[FFmpeg-devel] [PATCH] lavf/movenc: Replace dts by pts to calculate duration
manuelyuan
manuelyuan at 163.com
Thu Nov 7 11:55:18 EET 2019
From: Mengyang Yuan <manuelyuan at 163.com>
In this case, the input video is of dynamic frame rate and we don't want to
duplicate or drop frames, but the output video duration calculated by DTS is
incorrect, I solved it by using PTS.
There are many UGC videos with dynamic frame rates, which are represented by
PTS jumps. After transcoding with ffmpeg -vsync 0 or -vsync 2, the output
video duration becomes longer.By reading the code of x264/encoder/encoder.c,
I found that in order to predict the B frame, x264 needs to ensure that there
are enough reference frames when DTS = 0, so the DTS of these reference frames
will subtract the cache time. However, the cache time includes the part of PTS
jumps, which results in the abnormal small DTS.
Signed-off-by: Mengyang Yuan <manuelyuan at 163.com>
---
libavformat/movenc.c | 23 ++++++++++++++---------
libavformat/movenc.h | 2 ++
tests/ref/fate/movenc | 20 ++++++++++----------
tests/ref/lavf/mov | 4 ++--
tests/ref/lavf/mp4 | 4 ++--
5 files changed, 30 insertions(+), 23 deletions(-)
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 715bec1c2f..206aa48d8c 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1015,7 +1015,7 @@ static int get_cluster_duration(MOVTrack *track, int cluster_idx)
return 0;
if (cluster_idx + 1 == track->entry)
- next_dts = track->track_duration + track->start_dts;
+ next_dts = track->end_dts;
else
next_dts = track->cluster[cluster_idx + 1].dts;
@@ -5149,8 +5149,7 @@ static int mov_flush_fragment(AVFormatContext *s, int force)
mov->mdat_size = 0;
for (i = 0; i < mov->nb_streams; i++) {
if (mov->tracks[i].entry)
- mov->tracks[i].frag_start += mov->tracks[i].start_dts +
- mov->tracks[i].track_duration -
+ mov->tracks[i].frag_start += mov->tracks[i].end_dts -
mov->tracks[i].cluster[0].dts;
mov->tracks[i].entry = 0;
mov->tracks[i].end_reliable = 0;
@@ -5208,7 +5207,7 @@ static int mov_flush_fragment(AVFormatContext *s, int force)
int64_t duration = 0;
if (track->entry)
- duration = track->start_dts + track->track_duration -
+ duration = track->end_dts -
track->cluster[0].dts;
if (mov->flags & FF_MOV_FLAG_SEPARATE_MOOF) {
if (!track->mdat_buf)
@@ -5281,7 +5280,7 @@ static int check_pkt(AVFormatContext *s, AVPacket *pkt)
ref = trk->cluster[trk->entry - 1].dts;
} else if ( trk->start_dts != AV_NOPTS_VALUE
&& !trk->frag_discont) {
- ref = trk->start_dts + trk->track_duration;
+ ref = trk->end_dts;
} else
ref = pkt->dts; // Skip tests for the first packet
@@ -5494,7 +5493,7 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
* of the last packet of the previous fragment based on track_duration,
* which might not exactly match our dts. Therefore adjust the dts
* of this packet to be what the previous packets duration implies. */
- trk->cluster[trk->entry].dts = trk->start_dts + trk->track_duration;
+ trk->cluster[trk->entry].dts = trk->end_dts;
/* We also may have written the pts and the corresponding duration
* in sidx/tfrf/tfxd tags; make sure the sidx pts and duration match up with
* the next fragment. This means the cts of the first sample must
@@ -5546,13 +5545,17 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
"this case.\n",
pkt->stream_index, pkt->dts);
}
- trk->track_duration = pkt->dts - trk->start_dts + pkt->duration;
- trk->last_sample_is_subtitle_end = 0;
-
if (pkt->pts == AV_NOPTS_VALUE) {
av_log(s, AV_LOG_WARNING, "pts has no value\n");
pkt->pts = pkt->dts;
}
+ if (trk->start_pts == AV_NOPTS_VALUE) {
+ trk->start_pts = pkt->pts;
+ }
+ trk->track_duration = FFMAX(pkt->pts - trk->start_pts + pkt->duration, trk->track_duration);
+ trk->end_dts = pkt->dts + pkt->duration;
+ trk->last_sample_is_subtitle_end = 0;
+
if (pkt->dts != pkt->pts)
trk->flags |= MOV_TRACK_CTTS;
trk->cluster[trk->entry].cts = pkt->pts - pkt->dts;
@@ -6295,7 +6298,9 @@ static int mov_init(AVFormatContext *s)
* this is updated. */
track->hint_track = -1;
track->start_dts = AV_NOPTS_VALUE;
+ track->start_pts = AV_NOPTS_VALUE;
track->start_cts = AV_NOPTS_VALUE;
+ track->end_dts = AV_NOPTS_VALUE;
track->end_pts = AV_NOPTS_VALUE;
track->dts_shift = AV_NOPTS_VALUE;
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
diff --git a/libavformat/movenc.h b/libavformat/movenc.h
index 68d6f23a5a..ddad2631d7 100644
--- a/libavformat/movenc.h
+++ b/libavformat/movenc.h
@@ -116,7 +116,9 @@ typedef struct MOVTrack {
uint32_t tref_tag;
int tref_id; ///< trackID of the referenced track
int64_t start_dts;
+ int64_t start_pts;
