1 /* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 #ifndef TENSORFLOW_LITE_EXPERIMENTAL_MICROFRONTEND_LIB_FILTERBANK_UTIL_H_
16 #define TENSORFLOW_LITE_EXPERIMENTAL_MICROFRONTEND_LIB_FILTERBANK_UTIL_H_
17 
18 #include "tensorflow/lite/experimental/microfrontend/lib/filterbank.h"
19 
20 #ifdef __cplusplus
21 extern "C" {
22 #endif
23 
24 struct FilterbankConfig {
25   // number of frequency channel buckets for filterbank
26   int num_channels;
27   // maximum frequency to include
28   float upper_band_limit;
29   // minimum frequency to include
30   float lower_band_limit;
31   // unused
32   int output_scale_shift;
33 };
34 
35 // Fills the frontendConfig with "sane" defaults.
36 void FilterbankFillConfigWithDefaults(struct FilterbankConfig* config);
37 
38 // Allocates any buffers.
39 int FilterbankPopulateState(const struct FilterbankConfig* config,
40                             struct FilterbankState* state, int sample_rate,
41                             int spectrum_size);
42 
43 // Frees any allocated buffers.
44 void FilterbankFreeStateContents(struct FilterbankState* state);
45 
46 #ifdef __cplusplus
47 }  // extern "C"
48 #endif
49 
50 #endif  // TENSORFLOW_LITE_EXPERIMENTAL_MICROFRONTEND_LIB_FILTERBANK_UTIL_H_
51