1 /*
2  * Copyright 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef RESAMPLER_POLYPHASE_RESAMPLER_H
18 #define RESAMPLER_POLYPHASE_RESAMPLER_H
19 
20 #include <memory>
21 #include <vector>
22 #include <sys/types.h>
23 #include <unistd.h>
24 
25 #include "MultiChannelResampler.h"
26 #include "ResamplerDefinitions.h"
27 
28 namespace RESAMPLER_OUTER_NAMESPACE::resampler {
29 /**
30  * Resampler that is optimized for a reduced ratio of sample rates.
31  * All of the coefficients for each possible phase value are pre-calculated.
32  */
33 class PolyphaseResampler : public MultiChannelResampler {
34 public:
35     /**
36      *
37      * @param builder containing lots of parameters
38      */
39     explicit PolyphaseResampler(const MultiChannelResampler::Builder &builder);
40 
41     virtual ~PolyphaseResampler() = default;
42 
43     void readFrame(float *frame) override;
44 
45 protected:
46 
47     int32_t                mCoefficientCursor = 0;
48 
49 };
50 
51 } /* namespace RESAMPLER_OUTER_NAMESPACE::resampler */
52 
53 #endif //RESAMPLER_POLYPHASE_RESAMPLER_H
54