I think "Developers" can upload files anywhere. "Members" can only upload in the uploads forum. I guess you can PM a moderator to become a "Developer".
Of course you can discuss your pre-processor here, though if we're both going to get people to ABX, it might get a bit confusing. I guess it depends if you expect them to merge, or not.I am not an open source zealot, but for a useful discussion, you'll have to share pretty much exactly what it's doing - otherwise there's little hope of finding relevant problem samples without doing an exhaustive test.
... Can you try these:http://220.127.116.11/technical/reference/keys_1644ds.wav...
Wow! They're killer samples for this algorithm, and FLAC itself. I think they're still transparent (can you try ABX please?) but look at the bitrates (all FLAC)...keys_1644ds:lossless: 1078kbps (ratio=0.764)lossy: 829kbps (ratio=0.587)....
Quote from: shadowking on 18 June, 2007, 05:32:27 AM... Can you try these:http://18.104.22.168/technical/reference/keys_1644ds.wav...Just tried keys with wavPack lossy @ 350 kbps fast mode: terrible. triangle-2 from that page is very ugly too.I was afraid after having heard furious that there may be real life sound that makes look wavPack lossy pretty bad. Setting for my DAP (see signature) btw is excellent in comparison to plain wavPack usage - 32 kHz sampling frequency and s0.4 is a bit of an anti-killer setting. I did a lot of listening tests with it this weekend and I'm very content.Anyway this shows that a good quality control would be very much welcome for wavPack lossy. Usually a pretty moderate bitrate yields excellent results, but it's not always the case. Maybe this thread encourages David Bryant to go along this way.
... These cases will never happen on CD though. ...
I agree with halb27. A humongous lossy file in those cases is actually what a good VBR is supposed to do, to maintain the sound quality.In any case, here's a sample I'd like you to try, 2Bdecided.Very "Easy" SampleThis is a typical example of the kind of obnoxious music that I think compresses best with things such as WavPack lossy. It requires 1200+ kbps to be mathematically lossless, but even at 200 kbps and below it still sounds transparent to me. Maybe shadowking or others can try to ABX it at WavPack/Optimfrog lowest quality settings, I think it's transparent.The reason to test this sample would be to test how dynamic the range of 2Bdecided's VBR algorithm is. Will it choose a very low bitrate, and if it does will it still be transparent? By the way, this sample isn't clipped I made sure. Upon extraction, EAC reported the song's normalization as 98.8% amplitude.
I plan to install foobar2k next weekend and I can try to ABX some of the samples, sorry I didn't have enough time this past weekend. I figure I need to dedicate about a day to play with foobar first, and another day to do actual listening tests. But just to let people know, never from the start did I consider myself to have terrific hearing. I think I probably only have fairly good hearing, and it isn't as good as it used to be either, I'm in my late 20's. And even when I was in my teens, I think I had perfect undamaged hearing but when my friends and I did "single" blind-tests back in the early days of mp3, one of my friends easily defeated me in being able to differentiate certain things.
...This means, despite the original sample not clipping, the resulting file often clips. ...
To my untrained ear, 342kbps sounds *very* nice indeed - using fb2k & earbuds on my laptop - not a semi-pro ABX, just comparable to how I would actually listen to it.However, I can't play it on my iPAQ because GSPFlac.dll does not seem to handle this type of FLAC . Converted to WAV and GSPlayer still fails - hmmmmm....... something's wrong with my hardware. Nope, nothing wrong with hardware - just a 16bit limitation - it falls over with >16bit samples. Played all the other comparator samples in 69/79 and was pleased not to notice any degradation (caveat: on earbuds on an iPAQ). Very pleased.
Truncating can be bad.
I zero by rounding, not truncation.Maybe I'll try truncation instead.The problem is that it will introduce a DC bias which will accumulate if you go through many generations of processing. However, it should solve the clipping problem.Cheers,David.
I am only curious. How does the MATLAB rounding-function work? Round to even?
...This is the one that's 6dB quieter, and doesn't clip
342kbpsThis is a lossless 6dB quieter file for ABX comparison with the above
1269kbps...Given the aggressive processing this has received by lossy FLAC, I would really appreciate it if people could try to ABX.