lossyWAV 1.0.0 released., Added noise WAV bit reduction method. Options

[Nick.C]

lossyWAV 1.0.0b released:

CODE

lossyWAV 1.0.0b, Copyright © 2007,2008 Nick Currie. Copyleft.

This program is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful,but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program.  If not, see <http://www.gnu.org/licenses/>.

Usage   : lossyWAV <input wav file> <options>

Example : lossyWAV musicfile.wav

Quality Options:

-q, --quality <n>   quality preset (10=highest quality, 0=lowest bitrate;
                    -q 5 is generally accepted to be transparent)
                    default=-q 5.

Standard Options:

-c, --check         check if WAV file has already been processed; default=off.
                    errorlevel=16 if already processed, 0 if not.
-C, --correction    write correction file for processed WAV file; default=off.
-f, --force         forcibly over-write output file if it exists; default=off.
-h, --help          display help.
-L, --longhelp      display extended help.
-M, --merge         merge existing lossy.wav and lwcdf.wav files.
-N, --noclips       set allowable number of clips / channel / codec block to 0;
                    default=3,3,3,3,2,1,0,0,0,0,0 (-q 0 to -q 10)
-o, --outdir <dir>  destination directory for the output file(s).
-v, --version       display the lossyWAV version number.

Special thanks:

David Robinson for the method itself and motivation to implement it.
Don Cross for the Complex-FFT algorithm used.
Horst Albrecht for valuable tuning input and feedback.

Explanation, history and lossless codec settings in the wiki article

[edit] 1.0.0b necessitated by unknown WAV chunk handling error and 24-bit --correction / --merge parameter error.

Link to GNU GPLv3+ source code for lossyWAV 1.0.0b [/edit]

N.B.: lossyWAV 1.1.0b released here.


This post has been edited by Nick.C: Mar 20 2009, 23:18

Attached File(s)

 lossyWAV_1.0.0b.zip ( 64.18K ) Number of downloads: 1895

 

[beto]

I have not followed the development of lossyWAV closely. In my understanding it is a kind of pre-processor that takes out some information from the audio file that is unlikely to be heard anyway. After that you can use your favorite lossless encoder to encode the pre-processed WAV and reach better compression.

How does this compare to Wavpack lossy and Optimfrog Dualstream qualitywise? Is it on pair with those or is it superior/inferior? It is my understanding that lossyWAV uses the same concept as Wavpack or Dualstream (correct me if I am wrong).

[Nick.C]

I have not followed the development of lossyWAV closely. In my understanding it is a kind of pre-processor that takes out some information from the audio file that is unlikely to be heard anyway. After that you can use your favorite lossless encoder to encode the pre-processed WAV and reach better compression.

How does this compare to Wavpack lossy and Optimfrog Dualstream qualitywise? Is it on pair with those or is it superior/inferior? It is my understanding that lossyWAV uses the same concept as Wavpack or Dualstream (correct me if I am wrong).

lossyWAV rounds lower significant bits to zero. This adds white noise to the audio. The level of the added noise has been pre-calculated for each bit removed. The number of bits to remove is determined by processing the results of overlapping FFT analyses of at least 2 different lengths (64 samples and 1024 samples by default). The quality settings take the processed FFT results and make the processor remove more or less bits dependent on internal settings. --quality 5 is generally accepted to be transparent. It should be stated clearly now that lossyWAV is pure variable bitrate: different audio will result in a different lossless encoded bitrate for the same --quality setting (in a similar way that the lossless audio files encoded losslessly may have different bitrates).

I cannot comment on comparison with Wavpack and Optimfrog as to my knowledge no direct comparison has been carried out.

[beto]

...
--quality 5 is generally accepted to be transparent. It should be stated clearly now that lossyWAV is pure variable bitrate: different audio will result in a different lossless encoded bitrate for the same --quality setting (in a similar way that the lossless audio files encoded losslessly may have different bitrates).

I cannot comment on comparison with Wavpack and Optimfrog as to my knowledge no direct comparison has been carried out.

You cannot comment on Wavpack and Optimfrog, yet you claim that --quality 5 of your pre-processor is 'generally accepted to be transparent'. May I ask if any comparison was made to support that claim?

I mean no offense to you or anyone, I am just curious.