On Mon, Jan 31, 2022 at 02:51:12PM +0100, Mark Gaiser wrote:
> Signed-off-by: Mark Gaiser <markg85@gmail.com>
> ---
>  configure               |   1 +
>  doc/protocols.texi      |  30 ++++++
>  libavformat/Makefile    |   1 +
>  libavformat/ipfs.c      | 202 ++++++++++++++++++++++++++++++++++++++++
>  libavformat/protocols.c |   2 +
>  5 files changed, 236 insertions(+)
>  create mode 100644 libavformat/ipfs.c
> 
> diff --git a/configure b/configure
> index 5b19a35f59..e466f924a3 100755
> --- a/configure
> +++ b/configure
> @@ -3585,6 +3585,7 @@ udp_protocol_select="network"
>  udplite_protocol_select="network"
>  unix_protocol_deps="sys_un_h"
>  unix_protocol_select="network"
> +ipfs_protocol_select="https_protocol"
>  
>  # external library protocols
>  libamqp_protocol_deps="librabbitmq"
> diff --git a/doc/protocols.texi b/doc/protocols.texi
> index d207df0b52..7c9c0a4808 100644
> --- a/doc/protocols.texi
> +++ b/doc/protocols.texi
> @@ -2025,5 +2025,35 @@ decoding errors.
>  
>  @end table
>  
> +@section ipfs
> +
> +InterPlanetary File System (IPFS) protocol support. One can access files stored 
> +on the IPFS network through so called gateways. Those are http(s) endpoints.
> +This protocol wraps the IPFS native protocols (ipfs:// and ipns://) to be send 
> +to such a gateway. Users can (and should) host their own node which means this 
> +protocol will use your local machine gateway to access files on the IPFS network.
> +
> +If a user doesn't have a node of their own then the public gateway dweb.link is 
> +used by default.
> +
> +You can use this protocol in 2 ways. Using IPFS:
> +@example
> +ffplay ipfs://QmbGtJg23skhvFmu9mJiePVByhfzu5rwo74MEkVDYAmF5T
> +@end example
> +
> +Or the IPNS protocol (IPNS is mutable IPFS):
> +@example
> +ffplay ipns://QmbGtJg23skhvFmu9mJiePVByhfzu5rwo74MEkVDYAmF5T
> +@end example
> +
> +You can also change the gateway to be used:
> +
> +@table @option
> +
> +@item gateway
> +Defines the gateway to use. When nothing is provided the protocol will first try 
> +your local gateway. If that fails dweb.link will be used.
> +
> +@end table
>  
>  @c man end PROTOCOLS
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index 3dc6a479cc..983a77f4f2 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -656,6 +656,7 @@ OBJS-$(CONFIG_SRTP_PROTOCOL)             += srtpproto.o srtp.o
>  OBJS-$(CONFIG_SUBFILE_PROTOCOL)          += subfile.o
>  OBJS-$(CONFIG_TEE_PROTOCOL)              += teeproto.o tee_common.o
>  OBJS-$(CONFIG_TCP_PROTOCOL)              += tcp.o
> +OBJS-$(CONFIG_IPFS_PROTOCOL)             += ipfs.o
>  TLS-OBJS-$(CONFIG_GNUTLS)                += tls_gnutls.o
>  TLS-OBJS-$(CONFIG_LIBTLS)                += tls_libtls.o
>  TLS-OBJS-$(CONFIG_MBEDTLS)               += tls_mbedtls.o
> diff --git a/libavformat/ipfs.c b/libavformat/ipfs.c
> new file mode 100644
> index 0000000000..4cc65750ed
> --- /dev/null
> +++ b/libavformat/ipfs.c
> @@ -0,0 +1,202 @@
> +/*
> + * IPFS protocol.
> + * Copyright (c) 2021 Mark Gaiser
> + *
> + * 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 "libavutil/avassert.h"
> +#include "libavutil/avstring.h"
> +#include "libavutil/internal.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/tree.h"
> +#include "avformat.h"
> +#include <fcntl.h>
> +#if HAVE_IO_H
> +#include <io.h>
> +#endif
> +#if HAVE_UNISTD_H
> +#include <unistd.h>
> +#endif
> +#include <sys/stat.h>
> +#include <stdlib.h>
> +#include "os_support.h"
> +#include "url.h"
> +
> +typedef struct Context {
> +    AVClass *class;
> +    URLContext *inner;
> +    char *fulluri;
> +    char *gateway;
> +} Context;
> +
> +static int ipfs_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
> +{
> +    const char *gatewaysuffix;

> +    int ret = 0;

the initializuation seems redundant


> +    Context *c = h->priv_data;
> +    
> +    if (!av_strstart(uri, "ipfs://", &gatewaysuffix) &&
> +        !av_strstart(uri, "ipfs:", &gatewaysuffix)) {
> +        av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
> +        ret = AVERROR(EINVAL);
> +        goto err;
> +    }
> +    
> +    char* ipfs_gateway = "https://ipfs.io/ipfs/";
> +    
> +    c->fulluri = malloc(strlen(ipfs_gateway)+strlen(gatewaysuffix) + 1);
> +    
> +    strcpy(c->fulluri, ipfs_gateway);
> +    strcat(c->fulluri, gatewaysuffix);

malloc() should be av_malloc() unless there is some API interaction requiring otherwise
also all the  cpy/cat stuff should use "secure" size checking variants
but maybe something like av_asprintf() could simplify this all

[...]

thx


-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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