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/formats.texi | 6 ++++++
libavformat/avformat.h | 10 ++++++++++
libavformat/demux.c | 8 +++++++-
libavformat/mpegts.c | 4 +++-
libavformat/options_table.h | 1 +
tests/fate/demux.mak | 2 +-
6 files changed, 28 insertions(+), 3 deletions(-)
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/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
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