[FFmpeg-devel] [PATCH] avformat/mov: fix missing extra data updating
Zhao Zhili
quinkblack at foxmail.com
Tue Mar 29 21:04:46 EEST 2022
The stsc_index is checked and updated for the next sample. If the
next sample needs to update stsd_index and stsc_index, then only
stsc_index is updated, which leads to a missing
AV_PKT_DATA_NEW_EXTRADATA. For example, the sample in the second
chunk needs to update both.
entry[0]
first_chunk = 1
samples_per_chunk = 3
sample_description_index = 1
entry[1]
first_chunk = 2
samples_per_chunk = 1
sample_description_index = 2
entry[2]
first_chunk = 3
samples_per_chunk = 8
sample_description_index = 2
The fix is simple: first check and update stsd_index for current
sample, then check and update stsc_index for the next.
---
libavformat/mov.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 6c847de164..c9d4f2ef43 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -8591,20 +8591,20 @@ static int mov_read_packet(AVFormatContext *s, AVPacket *pkt)
/* Multiple stsd handling. */
if (sc->stsc_data) {
- /* Keep track of the stsc index for the given sample, then check
- * if the stsd index is different from the last used one. */
+ if (sc->stsc_data[sc->stsc_index].id > 0 &&
+ sc->stsc_data[sc->stsc_index].id - 1 < sc->stsd_count &&
+ sc->stsc_data[sc->stsc_index].id - 1 != sc->last_stsd_index) {
+ ret = mov_change_extradata(sc, pkt);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* Update the stsc index for the next sample */
sc->stsc_sample++;
if (mov_stsc_index_valid(sc->stsc_index, sc->stsc_count) &&
mov_get_stsc_samples(sc, sc->stsc_index) == sc->stsc_sample) {
sc->stsc_index++;
sc->stsc_sample = 0;
- /* Do not check indexes after a switch. */
- } else if (sc->stsc_data[sc->stsc_index].id > 0 &&
- sc->stsc_data[sc->stsc_index].id - 1 < sc->stsd_count &&
- sc->stsc_data[sc->stsc_index].id - 1 != sc->last_stsd_index) {
- ret = mov_change_extradata(sc, pkt);
- if (ret < 0)
- return ret;
}
}
--
2.31.1
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