Re: native DSD on PCI linux driver

On Tue, 26 Nov 2024 10:41:21 +0100, Filip Van Lunteren wrote:

Hello,

I am currently developing PCI audio output hardware and driver and want to integrate native DSD playback. I am struggling to find documentation on this. Is there DSD native support in ALSA? And how do I incorporate it? PCM is already set up and works.

AFAIK, in the driver side, there is not much special; it assumes that DSD samples are passed over the standard PCM stream, and the driver uses special formats SNDRV_PCM_FORMAT_DSD_U8, *_U16 and *_U32 (with _LE and _BE suffix) for 8, 16 and 32bit, instead of the standard SNDRV_PCM_FORMAT_U8, *_S16, etc. For those formats, the silence data is assumed to be 0x69, 0x6969, etc.

Takashi