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

Provided by: mjpegtools_2.1.0+debian-8.1build1_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