tree 1e3bbcdccb67ee1580eafbd10ef35369db3b4b51
parent ffe0c897c8322143af495417c39af4717ed4cdd4
author Lun Dong <lundong@google.com> 1655959934 -0700
committer Lun Dong <lundong@google.com> 1656362256 -0700

Add support for audio pre-processing (MFCC extraction)

This is the complete code change for adding audio pre-processing block (MFCC feature extraction).

The code was re-written in C based on http://google3/audio/dsp/mfcc/mfcc_mel.py, with necessary simplifications.

We also integrated audio pre-processing into daredevil, to allow for end-to-end simulations with .wav audio input.

Numerical correctness has been validated: extracted MFCC matches with
the reference (golden_whistle_spectrogram) and returned output is
correct (Whistling). Unit tests passed.

Profiling result: https://docs.google.com/document/d/1vAgRgZeVyOwIniiIp8RrmEvg3CB_p0PFgB2X9NLN4Fo
The pre-processing block adds a relatively constant number of extra instructions. So the percentage depends on the computational complexity of audio models (for daredevil: 65%)

Change-Id: I662914e68170e5e28384960ad345c3366f9fb627