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