On Oct 13 03:11:50, s...@skolma.com wrote:
> A questions about SNDIO and bit-perfect audio playback.
>
> I use a usb dac, audioquest dragonfly black 1.5,
> and headphones to listen to my digitised music collection,
> as i can conveniently move between my various devices.
>
> OpenBSD has detected this device
dmesg?
> and following FAQ13 i was able
> to have working playback of .wav and .flac audio files with ease
> via the various sndioctl commands.
> tested successfully with aucat, and ogg123,
> including other audio such as browser/yt.
> The dac supports several native bit rates,
This is the point where you should show the full output
of mixerctl -av and audioctl.
> and has a nice party_trick of changing physical logo colour
> based on the feed, the main ones being:
never mind the logo colour, show the actual audio settings,
as in mixerctl and audioctl
> 16bit / 44.1k, green. (cd quality)
> 24bit / 48k, blue (dvd quality)
> 24bit / 88.2k, orange,
> 24bit / 96k pink.
Are all of these stereo, or are some of them multichannel?
> In my testing, windows, mac, freebsd, openbsd, and linux
> all default to the 48k - blue mode allowing mulitple input streams.
Multiple input streams have nothing to do with the above settings.
By default, sndio will play what you feed it, mixing from multiple
inputs - as I suppose other audio systems do on other OSes;
this is not a property of the audio device.
By the way, sndiod defaults to 48k as well.
> eg music , brower video and system sounds.
> but is techncally up/down sampling based on feed.
Of course: how else are you gonna play a 8 kHZ audio file
when the device cannot do 8 kHz?
> For bit perfect to work correctly..
Stop right there: what do you mean by bit perfect?
The bits stored in a flac file are not the same bits
that arrive at the audio device to be played.
Are you just concerned with the upsampling?
(Or downsampling? Meaning you have music
stored in more than 24bit @ 96 kHz?
> normally the audio subsystem
What subsytem? sndio?
> would be configured to operate
> in exclusive mode. where only the music would be the output.
Meaning what? To the running sndiod, an input is an input,
there;s nothing distinguishing "music". What you probably mean
is giving e.g. ogg123 exclusive rights to open the audio device,
resp. exclusive rights to be sndiod's input, so that nothing else
is playing while ogg123 is playing. Is that what you mean?
(Even so, the bits of the ogg file are not the bits that reach
the audio device. Drop the "bit-perfect" lingo, this is imho
about exclusive audio device access.)
> does anyone know if SNDIO supports such mode?
> and how i might configure it.
I suppose you have already read sndiod(8) in its entirety ...
(You can also not run sndiod: then only one audio player
will have access to the underlying device.)
Jan
