HydrogenAudio

Lossless Audio Compression => WavPack => Topic started by: cd-rw.org on 2002-01-03 08:41:43

Title: WavPack lossy modes?
Post by: cd-rw.org on 2002-01-03 08:41:43
Anyone tried listening the lossy modes of WavPack? The author has implemented Monkey's original idea of a lossy+recovery file=lossless compression..

The lossy modes can deliver mp3-like bitrates.

www.wavpack.com (http://www.wavpack.com)
Title: WavPack lossy modes?
Post by: sven_Bent on 2002-01-03 08:53:21
look like a nice way of doing it

I' tried something similier with pictures

i use wavelets for the lossy compression. did a XOR of the original and lossy pictures.

use som lossles compression on the XOR image

But nomatter how much i tried with different ratios between the bits for the to "images" (80% lossy 20%lossles... 50/50 etc) nothing ever come below just using my lossles compresion on the entire file in the first place...

So i let the project to rest. :-(

btw Wavelets ROCKS for pictures..

trit it at www.luratech.com (http://www.luratech.com)

mcuh better quality then any jpeg kan give you
Title: WavPack lossy modes?
Post by: petracci on 2002-01-03 10:10:31
That's why all jpeg200 proposals had wavelets incorporated
Title: WavPack lossy modes?
Post by: sven_Bent on 2002-01-03 19:17:39
now when we have variable keyframes i have a theory that usign wavelets in keyframes would help increase quality as keyframes woudle be of higher qualtiy an alpha frames have and higher quality keyframe to relly on...
just my theory..if a had the brains to be a programmer. i woudle try it... but just not made of that stuff
Title: WavPack lossy modes?
Post by: bryant on 2002-01-03 20:22:44
The new beta version of WavPack with the greatly improved lossy mode and the "recovery" file option is not available on the WavPack website yet, but is here:

http://wavpack.com/wp393b.zip (http://wavpack.com/wp393b.zip)
Title: WavPack lossy modes?
Post by: tangent on 2002-01-03 20:43:33
Quote
Originally posted by sven_Bent
now when we have variable keyframes i have a theory that usign wavelets in keyframes would help increase quality as keyframes woudle be of higher qualtiy an alpha frames have and higher quality keyframe to relly on...
just my theory..if a had the brains to be a programmer. i woudle try it... but just not made of that stuff


You know what's better? 3D wavelets (the time domain is the 3rd dimension). Ogg Tarkin is currently in development doing that.
Title: WavPack lossy modes?
Post by: jordanp on 2002-01-04 02:14:46
Bryant, just wanted to thank you for you excellant program.  Solves a problem I've been mulling over for some time.  I like to keep my music on my computer so I can listen to it whenever I want, but I want to use lossless so I can burn cd's with my music should I need to.  Your software allows me to keep the lossy files on my hard drive so I can listen to them and I can burn the recovery files to cd-r should I need them again.  Thanks again for the great program.

Jordan
Title: WavPack lossy modes?
Post by: bryant on 2002-01-05 23:16:16
Jordan, I really appreciate the feedback. Thanks.

I also saw your post on Monkey's board and I'll e-mail Matt and offer him any help I can if he would like to put that support in.
Title: WavPack lossy modes?
Post by: layer3maniac on 2002-01-05 23:29:42
Unfortunately, I think Matt has pretty much given up on lossy. But this looks great! BTW, the sfx was also an awesome idea. Kudos! Hmmm, I think I see a GUI like... WavPackDrop on the horizon.
Title: WavPack lossy modes?
Post by: Dologan on 2002-01-08 03:43:31
I tested WavPack lossy modes with Ivan's hard.wav and was a bit disappointed. I could abx 16/16 the 448 kbps mode and even got a 13/16 with 512. I would describe the problem as some overbrightness, which is not really annoying, but definitely not transparent.
On the other hand, I am completely astonished with MPCs performance. Even with the -radio setting I could not tell the difference. It even outperforms lame with the standard preset, which I could abx without any problems.
Originally I thought this 'hybrid' mode was a great idea for archival (keep the lossy and burn the restore), but after this I am not so willing to spend my precious and scarce disk space on 384 kbps files which don't even sound as good as MPC -radio or AAC -normal.
I hope the quality would be improved for the non-beta 3.93 version, as the idea is still very good.

Regards,
~Dologan
Title: WavPack lossy modes?
Post by: bryant on 2002-01-08 19:01:46
Yeah, thanks, hard.wav is a killer for joint-stereo! I turned off joint-stereo and now 320 kbps is almost as good as 512 kbps was with joint-stereo on. I'll put up a new beta with an option to turn off joint-stereo (it's already supported in the format, there's just no switch for it).

I found another difficult file that is actually from a real CD. It's from the Fast and Furious (copy-protected) soundtrack and I posted a clip here:

ftp://syv.com/david/furious.wv (http://ftp://syv.com/david/furious.wv)

The second electronic noise bleep has many HF spikes that introduce audible noise below 448 kbps. Turning off joint-stereo doesn't help this one (it hurts, in fact) but I have an improved (but slower) decorrelator that does help significantly. I am trying to get this in as a "-h" option in the near future.

However, I still believe that for the vast majority of real music the compressor is transparent at 320 kbps. The intent is to provide lossless compression with a free bonus of a high-quality playable file of reasonable size. There's no way that WavPack's lossy mode can compete with perceptual codecs at low bitrates (except maybe on those test samples that sub-band coding has trouble with).

Thanks again for the input.
Title: WavPack lossy modes?
Post by: Dologan on 2002-01-09 01:04:40
I am glad if I was of any help.
Indeed WavPack's lossy modes are not expected to compare favorably with more complex and tuned formats like mpc, mp3, ogg and aac. I've now tried the 320 kbps mode with some real music (classical mostly) and found it to be quite transparent to me.
I tried the clip furious.wv that you provided and it's exactly as you described. 512 kbps is too transparent for my hearing and 448 is barely perceptible.
In any case, I want to congratulate you for your excellent program and thank  you for your effort on this fine piece of free software.

~Dologan