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NAME

       mp2enc - Simple MPEG-1 layer-II audio encoder

SYNOPSIS

       mp2enc  [-v  num]  [-b  bitrate_kbps]  [-r output_sampling_rate_hz] [-R
       rate,chans,bits] [-s ] [-m ] [-e ] [-V ] [-?]  -o output_filename

DESCRIPTION

       Mp2enc is a simple MPEG-1 layer-I/II audio encoder.  It is  actually  a
       very mildly warmed over version of the MPEG Software Simulation Group’s
       reference encoder.  It accepts a WAV file or stream on stdin and ouputs
       an  a  layer-I/II  elementary  audio  stream.   It  is  included in the
       mjpegtools(1) primarily for reasons of completeness and because  it  is
       able to perform sampling rate conversion.

       Those  seeking  a faster (and probably higher quality) layer II encoder
       are recommended to use toolame(1) which can be obtained from:

              http://www.planckenergy.com

GENERAL FUNCTION LETTERS

       -o output_filename
              Specifies the name for the output file.

              An integer format code (e.g. %d) in the  name  is  replaced  the
              number of the file generated (see printf(3)).

       -v num Set  verbosity  level to num.  0 = warnings and errors only, 1 =
              information as well, 2=really verbose.  -?  Display  a  synopsis
              of the command syntax.

       -R rate,chans,bits
              Indicate,  that  the  input  is raw PCM without header. You must
              specify 3 numbers: rate is the samplerate in Hz,  chans  is  the
              number  of  channels (1 or 2) and bits is the number of bits per
              sample. 8 bits are unsigned,  16  bits  are  signed  in  machine
              native byte order.

FUNCTION LETTERS CONTROLLING OUTPUT STREAM STRUCTURE

       -b bitrate

              This  sets  the  bit-rate  of  the  output  stream  in kBit/sec.
              Typical values for layer II might be  224kbps  for  good-quality
              audio suitable for capturing Dolby pro-logic signals.  A rate of
              192kbps or 128kbps is reasonable for  low  quality  audio  (e.g.
              mono  TV  audio).  Really high compression is, of course, better
              achieved using MPEG-1 layer III ("MP3") audio encoding or AAC. A
              more appropriate value for layer I might be 384kbps.

       -r sampling_rate
              Sets  the audio sampling rate of the reconstructed output signal
              in Hz.  Legal values are 32000, 44100 and 48000Hz.   mp2enc will
              automatically sample-rate convert the input signal if necessary.

       -l layer
              Sets the audio layer.  Legal values are 1 and 2. The default  is
              layer II.

       -s     Force  stereo  output.   A  mono input signal is channel doubled
              before encoding to make it stereo.  This is useful  for  players
              which simply can’t handle a non-stero signal.

       -m     Force  mono  output.  A stereo input signal is down-mixed before
              encoding.  Useful if you’ve captured a mono signal in stereo and
              your player can handle mono MPEG-1 Layer 2 audio.

       -e     Use CRC error protection.

       -V     Force  VCD  compatible  output. The primary effect of this is to
              make certain that the sampling rate is set to 44100 (-r  44100).
              The  VCD2.0  specifications  permit mono audio at 64, 96 and 192
              kbits/sec and stereo at 128, 192, 224, and 384 kbits/sec.  Using
              -V  checks that the bitrate is valid for the number of channels.
              The defaults (unless -m or  -b  are  used)  are  stereo  at  224
              kbits/sec.

       -o outputpathname
              The name of the output file to generate.  If ’-’ is given as the
              pathname output is written to standard output.

BUGS

       Mono output does not work for layer I.

AUTHOR

       This man page was written by Andrew Stevens.
       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

       mpeg2enc(1),  mp2enc(1), lavrec(1), lavplay(1), lav2yuv(1), lav2wav(1),
       yuvscaler(1)