[alsa-devel] [PATCH 0/3] ALSA: snd-usb: Some small fixes to make Playback Design products work

[Gabriel M. Beddingfield]

On 03/18/2013 06:49 AM, Daniel Mack wrote:
>>> Yes, I  thought about that for a while as well. In fact, the data format
>>> the device supports on these altsettings is "DSD", but that doesn't have
>>> a defined value in the UAC2 spec (and strictly speaking, DSD is not even
>>> PCM).
>>>
>>> So when a device is as unspecific as 'raw data', there's not much we can
>>> do about that except for exposing the same level of uncertainty down to
>>> the apps, right?
>>
>> Yes.  We can add a new format SND_PCM_FORMAT_RAW, but it's not much
>> better than SND_PCM_FORMAT_SPECIAL after all :)
>
> Yes. If at all, we should add a SND_PCM_FORMAT_DSD, and a quirk for that
> device. But given that there is no application for DSD in userspace
> either, we probably don't need to care.

+1

However, more and more applications are wanting to send non-linear PCM 
data through ALSA.  So, we probably /do/ need to care.

-gabriel