Need info re: "Oversampling" filters or algorithms

Support questions for Neutron Player only.
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kentajalli
Posts: 15
Joined: Wed Jan 06, 2016 4:59 pm

Need info re: "Oversampling" filters or algorithms

Post by kentajalli » Fri May 07, 2021 2:33 pm

Oversampling (seetings>audio hardware>oversampling) is a feature I am interested in.
I can not find any data regarding what Algorithms, filters is used within Neutron.
If it is an Interpolation oversampling, there must be a filter - does anyone has any info about that. (i.e. FIR or Sync etc.)
Also what Dithering is used by Neutron (i.e. TPDF , Shaped etc.)
Thanx

blaubär
Posts: 3312
Joined: Tue Apr 02, 2019 6:48 am

Re: Need info re: "Oversampling" filters or algorithms

Post by blaubär » Fri May 07, 2021 5:07 pm

kentajalli wrote:
Fri May 07, 2021 2:33 pm
Oversampling (seetings>audio hardware>oversampling) is a feature I am interested in.
I can not find any data regarding what Algorithms, filters is used within Neutron.
If it is an Interpolation oversampling, there must be a filter - does anyone has any info about that. (i.e. FIR or Sync etc.)
blaubär wrote:
Sun Jan 17, 2021 9:54 am
As to the question of how best to achieve upsampling in Neutron see the following discussion :
blaubär wrote:
Thu Feb 13, 2020 4:38 pm
Some things about the sampling rate that I found out in the meantime :

1. If Neutron resamples, it resamples the output of the decoder and feeds the DSP with the new sampling rate, so the DSP will work with the new sampling rate, and deliver data with this rate to the output.

2. If the firmware resamples, it will do so only after the DSP and only if it doesn't support the sampling rate delivered by the DSP. If the DSP delivers a supported sampling rate the firmware won't resample.

3. If you activate Audio Hardware > Oversampling then Audio Hardware > Frequency will be ignored.

4. Audio Hardware > Oversampling sets the sampling rate to an even multiple of the input. This is a good thing on its own, better than a non-even multiple. But if the resulting sampling rate isn't supported by the device the firmware will resample again after the DSP to the best suitable rate.

5. Audio Hardware > Frequency will set the sampling rate to a value supported by the device. This is a good thing on its own. But it might force Neutron to resample to an non-even multiple, which isn't as perfect as resampling to an even multiple.
It seems that in recent versions Neutron doesn't use non-supported sampling rates at all. So "Oversampling" means something like follow-source-frequency-multiplied-by-n. And should the device not support high-res-audio at all then Neutron will resample to 48 kHz no matter what else has been set.

kentajalli wrote:
Fri May 07, 2021 2:33 pm
Also what Dithering is used by Neutron (i.e. TPDF , Shaped etc.)
blaubär wrote:
Sun Jan 24, 2021 1:35 pm
On the equalizer screen you can activate or deactivate Dither.

This might improve your SNR ( signal noise ratio ) if you use any DSP ( digital signal processing, meaning resampling, equalizer, crossfeed, surround, compressor etc ). Neutron internally calculates with 64 bit or 32 bit. It often happens that whatever gets its output, which in most cases is the DAC ( digital analag converter ), cannot handle that many bits, so some have to be truncated. To mitigate the adverse effects of this truncation Dither can help.

See Audio Dithering: What You Need to Know
So, what is dither? It’s a form of low-level noise that is intentionally added to a digital audio file as it’s rendered to a lower bit depth.
and Dither
This leads to the dither solution. Rather than predictably rounding up or down in a repeating pattern, it is possible to round up or down in a random pattern.

kentajalli
Posts: 15
Joined: Wed Jan 06, 2016 4:59 pm

Re: Need info re: "Oversampling" filters or algorithms

Post by kentajalli » Fri May 07, 2021 5:31 pm

I don't mean to be ungrateful , but did you understand the questions?
I did a simple search before posting the question. those articles you sent do not answer my questions.

blaubär
Posts: 3312
Joined: Tue Apr 02, 2019 6:48 am

Re: Need info re: "Oversampling" filters or algorithms

Post by blaubär » Fri May 07, 2021 7:16 pm

kentajalli wrote:
Fri May 07, 2021 5:31 pm
I don't mean to be ungrateful , but did you understand the questions?
I did a simple search before posting the question. those articles you sent do not answer my questions.
Well, if they don't then they don't :D

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