Linux Sound subsystem development
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* SNDCTL_DSP_BUSY
@ 1999-10-22 21:22 Jirka Hanika
  1999-10-22 23:17 ` SNDCTL_DSP_BUSY Paco
  1999-10-25 10:07 ` SNDCTL_DSP_BUSY Thomas Sailer
  0 siblings, 2 replies; 3+ messages in thread
From: Jirka Hanika @ 1999-10-22 21:22 UTC (permalink / raw)
  To: linux-sound

Hi,

a programming question.

I need an ioctl or some other API to find out whether the sound card 
has completely processed the buffers.  Something exactly like 
ioctl(SNDCTL_DSP_SYNC), but an asynchronous breed.
I have looked at audio.c and there is no such ioctl.

The only solution known to me is to write the neutral sample (silence)
asynchronously to the sound card until a bufferfarmfull bytes is 
written, then ioctl(SNDCTL_DSP_RESET).  This is however ugly as 
12-bit FAT.

In case there is no better approach available, what would you think of a 
new ioctl (say SNDCTL_DSP_BUSY)?

Jirka

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: SNDCTL_DSP_BUSY
  1999-10-22 21:22 SNDCTL_DSP_BUSY Jirka Hanika
@ 1999-10-22 23:17 ` Paco
  1999-10-25 10:07 ` SNDCTL_DSP_BUSY Thomas Sailer
  1 sibling, 0 replies; 3+ messages in thread
From: Paco @ 1999-10-22 23:17 UTC (permalink / raw)
  To: linux-sound

On Fri, 22 Oct 1999, Jirka Hanika wrote:

> Hi,
> 
> a programming question.
> 
> I need an ioctl or some other API to find out whether the sound card 
> has completely processed the buffers.  Something exactly like 
> ioctl(SNDCTL_DSP_SYNC), but an asynchronous breed.
> I have looked at audio.c and there is no such ioctl.
> 
> The only solution known to me is to write the neutral sample (silence)
> asynchronously to the sound card until a bufferfarmfull bytes is 
> written, then ioctl(SNDCTL_DSP_RESET).  This is however ugly as 
> 12-bit FAT.
> 
> In case there is no better approach available, what would you think of a 
> new ioctl (say SNDCTL_DSP_BUSY)?
> 
> Jirka
> 


Hi, Jirka...

I'm slightly confused about what exactly it is that you want, but if you
simply want to wait for the soundcard to finish with the buffers before
your program progresses to the next stage, you can use a SNDCTL_DSP_POST.

Normally, the cards wait until the buffer is full before playing that
audio, but this will force the soundcard to play any data in the buffer,
even if the buffer is only partially filled.

Sorry if this is not the answer you are looking for, but I really wasn't
sure what the question was.

-Paco

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: SNDCTL_DSP_BUSY
  1999-10-22 21:22 SNDCTL_DSP_BUSY Jirka Hanika
  1999-10-22 23:17 ` SNDCTL_DSP_BUSY Paco
@ 1999-10-25 10:07 ` Thomas Sailer
  1 sibling, 0 replies; 3+ messages in thread
From: Thomas Sailer @ 1999-10-25 10:07 UTC (permalink / raw)
  To: linux-sound

Jirka Hanika wrote:

> I need an ioctl or some other API to find out whether the sound card
> has completely processed the buffers.  Something exactly like

SNDCTL_DSP_ODELAY

Tom

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~1999-10-25 10:07 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
1999-10-22 21:22 SNDCTL_DSP_BUSY Jirka Hanika
1999-10-22 23:17 ` SNDCTL_DSP_BUSY Paco
1999-10-25 10:07 ` SNDCTL_DSP_BUSY Thomas Sailer

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