1 /*
2  * Copyright (C) 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 AAUDIO_AAUDIO_MIXER_H
18 #define AAUDIO_AAUDIO_MIXER_H
19 
20 #include <stdint.h>
21 
22 #include <aaudio/AAudio.h>
23 #include <fifo/FifoBuffer.h>
24 
25 class AAudioMixer {
26 public:
AAudioMixer()27     AAudioMixer() {}
28 
29     void allocate(int32_t samplesPerFrame, int32_t framesPerBurst);
30 
31     void clear();
32 
33     /**
34      * Mix from this FIFO
35      * @param streamIndex for marking stream variables in systrace
36      * @param fifo to read from
37      * @param allowUnderflow if true then allow mixer to advance read index past the write index
38      * @return frames read from this stream
39      */
40     int32_t mix(int streamIndex, std::shared_ptr<android::FifoBuffer> fifo, bool allowUnderflow);
41 
42     float *getOutputBuffer();
43 
getFramesPerBurst()44     int32_t getFramesPerBurst() const { return mFramesPerBurst; }
45 
46 private:
47     void mixPart(float *destination, float *source, int32_t numFrames);
48 
49     std::unique_ptr<float[]> mOutputBuffer;
50     int32_t  mSamplesPerFrame = 0;
51     int32_t  mFramesPerBurst = 0;
52     int32_t  mBufferSizeInBytes = 0;
53 };
54 
55 #endif //AAUDIO_AAUDIO_MIXER_H
56