From fe42f94ce1023f9c2f7e86404c60afcee5b078a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Mon, 17 Nov 2014 15:26:17 +0200
Subject: [PATCH] dashenc: Don't segment all video streams when one stream gets
a keyframe
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This makes sure that segments actually start at a keyframe (and
makes sure we don't split segments twice in a row, with one segment
consisting of only a handful of packets), when one stream uses b-frames
while another one doesn't.
Signed-off-by: Martin Storsjö <martin@martin.st>
---
libavformat/dashenc.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 41caf6dcffb..065466169ea 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -75,7 +75,6 @@ typedef struct DASHContext {
int single_file;
OutputStream *streams;
int has_video, has_audio;
- int nb_segments;
int last_duration;
int total_duration;
char availability_start_time[100];
@@ -595,10 +594,13 @@ static void find_index_range(AVFormatContext *s, const char *dirname,
*index_length = AV_RB32(&buf[0]);
}
-static int dash_flush(AVFormatContext *s, int final)
+static int dash_flush(AVFormatContext *s, int final, int stream)
{
DASHContext *c = s->priv_data;
int i, ret = 0;
+ int cur_flush_segment_index = 0;
+ if (stream >= 0)
+ cur_flush_segment_index = c->streams[stream].segment_index;
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
@@ -609,6 +611,18 @@ static int dash_flush(AVFormatContext *s, int final)
if (!os->packets_written)
continue;
+ // Flush the single stream that got a keyframe right now.
+ // Flush all audio streams as well, in sync with video keyframes,
+ // but not the other video streams.
+ if (stream >= 0 && i != stream) {
+ if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
+ continue;
+ // Make sure we don't flush audio streams multiple times, when
+ // all video streams are flushed one at a time.
+ if (c->has_video && os->segment_index > cur_flush_segment_index)
+ continue;
+ }
+
if (!c->single_file) {
snprintf(filename, sizeof(filename), "chunk-stream%d-%05d.m4s", i, os->segment_index);
snprintf(full_path, sizeof(full_path), "%s%s", c->dirname, filename);
@@ -665,7 +679,7 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt)
DASHContext *c = s->priv_data;
AVStream *st = s->streams[pkt->stream_index];
OutputStream *os = &c->streams[pkt->stream_index];
- int64_t seg_end_duration = (c->nb_segments + 1) * (int64_t) c->min_seg_duration;
+ int64_t seg_end_duration = (os->segment_index) * (int64_t) c->min_seg_duration;
int ret;
// If forcing the stream to start at 0, the mp4 muxer will set the start
@@ -701,9 +715,8 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt)
}
}
- if ((ret = dash_flush(s, 0)) < 0)
+ if ((ret = dash_flush(s, 0, pkt->stream_index)) < 0)
return ret;
- c->nb_segments++;
}
if (!os->packets_written)
@@ -729,7 +742,7 @@ static int dash_write_trailer(AVFormatContext *s)
s->streams[0]->time_base,
AV_TIME_BASE_Q);
}
- dash_flush(s, 1);
+ dash_flush(s, 1, -1);
if (c->remove_at_exit) {
char filename[1024];
--
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