lossyWAV Development
Reply #777 – 2008-01-13 01:48:10
... Your samples 00000_00595ms, 09400_10400ms, 19800_21000ms, 21600_23100ms ... Finally I found the time to abx your samples (I had a lot of trouble trying to bring my system to an uptodate state - now I'm back to my old configuration). With your 00000_00595 samples I got at a 6/7 which in the end was 7/10. With 19800_21000 I also have the suspicion that something's wrong but could not abx it. With 21600_23100 I got at 6/8 and ended up 6/10. Though these aren't good results I think it's enough for a confirmation. I tried 0.6.6 on your samples. The results are better, but with 00000_00595 I got at 7/9 and ended up 7/10. So the problem is still there. I went back to 0.6.4RC1 and used a setting of -3 -nts 0. Now I can't abx the problem any more. So this is evidence that 2Bdecided is right and it's just a -nts problem. As for this I suggest we default -3 to -nts 0, -2 to -nts 2 and -1 to -nts 4, and keep -spf the way it was done with 0.6.4RC1 (IMO the high frequency range is covered already well by the short FFT with its low spreading value). I still feel uncomfortable with abrupt noise level changes, but maybe this is a wrong idea. At least it's not backed up by this sample. Average bitrage will increase again - something which isn't liked especially with -3. In the wiki there's encouragement already to use a higher -nts value than default for people who prefer a smaller filesize and accept minor errors. Maybe we should find a formulation which enforces this encouragement. [Vino Rosso]Meh - oh well, just back from my company's Christmas party to a variation order for lossyWAV - no problem..... On the plus side, if v0.6.4 RC1 with -3 -nts 0 solves the problem then we will all benefit from the 50% speedup found when I started investigating Alex B's problem and potential solutions. Not the end of the world then - just a few kbps extra..... On the face of it, maybe -nts 0 is the only acceptable starting point for the lowest quality option - so -nts -2 for -2 and -nts -4 for -1? Ouch - 462kbps for my 53 sample set (40.98MB). But, we want transparency at all quality presents - so be it.[/Vino Rosso]