[FFmpeg-devel] [PATCH 01/15] avformat/dashenc: allow setting segment durations per AdaptationSet
James Almer
jamrial at gmail.com
Sat Dec 21 20:02:38 EET 2019
Implemented as as a seg_duration key=value entry in the adaptation_sets muxer
option.
It has the same syntax as the global seg_duration option, and has precedence
over it if set.
Signed-off-by: James Almer <jamrial at gmail.com>
---
libavformat/dashenc.c | 49 ++++++++++++++++++++++++++++++++++---------
1 file changed, 39 insertions(+), 10 deletions(-)
diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 8c28fb6b6e..419043ee0b 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -31,6 +31,7 @@
#include "libavutil/intreadwrite.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
+#include "libavutil/parseutils.h"
#include "libavutil/rational.h"
#include "libavutil/time.h"
#include "libavutil/time_internal.h"
@@ -70,6 +71,7 @@ typedef struct Segment {
typedef struct AdaptationSet {
char id[10];
char *descriptor;
+ int64_t seg_duration;
enum AVMediaType media_type;
AVDictionary *metadata;
AVRational min_frame_rate, max_frame_rate;
@@ -85,6 +87,7 @@ typedef struct OutputStream {
int64_t init_start_pos, pos;
int init_range_length;
int nb_segments, segments_size, segment_index;
+ int64_t seg_duration;
Segment **segments;
int64_t first_pts, start_pts, max_pts;
int64_t last_dts, last_pts;
@@ -613,7 +616,7 @@ static void output_segment_list(OutputStream *os, AVIOContext *out, AVFormatCont
int timescale = c->use_timeline ? os->ctx->streams[0]->time_base.den : AV_TIME_BASE;
avio_printf(out, "\t\t\t\t<SegmentTemplate timescale=\"%d\" ", timescale);
if (!c->use_timeline) {
- avio_printf(out, "duration=\"%"PRId64"\" ", c->seg_duration);
+ avio_printf(out, "duration=\"%"PRId64"\" ", os->seg_duration);
if (c->streaming && os->availability_time_offset)
avio_printf(out, "availabilityTimeOffset=\"%.3f\" ",
os->availability_time_offset);
@@ -839,7 +842,7 @@ static int parse_adaptation_sets(AVFormatContext *s)
{
DASHContext *c = s->priv_data;
const char *p = c->adaptation_sets;
- enum { new_set, parse_id, parsing_streams, parse_descriptor } state;
+ enum { new_set, parse_id, parsing_streams, parse_descriptor, parse_seg_duration } state;
AdaptationSet *as;
int i, n, ret;
@@ -857,8 +860,11 @@ static int parse_adaptation_sets(AVFormatContext *s)
// syntax id=0,streams=0,1,2 id=1,streams=3,4 and so on
// option id=0,descriptor=descriptor_str,streams=0,1,2 and so on
+ // option id=0,seg_duration=2.5,streams=0,1,2 and so on
// descriptor is useful to the scheme defined by ISO/IEC 23009-1:2014/Amd.2:2015
// descriptor_str should be a self-closing xml tag.
+ // seg_duration has the same syntax as the global seg_duration option, and has
+ // precedence over it if set.
state = new_set;
while (*p) {
if (*p == ' ') {
@@ -876,7 +882,25 @@ static int parse_adaptation_sets(AVFormatContext *s)
if (*p)
p++;
state = parse_id;
- } else if (state == parse_id && av_strstart(p, "descriptor=", &p)) {
+ } else if (state != new_set && av_strstart(p, "seg_duration=", &p)) {
+ char str[32];
+ int64_t usecs = 0;
+
+ n = strcspn(p, ",");
+ snprintf(str, sizeof(str), "%.*s", n, p);
+ p += n;
+ if (*p)
+ p++;
+
+ ret = av_parse_time(&usecs, str, 1);
+ if (ret < 0) {
+ av_log(s, AV_LOG_ERROR, "Unable to parse option value \"%s\" as duration\n", str);
+ return ret;
+ }
+
+ as->seg_duration = usecs;
+ state = parse_seg_duration;
+ } else if (state != new_set && av_strstart(p, "descriptor=", &p)) {
n = strcspn(p, ">") + 1; //followed by one comma, so plus 1
if (n < strlen(p)) {
as->descriptor = av_strndup(p, n);
@@ -888,7 +912,7 @@ static int parse_adaptation_sets(AVFormatContext *s)
if (*p)
p++;
state = parse_descriptor;
- } else if ((state == parse_id || state == parse_descriptor) && av_strstart(p, "streams=", &p)) { //descriptor is optional
+ } else if ((state != new_set) && av_strstart(p, "streams=", &p)) { //descriptor and duration are optional
state = parsing_streams;
} else if (state == parsing_streams) {
AdaptationSet *as = &c->as[c->nb_as - 1];
@@ -1360,6 +1384,7 @@ static int dash_init(AVFormatContext *s)
os->first_pts = AV_NOPTS_VALUE;
os->max_pts = AV_NOPTS_VALUE;
os->last_dts = AV_NOPTS_VALUE;
+ os->seg_duration = as->seg_duration ? as->seg_duration : c->seg_duration;
os->segment_index = 1;
if (s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
@@ -1581,7 +1606,7 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
c->streams[stream].first_pts,
s->streams[stream]->time_base,
AV_TIME_BASE_Q);
- next_exp_index = (pts_diff / c->seg_duration) + 1;
+ next_exp_index = (pts_diff / c->streams[stream].seg_duration) + 1;
}
}
@@ -1597,6 +1622,9 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
// 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[stream]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO &&
+ s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO)
+ continue;
if (s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_AUDIO)
continue;
// Make sure we don't flush audio streams multiple times, when
@@ -1739,22 +1767,22 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt)
if (!os->availability_time_offset && pkt->duration) {
int64_t frame_duration = av_rescale_q(pkt->duration, st->time_base,
AV_TIME_BASE_Q);
- os->availability_time_offset = ((double) c->seg_duration -
+ os->availability_time_offset = ((double) os->seg_duration -
frame_duration) / AV_TIME_BASE;
}
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;
+ seg_end_duration = (int64_t) os->segment_index * os->seg_duration;
} else {
elapsed_duration = pkt->pts - os->start_pts;
- seg_end_duration = c->seg_duration;
+ seg_end_duration = os->seg_duration;
}
- if ((!c->has_video || st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) &&
- pkt->flags & AV_PKT_FLAG_KEY && os->packets_written &&
+ if (pkt->flags & AV_PKT_FLAG_KEY && os->packets_written &&
av_compare_ts(elapsed_duration, st->time_base,
seg_end_duration, AV_TIME_BASE_Q) >= 0) {
+ if (!c->has_video || st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
int64_t prev_duration = c->last_duration;
c->last_duration = av_rescale_q(pkt->pts - os->start_pts,
@@ -1772,6 +1800,7 @@ static int dash_write_packet(AVFormatContext *s, AVPacket *pkt)
"and use_template, or keep a stricter keyframe interval\n");
}
}
+ }
if ((ret = dash_flush(s, 0, pkt->stream_index)) < 0)
return ret;
--
2.24.1
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