1 /******************************************************************************
2  *
3  *  Copyright 2022 Google LLC
4  *
5  *  Licensed under the Apache License, Version 2.0 (the "License");
6  *  you may not use this file except in compliance with the License.
7  *  You may obtain a copy of the License at:
8  *
9  *  http://www.apache.org/licenses/LICENSE-2.0
10  *
11  *  Unless required by applicable law or agreed to in writing, software
12  *  distributed under the License is distributed on an "AS IS" BASIS,
13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  *  See the License for the specific language governing permissions and
15  *  limitations under the License.
16  *
17  ******************************************************************************/
18 
19 #ifndef __LC3_MDCT_H
20 #define __LC3_MDCT_H
21 
22 #include "common.h"
23 
24 
25 /**
26  * Forward MDCT transformation
27  * dt, sr          Duration and samplerate (size of the transform)
28  * sr_dst          Samplerate destination, scale transforam accordingly
29  * x, d            Temporal samples and delayed buffer
30  * y, d            Output `ns` coefficients and `nd` delayed samples
31  *
32  * `x` and `y` can be the same buffer
33  */
34 void lc3_mdct_forward(
35     enum lc3_dt dt, enum lc3_srate sr, enum lc3_srate sr_dst,
36     const float *x, float *d, float *y);
37 
38 /**
39  * Inverse MDCT transformation
40  * dt, sr          Duration and samplerate (size of the transform)
41  * sr_src          Samplerate source, scale transforam accordingly
42  * x, d            Frequency coefficients and delayed buffer
43  * y, d            Output `ns` samples and `nd` delayed ones
44  *
45  * `x` and `y` can be the same buffer
46  */
47 void lc3_mdct_inverse(
48     enum lc3_dt dt, enum lc3_srate sr, enum lc3_srate sr_src,
49     const float *x, float *d, float *y);
50 
51 
52 #endif /* __LC3_MDCT_H */
53