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    SubjectRe: Number of sound channels?
    Thomas Sailer wrote:
    > Alan Cox wrote:
    > >
    > > > The Via audio chip has a single read channel and a single write
    > > > channel. Do I treat this as a single channel with read and write
    > > > capability, or two separate channels?
    > >
    > > Single full duplex I think
    > Mostly I do it both ways - if /dev/dsp is opened O_RDONLY (or O_WRONLY),
    > another process is allowed to open it O_WRONLY (or O_RDONLY). If it
    > opens O_RDWR, noone else is allowed.

    This is how I implemented via_dsp_open as well.

    Is this why USB's audio device handling of SNDCTL_DSP_SETDUPLEX is null?

    return 0;

    > This is sometimes useful, Sun does it also that way (but it only
    > works if you can set the sampling rate independently for both
    > directions).

    Or you have cheap hardware with a fixed sample rate which is the same
    for both channels. :) AC97 1.0-compliancy requires at least that.

    Jeff Garzik | Just once, I wish we would encounter
    Building 1024 | an alien menace that wasn't immune to
    MandrakeSoft, Inc. | bullets. -- The Brigadier, "Dr. Who"

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