Ticket #182 (closed enhancement: wontfix)

Opened 12 years ago

Last modified 8 years ago

need some additional API to implement somthing similar to alsa_in and alsa_out

Reported by: torbenh Assigned to:
Priority: minor Milestone: FFADO 2.1
Component: Version: FFADO SVN (trunk)
Keywords: Cc:
The device the bug applies to:


in order to implement something similar to alsa_in (which can be found in the tools directory from jack1)

i need a way to determine the samplerate and/or buffer position of the sound interface.

you already stated, that you know the samplerate in firewire clock. so the alsa_in dll could operate on firewire clock, for example.

i also need some absolute value. but if the samplerate is quite accurate, it could be high granularity.

alsa_in operates like this:

double current_resamp_rate = 1.0;

process( nframes )
   snd_pcm_delay( pcm, &delay )

   offset = delay-target_delay;

   double resamp_rate = nframes/(nframes+offset);
   double diff_value = (current_resample_rate - resamp_rate) / catch_factor;

   current_resample_rate += diff_value;

   write( nframes * current_resample_rate );

I hope its clear, that this is in fact a dll.

So we might just use some cascades of dlls to get there.

Change History

05/17/09 04:31:22 changed by ppalmers

  • milestone changed from FFADO 2.0 to FFADO 2.1.

03/28/12 16:04:40 changed by jwoithe

Is there still an interest in implementing this? If so, please confirm and we'll start to work out what precisely is required to make this happen. Otherwise I guess this ticket can be closed.

04/27/12 06:56:22 changed by jwoithe

  • status changed from new to closed.
  • resolution set to wontfix.

I'm taking the lack of response over the past month as an indication that the need for these additional API calls has past. If in future it appears that they may be useful this ticket can be re-opened and the issue reconsidered.