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movenc: Don't assume that fragment durations in pts is equal to duration in dts

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For strict CFR, they should be pretty much equal, but if the stream
is VFR, there can be a sometimes significant difference.

Calculate the pts duration separately, used in sidx atoms and for
tfrf/tfxd boxes in smooth streaming ismv files.

Also make sure to reduce the duration of sidx entries according to
edit lists.

Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Martin Storsjö 2015-03-15 23:57:06 +02:00
parent 5c337353a2
commit 67a2912307
2 changed files with 25 additions and 9 deletions
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33
libavformat/movenc.c
View File

@ -2544,8 +2544,8 @@ static int mov_write_tfxd_tag(AVIOContext *pb, MOVTrack *track)
avio_wb24(pb, 0);
avio_wb64(pb, track->start_dts + track->frag_start +
track->cluster[0].cts);
avio_wb64(pb, track->start_dts + track->track_duration -
track->cluster[0].dts);
avio_wb64(pb, track->end_pts -
(track->cluster[0].dts + track->cluster[0].cts));
return update_size(pb, pos);
}
@ -2625,13 +2625,15 @@ static int mov_add_tfra_entries(AVIOContext *pb, MOVMuxContext *mov, int tracks,
// from the fields we have stored
info->time = track->start_dts + track->frag_start +
track->cluster[0].cts;
info->duration = track->end_pts -
(track->cluster[0].dts + track->cluster[0].cts);
// If the pts is less than zero, we will have trimmed
// away parts of the media track using an edit list,
// and the corresponding start presentation time is zero.
if (info->time < 0)
if (info->time < 0) {
info->duration += info->time;
info->time = 0;
info->duration = track->start_dts + track->track_duration -
track->cluster[0].dts;
}
info->tfrf_offset = 0;
mov_write_tfrf_tags(pb, mov, track);
}
@ -2724,13 +2726,15 @@ static int mov_write_sidx_tag(AVIOContext *pb,
entries = 1;
presentation_time = track->start_dts + track->frag_start +
track->cluster[0].cts;
duration = track->start_dts + track->track_duration -
track->cluster[0].dts;
duration = track->end_pts -
(track->cluster[0].dts + track->cluster[0].cts);
starts_with_SAP = track->cluster[0].flags & MOV_SYNC_SAMPLE;
// pts<0 should be cut away using edts
if (presentation_time < 0)
if (presentation_time < 0) {
duration += presentation_time;
presentation_time = 0;
}
} else {
entries = track->nb_frag_info;
presentation_time = track->frag_info[0].time;
@ -3172,6 +3176,7 @@ static int mov_flush_fragment(AVFormatContext *s)
// to be too long), but probably the best we can do - having a zero
// duration is bad as well.
track->track_duration += get_cluster_duration(track, track->entry - 2);
track->end_pts += get_cluster_duration(track, track->entry - 2);
if (!mov->missing_duration_warned) {
av_log(s, AV_LOG_WARNING,
"Estimating the duration of the last packet in a "
@ -3459,12 +3464,13 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
* be the same in all fragments. */
if ((mov->flags & FF_MOV_FLAG_DASH && !(mov->flags & FF_MOV_FLAG_FASTSTART)) ||
mov->mode == MODE_ISM)
pkt->pts = pkt->dts + trk->start_cts;
pkt->pts = pkt->dts + trk->end_pts - trk->cluster[trk->entry].dts;
} else {
/* New fragment, but discontinuous from previous fragments.
* Pretend the duration sum of the earlier fragments is
* pkt->dts - trk->start_dts. */
trk->frag_start = pkt->dts - trk->start_dts;
trk->end_pts = AV_NOPTS_VALUE;
trk->frag_discont = 0;
}
}
@ -3504,6 +3510,13 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
trk->cluster[trk->entry].flags = 0;
if (trk->start_cts == AV_NOPTS_VALUE)
trk->start_cts = pkt->pts - pkt->dts;
if (trk->end_pts == AV_NOPTS_VALUE)
trk->end_pts = trk->cluster[trk->entry].dts +
trk->cluster[trk->entry].cts + pkt->duration;
else
trk->end_pts = FFMAX(trk->end_pts, trk->cluster[trk->entry].dts +
trk->cluster[trk->entry].cts +
pkt->duration);
if (enc->codec_id == AV_CODEC_ID_VC1) {
mov_parse_vc1_frame(pkt, trk);
@ -3570,6 +3583,7 @@ static int mov_write_packet(AVFormatContext *s, AVPacket *pkt)
// duration, but only helps for this particular track, not
// for the other ones that are flushed at the same time.
trk->track_duration = pkt->dts - trk->start_dts;
trk->end_pts = pkt->pts;
mov_auto_flush_fragment(s);
}
}
@ -3905,6 +3919,7 @@ static int mov_write_header(AVFormatContext *s)
track->hint_track = -1;
track->start_dts = AV_NOPTS_VALUE;
track->start_cts = AV_NOPTS_VALUE;
track->end_pts = AV_NOPTS_VALUE;
if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
if (track->tag == MKTAG('m','x','3','p') || track->tag == MKTAG('m','x','3','n') ||
track->tag == MKTAG('m','x','4','p') || track->tag == MKTAG('m','x','4','n') ||

1
libavformat/movenc.h
View File

@ -105,6 +105,7 @@ typedef struct MOVTrack {
int tref_id; ///< trackID of the referenced track
int64_t start_dts;
int64_t start_cts;
int64_t end_pts;
int hint_track; ///< the track that hints this track, -1 if no hint track is set
int src_track; ///< the track that this hint track describes