[FFmpeg-devel] [PATCHv3 1/2] libavformat: Account for negative position differences in ff_configure_buffers_for_index

[Martin Storsjö]

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 at martin.st>
---
v3: Avoid mixed declarations and statements.

Reposting as part of the updated other patch, as it the previously posted
v3 didn't get any comments.
---
 libavformat/seek.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavformat/seek.c b/libavformat/seek.c
index a236e285c0..faa47f961f 100644
--- a/libavformat/seek.c
+++ b/libavformat/seek.c
@@ -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;
                 }
             }
-- 
2.37.1 (Apple Git-137.1)