Incorrect seek behavior using -ss

[tweeeeek@…]

When transcoding video files (seems to be independent of container & codec) to FLV, I'm experiencing strange behavior when attempting to seek/skip to a certain point in the video.

mencoder -of lavf -oac mp3lame -lameopts abr:br=128 -ss 10 -srate 44100 -ovc lavc -af resample=44100:0:0,lavcresample=44100 -vf scale=572:323,harddup -lavcopts vcodec=flv:vbitrate=1000:mbd=2:turbo -o 'output.flv' 'inputfile.avi'

The resulting FLV has a valid audio track, but the video track is comprised of 10 seconds of black frames, then the video starting from the 10 second mark. Seeking 30 seconds results in a video with 30 seconds of black frames, etc.

This occurs with the latest SVN sources (MEncoder SVN-r34077-4.4.3).

When testing against the mencoder binary packaged with my distribution (Ubuntu 10.04, MEncoder SVN-r1.0~rc3+svn20090426-4.4.3) this behavior does not occur, seek works as expected.

Job output:

MEncoder SVN-r34077-4.4.3 (C) 2000-2011 MPlayer Team
success: format: 0 data: 0x0 - 0xce9d800
AVI file format detected.
[aviheader] Video stream found, -vid 0
[aviheader] Audio stream found, -aid 1
VIDEO: [XVID] 624x352 12bpp 25.000 fps 954.3 kbps (116.5 kbyte/s)
[V] filefmt:3 fourcc:0x44495658 size:624x352 fps:25.000 ftime:=0.0400
==========================================================================
Requested audio codec family [mpg123] (afm=mpg123) not available.
Enable it at compilation.
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 2 ch, floatle, 118.6 kbit/3.86% (ratio: 14822->384000)
Selected audio codec: [ffmp3float] afm: ffmpeg (FFmpeg MPEG layer-3 audio)
==========================================================================
MUXER_LAVF *
REMEMBER: MEncoder's libavformat muxing is presently broken and can generate
INCORRECT files in the presence of B-frames. Moreover, due to bugs MPlayer
will play these INCORRECT files as if nothing were wrong!
*
OK, exit.
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [harddup]
Opening video filter: [scale w=572 h=323]
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Unsupported PixelFormat 61
Unsupported PixelFormat 53
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4)
==========================================================================
MP3 audio selected.
[mpeg4 @ 0xd34bc0]Invalid and inefficient vfw-avi packed B frames detected
Movie-Aspect is 1.77:1 - prescaling to correct movie aspect.
[swscaler @ 0xcaaae0]BICUBIC scaler, from yuv420p to yuv420p using MMX2
videocodec: libavcodec (572x324 fourcc=31564c46 [FLV1])
[VE_LAVC] High quality encoding selected (non-realtime)!
Pos: 0.0s 1f ( 1%) 0.00fps Trem: 0min 0mb A-V:0.000 [0:0]
VIDEO CODEC ID: 22
AUDIO CODEC ID: 15001, TAG: 0
Writing header...
[flv @ 0xcbaac0]Codec for stream 0 does not use global headers but container format requires global headers
[flv @ 0xcbaac0]Codec for stream 1 does not use global headers but container format requires global headers

1 duplicate frame(s)!
[flv @ 0xd34bc0]Error, Invalid timestamp=1, last=296
[flv @ 0xcbaac0]Application provided invalid, non monotonically increasing dts to muxer in stream 0: 11840 >= 40
Error while writing frame.
Pos: 0.9s 22f ( 1%) 0.00fps Trem: 0min 1mb A-V:0.084 [0:123]

Skipping frame!
Pos: 1.4s 36f ( 1%) 0.00fps Trem: 0min 2mb A-V:0.081 [1921:123]

Skipping frame!
Pos:1017.8s 25445f (62%) 68.91fps Trem: 3min 218mb A-V:0.054 [1011:123]
[mpeg4 @ 0xd34bc0]ac-tex damaged at 23 17
[mpeg4 @ 0xd34bc0]Error at MB: 703
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]marker does not match f_code
[mpeg4 @ 0xd34bc0]concealing 221 DC, 221 AC, 221 MV errors
Pos:1017.8s 25446f (62%) 68.91fps Trem: 3min 218mb A-V:0.054 [1011:123]
[mpeg4 @ 0xd34bc0]slice end not reached but screenspace end (8 left BF0000, score= -25443)
[mpeg4 @ 0xd34bc0]concealing 858 DC, 858 AC, 858 MV errors
Pos:1584.4s 39611f (100%) 71.06fps Trem: 0min 212mb A-V:0.004 [1001:123]

Flushing video frames.
Writing index...

Video stream: 1001.115 kbit/s (125139 B/s) size: 198265736 bytes 1584.360 secs 39611 frames

Audio stream: 123.902 kbit/s (15487 B/s) size: 24539203 bytes 1584.431 secs