[FFmpeg-devel] [PATCH] mov.c fix the duration for the last audio frame.

[FFmpeg-devel] [PATCH] mov.c fix the duration for the last audio frame.

[Wang Cao via ffmpeg-devel]

It is possible that the actual audio data only occupy part of the last audio frame. This can be signaled by duration in the "trun" atom. We should respect the metadata of file and set the duration correctly.
---
 libavformat/mov.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 45eca74d1d..caea36b495 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -5700,11 +5700,16 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
         sc->ctts_data[index_entry_pos].count = 1;
         sc->ctts_data[index_entry_pos].duration = ctts_duration;
+        if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
+            sc->ctts_data[index_entry_pos].duration = sample_duration;
+        } else {
+            sc->ctts_data[index_entry_pos].duration = ctts_duration;
+        }
         index_entry_pos++;
 
         av_log(c->fc, AV_LOG_TRACE, "AVIndex stream %d, sample %d, offset %"PRIx64", dts %"PRId64", "
-                "size %u, distance %d, keyframe %d\n", st->index,
-                index_entry_pos, offset, dts, sample_size, distance, keyframe);
+                "size %u, distance %d, keyframe %d duration %d\n", st->index,
+                index_entry_pos, offset, dts, sample_size, distance, keyframe, sc->ctts_data[index_entry_pos-1].duration);
         distance++;
         if (av_sat_add64(dts, sample_duration) != dts + (uint64_t)sample_duration)
             return AVERROR_INVALIDDATA;
@@ -9894,6 +9899,9 @@ static int mov_finalize_packet(AVFormatContext *s, AVStream *st, AVIndexEntry *s
     }
     if (sc->ctts_data && sc->ctts_index < sc->ctts_count) {
         pkt->pts = av_sat_add64(pkt->dts, av_sat_add64(sc->dts_shift, sc->ctts_data[sc->ctts_index].duration));
+        if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
+            pkt->duration = sc->ctts_data[sc->ctts_index].duration;
+        }
         /* update ctts context */
         sc->ctts_sample++;
         if (sc->ctts_index < sc->ctts_count &&
-- 
2.45.1.288.g0e0cd299f1-goog

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Re: [FFmpeg-devel] [PATCH] mov.c fix the duration for the last audio frame.

[Michael Niedermayer]

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On Thu, May 30, 2024 at 07:38:36PM +0000, Wang Cao via ffmpeg-devel wrote:
> It is possible that the actual audio data only occupy part of the last audio frame. This can be signaled by duration in the "trun" atom. We should respect the metadata of file and set the duration correctly.
> ---
>  libavformat/mov.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)

please add a fate test

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Its not that you shouldnt use gotos but rather that you should write
readable code and code with gotos often but not always is less readable

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