[Bf-blender-cvs] [95fcb418410] blender-v3.1-release: Fix T95378: Seek problems when timecodes are used

[Richard Antalik]

Commit: 95fcb4184108aff91eb46f4192af5b0826e486a7
Author: Richard Antalik
Date:   Tue Feb 1 22:47:22 2022 +0100
Branches: blender-v3.1-release
https://developer.blender.org/rB95fcb4184108aff91eb46f4192af5b0826e486a7

Fix T95378: Seek problems when timecodes are used

Function `IMB_indexer_get_seek_pos()` can return non 0 seek position for
frame index 0. This causes seeking to incorrect GOP and scanning ends
with failiure.

Hard-code first frame index seek position to 0.

Differential Revision: https://developer.blender.org/D13974

===================================================================

M	source/blender/imbuf/intern/indexer.c

===================================================================

diff --git a/source/blender/imbuf/intern/indexer.c b/source/blender/imbuf/intern/indexer.c
index a85ba65d014..00e96e7840b 100644
--- a/source/blender/imbuf/intern/indexer.c
+++ b/source/blender/imbuf/intern/indexer.c
@@ -247,8 +247,10 @@ struct anim_index *IMB_indexer_open(const char *name)
 
 uint64_t IMB_indexer_get_seek_pos(struct anim_index *idx, int frame_index)
 {
-  if (frame_index < 0) {
-    frame_index = 0;
+  /* This is hard coded, because our current timecode files return non zero seek position for index
+   * 0. Only when seeking to 0 it is guaranteed, that first packet will be read. */
+  if (frame_index <= 0) {
+    return 0;
   }
   if (frame_index >= idx->num_entries) {
     frame_index = idx->num_entries - 1;