Skip to content

Kalmalyzer/adpcm-68k

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

11 Commits
 
 
 
 
 
 
 
 
 
 
 
 

Repository files navigation

IMA ADPCM codec for PC, decoder for Amiga & Atari

This archive contains three things:

  • a WAV<->ADPCM codec written in C, both source and executable included
  • an ADPCM decoder optimized for 68000
  • an ADPCM replayer for Amiga, including a Paula audio driver

The C codec is reference code from Stichting Mathematisch Centrum (see source code for copyright). The 680x0 specific code has been written by Mikael Kalms ([email protected]) (see LICENSE.md for copyright).

#Performance

The 68k decoder decodes approximately 50k samples/second on an 8MHz Atari ST.

The Amiga replay routine will decompress samples during each VBlank, taking typically <5 scanlines on a 68060@50MHz.

##Changelog

v1.0: implemented replay of mono samples

v2.0: implemented replay of stereo samples

v2.1: changed mixahead calculation such that it supports both PAL-nointerlace and PAL-interlace screenmodes removed all FPU usage

v2.2: bugfix when reinitializing AdpcmSource

v2.3: Implemented chunk-based decoding for 68k version, plus 8bit output

v2.4: Fixed ridiculous bug in 14bit-output of realtime ADPCM replayer for Amiga. Sometimes, the lower 6 bits would be incorrect! 14bit output sound quality is where it should be now.

About

IMA ADPCM codec for PC, and decoder for Amiga and Atari ST

Resources

License

Stars

Watchers

Forks

Releases

No releases published

Packages

No packages published