Ubuntu Manpage: mp2enc - Simple MPEG-1 layer-II audio encoder

Provided by: mjpegtools_2.1.0+debian-6build1_amd64

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