Hi, On Wed, 23 Aug 2023, Amadeusz Sławiński wrote: > The easiest way would of course be to add specific formats like: > S20_MSB_LE > U20_MSB_LE > S20_MSB_BE > U20_MSB_BE > S24_MSB_LE > U24_MSB_LE > S24_MSB_BE > U24_MSB_BE > and one would know used formats exactly..., although I'm sure it is > problematic in some ways, considering HDA currently exposes S32_LE and just > sets msbits quietly and reports it after the fact to userspace. Not just HDA but this is basicly all drivers. And this is ok in most cases. I mean with the MSB variants, applications can produce/consume data with full container bit width (like S32_LE) and for many usages, this will just work (the LSB data will be zero, or non-zero and ignored). Reporting the effective msbit is really important though, as apps _should_ check the field and dither when needed (although mileage varies, if you look up common ALSA apps, few bother to check msbit info). Anyways, this information definitely needs to be exposed and made available to apps. But right, this is a bit orthogonal to the ability to _select_ a specific variant. That is currently not possible without your patchset. Br, Kai
