libavformat: Account for negative position differences in ff_configure_buffers_for_index

When scanning through the index, account for the fact that the
compared samples may be located in an unexpected order in the file;
this function is mainly interested in the absolute difference between
file locations.

Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Martin Storsjö 2023-03-24 23:08:10 +02:00
parent 182663a58a
commit 33d06de638

View File

@ -208,9 +208,11 @@ void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance)
for (; i2 < sti2->nb_index_entries; i2++) {
const AVIndexEntry *const e2 = &sti2->index_entries[i2];
int64_t e2_pts = av_rescale_q(e2->timestamp, st2->time_base, AV_TIME_BASE_Q);
int64_t cur_delta;
if (e2_pts < e1_pts || e2_pts - (uint64_t)e1_pts < time_tolerance)
continue;
pos_delta = FFMAX(pos_delta, e1->pos - e2->pos);
cur_delta = FFABS(e1->pos - e2->pos);
pos_delta = FFMAX(pos_delta, cur_delta);
break;
}
}