1 /* 2 * Copyright 2015 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 FLOWGRAPH_RAMP_LINEAR_H 18 #define FLOWGRAPH_RAMP_LINEAR_H 19 20 #include <atomic> 21 #include <unistd.h> 22 #include <sys/types.h> 23 24 #include "AudioProcessorBase.h" 25 26 namespace flowgraph { 27 28 class RampLinear : public AudioProcessorBase { 29 public: 30 explicit RampLinear(int32_t channelCount); 31 32 virtual ~RampLinear() = default; 33 34 int32_t onProcess(int64_t framePosition, int32_t numFrames) override; 35 36 /** 37 * This is used for the next ramp. 38 * Calling this does not affect a ramp that is in progress. 39 */ 40 void setLengthInFrames(int32_t frames); 41 getLengthInFrames()42 int32_t getLengthInFrames() const { 43 return mLengthInFrames; 44 } 45 46 /** 47 * This may be safely called by another thread. 48 * @param target 49 */ 50 void setTarget(float target); 51 getTarget()52 float getTarget() const { 53 return mTarget.load(); 54 } 55 56 /** 57 * Force the nextSegment to start from this level. 58 * 59 * WARNING: this can cause a discontinuity if called while the ramp is being used. 60 * Only call this when setting the initial ramp. 61 * 62 * @param level 63 */ forceCurrent(float level)64 void forceCurrent(float level) { 65 mLevelFrom = level; 66 mLevelTo = level; 67 } 68 69 AudioFloatInputPort input; 70 AudioFloatOutputPort output; 71 72 private: 73 74 float interpolateCurrent(); 75 76 std::atomic<float> mTarget; 77 78 int32_t mLengthInFrames = 48000.0f / 100.0f ; // 10 msec at 48000 Hz; 79 int32_t mRemaining = 0; 80 float mScaler = 0.0f; 81 float mLevelFrom = 0.0f; 82 float mLevelTo = 0.0f; 83 }; 84 85 } /* namespace flowgraph */ 86 87 #endif //FLOWGRAPH_RAMP_LINEAR_H 88