Comparison : 24bit/192KHz/stereo FLAC vs. APE, How can it be ? Options

[foorious]

Hi everybody,

I've just made a small comparison between Monkey's Audio 3.99 (Extra High Compression) and FLAC 1.21 (Compression level 8 ), using 24bit/192KHz/stereo files (the files were generated from a vinyl rip).

Of course I expected APE to perform slightly better than FLAC, like it usually does for 16bit/44KHz/stereo files (2-3%, maybe even 5%)... but I didn't really expect this !



Take a look at all the file sizes : we're talking about 20% difference here ! The total file size is 1,53 Go for APE vs. 1,88 Go for FLAC.

So I don't understand. I'm a genuine FLAC enthusiast (all my files are FLAC), but... how can it be ? Is there something wrong here ? Can we do something to improve all the FLAC file sizes ?

Thanks in advance for your explanation.

[foorious]

Thanks everyone for all your interesting answers.

Well, so it looks that FLAC isn't really well-suited at the moment for low-passed files, thus for 96 and 192 KHz files. Considering the results, I think it will be better for me to stick with FLAC for 16/44 files, but to switch to another format for 24/96 and 24/192 files. I don't like the idea of handling two different lossless formats in my collection, but the gap is huge, and I don't see any reason for losing almost 350 MB of disk space for a single album.

I secretly hope Josh Coalson has some ideas in store for improving FLAC's handling of HD audio files. We'll see !

Oh, one last question : in your opinion, is this issue related only to the frequency (96, 192 KHz) or also to the bits per sample ? In other words, would FLAC perform much better with 24bit/48KHz files than it does with 24bit/192KHz files ?

This post has been edited by foorious: Jul 27 2008, 16:41

[Dynamic]

Oh, one last question : in your opinion, is this issue related only to the frequency (96, 192 KHz) or also to the bits per sample ? In other words, would FLAC perform much better with 24bit/48KHz files than it does with 24bit/192KHz files ?

In conjunction with NickC's results, perhaps resampling (fb2k/Resampler) to 44.1 kHz and/or 48 kHz in the Convert DSP while retaining 24-bit output would answer that, and offer comparison between 16/44.1 and 24/44.1 when processed through lossyWAV (though it isn't certain the 16/44.1 is the same as a straight downconversion from the 24/96 files)

[Nick.C]

In conjunction with NickC's results, perhaps resampling (fb2k/Resampler) to 44.1 kHz and/or 48 kHz in the Convert DSP while retaining 24-bit output would answer that, and offer comparison between 16/44.1 and 24/44.1 when processed through lossyWAV (though it isn't certain the 16/44.1 is the same as a straight downconversion from the 24/96 files)

Taking onboard your comment regarding whether the 16/44.1 is a straight downconversion of the 24/96, I used the SSRC dsp plugin (ultra mode) in foobar2000 to resample the 24/96 version down to 48kHz and 44.1kHz and got the following:

24/96 lossless FLAC -5: 2954 kbit/s (926MiB); lossyWAV --standard|FLAC -5: 787 kbit/s (246MiB);
24/48 lossless FLAC -5: 1598 kbit/s (501MiB); lossyWAV --standard|FLAC -5: 517 kbit/s (162MiB);
24/44.1 lossless FLAC -5: 1489 kbit/s (466MiB); lossyWAV --standard|FLAC -5: 498 kbit/s (156MiB);

Also, I changed the bitdepth in foobar2000 and dithered the 24/96 version to 16/96 and got:

16/96 lossless FLAC -5: 1421 kbit/s (445MiB); lossyWAV --standard|FLAC -5: 776 kbit/s (243MiB);

This post has been edited by Nick.C: Jul 27 2008, 20:40

[GeSomeone]

24/44.1 lossless FLAC -5: 1489 kbit/s (466MiB); lossyWAV --standard|FLAC -5: 498 kbit/s (156MiB);

16/96 lossless FLAC -5: 1421 kbit/s (445MiB); lossyWAV --standard|FLAC -5: 776 kbit/s (243MiB);

Seems to me that FLAC has a "weakness" with compressing 24bit files (though I never have bothered with 192kHz). If you're looking for another codec (besides the mentioned Monkey or TAK), wavPack does better with 24bit files than FLAC too.

This post has been edited by GeSomeone: Aug 11 2008, 22:15

[TBeck]

If you're looking for another codec (besides the mentioned Monkey or TAK), wavPack does better with 24bit files then FLAC too.

Well, i have added the result for WavPack -hhx3 to my comparison above. It too seems to be less efficient with 192 KHz/ 24 Bit, only slightly better than FLAC. At least with my sample set.

This post has been edited by TBeck: Jul 28 2008, 18:04

[bryant]

If you're looking for another codec (besides the mentioned Monkey or TAK), wavPack does better with 24bit files then FLAC too.

Well, i have added the result for WavPack -hhx3 to my comparison above. It too seems to be less efficient with 192 KHz/ 24 Bit, only slightly better than FLAC. At least with my sample set.

Thanks for trying out WavPack! Since we're talking about non-standard files here, I think that -hhx4 (or higher) would be a much better choice (even though it's much slower). The -x values from 1-3 use pre-calculated filters while values from 4-6 generate custom filters.