The filter is implemented in C/C++ and embedded in a DLL. This allows me to load the DLL with Matlab and then analyze the output signal. Really great work flow.
So it was possible to measure the frequency response of a constant-Q 10 band equalizer:
Next steps are:
- improve asplib error detection to make it more stable
- create first version of the addon with adsp.template
- post some gui screenshots
- release first version for testing
- run some benchmarks
Short overview about technical details:
- EQ consists of digital Biquad filters with constant-Q design equations
- at the moment there is only a native [C/C++-Code] implementation
- variable amount of Biquads, e.g. it will be possible to have 10 Band- (beginner) or 31 Band-EQ (experts)
The first version of this addon will be really simple and you can only set the parameters for all channels. But in future versions I will add:
- presets (like vlc or other players)
- separate settings for all output channels of the configurated audio channel layout
- custom mode creation (create a custom eq for pre- or post mode of our new adsp-addon-handling feature)
- variable band configuration
- implement optimizations for SSE3, AVX, NEON,...
- integrate my LibXConvolver library to run an FIR-Filter as EQ with linear phase response
EDIT: Because a Biquad filter is very flexible (you can use it as low-, high-, bandpass filter or as notch filter), I renamed the addon to adsp.biquad.filters. I hope you guys like the new name. Some more news will follow.