From 3e75057a1d702ccc71f858095f64f6cd96f6461e Mon Sep 17 00:00:00 2001 From: Vishwanath Dixit Date: Wed, 11 Apr 2018 12:31:36 +0530 Subject: [PATCH] avformat/dashenc: setting @availabilityStartTime when the first frame is ready @availabilityStartTime specifies the anchor for the computation of the earliest availability time (in UTC) for any Segment in the Media Presentation. As per this requirement, the @AvailabilityStartTime should be set to the wallclock time at which the first frame of the first segment begins encoding. But, it was getting set only when the first segment was completely ready. Making the required correction in this patch. This correction is mainly needed to reduce the latency in live streaming use cases. --- libavformat/dashenc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c index bf06a7be3b..5d5310d004 100644 --- a/libavformat/dashenc.c +++ b/libavformat/dashenc.c @@ -743,9 +743,6 @@ static int write_manifest(AVFormatContext *s, int final) update_period = 500; avio_printf(out, "\tminimumUpdatePeriod=\"PT%"PRId64"S\"\n", update_period); avio_printf(out, "\tsuggestedPresentationDelay=\"PT%"PRId64"S\"\n", c->last_duration / AV_TIME_BASE); - if (!c->availability_start_time[0] && s->nb_streams > 0 && c->streams[0].nb_segments > 0) { - format_date_now(c->availability_start_time, sizeof(c->availability_start_time)); - } if (c->availability_start_time[0]) avio_printf(out, "\tavailabilityStartTime=\"%s\"\n", c->availability_start_time); format_date_now(now_str, sizeof(now_str)); @@ -1292,6 +1289,10 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt) if (os->first_pts == AV_NOPTS_VALUE) os->first_pts = pkt->pts; + if (!c->availability_start_time[0]) + format_date_now(c->availability_start_time, + sizeof(c->availability_start_time)); + if (c->use_template && !c->use_timeline) { elapsed_duration = pkt->pts - os->first_pts; seg_end_duration = (int64_t) os->segment_index * c->seg_duration;