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More => Old Versions => JRiver Media Center 20 for Windows => Topic started by: 8139david on February 05, 2015, 04:42:01 am

Title: [Solved]_Bitdepth automatic in device options_Why 24bits output on 16bits input?
Post by: 8139david on February 05, 2015, 04:42:01 am

My PC is connected via usb to an Audio-Gd Dac, which supports 24bits.

In JRiver, I have selected the device: Audiogd usb [WASAPI].
And by default, in the device settings, this is selected:
Bitdepth: automatic (recommended for best sound quality)
(NB: This is also selected: Open the device for exclusive access.)

When I play a cd recorded lossless (which is 16bits, 44khz), I see in JRiver's audio path:
Input: 44,1khz 16bits FLAC
No changes are being made.
Output: 44,1khz 24bits using WASAPI

NB: I have no effect selected in the DSP options.

What does this mean?
That the sound is inoccuously transformed into 24bits, perhaps by adding zeros?
I'd like to understand...

Thanks in advance,
David

Title: Re: Bitdepth automatic in Device options? Why 24bits output on 16bits input?
Post by: 6233638 on February 05, 2015, 05:53:43 am

Media Center always uses the highest bit-depth that your device supports.
The reason for doing this, is because the can be benefits to it, and there are no negative effects.
If you play a 16-bit file with a 24-bit output, the signal is just padded with zeros.

However, if you play a 16-bit file, and process the signal in any way - which includes things like volume control - this processing results in more than 16-bits of data.
So if you reduced the volume from 100% to 99%, playback would be interrupted because Media Center would have to stop playback to the device to change the output from 16-bit to 24-bit.
 
If you always output a 24-bit signal instead, playback will not be interrupted.
And if you are not doing any processing, 16-bits padded with zeros to 24-bit, is identical to 16-bit.