[FFmpeg-trac] #327(avformat:new): artifacts when seeking in mpeg4 avi (regression)

[FFmpeg]

#327: artifacts when seeking in mpeg4 avi (regression)
----------------------+-------------------------
 Reporter:  exobuzz   |        Type:  defect
   Status:  new       |    Priority:  normal
Component:  avformat  |     Version:  git-master
 Keywords:            |  Blocked By:
 Blocking:            |  Reproduced:  0
 Analyzed:  0         |
----------------------+-------------------------
 Since the patch:

 commit 187528441ab936c102b8e72f38925cc10fc14abc
 Author: Michael Niedermayer <michaelni at gmx.at>
 Date:   Fri May 6 03:52:16 2011 +0200

     avidec: correct frame_offset for seeking

 I have artifacts when seeking on an avi file. the file is mpeg4 avi
 encoded with mencoder and is 5713978482 bytes in length. if i chop (with
 dd) the first 20 or 200mb of the file, the piece seeks correctly. (testing
 with ffplay)

 playing (and seeking) the full file with the problem

 {{{
 $ ./ffplay artifacts_when_seeking.avi
 ffplay version N-30884-g54dd50d, Copyright (c) 2003-2011 the FFmpeg
 developers
   built on Jun 20 2011 23:10:06 with gcc 4.5.2
   configuration:
   libavutil    51.  9. 1 / 51.  9. 1
   libavcodec   53.  7. 0 / 53.  7. 0
   libavformat  53.  4. 0 / 53.  4. 0
   libavdevice  53.  1. 1 / 53.  1. 1
   libavfilter   2. 23. 0 /  2. 23. 0
   libswscale    0. 14. 1 /  0. 14. 1
 [avi @ 0x13b01c0] non-interleaved AVI
 Input #0, avi, from 'artifacts_when_seeking.avi':
   Metadata:
     encoder         : MEncoder 1.0rc4-4.5.2
   Duration: 02:13:54.16, start: 0.000000, bitrate: 5689 kb/s
     Stream #0.0: Video: mpeg4, yuv420p, 1280x544 [PAR 1:1 DAR 40:17], 24
 tbr, 24 tbn, 24 tbc
     Stream #0.1: Audio: dca (DTS), 48000 Hz, 5.1, s16, 1536 kb/s
 [dca @ 0x13af5e0] Not a valid DCA frame=   43KB sq=    0B f=0/0   f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe0B f=0/0
 [dca @ 0x13af5e0] Not a valid DCA frame=   27KB sq=    0B f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe
 [dca @ 0x13af5e0] Not a valid DCA frame=  285KB sq=    0B f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe0B f=0/0
 [dca @ 0x13af5e0] Not a valid DCA frame=  575KB sq=    0B f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe0B f=0/0
 [dca @ 0x13af5e0] Not a valid DCA frame=  682KB sq=    0B f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe0B f=0/0
 [dca @ 0x13af5e0] Not a valid DCA frame=  627KB sq=    0B f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe0B f=0/0
 [dca @ 0x13af5e0] Not a valid DCA frame=  674KB sq=    0B f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe0B f=0/0
 [dca @ 0x13af5e0] Not a valid DCA frame=  378KB sq=    0B f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe0B f=0/0
 [dca @ 0x13af5e0] Not a valid DCA frame=  423KB sq=    0B f=0/0
 [mpeg4 @ 0x13675c0] warning: first frame is no keyframe0B f=0/0
  188.34 A-V:  0.008 s:0.0 aq=  321KB vq=  392KB sq=    0B f=0/0
 }}}

 revert two commits - the one mentioned and a update from ticket #271

 {{{
 $ git revert -n a7e4342fc1a0e962b829a9a194d034fa38590951
 $ git revert -n 187528441ab936c102b8e72f38925cc10fc14abc
 }}}

 i am then able to seek ok without the artifacts

 {{{
 $ ./ffplay artifacts_when_seeking.avi
 ffplay version N-30884-g54dd50d, Copyright (c) 2003-2011 the FFmpeg
 developers
   built on Jun 20 2011 23:10:06 with gcc 4.5.2
   configuration:
   libavutil    51.  9. 1 / 51.  9. 1
   libavcodec   53.  7. 0 / 53.  7. 0
   libavformat  53.  4. 0 / 53.  4. 0
   libavdevice  53.  1. 1 / 53.  1. 1
   libavfilter   2. 23. 0 /  2. 23. 0
   libswscale    0. 14. 1 /  0. 14. 1
 [avi @ 0x2d850c0] non-interleaved AVI
 Input #0, avi, from 'artifacts_when_seeking.avi':
   Metadata:
     encoder         : MEncoder 1.0rc4-4.5.2
   Duration: 02:13:54.16, start: 0.000000, bitrate: 5689 kb/s
     Stream #0.0: Video: mpeg4, yuv420p, 1280x544 [PAR 1:1 DAR 40:17], 24
 tbr, 24 tbn, 24 tbc
     Stream #0.1: Audio: dca (DTS), 48000 Hz, 5.1, s16, 1536 kb/s
 [dca @ 0x2d844c0] Not a valid DCA frame=   19KB sq=    0B f=0/0   f=0/0
  364.79 A-V: -0.002 s:0.0 aq=  319KB vq=  840KB sq=    0B f=0/0
     Last message repeated 8 times
 }}}

 here is a snippet from the beginning of the file (20mb). if you need
 anything else please let me know.
 http://www.datafilehost.com/download-a1793e98.html

-- 
Ticket URL: <http://www.ffmpeg.org/trac/ffmpeg/ticket/327>
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