[MEncoder-users] video errors mpeg copy

[Mike Petersen]

Hello,
i'm using mencoder to cut an mpeg movie. Mostly it is working fine with 
this command :
mencoder -oac copy -ovc copy -of mpeg -mpegopts format=dvd -ss 10.0 
-endpos 10.0 source_file -forceidx -o target_file

But sometimes the picture gets lots of distortions (nearly the whole 
picture is green). I've found out that this is caused by files with a 
fps of 50.

ffmpeg info :
FFmpeg version SVN-rUNKNOWN, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --enable-gpl --enable-pp --enable-swscaler 
--enable-pthreads --enable-libvorbis --enable-libtheora --enable-libogg 
--enable-libgsm --enable-dc1394 --disable-debug --enable-shared 
--prefix=/usr
  libavutil version: 1d.49.3.0
  libavcodec version: 1d.51.38.0
  libavformat version: 1d.51.10.0
  built on Mar 12 2008 14:31:53, gcc: 4.2.3 (Ubuntu 4.2.3-2ubuntu4)

Seems stream 0 codec frame rate differs from container frame rate: 25.00 
(25/1) -> 50.00 (50/1)
Input #0, mpeg, from '0805090031.mpg':
  Duration: 01:18:26.3, start: 0.360000, bitrate: 5975 kb/s
  Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576, 5700 kb/s, 
50.00 fps(r)
  Stream #0.1[0x80]: Audio: 0x0000, 48000 Hz, stereo, 192 kb/s


mplayer info :
MPEG-PS file format detected.
VIDEO:  MPEG2  720x576  (aspect 2)  25.000 fps  5700.0 kbps (712.5 kbyte/s)
xscreensaver_disable: Could not find XScreenSaver window.
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 720 x 576 (preferred colorspace: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.
VDecoder init failed :(
Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder libmpeg2-v0.4.0b
Selected video codec: [mpeg12] vfm: libmpeg2 (MPEG-1 or 2 (libmpeg2))
==========================================================================
==========================================================================
Forced audio codec: mad
Opening audio decoder: [liba52] AC3 decoding with liba52
Using SSE optimized IMDCT transform
Using MMX optimized resampler
AUDIO: 48000 Hz, 2 ch, s16le, 192.0 kbit/12.50% (ratio: 24000->192000)
Selected audio codec: [a52] afm: liba52 (AC3-liba52)
==========================================================================
AO: [pulse] Failed to connect to server: Connection refused
AO: [alsa] 48000Hz 2ch s16le (2 bytes per sample)
Starting playback...


If i add the options "-noskip -mc 0" the picture is better but there are 
still some errors every few seconds and it seems that the movie is 
running to slow.

I already tried options like ofps and used ffmpeg for cutting but the 
result seems to be the same, the best i got is the errors every few seconds.

Does anyone know how i can fix this ?

Thanks

Regards
Mike