void LVAudioresample_LowQuality(M4OSA_Int16* out, M4OSA_Int16* input,
M4OSA_Int32 outFrameCount, M4OSA_Context resamplerContext) {
VideoEditorResampler *context =
(VideoEditorResampler *)resamplerContext;
int32_t *pTmpBuffer = NULL;
context->nbSamples = (context->inSamplingRate * outFrameCount) / context->outSamplingRate;
memcpy(context->mInput,input,(context->nbSamples * context->nbChannels * sizeof(int16_t)));
/*
SRC module always gives stereo output, hence 2 for stereo audio
*/
pTmpBuffer = (int32_t*)malloc(outFrameCount * 2 * sizeof(int32_t));
memset(pTmpBuffer, 0x00, outFrameCount * 2 * sizeof(int32_t));
context->mResampler->resample((int32_t *)pTmpBuffer,
(size_t)outFrameCount, (VideoEditorResampler *)resamplerContext);
// Convert back to 16 bits
ditherAndClamp((int32_t*)out, pTmpBuffer, outFrameCount);
free(pTmpBuffer);
pTmpBuffer = NULL;
}
status_t VideoEditorSRC::read(
MediaBuffer **buffer_out, const ReadOptions *options) {
ALOGV("read %p(%p)", this, mSource.get());
*buffer_out = NULL;
if (!mStarted) {
return ERROR_END_OF_STREAM;
}
if (mResampler) {
// Store the seek parameters
int64_t seekTimeUs;
ReadOptions::SeekMode mode = ReadOptions::SEEK_PREVIOUS_SYNC;
if (options && options->getSeekTo(&seekTimeUs, &mode)) {
ALOGV("read Seek %lld", seekTimeUs);
mSeekTimeUs = seekTimeUs;
mSeekMode = mode;
}
// We ask for 1024 frames in output
// resampler output is always 2 channels and 32 bits
const size_t kOutputFrameCount = 1024;
const size_t kBytes = kOutputFrameCount * 2 * sizeof(int32_t);
int32_t *pTmpBuffer = (int32_t *)calloc(1, kBytes);
if (!pTmpBuffer) {
ALOGE("calloc failed to allocate memory: %d bytes", kBytes);
return NO_MEMORY;
}
// Resample to target quality
mResampler->resample(pTmpBuffer, kOutputFrameCount, this);
if (mStopPending) {
stop();
mStopPending = false;
}
// Change resampler and retry if format change happened
if (mFormatChanged) {
mFormatChanged = false;
checkAndSetResampler();
free(pTmpBuffer);
return read(buffer_out, NULL);
}
// Create a new MediaBuffer
int32_t outBufferSize = kOutputFrameCount * 2 * sizeof(int16_t);
MediaBuffer* outBuffer = new MediaBuffer(outBufferSize);
// Convert back to 2 channels and 16 bits
ditherAndClamp(
(int32_t *)((uint8_t*)outBuffer->data() + outBuffer->range_offset()),
pTmpBuffer, kOutputFrameCount);
free(pTmpBuffer);
// Compute and set the new timestamp
sp<MetaData> to = outBuffer->meta_data();
int64_t totalOutDurationUs = (mAccuOutBufferSize * 1000000) / (mOutputSampleRate * 2 * 2);
int64_t timeUs = mInitialTimeStampUs + totalOutDurationUs;
to->setInt64(kKeyTime, timeUs);
// update the accumulate size
mAccuOutBufferSize += outBufferSize;
*buffer_out = outBuffer;
} else {
// Resampling not required. Read and pass-through.
MediaBuffer *aBuffer;
status_t err = mSource->read(&aBuffer, options);
if (err != OK) {
ALOGV("read returns err = %d", err);
}
if (err == INFO_FORMAT_CHANGED) {
checkAndSetResampler();
return read(buffer_out, NULL);
}
// EOS or some other error
if(err != OK) {
stop();
*buffer_out = NULL;
return err;
}
*buffer_out = aBuffer;
}
return OK;
}
