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 #define LOG_TAG "AAudioService"
18 //#define LOG_NDEBUG 0
19 #include <utils/Log.h>
20
21 #include <cstring>
22 #include "AAudioMixer.h"
23
24 using android::WrappingBuffer;
25 using android::FifoBuffer;
26 using android::fifo_frames_t;
27
~AAudioMixer()28 AAudioMixer::~AAudioMixer() {
29 delete[] mOutputBuffer;
30 }
31
allocate(int32_t samplesPerFrame,int32_t framesPerBurst)32 void AAudioMixer::allocate(int32_t samplesPerFrame, int32_t framesPerBurst) {
33 mSamplesPerFrame = samplesPerFrame;
34 mFramesPerBurst = framesPerBurst;
35 int32_t samplesPerBuffer = samplesPerFrame * framesPerBurst;
36 mOutputBuffer = new float[samplesPerBuffer];
37 mBufferSizeInBytes = samplesPerBuffer * sizeof(float);
38 }
39
clear()40 void AAudioMixer::clear() {
41 memset(mOutputBuffer, 0, mBufferSizeInBytes);
42 }
43
mix(FifoBuffer * fifo,float volume)44 bool AAudioMixer::mix(FifoBuffer *fifo, float volume) {
45 WrappingBuffer wrappingBuffer;
46 float *destination = mOutputBuffer;
47 fifo_frames_t framesLeft = mFramesPerBurst;
48
49 // Gather the data from the client. May be in two parts.
50 fifo->getFullDataAvailable(&wrappingBuffer);
51
52 // Mix data in one or two parts.
53 int partIndex = 0;
54 while (framesLeft > 0 && partIndex < WrappingBuffer::SIZE) {
55 fifo_frames_t framesToMix = framesLeft;
56 fifo_frames_t framesAvailable = wrappingBuffer.numFrames[partIndex];
57 if (framesAvailable > 0) {
58 if (framesToMix > framesAvailable) {
59 framesToMix = framesAvailable;
60 }
61 mixPart(destination, (float *)wrappingBuffer.data[partIndex], framesToMix, volume);
62
63 destination += framesToMix * mSamplesPerFrame;
64 framesLeft -= framesToMix;
65 }
66 partIndex++;
67 }
68 fifo->getFifoControllerBase()->advanceReadIndex(mFramesPerBurst - framesLeft);
69 if (framesLeft > 0) {
70 //ALOGW("AAudioMixer::mix() UNDERFLOW by %d / %d frames ----- UNDERFLOW !!!!!!!!!!",
71 // framesLeft, mFramesPerBurst);
72 }
73 return (framesLeft > 0); // did not get all the frames we needed, ie. "underflow"
74 }
75
mixPart(float * destination,float * source,int32_t numFrames,float volume)76 void AAudioMixer::mixPart(float *destination, float *source, int32_t numFrames, float volume) {
77 int32_t numSamples = numFrames * mSamplesPerFrame;
78 // TODO maybe optimize using SIMD
79 for (int sampleIndex = 0; sampleIndex < numSamples; sampleIndex++) {
80 *destination++ += *source++ * volume;
81 }
82 }
83
getOutputBuffer()84 float *AAudioMixer::getOutputBuffer() {
85 return mOutputBuffer;
86 }
87