avformat/mov: add interleaved_read option

For badly interleaved files, interleave packets from multiple tracks at the demuxer level can trigger seeking back and forth, which can be dramatically slow depending on the protocol. Demuxer level interleave can be useless sometimes, e.g., reading mp4 via http and then transcoding/remux to DASH. Disable this option when you don't need the demuxer level interleave, and want to avoid the IO penalizes.

Zhao Zhili committed 3 years ago

Commit a8d9da41 parent 6434e444 files · +13 −2Browse files

Unified · Split

4 files

doc/demuxers.texi +7 −0
libavformat/isom.h +1 −0
libavformat/mov.c +4 −1
libavformat/version.h +1 −1

doc/demuxers.texi+7−0

@@ -779,6 +779,13 @@ cast to int32 are used to adjust onward dts. · 778 unmodified lines
779	779
780	780	Unit is the track time scale. Range is 0 to UINT_MAX. Default is @code{UINT_MAX - 48000*10} which allows upto
781	781	a 10 second dts correction for 48 kHz audio streams while accommodating 99.9% of @code{uint32} range.
	782	+
	783	+@item interleaved_read
	784	+Interleave packets from multiple tracks at demuxer level. For badly interleaved files, this prevents playback issues
	785	+caused by large gaps between packets in different tracks, as MOV/MP4 do not have packet placement requirements.
	786	+However, this can cause excessive seeking on very badly interleaved files, due to seeking between tracks, so disabling
	787	+it may prevent I/O issues, at the expense of playback.
	788	+
782	789	@end table
783	790
784	791	@subsection Audible AAX

libavformat/isom.h+1−0

@@ -327,6 +327,7 @@ typedef struct MOVContext { · 326 unmodified lines
327	327	int64_t extent_offset;
328	328	} *avif_info;
329	329	int avif_info_size;
	330	+ int interleaved_read;
330	331	} MOVContext;
331	332
332	333	int ff_mp4_read_descr_len(AVIOContext *pb);

libavformat/mov.c+4−1

@@ -8780,6 +8780,8 @@ static AVIndexEntry mov_find_next_sample(AVFormatContext s, AVStream **st) · 8779 unmodified lines
8780	8780	AVIndexEntry *sample = NULL;
8781	8781	int64_t best_dts = INT64_MAX;
8782	8782	int i;
	8783	+ MOVContext *mov = s->priv_data;
	8784	+ int no_interleave = !mov->interleaved_read \|\| !(s->pb->seekable & AVIO_SEEKABLE_NORMAL);
8783	8785	for (i = 0; i < s->nb_streams; i++) {
8784	8786	AVStream *avst = s->streams[i];
8785	8787	FFStream *const avsti = ffstream(avst);
@@ -8788,7 +8790,7 @@ static AVIndexEntry mov_find_next_sample(AVFormatContext s, AVStream **st) · 2 unmodified lines
8788	8790	AVIndexEntry *current_sample = &avsti->index_entries[msc->current_sample];
8789	8791	int64_t dts = av_rescale(current_sample->timestamp, AV_TIME_BASE, msc->time_scale);
8790	8792	av_log(s, AV_LOG_TRACE, "stream %d, sample %d, dts %"PRId64"\n", i, msc->current_sample, dts);
8791		− if (!sample \|\| (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL) && current_sample->pos < sample->pos) \|\|
	8793	+ if (!sample \|\| (no_interleave && current_sample->pos < sample->pos) \|\|
8792	8794	((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
8793	8795	((msc->pb != s->pb && dts < best_dts) \|\| (msc->pb == s->pb && dts != AV_NOPTS_VALUE &&
8794	8796	((FFABS(best_dts - dts) <= AV_TIME_BASE && current_sample->pos < sample->pos) \|\|
@@ -9282,6 +9284,7 @@ static const AVOption mov_options[] = { · 487 unmodified lines
9282	9284	{ "enable_drefs", "Enable external track support.", OFFSET(enable_drefs), AV_OPT_TYPE_BOOL,
9283	9285	{.i64 = 0}, 0, 1, FLAGS },
9284	9286	{ "max_stts_delta", "treat offsets above this value as invalid", OFFSET(max_stts_delta), AV_OPT_TYPE_INT, {.i64 = UINT_MAX-48000*10 }, 0, UINT_MAX, .flags = AV_OPT_FLAG_DECODING_PARAM },
	9287	+ { "interleaved_read", "Interleave packets from multiple tracks at demuxer level", OFFSET(interleaved_read), AV_OPT_TYPE_BOOL, {.i64 = 1 }, 0, 1, .flags = AV_OPT_FLAG_DECODING_PARAM },
9285	9288
9286	9289	{ NULL },
9287	9290	};

libavformat/version.h+1−1

@@ -32,7 +32,7 @@ · 31 unmodified lines
32	32	#include "version_major.h"
33	33
34	34	#define LIBAVFORMAT_VERSION_MINOR 12
35		−#define LIBAVFORMAT_VERSION_MICRO 100
	35	+#define LIBAVFORMAT_VERSION_MICRO 101
36	36
37	37	#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
38	38	LIBAVFORMAT_VERSION_MINOR, \

avformat/mov: add interleaved_read option

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