[alsa-devel] Juli@ ICE1724 and 24 bit audio

Demian Martin demianm_1 at yahoo.com
Wed Feb 11 02:06:32 CET 2009

I confirmed that aplay and plughw:0,1 work fine. Aplay and hw:0,1 don't work
at all.

And that Xine is the culprit. Now to find out how to fix/work around Xine.

Demian Martin
Product Design Services

-----Original Message-----
From: Pavel Hofman [mailto:pavel.hofman at insite.cz] 
Sent: Tuesday, February 10, 2009 7:35 AM
To: Vedran Miletić
Cc: Demian Martin; alsa-devel at alsa-project.org
Subject: Re: [alsa-devel] Juli@ ICE1724 and 24 bit audio

What makes you guys think the plug plugin trims the data down to 16bits? 
  Sure if the rate is changed (the source code suggests only the 
low-quality linear rate algorithm supports above-16bit format - 
operation convert, the other resampling algorithms convert using the 
operation convert_s16).

Ice1724 supports all the general rates natively, the rate conversion in 
the plug plugin should not kick in for common audio formats. The only 
case I can think of would be switching Juli to external SPDIF-IN clock - 
the hw.rate_min = hw.rate_max = actual_rate and the automatic rate 
conversion could happen.

I did not use the hw device in my tests since all the tested tracks 
would have to be 32-bit for the hw device to accept the format when 
played via my favorite aplay.

My 2 cents guess is xine does the conversion.



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