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 OBOE_POLYPHASE_RESAMPLER_H
18 #define OBOE_POLYPHASE_RESAMPLER_H
19 
20 #include <memory>
21 #include <vector>
22 #include <sys/types.h>
23 #include <unistd.h>
24 #include "MultiChannelResampler.h"
25 
26 namespace resampler {
27 /**
28  * Resampler that is optimized for a reduced ratio of sample rates.
29  * All of the coefficients for each possible phase value are pre-calculated.
30  */
31 class PolyphaseResampler : public MultiChannelResampler {
32 public:
33     /**
34      *
35      * @param builder containing lots of parameters
36      */
37     explicit PolyphaseResampler(const MultiChannelResampler::Builder &builder);
38 
39     virtual ~PolyphaseResampler() = default;
40 
41     void readFrame(float *frame) override;
42 
43 protected:
44 
45     int32_t                mCoefficientCursor = 0;
46 
47 };
48 
49 }
50 
51 #endif //OBOE_POLYPHASE_RESAMPLER_H
52