Filtering white noise in vs1063a

Writing software that inputs and/or outputs audio and performs DSP algorithms such as filters, new codecs or audio effects.
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demonoR
Senior User
Posts: 59
Joined: Sun 2011-01-16 20:08

Filtering white noise in vs1063a

Post by demonoR » Sun 2018-01-07 0:01

Good day,

Is it possible to filter that white noise which is from mic?

Can you check it please for me, i created a little sample.

I use this settings:

LoadPlugin(venc1063_patch, 1613);
WriteRegister16(SCIR_AICTRL0, 16000);
WriteRegister16(SCIR_AICTRL1, 0);
WriteRegister16(SCIR_AICTRL2, 10 * 0x0400);
WriteRegister16(SCIR_AICTRL3, (audio_format));
WriteRegister16(SCIR_WRAMADDR, 0xE0C0);
WriteRegister16(SCIR_MODE, SM_ENCODE | SM_SDINEW | ReadRegister(SCIR_MODE));
WriteRegister16(SCIR_AIADDR, 0x0050); /* Activate recording! */

Thank you,
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noise_test1.wav
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Henrik
VLSI Staff
Posts: 1052
Joined: Tue 2010-06-22 14:10

Re: Filtering white noise in vs1063a

Post by Henrik » Tue 2018-01-09 11:31

Hello!

From your code it isn't clear if you use the line input or microphone input, although it sounds like you are using the microphone input.

If you are using the microphone input (SM_LINE1 = 0 in register SCI_MODE), then this amount of background noise is normal, especially with your 20 dB digital amplification (SCI_AICTRL2 = 10*0x400 = +20 dB digital gain). You may get lower background noise if you preamplify your signal by 20 dB using a low-noise op-amp, then removing the software gain (SCI_AICTRL2 = 0x400).

Kind regards,
- Henrik
Good signatures never die. They just fade away.

demonoR
Senior User
Posts: 59
Joined: Sun 2011-01-16 20:08

Re: Filtering white noise in vs1063a

Post by demonoR » Tue 2018-01-09 16:53

Good day Henrik,

Thank you, for your answer, yes I am using microphone input.

I know that this is normal.

1. You said i can use some low noise op amp, do you have some schematic, or which one you prefer?

2. Is it possible to filter some noise with some plugin for vs1063a?

I can filter some noise in PCM, but for OGG or other compressed format it is not possible.

Thank you!

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