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SubjectRe: SB and 2.1.126 [NOT THE COMPILE PROBLEM]
Mike wrote:
>
> Having gently persuaded 2.1.126 to compile by applying:
>

>
> it all seemed fine. But sound is broken in quake (although everything
> else seems to be happy). With quake, I just get white noise. Any ideas?
>
Yes I know why.

I have written the patch to have sb16 run full duplex but
this means programming both the 8 and the 16 bit dma
channels simultaneously.

Consequences:
if we record at 16 bit we must do playback at 8 bit
and viceversa.

Format conversions are handled transparently, so
the process using the device should not worry.

For write_only or read_only processes, they can
either allocate 16 or 8 bit.

This should be the quake case but quake is opening the
device in read_write mode, so it gets 16 bit input
and 8 bit playback. I said transparent !!! This is so
unless you use the mmap technique ( quake uses it ), which
implies that no software conversion can happen.

Hence these two possibilities exist:
1. We patch quake to have it open /dev/dsp read_only
( any volunteer ?? )

2. We all wait until Alan shows up ( anyone knows where
is Alan ? ) and he decides whether he accepts the solution
I have proposed to have full duplex keep working and
quake too.

( The solution is to have the card be full duplex unless
you start by writing data to the device * quake *. This
means that for full duplex use you must always read first
from the device. The SETTRIGER ioctl always tries to
activate recording first if instructed to start both
recording and playback so the approach should work fine )

Hope this makes the quake problem clear

Cheers


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