Add Audio Variables

[Akkiiitj]

Description

Currently, the audio processing pipeline computes FFT data but does not extract distinct frequency bands (Bass, Mid, Treble) or their attenuated versions. This issue proposes adding support for:

• Bass, Mid, Treble Extraction: Compute frequency band loudness values from FFT.
• Attenuation Variables: Compute smoothed versions (bassAtt, midAtt, trebleAtt) using an exponential moving average (EMA).

Files

Relevant files where modifications will be required:

• [Audio.cpp](https://github.com/divyansh1010x/MPV/blob/main/src/Audio.cpp)
• [Audio.h](https://github.com/divyansh1010x/MPV/blob/main/src/Audio.h)
• [FFTProcessor.cpp](https://github.com/divyansh1010x/MPV/blob/main/audio/FFTProcessor.cpp)
• [FFTProcessor.h](https://github.com/divyansh1010x/MPV/blob/main/audio/FFTProcessor.h)

To Reproduce

Not applicable as this is a feature request.

Expected Behavior

-Compute separate loudness values for Bass, Mid, and Treble using FFT magnitudes.
-Implement smoothed loudness values.

Actual Behavior

Currently, the FFT processing returns raw magnitude data without frequency band separation or attenuation.

Tasks

• Compute separate loudness values for Bass, Mid, and Treble using FFT magnitudes.
• Implement smoothed loudness values using an exponential moving average (EMA).

Possible Fixes

-Define frequency ranges to extract relevant data.
-Aggregate energy from selected bins.
-Implement a smoothing function to stabilize output values.

Additional Information

• Reference from projectM implementation (bass, bassAtt, mid, midAtt, treble, trebleAtt).
• Verify performance impact of additional computations.
• Ensure real-time performance is not significantly affected.