AVPacket.duration is mostly made up and thus completely useless, this is
especially true for video streams.
---
libavformat/avformat.h | 9 +++++++++
libavformat/utils.c | 22 +++++++++++++++++++---
2 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index e292206..55cbc9e 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -721,6 +721,15 @@ typedef struct AVStream {
int64_t codec_info_duration;
int nb_decoded_frames;
int found_decoder;
+
+ /**
+ * Those are used for average framerate estimation.
+ */
+ int64_t fps_first_dts;
+ int fps_first_dts_idx;
+ int64_t fps_last_dts;
+ int fps_last_dts_idx;
+
} *info;
int pts_wrap_bits; /**< number of bits in pts (used for wrapping control)
*/
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 8dbf1e5..2a43645 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -2287,6 +2287,8 @@ int avformat_find_stream_info(AVFormatContext *ic,
AVDictionary **options)
for (i=0; i<ic->nb_streams; i++) {
ic->streams[i]->info->last_dts = AV_NOPTS_VALUE;
+ ic->streams[i]->info->fps_first_dts = AV_NOPTS_VALUE;
+ ic->streams[i]->info->fps_last_dts = AV_NOPTS_VALUE;
}
count = 0;
@@ -2395,6 +2397,15 @@ int avformat_find_stream_info(AVFormatContext *ic,
AVDictionary **options)
break;
}
st->info->codec_info_duration += pkt->duration;
+ if (pkt->dts != AV_NOPTS_VALUE) {
+ if (st->info->fps_first_dts == AV_NOPTS_VALUE) {
+ st->info->fps_first_dts = pkt->dts;
+ st->info->fps_first_dts_idx = st->codec_info_nb_frames;
+ } else if (pkt->dts > st->info->fps_first_dts) {
+ st->info->fps_last_dts = pkt->dts;
+ st->info->fps_last_dts_idx = st->codec_info_nb_frames;
+ }
+ }
}
{
int64_t last = st->info->last_dts;
@@ -2454,10 +2465,15 @@ int avformat_find_stream_info(AVFormatContext *ic,
AVDictionary **options)
for(i=0;i<ic->nb_streams;i++) {
st = ic->streams[i];
if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
- if (st->codec_info_nb_frames>2 && !st->avg_frame_rate.num &&
st->info->codec_info_duration)
+ /* estimate average framerate if not set by demuxer */
+ if (!st->avg_frame_rate.num && st->info->fps_last_dts !=
AV_NOPTS_VALUE) {
+ int64_t delta_dts = st->info->fps_last_dts -
st->info->fps_first_dts;
+ int delta_packets = st->info->fps_last_dts_idx -
st->info->fps_first_dts_idx;
+
av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
-
(st->codec_info_nb_frames-2)*(int64_t)st->time_base.den,
-
st->info->codec_info_duration*(int64_t)st->time_base.num, 60000);
+ delta_packets*(int64_t)st->time_base.den,
+ delta_dts*(int64_t)st->time_base.num, 60000);
+ }
// the check for tb_unreliable() is not completely correct, since
this is not about handling
// a unreliable/inexact time base, but a time base that is finer
than necessary, as e.g.
// ipmovie.c produces.
--
1.7.10.4
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