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mp2enc(1)		      MJPEG tools manual		     mp2enc(1)

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	mjpeg-
       tools(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  na-
	      tive byte	order.

FUNCTION LETTERS CONTROLLING OUTPUT STREAM STRUCTURE
       -b bitrate

	      This  sets the bit-rate of the output stream in kBit/sec.	 Typi-
	      cal 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 be-
	      fore  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)

MJPEG Tools Team		  2 June 2001			     mp2enc(1)

NAME | SYNOPSIS | DESCRIPTION | GENERAL FUNCTION LETTERS | FUNCTION LETTERS CONTROLLING OUTPUT STREAM STRUCTURE | BUGS | AUTHOR | SEE ALSO

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