_recv);
>> + ffurl_close(whip->dtls_uc);
>> +}
>> +
>> +static int whip_check_bitstream(AVFormatContext *s, AVStream *st, const AVPacket *pkt)
>> +{
>> + int ret = 1, extradata_isom = 0;
>> + uint8_t *b = pkt->data;
>> + WHIPContext *whip = s->priv_data;
>> +
>> + if (st->codecpar->codec_id == AV_CODEC_ID_H264) {
>> + extradata_isom = st->codecpar->extradata_size > 0 && st->codecpar->extradata[0] == 1;
>> + if (pkt->size >= 5 && AV_RB32(b) != 0x0000001 && (AV_RB24(b) != 0x000001 || extradata_isom)) {
>> + ret = ff_stream_add_bitstream_filter(st, "h264_mp4toannexb", NULL);
>> + av_log(whip, AV_LOG_VERBOSE, "WHIP: Enable BSF h264_mp4toannexb, packet=[%x %x %x %x %x ...], extradata_isom=%d\n",
>> + b[0], b[1], b[2], b[3], b[4], extradata_isom);
>> + } else
>> + whip->h264_annexb_insert_sps_pps = 1;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +#define OFFSET(x) offsetof(WHIPContext, x)
>> +#define DEC AV_OPT_FLAG_DECODING_PARAM
>> +static const AVOption options[] = {
>> + { "handshake_timeout", "Timeout in milliseconds for ICE and DTLS handshake.", OFFSET(handshake_timeout), AV_OPT_TYPE_INT, { .i64 = 5000 }, -1, INT_MAX, DEC },
>> + { "pkt_size", "The maximum size, in bytes, of RTP packets that send out", OFFSET(pkt_size), AV_OPT_TYPE_INT, { .i64 = 1200 }, -1, INT_MAX, DEC },
>> + { "authorization", "The optional Bearer token for WHIP Authorization", OFFSET(authorization), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
>> + { "cert_file", "The optional certificate file path for DTLS", OFFSET(cert_file), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
>> + { "key_file", "The optional private key file path for DTLS", OFFSET(key_file), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
>> + { NULL },
>> +};
>> +
>> +static const AVClass whip_muxer_class = {
>> + .class_name = "WHIP muxer",
>> + .item_name = av_default_item_name,
>> + .option = options,
>> + .version = LIBAVUTIL_VERSION_INT,
>> +};
>> +
>> +const FFOutputFormat ff_whip_muxer = {
>> + .p.name = "whip",
>> + .p.long_name = NULL_IF_CONFIG_SMALL("WHIP(WebRTC-HTTP ingestion protocol) muxer"),
>> + .p.audio_codec = AV_CODEC_ID_OPUS,
>> + .p.video_codec = AV_CODEC_ID_H264,
>> + .p.flags = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
>> + .p.priv_class = &whip_muxer_class,
>> + .priv_data_size = sizeof(WHIPContext),
>> + .init = whip_init,
>> + .write_packet = whip_write_packet,
>> + .deinit = whip_deinit,
>> + .check_bitstream = whip_check_bitstream,
>> +};
>> --
>> 2.49.0
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
> Pushed,
>
> BTW, if you other developers want fix other problems, patchwelcome,
>
> To Jack, you can continue submit more patches for whip in ffmpeg.
I will add some documentation about DTLS first, and then try to add new features to whip. Thanks to @Sean-Der for helping me quickly familiarize myself with openssl and get this done. I’ll improve this feature with him😄
>
>
> Thanks
> Steven
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
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next prev parent reply other threads:[~2025-06-04 3:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-17 9:24 Jack Lau via ffmpeg-devel
2025-05-20 11:37 ` Steven Liu
2025-06-04 3:21 ` Steven Liu
2025-06-04 3:38 ` Jack Lau [this message]
2025-06-04 11:34 ` Kieran Kunhya via ffmpeg-devel
2025-06-04 11:46 ` Steven Liu
2025-06-04 22:20 ` Kieran Kunhya via ffmpeg-devel
2025-06-04 23:03 ` Jack Lau
2025-06-05 13:15 ` Kieran Kunhya via ffmpeg-devel
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