NAME

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

SYNOPSIS

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

DESCRIPTION

       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).

OPTIONS

       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 Chanels

       -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).

BUGS

       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.

AUTHOR

       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:
         mjpeg-users@lists.sourceforge.net

       For more info, see our website at
              http://mjpeg.sourceforge.net

SEE ALSO

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