Simple WAV Delta Filter

[david_werecat]

WavDelta is a simple filter for .wav files which reduces the size of the file header and delta codes the sound data. It works for .wav files in PCM format at any sample rate and most bit depths. It may not be completely lossless for all files, since it simplifies the file header and rebuilds it during decoding. I've included the full project and vb.net source code with the executable.

music.wav (44,285,996 bytes) ->             7z -> 38,007,792 bytes
music.wav (44,285,996 bytes) -> WavDelta -> 7z -> 30,788,582 bytes

[Karhunen]

Is this similar to the delta filter for XZ tools ( lzma2 ) ?

[david_werecat]

XZ seems to implement a general delta filter for data, whereas WavDelta is specifically for .wav files. The delta filter in WavDelta is different since it interprets the input data as variable length integers rather than multiple channels of bytes.

I've attached a program which uses a similar method to the XZ delta filter.

CHDelta:4+lzma   31,632,985 bytes
delta:4+lzma     31,632,639 bytes
WavDelta+lzma    30,788,582 bytes

[Skymmer]

A small test on 4 Hero '2004 - The Remix Album - Volume 1. CD1 being converted to one WAV file.
LZMA means lzma:a1:mfbt4:d30:fb64.

Original                 834 722 612
LZMA                     731 934 490
7z f=delta:4 + LZMA      632 536 681
WavDelta + LZMA          624 986 238
MM + LZMA                624 971 152
MM -r1 + LZMA            595 848 603

Bulat's MM is unbeatable here

[Bulat Ziganshin]

btw, it may be used via fazip:

fazip mm:r1 <infile >outfile

or even

fazip mm:r1+lzma <infile >outfile

unfortunately, there is no 64-bit compilation of fazip yet

MM homepage: http://freearc.org/Research.aspx
Discussion: http://encode.su/threads/835

[david_werecat]

Thanks for the benchmark, it seems that MM is a much better preprocessor. Excellent work as always, Bulat .