2009-05-04 03:15:41     audio codec and /dev/dsp interface

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2009-05-04 03:15:41     audio codec and /dev/dsp interface

Vasanth Nayak (INDIA)

Message: 73541   

 

Hi,

 

         From the hardware data sheet of BF527, it says it has integrated 24 bit audio codec. (derivative of SSM2603). But the audio interface through /dev/dsp allows for maximum of 16 bit data to be sent to the audio driver? Does anybody know of  any way of sending 24-bit data to the DAC of the integrated 24-bit  audio codec ?

 

Vasanth

 

 

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2009-05-04 09:59:25     Re: audio codec and /dev/dsp interface

Robin Getz (UNITED STATES)

Message: 73566   

 

Vasanth:

 

I believe the OSS interface (/dev/dsp) is limited to 16-bit (but I could be wrong - Cliff would know for sure). If you want higher - you need to use ALSA.

 

-Robin

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2009-05-04 22:05:20     Re: audio codec and /dev/dsp interface

Cliff Cai (CHINA)

Message: 73601   

 

Vasanth,

 

The OSS emulation in latest ALSA supports up to 32-bit data format.

 

 

 

Cliff

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2009-05-06 02:57:30     Re: audio codec and /dev/dsp interface

Vasanth Nayak (INDIA)

Message: 73728   

 

Hi Cliff,

 

                 what is the header file needed to use OSS emulation ? Is the 32 bit audio support included in 2008R1.5 release of uCLinux ?

 

 

 

Vasanth

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2009-05-06 21:15:22     Re: audio codec and /dev/dsp interface

Cliff Cai (CHINA)

Message: 73785   

 

Vasanth:

 

        1.Oss emulation is enabled by default in our dist.You can take a look at the Kconfig under sound/core/.

 

         2.32 bit is not supported in 20081.5,but supported in trunk head.See pcm_oss.c in sound/core/oss/

 

 

 

Cliff

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