Messages in this thread | | | Date | Thu, 19 Oct 2000 17:24:51 -0400 | From | Jeff Garzik <> | Subject | Re: RFC: big ac97_codec audio update |
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Rui Sousa wrote: > On Thu, 19 Oct 2000, Jeff Garzik wrote: > > We need the dynamic bit resolution detection.
> Isn't this producing noise/pops? (since you maximize the volume).
During audio init I hear pops, but then again I heard pops during audio init before these changes too :)
> > Judging from comments already received, it looks like we need to do > > logarithmic instead of linear scaling for the OSS mixer values (0 - > > 100).
> ? The scale (AC97 and OSS) is linear in dB units which is,I believe, how > we perceive sound.
With maestro, trident, and via at least, the volume has to be at 80% or so before any sound can be heard.
> Could you include this macro (it gives you perfect accuracy and > prevents mistakes): > > /* scales the range a:b to min:max rounding to the nearest integer */ > #define scale_range(val, a, b, min, max) \ > ((((val) - a) * ((max) - (min)) + (min) * (b - a)) * > 1000 + (b - a) * 500) / (1000 * (b - a))
> I will provide a patch if you agree.
Please do...
> Everything else looks ok but I still need to test it.
Thanks!
Jeff
-- Jeff Garzik | The difference between laziness and Building 1024 | prioritization is the end result. MandrakeSoft | - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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