* AC3Enc: remove first 256 samples (encoded stream is shifted by 256 samples)
* AC3Parser: optimize get_coefs
* AC3Parser: add properties:
  dither - turn dithering on/off (for debug)
  drc - turn DRC on/off
  drc_heavy - turn heavy DRC compression on/off
  crc - use CRC flag
* AC3Parser: CRC check for low endian
* AC3Parser: get rid of warnings in floor_tbl table
* AC3Parser: add comments to tables, review tables
* AC3Parser: add block-level decoding support
* AC3Parser: verify bit allocation conditions:
  (do we need to make _full_ bit allocation if deltbaie = 1?)
* AC3Parser: grouped mantissas verification (may be out of range)
* AC3Parser: constraint p.41 s5.4.3.14 (coupling coordinates)
* AC3Parser: think about error-recovery strategy
* AC3Parser: think about performance

* MPAParser: intensity_stereo for Layer I/II? (see mode_extension)
* MPAParser: add mp3 support
* MPAParser: add multichannel support
* MPAParser: add free-format support
* MPAParser: think about error-recovery strategy
* MPAParser: think about performance

* FileParser: make it Source descendant?
* FileParser: add timing (get_time() call?):
  Update time according to file position at seek() call
  Update time with each frame decoded? (dejitter can do it)
  (i.e. File parser should be timing generator)

* New: RAWFile class to work with raw PCM files
* New: WAVFile class to work with WAV files
* New: AAC parser (far future)
* New: OGG parser (far future)
