jackd's dither parm – why?

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bluebell
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jackd's dither parm – why?

Post by bluebell »

jackd can be configured with dithering, e.g. when using the ALSA backend.

I have no idea when dithering would make sense since jackd configures the audio adapter to use the configured sampling frequency.

Any ideas?

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lilith
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Re: jackd's dither parm – why?

Post by lilith »

I just asked that at IRC:
I have a question with an issue that I try to solve since 2016 or so. I'm using Claudia from KXstudio. With Jack and Pulseaudio everything is fine. When I use the Alsa -> Loop -> Jack Bridge I get crackling when playing something through Chromium. When I play something in Audacity using Alsa directly everything is fine. Is there anything done with the audio signal when going through the bridge which might explain this?
Can this maybe be the problem here?

edit: falkTX answered at IRC and the problem could be that the audio format supported by aloop is not extensive. So obviously my Zoom R8 uses a driver which does not support the audio format of the aloop bridge.
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Re: jackd's dither parm – why?

Post by AlexTheBassist »

bluebell wrote:I have no idea when dithering would make sense since jackd configures the audio adapter to use the configured sampling frequency.
This isn't about sample rate, it's used to run JACK in 16 bit mode when an ADC/DAC doesn't support 16 bit. You should use that when exporting audio to 16 bit 44100 Hz from your DAW, i. e. when you plan to print it to a real CD or upload you album to a marketplace which doesn't do all necessary conversions by itself.
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Re: jackd's dither parm – why?

Post by bluebell »

AlexTheBassist wrote:
bluebell wrote:I have no idea when dithering would make sense since jackd configures the audio adapter to use the configured sampling frequency.
This isn't about sample rate, it's used to run JACK in 16 bit mode when an ADC/DAC doesn't support 16 bit. You should use that when exporting audio to 16 bit 44100 Hz from your DAW, i. e. when you plan to print it to a real CD or upload you album to a marketplace which doesn't do all necessary conversions by itself.
I use Audacity to do that, and Audacity does the dithering itself (with configurable quality).

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Re: jackd's dither parm – why?

Post by AlexTheBassist »

bluebell wrote:I use Audacity to do that, and Audacity does the dithering itself (with configurable quality).
You misunderstand what it does. Audacity doesn't do any dithering on the fly, only when exporting. This JACK parameter allows to dither internally in the server, without any external appliances.
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