[flac-dev] FLAC compression experiment

z1x2c3v4z1x2c3v4 z1x2c3v4z1x2c3v4 at hotmail.com
Sat Aug 19 21:37:29 UTC 2017

Hi FLAC team.

I feel I have found a super high compression way of FLAC. I have tested a 1 hour WAV file of 440HTZ with a 5,25,50,75,100 normalize volume preset. This dramatically changes the compression size of the end FLAC file even though the WAV file size is identical for all 5 WAV files. Only the volume is different. When you renormalize the WAV to its original volume the file is still 100% original.

My tests are the following.

source file WAV. 1 hour 440HTZ tone. 600MB.

volume at 100. FLAC file size is  184MB.

volume at 75. FLAC file size is  166MB.

volume at 50. FLAC file size is  143MB.

volume at 25. FLAC file size is  109MB.

volume at 5. FLAC file size is  96MB.

From184MB to 96MB.

As you can see from the full 100 normalize volume to the 5 normalize volume it is half the file size.

So to put it. I think that you should have your compression of FLAC to also include a normalize volume shift to further compress the end product. Either have a default setting or allow a user to input an option in the command line arguments to add a normalize volume value. Then to uncompress it back to a WAV file FLAC would read the volume header in the FLAC file to apply the WAV original normalize volume and expand it back to its original state.

Then have the FLAC decoder for all the players out there to read the volume header so to play the FLAC at the WAV original normalize volume.

I hope I have helped to develop FLAC further.
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