On Mon, Apr 20, 2015 at 8:32 PM, Andreas Cadhalpun <andreas.cadhal...@googlemail.com> wrote: >>>> The long version: >>>> >>>> ath should approximate the shape of the absolute hearing threshold, so >>>> yes, it's best if it really uses the minimum, since that will prevent >>>> clipping of the ath curve and result in a more accurate threshold >>>> computation. >>> >>> So you agree with my patch fixing minath? >>> Or would you prefer a version with: >>> minath = ath(3410 - 0.733 * ATH_ADD, ATH_ADD) >> >> Well, that's not really closer to the minimum (a few tests with gnuplot say). > > Are you sure your plots were done correctly? > Because I'm quite sure this is the correct first order approximation > of the minimum. > > For ATH_ADD = 4 this gives 3407.068, which is quite close to Michael's value > (3407.080774800152).
I checked the formula several times, but still, I could have made a mistake. > >> But yeah, something that makes it closer, sure. >> >> I'd try to symbollicaly deriving the minimum if you really mean to >> improve that (should be doable, it's all differentiable stuff). > > I actually derived the dependency of the minimum on ATH_ADD in first > order around ATH_ADD = 0 (using sagemath). ATH_ADD is defined as 4, that may make a significant difference (changes a high-order term). _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
