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/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "chre/platform/platform_audio.h"
#include <cinttypes>
#include "chre/core/audio_request_manager.h"
#include "chre/core/audio_util.h"
#include "chre/core/event_loop_manager.h"
#include "chre/platform/fatal_error.h"
#include "chre/platform/log.h"
#include "chre/platform/system_time.h"
namespace chre {
namespace {
//! The fixed sampling rate for audio data when running CHRE on Android.
constexpr uint32_t kAndroidAudioSampleRate = 16000;
//! The minimum buffer size in samples.
constexpr uint32_t kAndroidAudioMinBufferSize = kAndroidAudioSampleRate / 10;
//! The maximum buffer size in samples.
constexpr uint32_t kAndroidAudioMaxBufferSize = kAndroidAudioSampleRate * 10;
} // namespace
void PlatformAudioBase::audioReadCallback(void *cookie) {
auto *platformAudio = static_cast<PlatformAudio *>(cookie);
auto &dataEvent = platformAudio->mDataEvent;
Nanoseconds samplingTime = AudioUtil::getDurationFromSampleCountAndRate(
platformAudio->mNumSamples, kAndroidAudioSampleRate);
dataEvent.timestamp =
(SystemTime::getMonotonicTime() - samplingTime).toRawNanoseconds();
if (dataEvent.format == CHRE_AUDIO_DATA_FORMAT_16_BIT_SIGNED_PCM) {
uint32_t intervalNumSamples = AudioUtil::getSampleCountFromRateAndDuration(
kAndroidAudioSampleRate, platformAudio->mEventDelay);
// Determine how much new audio data is required to be read from the device.
// Samples that are already buffered by this implementation may be reused.
int16_t *audioBuffer = platformAudio->mBuffer.data();
uint32_t readAmount = platformAudio->mNumSamples;
if (intervalNumSamples > platformAudio->mNumSamples) {
uint32_t seekAmount = intervalNumSamples - platformAudio->mNumSamples;
audioBuffer = &platformAudio->mBuffer.data()[seekAmount];
readAmount = platformAudio->mNumSamples - seekAmount;
}
// Perform a blocking read. A timeout of 1 nanoasecond is passed here to
// ensure that we read exactly the amount of requested audio frames. The
// timer ensures that we wait approximately long enough to read the
// requested number of samples and the timeout ensures that they match
// exactly.
int32_t framesRead =
AAudioStream_read(platformAudio->mStream, audioBuffer, readAmount, 1);
if (framesRead != static_cast<int32_t>(platformAudio->mNumSamples)) {
FATAL_ERROR("Failed to read requested number of audio samples");
} else {
EventLoopManagerSingleton::get()
->getAudioRequestManager()
.handleAudioDataEvent(&dataEvent);
}
} else {
FATAL_ERROR("Unimplemented data format");
}
}
PlatformAudio::PlatformAudio() {
if (!mTimer.init()) {
FATAL_ERROR("Failed to initialize audio timer");
}
aaudio_result_t result = AAudio_createStreamBuilder(&mStreamBuilder);
if (result != AAUDIO_OK) {
FATAL_ERROR("Failed to create audio stream builder with %" PRId32, result);
}
AAudioStreamBuilder_setDirection(mStreamBuilder, AAUDIO_DIRECTION_INPUT);
AAudioStreamBuilder_setSharingMode(mStreamBuilder,
AAUDIO_SHARING_MODE_SHARED);
AAudioStreamBuilder_setSampleRate(mStreamBuilder, kAndroidAudioSampleRate);
AAudioStreamBuilder_setChannelCount(mStreamBuilder, 1);
AAudioStreamBuilder_setFormat(mStreamBuilder, AAUDIO_FORMAT_PCM_I16);
AAudioStreamBuilder_setBufferCapacityInFrames(mStreamBuilder,
kAndroidAudioMaxBufferSize);
result = AAudioStreamBuilder_openStream(mStreamBuilder, &mStream);
if (result != AAUDIO_OK) {
FATAL_ERROR("Failed to create audio stream with %" PRId32, result);
}
int32_t bufferSize = AAudioStream_getBufferCapacityInFrames(mStream);
LOGD("Created audio stream with %" PRId32 " frames buffer size", bufferSize);
mMinBufferDuration = AudioUtil::getDurationFromSampleCountAndRate(
kAndroidAudioMinBufferSize, kAndroidAudioSampleRate)
.toRawNanoseconds();
mMaxBufferDuration = AudioUtil::getDurationFromSampleCountAndRate(
bufferSize, kAndroidAudioSampleRate)
.toRawNanoseconds();
result = AAudioStream_requestStart(mStream);
if (result != AAUDIO_OK) {
FATAL_ERROR("Failed to start audio stream with %" PRId32, result);
}
mBuffer.resize(bufferSize);
initAudioDataEvent();
}
PlatformAudio::~PlatformAudio() {
AAudioStream_close(mStream);
AAudioStreamBuilder_delete(mStreamBuilder);
}
void PlatformAudio::init() {
// TODO: Implement this.
}
void PlatformAudio::setHandleEnabled(uint32_t handle, bool enabled) {
// TODO: Implement this.
}
bool PlatformAudio::requestAudioDataEvent(uint32_t handle, uint32_t numSamples,
Nanoseconds eventDelay) {
mNumSamples = numSamples;
mEventDelay = eventDelay;
mDataEvent.sampleCount = numSamples;
return mTimer.set(audioReadCallback, this, eventDelay);
}
void PlatformAudio::cancelAudioDataEventRequest(uint32_t handle) {
mTimer.cancel();
}
void PlatformAudio::releaseAudioDataEvent(struct chreAudioDataEvent *event) {}
size_t PlatformAudio::getSourceCount() {
// Hardcoded at one as the Android platform only surfaces the default mic.
return 1;
}
bool PlatformAudio::getAudioSource(uint32_t handle,
chreAudioSource *audioSource) const {
bool success = false;
if (handle == 0) {
audioSource->name = "Default Android Audio Input";
audioSource->sampleRate = kAndroidAudioSampleRate;
audioSource->minBufferDuration = mMinBufferDuration;
audioSource->maxBufferDuration = mMaxBufferDuration;
audioSource->format = mDataEvent.format;
success = true;
}
return success;
}
void PlatformAudioBase::initAudioDataEvent() {
mDataEvent.version = CHRE_AUDIO_DATA_EVENT_VERSION;
memset(mDataEvent.reserved, 0, sizeof(mDataEvent.reserved));
mDataEvent.handle = 0;
mDataEvent.sampleRate = kAndroidAudioSampleRate;
mDataEvent.format = CHRE_AUDIO_DATA_FORMAT_16_BIT_SIGNED_PCM;
mDataEvent.samplesS16 = mBuffer.data();
}
} // namespace chre
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