WavPack VBR (quality oriented) mode Options

[softrunner]

bryant, are you going to implement some quality mode in WavPack? Three years ago you wrote: "I would someday like to add a VBR “quality based” mode to WavPack hybrid (which would counter one advantage of LossyWAV)". Maybe the time for it has come? I do not see, how it is possible to be satisfied with ABR, because for some files 192 kbps is enough, and some needs 400+ kbps. Using 400+ kbps for all files hits file size, while using lower bitrate hits quality.

[shadowking]

I would like this too. I still think you will end up with 350..400k for normal signals but critical signals could get a lot more. Moreover, quality differences between the modes will be eliminated.

ABR is less flexible but not really worse than VBR in the higher bitrates. As you said 400+k would suffice but is wasteful. For lossywav I find that without noise shaping you also need a similar rate and 350k at the very least. I think with these codecs to cannot achieve consistently good quality and make it alternative to the TC: you need double the rate - 300k or more.

Currently I find a setting of -b4 -x5 to be sufficient so far on my collection of 400 cd's. This yields 370k on average.

[darkbyte]

Although i'm testing Opus nowadays for portable use i vote for this. It would be still awesome if the achievements of LossyWAV could be more tightly intergrated with WavPack hybrid for example.

[softrunner]

Currently I find a setting of -b4 -x5 to be sufficient so far on my collection of 400 cd's. This yields 370k on average.

Do you remove .wvc files (permanently)?

This post has been edited by softrunner: Mar 25 2013, 03:22

[bryant]

I still would like to work on this as an enhancement to the lossy mode some day, but the problem is that I really don't know how to go about it. I tried a real psychoacoustic hearing model early on but abandoned it when it didn't work well. I have thought about adding some simple analysis that would tweak up or down the bitrate (maybe based on a tonality estimate) but I'm not sure if that would work well either. I don't have the time to get involved with the level of testing and tweaking that LossyWAV went through, and I don't think I can use the LossyWAV algorithm directly because I would end up with the exact same bitrate.

If anyone else wanted to give this a shot I would be happy to help and bounce ideas around, but at this point I don't have the spare time to put any effort into it myself.

[shadowking]

Currently I find a setting of -b4 -x5 to be sufficient so far on my collection of 400 cd's. This yields 370k on average.

Do you remove .wvc files (permanently)?

I think its not a bad idea to back them up (.WVC) to external HDD or optical media. Use only .WV as your main collection and include them in your backup routine.


To be clear I am usually happy with lame 150..200k as long as you don't use DSP, transcode, have unusual listening habit, have or listen to particular troublesome samples. In that sense lossless offers little to no benefit and ripping straight to Lame -V3 is fine with me. I would however like the ability to transcode to another format, bitrate or even CBR. I would like high quality - some thing a bit more than mp3. At the same time like yourself I consider lossless excessive: 370k vs 870k. The ability to go lossless may also be important and mp3, mpc, acc ,ogg don't make that easy or possible at all.

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[softrunner]

I still would like to work on this as an enhancement to the lossy mode some day, but the problem is that I really don't know how to go about it. I tried a real psychoacoustic hearing model early on but abandoned it when it didn't work well. I have thought about adding some simple analysis that would tweak up or down the bitrate (maybe based on a tonality estimate) but I'm not sure if that would work well either. I don't have the time to get involved with the level of testing and tweaking that LossyWAV went through, and I don't think I can use the LossyWAV algorithm directly because I would end up with the exact same bitrate.

If anyone else wanted to give this a shot I would be happy to help and bounce ideas around, but at this point I don't have the spare time to put any effort into it myself.

It is sad, because if you don't do it, probably nobody will. Some first step is needed, then, at least, some testing will be possible. Currently there is nothing to work with.

I think its not a bad idea to back them up (.WVC) to external HDD or optical media. Use only .WV as your main collection and include them in your backup routine.

This is not my case, I would like to drop it permanently.

[shadowking]

Perhaps making an experimental encoder using simple tonality estimation would be a start. Maybe if it works with the current DNS quality might be better than expected.

[shadowking]

Currently I find a setting of -b4 -x5 to be sufficient so far on my collection of 400 cd's. This yields 370k on average.

Do you remove .wvc files (permanently)?

I would too. But keeping them is not always for quality reasons. It just adds flexibility . One thing is that these days I am against using the -hh or even -h for lossy mode as I find a normal mode + -x to work better without altering decoding speed. I still have old encodes with -hh and cannot reverse it.

I find it easy to move the correction files to a zip archive dump that file offline.

I don't think one has to distrust ABR. Its true that a proper tuned VBR is ideal, but the current system is also safe even for high demand using -b350x5 . The -x and -dns are doing constant analysis to prevent quality from falling too much. So there is a very basic 'psymodel' in place.