From 456e93bfdd4cbc5e995dea415019abd0703d0e16 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Storsj=C3=B6?= Date: Fri, 28 Nov 2014 10:43:53 +0200 Subject: [PATCH] dashenc: Adjust the start time of a segment to the end of the previous segment MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is the same adjustment that the mp4 muxer does to the start timestamp of fragments, since the timestamp of a sample in an mp4 file is implicit from the sum of earlier sample durations. This avoids gaps in the timeline (which can stop dash.js from playing it back), and makes sure the timestamp on the segmenter level matches what the mp4 muxer actually writes into the segments. This is only an issue if the AVPacket duration of the last packet of a segment doesn't point to the actual start timestamp of the next packet (the first in the next segment). Signed-off-by: Martin Storsjö --- libavformat/dashenc.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c index a55cd67cc0..b4fd1949e7 100644 --- a/libavformat/dashenc.c +++ b/libavformat/dashenc.c @@ -652,6 +652,7 @@ static int dash_write_header(AVFormatContext *s) set_codec_str(s, os->ctx->streams[0]->codec, os->codec_str, sizeof(os->codec_str)); os->first_dts = AV_NOPTS_VALUE; + os->end_dts = AV_NOPTS_VALUE; os->segment_index = 1; } @@ -861,8 +862,15 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt) return ret; } - if (!os->packets_written) - os->start_dts = pkt->dts; + if (!os->packets_written) { + // If we wrote a previous segment, adjust the start time of the segment + // to the end of the previous one (which is the same as the mp4 muxer + // does). This avoids gaps in the timeline. + if (os->end_dts != AV_NOPTS_VALUE) + os->start_dts = os->end_dts; + else + os->start_dts = pkt->dts; + } os->end_dts = pkt->dts + pkt->duration; os->packets_written++; return ff_write_chained(os->ctx, 0, pkt, s);