// Copyright 2019 The MediaPipe Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

syntax = "proto2";

package mediapipe;

import "mediapipe/framework/calculator.proto";

message MelSpectrumCalculatorOptions {
  extend CalculatorOptions {
    optional MelSpectrumCalculatorOptions ext = 78581812;
  }
  // The fields are to populate the config parameters in
  // audio/dsp/mfcc/mel_filterbank.h
  // but the names are chose to mirror
  // audio/hearing/filterbanks/cochlea_gammatone_filterbank.proto
  // and the default values match those in
  // speech/greco3/frontend/filter_bank.proto .

  // Total number of frequency bands to use.
  optional int32 channel_count = 1 [default = 20];
  // Lower edge of lowest triangular Mel band.
  optional float min_frequency_hertz = 2 [default = 125.0];
  // Upper edge of highest triangular Mel band.
  optional float max_frequency_hertz = 3 [default = 3800.0];
}

message MfccCalculatorOptions {
  extend CalculatorOptions {
    optional MfccCalculatorOptions ext = 78450441;
  }

  // Specification of the underlying mel filterbank.
  optional MelSpectrumCalculatorOptions mel_spectrum_params = 1;

  // How many MFCC coefficients to emit.
  optional uint32 mfcc_count = 2 [default = 13];
}