Hi,
On 5/20/2016 7:01 PM, Mark Brown wrote:
On Fri, May 20, 2016 at 11:12:39AM +0800, John Hsu wrote:
On 5/19/2016 1:05 AM, Mark Brown wrote:
[PATCH] ASoC: nau8825: apply BIQ to reduce recording signal DC offset
This is hard to review since it's quite complex and doing things that
look like they might be using general purpose parts of the chip for
specialist purposes.
We find there is a DC offset issue when recording. For the issue, it
needs a HPF in ADC to reduce the offset, but no such hardware circuit.
Thus, the driver configures the biquard filter as HPF when headset
connected. It is a must setup for the codec. This patch sets the
coefficients A1, A2, B0, B1, and B3 in the biquad filter to make the
HPF funciton.
I understand what it's doing but obviously a biquad filter isn't
specialized for this function...
Yes, the biquad filter is general purpose feature. Could you give us
suggestion about how to implement the biquad filter for common fea-
ture and to fix DC offset as well?
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