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 #include "chre/platform/platform_audio.h"
18
19 #include <cinttypes>
20
21 #include "chre/core/audio_request_manager.h"
22 #include "chre/core/audio_util.h"
23 #include "chre/core/event_loop_manager.h"
24 #include "chre/platform/fatal_error.h"
25 #include "chre/platform/log.h"
26 #include "chre/platform/system_time.h"
27
28 namespace chre {
29
30 namespace {
31
32 //! The fixed sampling rate for audio data when running CHRE on Android.
33 constexpr uint32_t kAndroidAudioSampleRate = 16000;
34
35 //! The minimum buffer size in samples.
36 constexpr uint32_t kAndroidAudioMinBufferSize = kAndroidAudioSampleRate / 10;
37
38 //! The maximum buffer size in samples.
39 constexpr uint32_t kAndroidAudioMaxBufferSize = kAndroidAudioSampleRate * 10;
40
41 } // namespace
42
audioReadCallback(void * cookie)43 void PlatformAudioBase::audioReadCallback(void *cookie) {
44 auto *platformAudio = static_cast<PlatformAudio *>(cookie);
45
46 auto &dataEvent = platformAudio->mDataEvent;
47 Nanoseconds samplingTime = AudioUtil::getDurationFromSampleCountAndRate(
48 platformAudio->mNumSamples, kAndroidAudioSampleRate);
49 dataEvent.timestamp =
50 (SystemTime::getMonotonicTime() - samplingTime).toRawNanoseconds();
51
52 if (dataEvent.format == CHRE_AUDIO_DATA_FORMAT_16_BIT_SIGNED_PCM) {
53 uint32_t intervalNumSamples = AudioUtil::getSampleCountFromRateAndDuration(
54 kAndroidAudioSampleRate, platformAudio->mEventDelay);
55
56 // Determine how much new audio data is required to be read from the device.
57 // Samples that are already buffered by this implementation may be reused.
58 int16_t *audioBuffer = platformAudio->mBuffer.data();
59 uint32_t readAmount = platformAudio->mNumSamples;
60 if (intervalNumSamples > platformAudio->mNumSamples) {
61 uint32_t seekAmount = intervalNumSamples - platformAudio->mNumSamples;
62 audioBuffer = &platformAudio->mBuffer.data()[seekAmount];
63 readAmount = platformAudio->mNumSamples - seekAmount;
64 }
65
66 // Perform a blocking read. A timeout of 1 nanoasecond is passed here to
67 // ensure that we read exactly the amount of requested audio frames. The
68 // timer ensures that we wait approximately long enough to read the
69 // requested number of samples and the timeout ensures that they match
70 // exactly.
71 int32_t framesRead =
72 AAudioStream_read(platformAudio->mStream, audioBuffer, readAmount, 1);
73 if (framesRead != static_cast<int32_t>(platformAudio->mNumSamples)) {
74 FATAL_ERROR("Failed to read requested number of audio samples");
75 } else {
76 EventLoopManagerSingleton::get()
77 ->getAudioRequestManager()
78 .handleAudioDataEvent(&dataEvent);
79 }
80 } else {
81 FATAL_ERROR("Unimplemented data format");
82 }
83 }
84
PlatformAudio()85 PlatformAudio::PlatformAudio() {
86 if (!mTimer.init()) {
87 FATAL_ERROR("Failed to initialize audio timer");
88 }
89
90 aaudio_result_t result = AAudio_createStreamBuilder(&mStreamBuilder);
91 if (result != AAUDIO_OK) {
92 FATAL_ERROR("Failed to create audio stream builder with %" PRId32, result);
93 }
94
95 AAudioStreamBuilder_setDirection(mStreamBuilder, AAUDIO_DIRECTION_INPUT);
96 AAudioStreamBuilder_setSharingMode(mStreamBuilder,
97 AAUDIO_SHARING_MODE_SHARED);
98 AAudioStreamBuilder_setSampleRate(mStreamBuilder, kAndroidAudioSampleRate);
