For Transcoder specific information see README_TRANSCODER
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I believe that this is a complete AAC IS-compliant 
	Main and Low Complexity profile decoder.

Recently added features are:
	TNS max_bands, max_order is checked for all sampling rates and
		profiles
	modifications to data stream element
	all sampling rates supported
	pulse data limited to long blocks (and a bug fixed in that code)
	matrix mixdown fields in program config element
	prediction changed to low memory complexity algorithm
	ADIF headers supported and checked.

However none of the coupling channel code (coupling.c) has been tested.

There is the output channel naming convention:
	channel		name
	mono		*_f00.pcm
stereo
	left		*_f01.pcm
	right		*_f02.pcm
5.1
	center		*_f00.pcm
	left		*_f01.pcm
	right		*_f02.pcm
	left surr.	*_b00.pcm
	right surr.	*_b01.pcm
	lfe		*_l00.pcm

This labeling scheme supports the full-up 48.2 channel Main profile
configuration. For front channels the "00" index is the center channel.
For back channels the highest even index is the center channel (note
that 5.1 does not have a center back channel).  The "pcm" extension
indicates that the file is mono 16-bit 2's complement with no header.
Alternatively, the decoder can write AIFF files, in which case the file
extension is "aif".

Command line arguments are:

usage:  dec [options] chan_file pcm_file
        options are:
        -a create AIFF output files
        -i [prog_tag] ADIF header present (first prog is default)
        -p profile (Main or LC, Main is default)
        -s sampling_frequency, Hz (48 kHz is default)
        -D[a-Z] (enable debugging printouts)

Some more explanation:
	-a AIFF output files, one per channel. 
	-i indicates the presence of an ADIF header and associated
	program_config_element's. The arg selects the program in the 
	case of multiple program_config_element's in the header.
	
	-p is only useful if there is no program_config_element in the
	bitstream.
	
	-s is required if you want to write AIFF files and the sampling
	rate is not 48kHz, even if a program_config_element is present
	(sorry about that).
	
	-D is for debugging/diagnostic. Grep the code to see what it
	can do.

Schuyler
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Schuyler Quackenbush				Phone:	(908) 582-4210
Member of Technical Staff			FAX:	(908) 582-4271
AT&T Laboratories, Room 2D-555			Email:	srq@research.att.com
600 Mountain Avenue				
Murray Hill, NJ 07974, USA
