From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.ffmpeg.org (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id 3705944B44 for ; Tue, 17 Jun 2025 18:42:13 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id 034EE68D731; Tue, 17 Jun 2025 21:42:09 +0300 (EEST) Received: from iq.passwd.hu (iq.passwd.hu [217.27.212.140]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id 8B1BF68D645 for ; Tue, 17 Jun 2025 21:42:01 +0300 (EEST) Received: from localhost (localhost [127.0.0.1]) by iq.passwd.hu (Postfix) with ESMTP id 4DF56ECAC4 for ; Tue, 17 Jun 2025 20:39:08 +0200 (CEST) X-Virus-Scanned: amavisd-new at passwd.hu Received: from iq.passwd.hu ([127.0.0.1]) by localhost (iq.passwd.hu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6Y-MjUqL5SDJ for ; Tue, 17 Jun 2025 20:39:05 +0200 (CEST) Received: from iq (iq [217.27.212.140]) by iq.passwd.hu (Postfix) with ESMTPS id A0376ECABC for ; Tue, 17 Jun 2025 20:39:05 +0200 (CEST) Date: Tue, 17 Jun 2025 20:39:05 +0200 (CEST) From: Marton Balint To: FFmpeg development discussions and patches In-Reply-To: <20250617143659.26607-1-pkoshevoy@gmail.com> Message-ID: <7822783e-7117-d3ac-51fa-c83a8d9786b8@passwd.hu> References: <20250617143659.26607-1-pkoshevoy@gmail.com> MIME-Version: 1.0 Subject: Re: [FFmpeg-devel] [PATCH] avformat/demux: Add allow_codec_changes option to AVFormatContext (v2) X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On Tue, 17 Jun 2025, Pavel Koshevoy wrote: > Make runtime AVStream.codecpar codec_id updates optional and disabled > by default, so that avformat API clients can enable this feature explicitly > when they add support for runtime codec changes. > > Accordingly, codec_close should not assume that the codec_id cannot change. > This fixes 'ffprobe 1_poc.mp4' segfault introduced with > commit 0021484d05f9b0f032fa319399de6e24eea0c04f. > --- > doc/APIchanges | 3 +++ > doc/formats.texi | 6 ++++++ > libavformat/avformat.h | 10 ++++++++++ > libavformat/demux.c | 8 +++++++- > libavformat/mpegts.c | 4 +++- > libavformat/options_table.h | 1 + > libavformat/version.h | 2 +- > tests/fate/demux.mak | 2 +- > 8 files changed, 32 insertions(+), 4 deletions(-) > > diff --git a/doc/APIchanges b/doc/APIchanges > index 91710bb27d..29b3389094 100644 > --- a/doc/APIchanges > +++ b/doc/APIchanges > @@ -2,6 +2,9 @@ The last version increases of all libraries were on 2025-03-28 > > API changes, most recent first: > > +2025-06-17 - xxxxxxxxxx - lavf 62.2.100 - avformat.h > + Add AVFormatContext.allow_codec_changes AVOption. Considering that this is a simple boolean option, maybe you should use AVFormatContext->flags instead, so no new field need to be added, only a new flag. Thanks, Marton > + > 2025-05-21 - xxxxxxxxxx - lavu 60.3.100 - avassert.h > Add av_unreachable() and av_assume() macros. > > diff --git a/doc/formats.texi b/doc/formats.texi > index 876a9e92b3..d18613f8bd 100644 > --- a/doc/formats.texi > +++ b/doc/formats.texi > @@ -228,6 +228,12 @@ would require too many resources due to a large number of streams. > Skip estimation of input duration if it requires an additional probing for PTS at end of file. > At present, applicable for MPEG-PS and MPEG-TS. > > +@item allow_codec_changes @var{bool} (@emph{input}) > +Allow AVStream.codecpar codec_type and codec_id to change at runtime > +(for example when MPEG-TS PMT ES stream_type changes at runtime). > +This is disabled by default, because most clients of avformat API > +do not support random mid-stream codec changes. > + > @item duration_probesize @var{integer} (@emph{input}) > Set probing size, in bytes, for input duration estimation when it actually requires > an additional probing for PTS at end of file (at present: MPEG-PS and MPEG-TS). > diff --git a/libavformat/avformat.h b/libavformat/avformat.h > index b6c63e2237..c6956626b5 100644 > --- a/libavformat/avformat.h > +++ b/libavformat/avformat.h > @@ -1884,6 +1884,16 @@ typedef struct AVFormatContext { > * @see skip_estimate_duration_from_pts > */ > int64_t duration_probesize; > + > + /** > + * Allow AVStream.codecpar codec_type and codec_id to change at runtime > + * (for example when MPEG-TS PMT ES stream_type changes at runtime). > + * This is disabled by default, because most clients of avformat API > + * do not support random mid-stream codec changes. > + * - muxing: unused > + * - demuxing: set by user > + */ > + int allow_codec_changes; > } AVFormatContext; > > /** > diff --git a/libavformat/demux.c b/libavformat/demux.c > index ecd4f40da9..3749ab67a3 100644 > --- a/libavformat/demux.c > +++ b/libavformat/demux.c > @@ -1292,9 +1292,15 @@ static int codec_close(FFStream *sti) > { > AVCodecContext *avctx_new = NULL; > AVCodecParameters *par_tmp = NULL; > + const AVCodec *new_codec = NULL; > int ret; > > - avctx_new = avcodec_alloc_context3(sti->avctx->codec); > + new_codec = > + (sti->avctx->codec_id != sti->pub.codecpar->codec_id) ? > + avcodec_find_decoder(sti->pub.codecpar->codec_id) : > + sti->avctx->codec; > + > + avctx_new = avcodec_alloc_context3(new_codec); > if (!avctx_new) { > ret = AVERROR(ENOMEM); > goto fail; > diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c > index deb69a0548..0c78e870bb 100644 > --- a/libavformat/mpegts.c > +++ b/libavformat/mpegts.c > @@ -2510,7 +2510,9 @@ static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len > if (!st) > goto out; > > - if (pes && pes->stream_type != stream_type) > + if (pes && (!pes->stream_type || > + (pes->stream_type != stream_type && > + ts->stream->allow_codec_changes))) > mpegts_set_stream_info(st, pes, stream_type, prog_reg_desc); > > add_pid_to_program(prg, pid); > diff --git a/libavformat/options_table.h b/libavformat/options_table.h > index e2e690fd2a..e949d60c3e 100644 > --- a/libavformat/options_table.h > +++ b/libavformat/options_table.h > @@ -106,6 +106,7 @@ static const AVOption avformat_options[] = { > {"skip_estimate_duration_from_pts", "skip duration calculation in estimate_timings_from_pts", OFFSET(skip_estimate_duration_from_pts), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, D}, > {"max_probe_packets", "Maximum number of packets to probe a codec", OFFSET(max_probe_packets), AV_OPT_TYPE_INT, { .i64 = 2500 }, 0, INT_MAX, D }, > {"duration_probesize", "Maximum number of bytes to probe the durations of the streams in estimate_timings_from_pts", OFFSET(duration_probesize), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, D}, > +{"allow_codec_changes", "Allow AVStream.codecpar codec_type and codec_id to change at runtime", OFFSET(allow_codec_changes), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, D}, > {NULL}, > }; > > diff --git a/libavformat/version.h b/libavformat/version.h > index a7c80dc564..904e7f06aa 100644 > --- a/libavformat/version.h > +++ b/libavformat/version.h > @@ -31,7 +31,7 @@ > > #include "version_major.h" > > -#define LIBAVFORMAT_VERSION_MINOR 1 > +#define LIBAVFORMAT_VERSION_MINOR 2 > #define LIBAVFORMAT_VERSION_MICRO 100 > > #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \ > diff --git a/tests/fate/demux.mak b/tests/fate/demux.mak > index ead5ad4b10..4a39e950b9 100644 > --- a/tests/fate/demux.mak > +++ b/tests/fate/demux.mak > @@ -158,7 +158,7 @@ FATE_SAMPLES_DEMUX-$(CONFIG_XWMA_DEMUXER) += fate-xwma-demux > fate-xwma-demux: CMD = crc -i $(TARGET_SAMPLES)/xwma/ergon.xwma -c:a copy > > FATE_FFPROBE_DEMUX-$(CONFIG_MPEGTS_DEMUXER) += fate-ts-demux > -fate-ts-demux: CMD = ffprobe_demux $(TARGET_SAMPLES)/ac3/mp3ac325-4864-small.ts > +fate-ts-demux: CMD = ffprobe_demux $(TARGET_SAMPLES)/ac3/mp3ac325-4864-small.ts -allow_codec_changes 1 > > FATE_FFPROBE_DEMUX-$(CONFIG_MPEGTS_DEMUXER) += fate-ts-timed-id3-demux > fate-ts-timed-id3-demux: CMD = ffprobe_demux $(TARGET_SAMPLES)/mpegts/id3.ts > -- > 2.43.0 > > _______________________________________________ > 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". > _______________________________________________ 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".