[LAD] resampling with sp/dif

fons at kokkinizita.net fons at kokkinizita.net
Mon Apr 19 12:32:45 UTC 2010


On Mon, Apr 19, 2010 at 12:38:35PM +0200, Conrad Berhörster wrote:

> i want to grab some external sources (cdplayer)  with jack. i run a jack 
> instance with 48000 Hz and it works perfectly with my cd player and ardour. 
> but if i take a cheaper cdplayer, the signal will only be came in with 44100, 
> because there seems no resample and sync between the master (soundcard) and 
> slave (cheapoCD) . so, the signal will always being played to slow. i found a 
> workaround with a small external box, which resamples the incoming signal 
> before it get into the soundcard. 
> 
> Since a while, i think about a software solution, which puzzles me a bit. if i 
> doing the process without the  external resampler, what must be done with the 
> signal. 
> If the original source is 44100 Hz, the incoming signal is 48000 (because of 
> jack). if i try to resample it, the current buffer get shorter, because the 
> signal need to be decreased. 
> How can a correct resampling process be done? 

Jack clients all see the same sample rate and buffer
size, so the resampling would need to be done in the
backend (the 'driver' that links Jack to ALSA or FFADO).

Ciao,

-- 
FA

O tu, che porte, correndo si ?
E guerra e morte !



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