From 7a1a63e34fa46af18311c2493fdaec9a93bdb750 Mon Sep 17 00:00:00 2001 From: Martin Storsjö Date: Mon, 17 Nov 2014 14:34:46 +0200 Subject: dashenc: Use pts for MPD timeline timestamps MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This should be more correct. This also should give more sensible switching between video streams with different amount of b-frame delay. The current dash.js release (1.2.0) fails to start playback of such files from the start (if the start pts is > 0), but this has been fixed in the current git version of dash.js. Also enable the use of edit lists, so that streams in many cases start at pts=0. Signed-off-by: Martin Storsjö --- libavformat/dashenc.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) (limited to 'libavformat/dashenc.c') diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c index 5afc40b1c3..5e06e35c9d 100644 --- a/libavformat/dashenc.c +++ b/libavformat/dashenc.c @@ -68,7 +68,7 @@ typedef struct OutputStream { int init_range_length; int nb_segments, segments_size, segment_index; Segment **segments; - int64_t first_dts, start_dts, end_dts; + int64_t first_pts, start_pts, max_pts; int bit_rate; char bandwidth_str[64]; @@ -627,6 +627,7 @@ static int dash_write_header(AVFormatContext *s) os->init_start_pos = 0; av_dict_set(&opts, "movflags", "frag_custom+dash+delay_moov", 0); + av_dict_set(&opts, "use_editlist", "1", 0); if ((ret = avformat_write_header(ctx, &opts)) < 0) { goto fail; } @@ -647,8 +648,8 @@ static int dash_write_header(AVFormatContext *s) c->has_audio = 1; 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->first_pts = AV_NOPTS_VALUE; + os->max_pts = AV_NOPTS_VALUE; os->segment_index = 1; } @@ -687,6 +688,8 @@ static int add_segment(OutputStream *os, const char *file, return AVERROR(ENOMEM); av_strlcpy(seg->file, file, sizeof(seg->file)); seg->time = time; + if (seg->time < 0) // If pts<0, it is expected to be cut away with an edit list + seg->time = 0; seg->duration = duration; seg->start_pos = start_pos; seg->range_length = range_length; @@ -770,7 +773,7 @@ static int dash_flush(AVFormatContext *s, int final, int stream) start_pos = avio_tell(os->ctx->pb); if (!c->single_file) { - dash_fill_tmpl_params(filename, sizeof(filename), c->media_seg_name, i, os->segment_index, os->bit_rate, os->start_dts); + dash_fill_tmpl_params(filename, sizeof(filename), c->media_seg_name, i, os->segment_index, os->bit_rate, os->start_pts); snprintf(full_path, sizeof(full_path), "%s%s", c->dirname, filename); snprintf(temp_path, sizeof(temp_path), "%s.tmp", full_path); ret = ffurl_open(&os->out, temp_path, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL); @@ -795,7 +798,7 @@ static int dash_flush(AVFormatContext *s, int final, int stream) if (ret < 0) break; } - add_segment(os, filename, os->start_dts, os->end_dts - os->start_dts, start_pos, range_length, index_length); + add_segment(os, filename, os->start_pts, os->max_pts - os->start_pts, start_pos, range_length, index_length); av_log(s, AV_LOG_VERBOSE, "Representation %d media segment %d written to: %s\n", i, os->segment_index, full_path); } @@ -834,25 +837,25 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt) // If forcing the stream to start at 0, the mp4 muxer will set the start // timestamps to 0. Do the same here, to avoid mismatches in duration/timestamps. - if (os->first_dts == AV_NOPTS_VALUE && + if (os->first_pts == AV_NOPTS_VALUE && s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_MAKE_ZERO) { pkt->pts -= pkt->dts; pkt->dts = 0; } - if (os->first_dts == AV_NOPTS_VALUE) - os->first_dts = pkt->dts; + if (os->first_pts == AV_NOPTS_VALUE) + os->first_pts = pkt->pts; if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) && pkt->flags & AV_PKT_FLAG_KEY && os->packets_written && - av_compare_ts(pkt->dts - os->first_dts, st->time_base, + av_compare_ts(pkt->pts - os->first_pts, st->time_base, seg_end_duration, AV_TIME_BASE_Q) >= 0) { int64_t prev_duration = c->last_duration; - c->last_duration = av_rescale_q(pkt->dts - os->start_dts, + c->last_duration = av_rescale_q(pkt->pts - os->start_pts, st->time_base, AV_TIME_BASE_Q); - c->total_duration = av_rescale_q(pkt->dts - os->first_dts, + c->total_duration = av_rescale_q(pkt->pts - os->first_pts, st->time_base, AV_TIME_BASE_Q); @@ -873,12 +876,15 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt) // 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; + if (os->max_pts != AV_NOPTS_VALUE) + os->start_pts = os->max_pts; else - os->start_dts = pkt->dts; + os->start_pts = pkt->pts; } - os->end_dts = pkt->dts + pkt->duration; + if (os->max_pts == AV_NOPTS_VALUE) + os->max_pts = pkt->pts + pkt->duration; + else + os->max_pts = FFMAX(os->max_pts, pkt->pts + pkt->duration); os->packets_written++; return ff_write_chained(os->ctx, 0, pkt, s); } @@ -892,10 +898,10 @@ static int dash_write_trailer(AVFormatContext *s) // If no segments have been written so far, try to do a crude // guess of the segment duration if (!c->last_duration) - c->last_duration = av_rescale_q(os->end_dts - os->start_dts, + c->last_duration = av_rescale_q(os->max_pts - os->start_pts, s->streams[0]->time_base, AV_TIME_BASE_Q); - c->total_duration = av_rescale_q(os->end_dts - os->first_dts, + c->total_duration = av_rescale_q(os->max_pts - os->first_pts, s->streams[0]->time_base, AV_TIME_BASE_Q); } -- cgit v1.2.3