On Mon, 25 Aug 2008 15:27:11 -0500, Mike McCarty wrote:
Michael Schwendt wrote:
> On Mon, 25 Aug 2008 14:26:25 -0500, Mike McCarty wrote:
>
>> Can anyone tell me what formats /dev/dsp, /dev/dsp56k,
>> /dev/audio, etc. expect? It seems that I can copy
>> a WAV format file directly to /dev/dsp and get recognizable
>> sound. I wonder just what format they actually expect.
>
> /dev/audio used to accept µ-law encoding, /dev/dsp accepts raw pcm as
> configured via ioctl. The device doesn't evaluate any WAV header.
Thanks! So, if I want to use sox, I can specify the output to be
/dev/dsp and raw, and the input format to be whatever corresponds.
Ask kernel devs whether you can still expect a specific raw format.
There are several parameters that must match: bits per sample,
signed/unsigned samples, number of channels (mono/stereo), frequency
Btw, it's likely that /dev/dsp will go away in the future, as it's
only a compatibility device file for the old OSS driver architecture
(unload a kernel module, and the device file is gone). ALSA uses
different device files.