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    SubjectRe: Mac mini sound woes
    On Mon, 2005-03-28 at 22:36 -0500, Lee Revell wrote:
    > On Mon, 2005-03-28 at 09:42 +1000, Benjamin Herrenschmidt wrote:
    > > It seems that Apple's driver has an in-kernel framework for doing volume
    > > control, mixing, and other horrors right in the kernel, in temporary
    > > buffers, just before they get DMA'ed (gack !)
    > >
    > > I want to avoid something like that. How "friendly" would Alsa be to
    > > drivers that don't have any HW volume control capability ? Does typical
    > > userland libraries provide software processing volume control ? Do you
    > > suggest I just don't do any control ? Or should I implement a double
    > > buffer scheme with software gain as well in the kernel driver ?
    > alsa-lib handles both mixing (dmix plugin) and volume control (softvol
    > plugin) in software for codecs like this that don't do it in hardware.
    > Since Windows does mixing and volume control in the kernel (ugh) it's
    > increasingly common to find devices that cannot do these. You don't
    > need to handle it in the driver at all.

    Yah, OS X does it in the kernel too lately ... at least Apple drivers
    are doing it, it's not a "common" lib. They also split treble/bass that
    way when you have an iSub plugged on USB and using the machine internal
    speakers for treble.

    > dmix has been around for a while but softvol plugin is very new, you
    > will need ALSA CVS or the upcoming 1.0.9 release.



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