Module: libav Branch: master Commit: bef3b1f59f036aba4a5fe599b2480f6bd9e6b280
Author: Martin Storsjö <[email protected]> Committer: Martin Storsjö <[email protected]> Date: Tue Nov 3 22:16:21 2015 +0200 movenc: Allow setting start_dts/start_cts before writing actual packets By writing a zero-sized packet, the caller can communicate the start_dts/start_cts for the stream without actually writing the first packet. This allows doing random-access writing of fragments when the start dts of the stream isn't zero, so that the edit list in the moov is written based on timestamps from the nominal start time signaled via the zero-sized packet, while the first proper packet written corresponds to a later fragment. To avoid potential unexpected behaviour, empty packets only set start_dts if the frag_discont flag is set. Signed-off-by: Martin Storsjö <[email protected]> --- libavformat/movenc.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/libavformat/movenc.c b/libavformat/movenc.c index ac452b1..9f7cca9 100644 --- a/libavformat/movenc.c +++ b/libavformat/movenc.c @@ -3585,9 +3585,6 @@ static int mov_write_packet(AVFormatContext *s, AVPacket *pkt) int64_t frag_duration = 0; int size = pkt->size; - if (!pkt->size) - return 0; /* Discard 0 sized packets */ - if (mov->flags & FF_MOV_FLAG_FRAG_DISCONT) { int i; for (i = 0; i < s->nb_streams; i++) @@ -3595,6 +3592,18 @@ static int mov_write_packet(AVFormatContext *s, AVPacket *pkt) mov->flags &= ~FF_MOV_FLAG_FRAG_DISCONT; } + if (!pkt->size) { + if (trk->start_dts == AV_NOPTS_VALUE && trk->frag_discont) { + trk->start_dts = pkt->dts; + if (pkt->pts != AV_NOPTS_VALUE) + trk->start_cts = pkt->pts - pkt->dts; + else + trk->start_cts = 0; + } + + return 0; /* Discard 0 sized packets */ + } + if (trk->entry) frag_duration = av_rescale_q(pkt->dts - trk->cluster[0].dts, s->streams[pkt->stream_index]->time_base, _______________________________________________ libav-commits mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-commits
