Re: full duplex sound card dirve

On Sun, 11 Jul 2004 18:25:03 +0100
Bruce M Simpson <bms_at_spc.org> wrote:

> On Sat, Jul 10, 2004 at 11:01:05AM -0400, Richard Neese wrote:
> > is anyone working on full   duplex drivered for fbsd and soundcards. half the 
> > apps I use say the sound is only half duplex.  like kphone wich  we   are 
> > porting and    cpphone   and a few other     including asterisk0 pbx  look at 
> > te sound card and report it as half duplex. 
> 
> The vast majority of the drivers we ship are full duplex, but it's possible
> that the applications concerned might not be getting this information. Many
> recent commits have happened in this area, particularly with regard to
> Linux emulation.

I've committed the SNDCTL_DSP_SETDUPLEX ioctl (including the linux
emulation parts). This ioctl failed before, even if the soundcard was
already in full duplex mode. A workaround for all releases upto and
including 5.2.1 is to check with the SNDCTL_DSP_GETCAPS if the card
already is in full duplex mode. Here's a snippet of code how to test it:
---snip---
    retval = ioctl(fd, SNDCTL_DSP_GETCAPS, &val);
    if (-1 == retval) {
        perror("GETCAPS");
        exit(1);
    }

    printf("duplex: ");
    if (FALSE == DSP_CAP_DUPLEX & val) {
        printf("not ");
    }
    puts("supported");
---snip---

In FreeBSd all of the soundcards with full duplex capability will be
already in full duplex mode when the dsp device gets opened.

Bye,
Alexander.

-- 
           I'm available to get hired (preferred in .lu).

http://www.Leidinger.net                       Alexander _at_ Leidinger.net
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