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]

Just a simple question : do TAK, APE and Optimfrog support multichannel ?
I'm asking this because otherwise they would be quite useless for most 24/192 files : the files for my initial example were stereo, but most 24bit files are also multichannel AFAIK (e.g. DVD-A)...

This reference wiki article says TAK, APE and Optimfrog do not support multichannel (maybe it needs to be updated ?), which would make WavPack the only serious alternative to FLAC for multichannel files : http://wiki.hydrogenaudio.org/index.php?ti...less_comparison

BTW I'd really love if Josh Coalson would come across this thread. Hey, if TBeck has been able to fine-tune TAK and gain 10% in only a few hours time, maybe Josh could do something similar with FLAC ?

EDIT : PM sent to Josh to inform him about this topic.

This post has been edited by foorious: Jul 31 2008, 17:55

[GeSomeone]

I'm asking this because otherwise they would be quite useless for most 24/192 files : the files for my initial example were stereo, but most 24bit files are also multichannel AFAIK (e.g. DVD-A)...

I'd like to make a correction here. On DVD-Audio only stereo tracks (groups) can be 24bit/192kHz, the max for multi channel is 24bit/96kHz but 24/48 is not uncommon.
The 192kHz sample rate is rather rare (on DVD-A) because it takes up a lot of space and often the (digital) sources were in a lower bit rate.

@TBeck, Bryant or whoelse needs 1 or 2 (classical) 192kHz files for a test, have a look on the Lyndberg Lyd (2L) HiRes Download - test bench page.

[TBeck]

@TBeck, Bryant or whoelse needs 1 or 2 (classical) 192kHz files for a test, have a look on the Lyndberg Lyd (2L) HiRes Download - test bench page.

Thank you!

Especially the multi channel files will be useful for me.

Unfortunately the 192 KHz files are bad examples... I've performed a frequency analysis with cooledit and it looks quite strange: Above about 48 KHz there seems to be a lot of noise. Possibly this is due to the noise shaping mentioned at the bottom of the download page: "DSD signals further require a noise shaping process to sustain the dynamic range of 120 dB within the primary bandwidth of 20 Hz - 20 kHz but that causes the noise spectrum to increase above 22 kHz." But i am not an expert in this area.

I am sure those files will be very FLAC-friendly: Because of the high pitched noise they will not show it's inefficiency when dealing with low passed alike files.

[TBeck]

I am sure those files will be very FLAC-friendly: Because of the high pitched noise they will not show it's inefficiency when dealing with low passed alike files.

I've got time to test it:

CODE

FLAC 1.2.1
  -8               54.65
  
Monkey's Audio 3.99
  Extra            53.34
  
TAK 2.0 (Developer version)
  -p3m             53.51

Exactly what i expected.

But what are such 192 KHz files good for? Twice the space requirements than 96 KHz recordings only to add noise above 48 KHz?

[GeSomeone]

But what are such 192 KHz files good for? Twice the space requirements than 96 KHz recordings only to add noise above 48 KHz?

I forgot that L2 likes to record in (what they call) DXD, which is like DSD but twice the sample four times the data rate of DSD.
As I said I didn't bother with the 192kHz but the 96kHz 5.1 at least sounded pretty good.

BTW could there be a -A function that could improve compression of 192kHz files?

This post has been edited by GeSomeone: Aug 19 2008, 13:30

[TBeck]

But what are such 192 KHz files good for? Twice the space requirements than 96 KHz recordings only to add noise above 48 KHz?

I forgot that L2 likes to record in (what they call) DXD, which is like DSD but twice the sample rate.
As I said I didn't bother with the 192kHz but the 96kHz 5.1 at least sounded pretty good.

Thanks for the info!

The 96 KHz files don't show any abnormalities in my evaluations.