| #include "SineSource.h" |
| |
| #include <math.h> |
| |
| #include <media/stagefright/MediaBufferGroup.h> |
| #include <media/stagefright/MediaDebug.h> |
| #include <media/stagefright/MediaDefs.h> |
| #include <media/stagefright/MetaData.h> |
| |
| namespace android { |
| |
| SineSource::SineSource(int32_t sampleRate, int32_t numChannels) |
| : mStarted(false), |
| mSampleRate(sampleRate), |
| mNumChannels(numChannels), |
| mPhase(0), |
| mGroup(NULL) { |
| CHECK(numChannels == 1 || numChannels == 2); |
| } |
| |
| SineSource::~SineSource() { |
| if (mStarted) { |
| stop(); |
| } |
| } |
| |
| status_t SineSource::start(MetaData *params) { |
| CHECK(!mStarted); |
| |
| mGroup = new MediaBufferGroup; |
| mGroup->add_buffer(new MediaBuffer(kBufferSize)); |
| |
| mPhase = 0; |
| mStarted = true; |
| |
| return OK; |
| } |
| |
| status_t SineSource::stop() { |
| CHECK(mStarted); |
| |
| delete mGroup; |
| mGroup = NULL; |
| |
| mStarted = false; |
| |
| return OK; |
| } |
| |
| sp<MetaData> SineSource::getFormat() { |
| sp<MetaData> meta = new MetaData; |
| meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_AUDIO_RAW); |
| meta->setInt32(kKeyChannelCount, mNumChannels); |
| meta->setInt32(kKeySampleRate, mSampleRate); |
| |
| return meta; |
| } |
| |
| status_t SineSource::read( |
| MediaBuffer **out, const ReadOptions *options) { |
| *out = NULL; |
| |
| MediaBuffer *buffer; |
| status_t err = mGroup->acquire_buffer(&buffer); |
| |
| if (err != OK) { |
| return err; |
| } |
| |
| size_t frameSize = mNumChannels * sizeof(int16_t); |
| size_t numFramesPerBuffer = buffer->size() / frameSize; |
| |
| int16_t *ptr = (int16_t *)buffer->data(); |
| |
| const double k = kFrequency / mSampleRate * (2.0 * M_PI); |
| |
| double x = mPhase * k; |
| for (size_t i = 0; i < numFramesPerBuffer; ++i) { |
| int16_t amplitude = (int16_t)(32767.0 * sin(x)); |
| |
| *ptr++ = amplitude; |
| if (mNumChannels == 2) { |
| *ptr++ = amplitude; |
| } |
| |
| x += k; |
| } |
| |
| buffer->meta_data()->setInt64( |
| kKeyTime, ((int64_t)mPhase * 1000000) / mSampleRate); |
| |
| mPhase += numFramesPerBuffer; |
| |
| buffer->set_range(0, numFramesPerBuffer * frameSize); |
| |
| *out = buffer; |
| |
| return OK; |
| } |
| |
| } // namespace android |