i810 & wineoss & sound formats

Eric Pouech eric.pouech at wanadoo.fr
Mon Nov 4 12:03:48 CST 2002

> But according to the OSS spect this ioctl call is not garanteed to give
> you the actual sampling frequency you asked for. So if the device only
> supports 11025Hz, ioctl will return success but you will find that after
> the call smplrate==11025.
> So it seems it would be more correct to do:
>      smplrate = 44100;
>      if (ioctl(ossdev->fd, SNDCTL_DSP_SPEED, &smplrate) == 0 &&
>          smplrate==44100) {
>          ... this format is supported ...
>      }
in fact the real test would even be more complicated and should use the
NEAR_MATCH macro (some cards report for example 11000 when asked for
however this is only used in waveXXXGetDevCaps (and I'm not sure lots of
apps use this API to get the supported formats)
in most of the cases, returning 0xFFFF as the format set should be
(or 0xFFFFF)

> Which leads me to the following questions:
>   * should waveOutGetDevCaps consider that a format is supported as long
> as we can up-sample to a format that is?
I think we shouldn't care for now. as far as we support the correct
in the upper layer, the best behavior would be:
- return as many formats as we can in waveoutgetdevcaps
- while opening, if the requested format isn't supported, then report an
  (as your previous patch does)
- the handling of the WAVE_FORMAT_DIRECT is already done at the winmm

correctly returning the supported formats wouldn't change the behavior
a functional point of view. only performance would be better.
but to my knowledge capacity introspection is mostly done using the
WAVE_FORMAT_QUERY flag in waveXXXOpen, not the waveXXXGetDevCaps

>   * what does the b mean in 'formats=bfff'? I could not find any
> documentation...
those are from the latest XP SDK
#define WAVE_FORMAT_96M08      0x00010000       /* 96     kHz, Mono,  
8-bit  */
#define WAVE_FORMAT_96S08      0x00020000       /* 96     kHz, Stereo,
8-bit  */
#define WAVE_FORMAT_96M16      0x00040000       /* 96     kHz, Mono,  
16-bit */
#define WAVE_FORMAT_96S16      0x00080000       /* 96     kHz, Stereo,
16-bit */


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