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       lav2wav - Extract the audio out of MJPEG container files to stdout


       lav2wav  [-s num] [-c num] [-v num] [-I] [-R] [-r samplerate, bitesize,
       channels] lavfile1 [lavfile2 ... lavfileN]


       lav2wav can be used to extract the audio to stdout.  This  output  goes
       to  stdout  and  can  be  saved as a wav file or piped to another sound
       processing tool that is able to handle the wav  format.   This  can  be
       mp2enc and toolame for mpeg layer 2 audio, or for example lame for mpeg
       layer 3 audio.

       The input files may be any combination of AVI (.avi),  Quicktime  (.qt)
       or  editlist  files  so  long  as they are all lavtools- readable (e.g.
       MJPEG-encoded AVI/Quicktime or DV type 2 AVI).


       lav2wav accepts the following options:

       -s num
            Start extracting at video frame (num)

       -c num
            Extract (num) frames of audio

       -v num
            Verbosity level (0, 1 or 2)

       -I   Ignore unsupported bitrates/bits per sample

       -R   If the file does  not  contain  any  sound.  lav2wav  will  create
            silence  with  44100kHz  Sampelrate,  16  Bit  audio bitsize and 2

       -r sr,bs,ch
            If the file does not  contain  any  sound  lav2wav  will  generate
            silence  with  the  values  you supply the samplerate (sr), audio-
            bitsize (bs) and channel (ch).


       The "WAV" file format (technically: RIFF) is really very much less than
       ideal  for  a tool intended to be used in pipelines as lav2wav is.  The
       problem is that the header includes a field specifying  the  length  of
       the  file.   This  can’t  be  filled  in  except by seeking back to the
       begining and over-writing.  If the output  is  unseekable  (e.g.  pipe)
       lav2wav  simply  writes a large length into the header and leaves it at
       that.  Most tools like sox(1) or mp2enc(1)  either  ignore  the  length
       field anyway or only give a warning.
       The  audio  length  is  inacurate  calculated  when  lav2wav  generates
       silence.  This happens only if you have  NTSC  framerate  and  than  it
       creates for every hour of video 1.1498sec too less of silence.


       This man page was written by Bernhard Praschinger.
       If  you  have  questions, remarks, problems or you just want to contact
       the developers, the main mailing list for the MJPEG-tools is:

       For more info, see our website at


       mjpegtools(1), mp2enc(1), sox(1)