int64_t start_cts;
+ int64_t end_dts;
int64_t end_pts;
int end_reliable;
int64_t dts_shift;
diff --git a/tests/ref/fate/movenc b/tests/ref/fate/movenc
index 5e8f324ea3..e5395aa521 100644
--- a/tests/ref/fate/movenc
+++ b/tests/ref/fate/movenc
@@ -12,7 +12,7 @@ write_data len 36, time nopts, type header atom ftyp
write_data len 2629, time nopts, type header atom -
write_data len 908, time 1000000, type sync atom moof
write_data len 110, time nopts, type trailer atom -
-c184e168ac1e5bb3d9c70e580ab6179c 3683 non-empty-moov-no-elst
+be2119166851ee710a0cd96f5c3755a6 3683 non-empty-moov-no-elst
write_data len 20, time nopts, type header atom ftyp
write_data len 1171, time nopts, type header atom -
write_data len 728, time 0, type sync atom moof
@@ -108,8 +108,8 @@ c3681590a292cb9ca19a5a982e530166 1219 delay-moov-elst-signal-init-discont
write_data len 996, time 966667, type sync atom sidx
aa5462cc0d2144f72154d9c309edb57d 996 delay-moov-elst-signal-second-frag-discont
write_data len 110, time nopts, type trailer atom -
-write_data len 1243, time nopts, type header atom ftyp
-dac14c8795d5cbd91ae770c6e2880c62 1243 delay-moov-elst-signal-init-discont-largets
+write_data len 1219, time nopts, type header atom ftyp
+c3681590a292cb9ca19a5a982e530166 1219 delay-moov-elst-signal-init-discont-largets
write_data len 996, time 279621233333, type sync atom sidx
41cac4c3df656a87bb38363fdcd745e6 996 delay-moov-elst-signal-second-frag-discont-largets
write_data len 110, time nopts, type trailer atom -
@@ -119,10 +119,10 @@ write_data len 996, time 5166667, type sync atom sidx
write_data len 148, time nopts, type trailer atom -
f12d4a0e054abcc508cc0d28cb320e57 4935 vfr
write_data len 1219, time nopts, type header atom ftyp
-write_data len 2572, time -333333, type sync atom sidx
-write_data len 996, time 5166667, type sync atom sidx
+write_data len 3472, time -333333, type sync atom sidx
+write_data len 1460, time 5133333, type sync atom sidx
write_data len 148, time nopts, type trailer atom -
-f12d4a0e054abcc508cc0d28cb320e57 4935 vfr-noduration
+202e3030545f4237eea43efba08f9f88 6299 vfr-noduration
write_data len 1231, time nopts, type header atom ftyp
write_data len 1500, time -333333, type sync atom moof
write_data len 1500, time nopts, type unknown atom -
@@ -133,13 +133,13 @@ write_data len 1004, time nopts, type unknown atom -
write_data len 148, time nopts, type trailer atom -
3c2c3f98c8a047f0ecefff07570fd457 9299 large_frag
write_data len 1231, time nopts, type header atom ftyp
-write_data len 684, time -33333, type sync atom moof
-write_data len 504, time 800000, type boundary atom moof
-write_data len 420, time 1266667, type boundary atom moof
+write_data len 620, time -33333, type sync atom moof
+write_data len 432, time 500000, type boundary atom moof
+write_data len 480, time 1166667, type boundary atom moof
write_data len 668, time 1566667, type sync atom moof
write_data len 440, time 2233333, type boundary atom moof
write_data len 262, time nopts, type trailer atom -
-edd19deae2b70afcf2cd744b89b7013d 4209 vfr-noduration-interleave
+2e93b0e5027b4e27a0dd23e9f749a84d 4133 vfr-noduration-interleave
write_data len 1231, time nopts, type header atom ftyp
write_data len 916, time 0, type sync atom moof
write_data len 908, time 1000000, type sync atom moof
diff --git a/tests/ref/lavf/mov b/tests/ref/lavf/mov
index 75a0c4892d..13ab0f4e8f 100644
--- a/tests/ref/lavf/mov
+++ b/tests/ref/lavf/mov
@@ -1,7 +1,7 @@
-11bd76730274924e02623172b82b5236 *tests/data/lavf/lavf.mov
+b5bc7dbee83ca51ce0ec3270ff4cb68a *tests/data/lavf/lavf.mov
357539 tests/data/lavf/lavf.mov
tests/data/lavf/lavf.mov CRC=0xbb2b949b
-6efa586655e3db043cb29668f5216610 *tests/data/lavf/lavf.mov
+5210f9308b6d26d1eb6c1e4584879bd7 *tests/data/lavf/lavf.mov
366621 tests/data/lavf/lavf.mov
tests/data/lavf/lavf.mov CRC=0xa9793231
c80c625ded376602e71d5aa6ac6fdb1c *tests/data/lavf/lavf.mov
diff --git a/tests/ref/lavf/mp4 b/tests/ref/lavf/mp4
index 8482812380..0275ace9aa 100644
--- a/tests/ref/lavf/mp4
+++ b/tests/ref/lavf/mp4
@@ -1,7 +1,7 @@
-ebca72c186a4f3ba9bb17d9cb5b74fef *tests/data/lavf/lavf.mp4
+e469124650c123ad87974930b8faae2e *tests/data/lavf/lavf.mp4
312457 tests/data/lavf/lavf.mp4
tests/data/lavf/lavf.mp4 CRC=0x9d9a638a
-9944512475d82d2d601f3c96101bdf9c *tests/data/lavf/lavf.mp4
+dd1c6780572514682205ec9f3681a9a2 *tests/data/lavf/lavf.mp4
321343 tests/data/lavf/lavf.mp4
tests/data/lavf/lavf.mp4 CRC=0xe8130120
7b3e71f294901067046c09f03a426bdc *tests/data/lavf/lavf.mp4
--
2.17.2 (Apple Git-113)
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