av_interleave_packet_per_dts waits until it gets a frame for each stream before outputting packets in interleaved order.
Sparse streams tend to add up latency and in specific cases end up allocating a large amount of memory. Emit the top packet from the packet_buffer if it has a time delta larger than max_delay. Original report of the issue and initial proposed solution by [email protected] on bug 31. --- libavformat/avformat.h | 3 +++ libavformat/utils.c | 39 ++++++++++++++++++++++++++++++++++----- 2 files changed, 37 insertions(+), 5 deletions(-) diff --git a/libavformat/avformat.h b/libavformat/avformat.h index 367ba1e..7a73866 100644 --- a/libavformat/avformat.h +++ b/libavformat/avformat.h @@ -887,6 +887,9 @@ typedef struct AVFormatContext { #if FF_API_PRELOAD attribute_deprecated int preload; #endif + /** + * maximum muxing/demuxing delay in microseconds + */ int max_delay; #if FF_API_LOOP_OUTPUT diff --git a/libavformat/utils.c b/libavformat/utils.c index 10e79eb..d036480 100644 --- a/libavformat/utils.c +++ b/libavformat/utils.c @@ -3138,19 +3138,48 @@ static int ff_interleave_compare_dts(AVFormatContext *s, AVPacket *next, AVPacke return comp > 0; } -int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush){ +int av_interleave_packet_per_dts(AVFormatContext *s, + AVPacket *out, AVPacket *pkt, int flush) +{ + AVPacket *top_pkt; AVPacketList *pktl; - int stream_count=0; + int stream_count = 0; + int64_t delta_dts = INT64_MIN; + int64_t top_dts, last_dts; int i; if(pkt){ ff_interleave_add_packet(s, pkt, ff_interleave_compare_dts); } - for(i=0; i < s->nb_streams; i++) - stream_count+= !!s->streams[i]->last_in_packet_buffer; + if (s->max_delay && s->packet_buffer) { + top_pkt = &s->packet_buffer->pkt; + top_dts = av_rescale_q(top_pkt->dts, + s->streams[top_pkt->stream_index]->time_base, + AV_TIME_BASE_Q); + + for (i = 0; i < s->nb_streams; i++) { + const AVPacketList *last = s->streams[i]->last_in_packet_buffer; + if (!last) continue; + + last_dts = av_rescale_q(last->pkt.dts, + s->streams[i]->time_base, + AV_TIME_BASE_Q); + delta_dts = FFMAX(delta_dts, last_dts - top_dts); + stream_count++; + } + + if (delta_dts > s->max_delay) { + av_log(s, AV_LOG_DEBUG, + "Deadline reached, emitting a packet\n"); + flush = 1; + } + } else { + for (i = 0; i < s->nb_streams; i++) + stream_count += !!s->streams[i]->last_in_packet_buffer; + } - if(stream_count && (s->nb_streams == stream_count || flush)){ + if (stream_count && (s->nb_streams == stream_count || flush)) { pktl= s->packet_buffer; *out= pktl->pkt; -- 1.7.8.rc1 _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
