[MPlayer-users] mencoder audio corruption - using pcm with libdv encoding

[Bradley Rosser]

I'm trying to use mencoder 0.90 under Linux 2.4.16 to convert my movies 
into digital video, so I can copy the video to my camcorder and thence
to my television.  It's the only way I can view my movies on the big 
screen, as I don't have a working tv-out on my video card.

I'm using mencoder to convert the movies into DV files which I then pass 
through 'dvavi' (from the libdv package) to convert into 'raw' digital 
video, which I can then send to the camcorder with 'dvconnect'.

'dvavi' won't accept audio encoded with mp3lame, so I have to use the
'pcm' audio encoding:

   mencoder -vop scale=720:576 -ovc libdv -oac pcm -o dv.avi FILE.mpg

I tested this command on nine video files of varying formats and
quality.  With one it worked *perfectly*; mencoder produced 'dv.avi'
which I then ran through 'dvavi' and played into the camcorder.

Unfortunately I have a problem with the audio produced by mencoder for
the other eight tests; in all cases there's a rapid 'clicking' present
in the sound, at a frequency say around 5-10 per minute.  I can hear the 
loud clicking when playing the mencoder-produced 'dv.avi' with mplayer 
or other players.

mencoder reported this for the 'perfect' video file:

  VIDEO:  MPEG1  352x240  (aspect 12)  23.98 fps  1150.0 kbps (143.8 kbyte/s)
  [V] filefmt:2  fourcc:0x10000001  size:352x240  fps:23.98 ftime:=0.0417
  ...
  Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
  MP3lib: init layer2&3 finished, tables done
  AUDIO: 44100 Hz, 2 ch, 16 bit (0x10), ratio: 28000->176400 (224.0 kbit)
  Selected audio codec: [mp3] afm:mp3lib (mp3lib MPEG layer-2, layer-3)

One of the other 'bad' files was an MPEG2 file, but to my naive eyes 
seems to have the same audio encoding as the first:

  VIDEO:  MPEG2  480x480  (aspect 2)  29.97 fps  2050.0 kbps (256.2 kbyte/s)
  [V] filefmt:2  fourcc:0x10000002  size:480x480  fps:29.97 ftime:=0.0334
  ...
  Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
  MP3lib: init layer2&3 finished, tables done
  AUDIO: 44100 Hz, 2 ch, 16 bit (0x10), ratio: 28000->176400 (224.0 kbit)
  Selected audio codec: [mp3] afm:mp3lib (mp3lib MPEG layer-2, layer-3)

Can anyone give me any ideas as to how I can try and get rid of this 
distortion in the sound track produced by mencoder?  Otherwise I won't 
be able to watch my movies on the big screen!  :-(

I'd be happy to provide the full output of mencoder, sample input files 
or any other information.  Any help would be most appreciated.

Thanks,


Brad Rosser
b_rosser at yahoo.com



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