Oboe 1.5 A library for creating real-time audio apps on Android

LatencyTuner.h
1 /*
2 * Copyright 2017 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_LATENCY_TUNER_
18 #define OBOE_LATENCY_TUNER_
19
20 #include <atomic>
21 #include <cstdint>
22 #include "oboe/Definitions.h"
23 #include "oboe/AudioStream.h"
24
25 namespace oboe {
26
41 class LatencyTuner {
42 public:
43
49 explicit LatencyTuner(AudioStream &stream);
50
57 explicit LatencyTuner(AudioStream &stream, int32_t maximumBufferSize);
58
67 Result tune();
68
77 void requestReset();
78
84 bool isAtMaximumBufferSize();
85
91 void setMinimumBufferSize(int32_t bufferSize) {
92 mMinimumBufferSize = bufferSize;
93 }
94
95 int32_t getMinimumBufferSize() const {
96 return mMinimumBufferSize;
97 }
98
108 void setBufferSizeIncrement(int32_t sizeIncrement) {
109 mBufferSizeIncrement = sizeIncrement;
110 }
111
112 int32_t getBufferSizeIncrement() const {
113 return mBufferSizeIncrement;
114 }
115
116 private:
117
124 void reset();
125
126 enum class State {
127 Idle,
128 Active,
129 AtMax,
130 Unsupported
131 } ;
132
133 // arbitrary number of calls to wait before bumping up the latency
134 static constexpr int32_t kIdleCount = 8;
135 static constexpr int32_t kDefaultNumBursts = 2;
136
137 AudioStream &mStream;
138 State mState = State::Idle;
139 int32_t mMaxBufferSize = 0;
140 int32_t mPreviousXRuns = 0;
141 int32_t mIdleCountDown = 0;
142 int32_t mMinimumBufferSize;
143 int32_t mBufferSizeIncrement;
144 std::atomic<int32_t> mLatencyTriggerRequests{0}; // TODO user atomic requester from AAudio
145 std::atomic<int32_t> mLatencyTriggerResponses{0};
146 };
147
148 } // namespace oboe
149
150 #endif // OBOE_LATENCY_TUNER_
oboe::LatencyTuner::setBufferSizeIncrement
void setBufferSizeIncrement(int32_t sizeIncrement)
Definition: LatencyTuner.h:108
oboe::LatencyTuner::requestReset
void requestReset()
oboe::AudioStream
Definition: AudioStream.h:44
oboe::LatencyTuner::isAtMaximumBufferSize
bool isAtMaximumBufferSize()
oboe::LatencyTuner::LatencyTuner
LatencyTuner(AudioStream &stream)
oboe::LatencyTuner::tune
Result tune()
oboe::Result
Result
Definition: Definitions.h:131
oboe::LatencyTuner
Definition: LatencyTuner.h:41
oboe::LatencyTuner::setMinimumBufferSize
void setMinimumBufferSize(int32_t bufferSize)
Definition: LatencyTuner.h:91
oboe
Definition: AudioStream.h:31