[Question] native DSD support?

[RJVB]

Mostly out of curiosity: what options are there for native DSD support on the various platforms QMPlay2 runs on - with native meaning something like sending DSD rather than PCM to DACs supporting it?

[zaps166]

I don't have any DSD DAC to test it, also I doubt FFmpeg can read DSD instead of PCM 🤔

[TaxicabMessiah]

I don't have any DSD DAC to test it, also I doubt FFmpeg can read DSD instead of PCM 🤔

FYI there is a type of DSD called DXD which is actually just a high resolution PCM (384khz/24 bit I think) so it would be possible to be DXD compatible.

[RJVB]

On Friday January 02 2026 13:01:43 Błażej Szczygieł wrote: I don't have any DSD DAC to test it, also I doubt FFmpeg can read DSD instead of PCM 🤔

FFmpeg can read them, but (by default?) it will convert them to PCM (and we have to trust it does that properly)

[RJVB]

On Friday January 02 2026 13:06:55 TaxicabMessiah wrote: FYI there is a type of DSD called DXD which is actually just a high resolution PCM (384khz/24 bit I think) so it would be possible to be DXD compatible.

The "Bah, Humbug" time of year is over, and we're not yet in April ;) DXD is indeed "just" a "crazy high resolution" PCM format. It's what studios use nowadays. PCM is a lot easier to use in DAWs etc. after all. DSD is something else entirely: it's a 1-bit stream with a rate of at least 2.8224 MEGA Herz (64x 44.1kHz, hence DSD64); that's the format you find on SACDs. DSD256 is 4 times faster/bigger/maybe-better, DSD512 is, well, through the roof. https://en.wikipedia.org/wiki/Direct_Stream_Digital

[RJVB]

FFmpeg can read them, but (by default?) it will convert them to PCM (and we have to trust it does that properly)

Anyway, what do you ask of FFmpeg, for playing back audio, IOW, is there an equivalent commandline option and what would it be?

[zaps166]

I never used DSD, all I know is that FFmpeg can convert it to PCM, but never tried it.

[RJVB]

Without a DSD-native DAC there isn't much else you could do with them either... There is "D.O.P" though. DSD-over-PCM. Somehow it manages to store the unaltered DSD signal in PCM samples that sound as low-level noise when played on a DAC that doesn't support DSD. If FFmpeg supports this format then the "easy" solution would be to provide a toggle that tells FFmpeg to use it, and then play back the samples you receive as if they were regular PCM. The DAC should pick up on the rest. People without such a DAC can use the current PCM conversion, or use something like `dsf2flac` to do it themselves (and save a lot of diskspace ;) ).

[zaps166]

Do you have any DSD file?

[RJVB]

Do you have any DSD file?

1 - for testing :D Found it here: https://www.oppodigital.com/hra/dsd-by-davidelias.aspx

[zaps166]

It plays normally in QMPlay2 as 32-bit float, 352.8 kHz PCM audio. I can see noise starting at around 48 kHz up to 176 kHz.

Currently no way for native support, because nobody have such hardware 😄

Btw. are such DACs have support in ALSA? Or for USB devices I have to use libusb and write driver in QMPlay2 😄 ?

[RJVB]

On Monday January 05 2026 09:39:08 Błażej Szczygieł wrote: zaps166 left a comment (zaps166/QMPlay2#989) It plays normally in QMPlay2 as 32-bit float, 352.8 kHz PCM audio. I can see noise starting at around 48 kHz up to 176 kHz.

Well, there you can maybe see but certainly not hear it ... unless it causes interference in audible frequencies (which it well might dependending on what else happens in the playback chain).

Currently no way for native support, because nobody have such hardware 😄

Most recent'ish DACs also catering to the audiophile market should support the format. I had a +-40 bucks dongle Hidizs DAC that does (or did, as it somehow got fried). Waiting for a replacement to arrive from China...

Btw. are such DACs have support in ALSA? Or for USB devices I have to use libusb and write driver in QMPlay2 😄 ?

https://help.nativedsd.com/en/articles/6948867-playing-dsd-files-on-linux ;)

[zaps166]

Well, there you can maybe see but certainly not hear it ...

Yeah, but I'm not sure if it should output to loudspeakers...

[RJVB]

Yeah, but I'm not sure if it should output to loudspeakers...

OK, so the question is indeed if you can actually hear it from the output, or if you see it in your spectrum. And then 2nd question: what's the power? There are filters in DACs (apparently the nyquist problem also occurs with D-to-A conversion) and then of course the amp driving the speakers has a limited bandwidth too.

[zaps166]

I'll check if this noise outs of my ancient ampli and ALC1220 at 192kHz 😄