99 AAudioStreamBuilder_setChannelCount(mStreamBuilder, 1);
100 AAudioStreamBuilder_setFormat(mStreamBuilder, AAUDIO_FORMAT_PCM_I16);
101 AAudioStreamBuilder_setBufferCapacityInFrames(mStreamBuilder,
102 kAndroidAudioMaxBufferSize);
103
104 result = AAudioStreamBuilder_openStream(mStreamBuilder, &mStream);
105 if (result != AAUDIO_OK) {
106 FATAL_ERROR("Failed to create audio stream with %" PRId32, result);
107 }
108
109 int32_t bufferSize = AAudioStream_getBufferCapacityInFrames(mStream);
110 LOGD("Created audio stream with %" PRId32 " frames buffer size", bufferSize);
111
112 mMinBufferDuration = AudioUtil::getDurationFromSampleCountAndRate(
113 kAndroidAudioMinBufferSize, kAndroidAudioSampleRate)
114 .toRawNanoseconds();
115 mMaxBufferDuration = AudioUtil::getDurationFromSampleCountAndRate(
116 bufferSize, kAndroidAudioSampleRate)
117 .toRawNanoseconds();
118
119 result = AAudioStream_requestStart(mStream);
120 if (result != AAUDIO_OK) {
121 FATAL_ERROR("Failed to start audio stream with %" PRId32, result);
122 }
123
124 mBuffer.resize(bufferSize);
125 initAudioDataEvent();
126 }
127
~PlatformAudio()128 PlatformAudio::~PlatformAudio() {
129 AAudioStream_close(mStream);
130 AAudioStreamBuilder_delete(mStreamBuilder);
131 }
132
init()133 void PlatformAudio::init() {
134 // TODO: Implement this.
135 }
136
setHandleEnabled(uint32_t handle,bool enabled)137 void PlatformAudio::setHandleEnabled(uint32_t handle, bool enabled) {
138 // TODO: Implement this.
139 }
140
requestAudioDataEvent(uint32_t handle,uint32_t numSamples,Nanoseconds eventDelay)141 bool PlatformAudio::requestAudioDataEvent(uint32_t handle, uint32_t numSamples,
142 Nanoseconds eventDelay) {
143 mNumSamples = numSamples;
144 mEventDelay = eventDelay;
145 mDataEvent.sampleCount = numSamples;
146 return mTimer.set(audioReadCallback, this, eventDelay);
147 }
148
cancelAudioDataEventRequest(uint32_t handle)149 void PlatformAudio::cancelAudioDataEventRequest(uint32_t handle) {
150 mTimer.cancel();
151 }
152
releaseAudioDataEvent(struct chreAudioDataEvent * event)153 void PlatformAudio::releaseAudioDataEvent(struct chreAudioDataEvent *event) {}
154
getSourceCount()155 size_t PlatformAudio::getSourceCount() {
156 // Hardcoded at one as the Android platform only surfaces the default mic.
157 return 1;
158 }
159
getAudioSource(uint32_t handle,chreAudioSource * audioSource) const160 bool PlatformAudio::getAudioSource(uint32_t handle,
161 chreAudioSource *audioSource) const {
162 bool success = false;
163 if (handle == 0) {
164 audioSource->name = "Default Android Audio Input";
165 audioSource->sampleRate = kAndroidAudioSampleRate;
166 audioSource->minBufferDuration = mMinBufferDuration;
167 audioSource->maxBufferDuration = mMaxBufferDuration;
168 audioSource->format = mDataEvent.format;
169 success = true;
170 }
171
172 return success;
173 }
174
initAudioDataEvent()175 void PlatformAudioBase::initAudioDataEvent() {
176 mDataEvent.version = CHRE_AUDIO_DATA_EVENT_VERSION;
177 memset(mDataEvent.reserved, 0, sizeof(mDataEvent.reserved));
178 mDataEvent.handle = 0;
179 mDataEvent.sampleRate = kAndroidAudioSampleRate;
180 mDataEvent.format = CHRE_AUDIO_DATA_FORMAT_16_BIT_SIGNED_PCM;
181 mDataEvent.samplesS16 = mBuffer.data();
182 }
183
184 } // namespace chre
185