[alsa-devel] S24_LE Mode for USB Driver

Charles Eidsness charles.eidsness at ieee.org
Thu Aug 7 22:25:50 CEST 2008

Hi All,

It looks like the parse_audio_format_i_type function at line 2369 of usbaudio.c 
(linux v2.6.23) doesn't support the case where  bSubframeSize (fmt[5]) = 4 bytes 
and  bBitResolution (fmt[6]) = 24 bits, which should correspond to a S24_LE (or 
BE) type. I'm developing a new USD DAC which supports this mode (24-bit sample 
in a 4 byte package). Right now Linux sends me S32_LE formated data, which is 
wrong. Would it be possible to expand this function to support S24_LE/BE? It 
would only require adding a few lines of code.


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