Rockbox Support for Wavpack Hybrid Compression
Wavpack Hybrid Compression
The Wavpack audio codec
supports an unusual "hybrid" compression mode. In this mode, a traditional lossy file is complemented by a "correction" file. When the two are decoded together, the original input bitstream can be recreated exactly. The lossy file may also be decoded on its own.
Rockbox currently handles lossy files but ignores the correction files.
- Correctly decode hybrid files on a PC with Rockbox code (complete and verified for stereo files)
- Implement support for buffering two (or more) files in a codec-independent manner (vaguely working)
- Ensure real-time decoding on a Rockbox target (decoding but not tested real-time on target)
- Implement seeking in hybrid files with correction info present (should already work imprecisely, but untested)
- Add support for and check more obscure formats, like hybrid mono lossless and old-style hybrid shaping code
Wavpack spec description: here
Wavpack file format: here
Decoding of stereo hybrid lossless files functions off-target. The patch is at http://q3q.us/hybrid2.patch
. This does NOT run on a device; use http://q3q.us/codec-executor.tar.bz2
to run the codec!
Decoding on-target works via a modification to the buffering system at http://q3q.us/buffer.patch
. This will NOT play nice with other files and is not ready for general consumption.
Currently fixing buffering code interactions to avoid data corruption
Copyright © by the contributing authors.