[linux-audio-user] Jack+Alsa troubles

davidrclark at earthlink.net davidrclark at earthlink.net
Sat Aug 21 10:03:20 EDT 2004


There are two slightly different ways in which ALSA addresses sound
cards.  One is more directly: hw:0, the other indirectly: plughw:0.
If jack cannot talk to the hardware directly (hw:0 or equivalently
via82xx), it can probably talk to it using plughw:0.  (If via82xx is
the second card, then plughw:1 and so on.)

A suggestion was made to "try -r 48000."  I believe that doing this
will cause a 44100 file to be sent to the card at an incorrect rate.
Data need to be sent to the card at the rate of the file, but if 
the hardware cannot do it, using plughw is required, using the rate
of the file, not the card rate.  Sending a 44100 file at 48000 will
cause pitch shifting upwards by about 1.5 semitones.

Somebody please correct me if I've misspoken here, but this is 
definitely the way my Terratec EWX 2496 functions.
 
Regards,
Dave.





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