blender
/
blender
136
404
Fork 586
Code Issues 6.2k Pull Requests 762 Projects 19 Wiki Activity

Fix T87967: M2T video seeking is broken 

Bug caused by integer overflow in ffmpeg_generic_seek_workaround().
Function max_ii() was used to limit int_64tvalue.

After fixing the issue there was another issue, where near-infinite loop
was caused by requested_pos being very large and stream being cut in a
way, that it was missing keyframe at beginning.
This was fixed by checking if we are reading beyond file content.

Reviewed By: zeddb

Differential Revision: https://developer.blender.org/D11888
This commit is contained in:
Richard Antalik 2021-08-16 14:35:23 +02:00 committed by Sebastian Parborg
parent 2946f72a2a
commit 118946d195
Notes: blender-bot 2023-02-14 03:59:42 +01:00 
Referenced by issue #87967, M2T video seeking is broken
1 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
source/blender/imbuf/intern/anim_movie.c
View File

@ -1213,7 +1213,7 @@ static int ffmpeg_generic_seek_workaround(struct anim *anim,
/* Step backward frame by frame until we find the key frame we are looking for. */
while (current_pts != 0) {
current_pts = *requested_pts - (int64_t)round(offset * steps_per_frame);
current_pts = max_ii(current_pts, 0);
current_pts = MAX2(current_pts, 0);
/* Seek to timestamp. */
if (av_seek_frame(anim->pFormatCtx, anim->videoStream, current_pts, AVSEEK_FLAG_BACKWARD) <
@ -1243,11 +1243,12 @@ static int ffmpeg_generic_seek_workaround(struct anim *anim,
/* We found the I-frame we were looking for! */
break;
}
if (cur_pts == prev_pts) {
/* We got the same key frame packet twice.
* This probably means that we have hit the beginning of the stream. */
break;
}
}
if (cur_pts == prev_pts) {
/* We got the same key frame packet twice.
* This probably means that we have hit the beginning of the stream. */
break;
}
prev_pts = cur_pts;