On Tue, Apr 21, 2015 at 12:50 PM, Andreas Cadhalpun <[email protected]> wrote: > On 21.04.2015 02:20, Claudio Freire wrote: >> On Mon, Apr 20, 2015 at 9:13 PM, Michael Niedermayer <[email protected]> >> wrote: >>> On Mon, Apr 20, 2015 at 09:07:14PM -0300, Claudio Freire wrote: >>>> On Mon, Apr 20, 2015 at 8:59 PM, Claudio Freire <[email protected]> >>>> wrote: >>>>> On Mon, Apr 20, 2015 at 8:32 PM, Andreas Cadhalpun >>>>> <[email protected]> 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. >>>> >>>> >>>> This is what I did if you want to check it out (maybe you spot the mistake) >>>> >>>> gnuplot> ath(f,a) = _ath(f/1000.0, a) >>>> gnuplot> _ath(f,a) = 3.64 * f**(-0.8) - 6.8 * exp(-0.6 * (f-3.4) * >>>> (f-3.4)) + 6.0 * exp(-0.15 * (f-8.7) * (f-8.7)) + (0.6 + 0.04 * a) * >>>> 0.001 * f * f * f >>> ^^^^^^^^^^ >>> missing * f >> >> Much better now :) >> >> So yes. I'd say it's a good change. > > OK, patch attached. > > Best regards, > Andreas
Is this patch still needed? -- Vittorio _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
