For general information see README

The aacPubDec has been modified in a way that it can transcode 
a Version 1 aac bitstream into an (version 2) error resilient bitstream. 
Two functions can be distinguished:

1. error resilience trancoding

Parts of the bitstreams are transcoded in order to increase the error
resilience of these parts. All tools are implemented:

HCR   transcodes the spectral_data()    part.
VCB11 transcodes the section_data()     part.
RVLC  transcodes the scalefactor_data() part.

2. interface to the error protection tool

Data elements are collected within error sensitivity category (esc)
instances, depending on its error sensitivity. This is done according to
the description of the standard. Optional instances are only used uppon
request, i. e. the number of instances differs depending on the setup.

-------
The command line looks like: 

aactrans [options] <in_file> <out_file>
options are:
 -i <prog_tag> (ADIF header present)
 -p <profile>  (Main or LC, Main is default)
 -s <sampling_frequency>, Hz (48000 is default)
 -C channel configuration
 -t tns usage flag (0/1)
 -L switch to Low Delay
 -F frameLengthFlag: use frame length 960 (default: 1024)
                     for Low Delay:   480 (default:  512)
 -l length_of_longest_codeword within bitstream (not standard)
 -r <mode> HCR within spectral data, length_of_longest_codeword and 
                                     length_of_spectral_data within bitstream
    modi: 0 - raw (not standard)
          1 - codeword pre-sorting (not standard)
          2 - consecutive HCR (not standard)
          3 - codeword pre-sorting and consecutive HCR
 -c virtual codebooks are used to encode codebook 11 within section data
 -f <mode> error resilient coding of scalefactor data, modi:
         0 - pure aac bitstream
         1 - length of sf data in bitstream (not standard)
         2 - 1 + rvlc coding of sf data (not standard)
         3 - 2 + additional bit allowing enhanced concealment
 -D[a-Z] (enable debugging printouts)

(2000-05-16 RS)
-------------------------------------------------------------------------------------------
