How to see what bit depth audio jack uses?

[digitsun]

Recently I learned that jackd (jack2) uses 32 bit floating point for audio process (that's the standard on music production world).

I suppose that is possible change that option, but for a good documentation for my learning I want to know How to see my actual parameters of jack (in terminal of course), specially the bit depth option.

Hint: In source code exists the next line: JACK_DEFAULT_AUDIO_TYPE

[Linuxmusician01]

Start Jack from the command line! Example:

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jackd -d alsa --device hw:0

Output:

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jackdmp 1.9.12
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2016 Grame.
Copyright 2016-2017 Filipe Coelho.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
no message buffer overruns
no message buffer overruns
no message buffer overruns
JACK server starting in realtime mode with priority 10
self-connect-mode is "Don't restrict self connect requests"
audio_reservation_init
Acquire audio card Audio0
creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods
ALSA: final selected sample format for capture: 16bit little-endian
ALSA: use 2 periods for capture
ALSA: final selected sample format for playback: 16bit little-endian
ALSA: use 2 periods for playback

If you examine this cryptic output closely you'll see the following: sample format for capture: 16bit.




P.S. You can send a command (i.e. Jackaudio) to the background so you can close the terminal window and still have Jack running with the ampersand (&):

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jackd -d alsa --device hw:0 &

[digitsun]

Thanks @Linuxmusician01 Useful tip!

And... How do you modify that option? I'm looking in

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man jackd

and the only parameter maybe be possible is -b:

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-b, --bit-depth int

Is possible to change the option to 24bits?

[Linuxmusician01]

Thanks @Linuxmusician01 Useful tip!

And... How do you modify that option? I'm looking in

Code: Select all

man jackd

and the only parameter maybe be possible is -b:

Code: Select all

-b, --bit-depth int

Is possible to change the option to 24bits?

That's an option for the Netone (no idea what that is actually) backend, we use Alsa.

You could try:

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 -S, --shorts
              Try to configure card for 16-bit samples first, only trying 32-bits if unsuccessful.  Default is to prefer 32-bit samples.

[merlyn]

Recently I learned that jackd (jack2) uses 32 bit floating point for audio process ...

That's right. What then does the question "How to see what bit depth audio jack uses?" mean?

Clue : Is JACK a piece of hardware?