void Resampler::resample(const AudioBuffer &dataIn, AudioBuffer &dataOut)
{
const double inputFreq = dataIn.getSampleRate();
const double outputFreq = dataOut.getSampleRate();
const double sampleFactor = outputFreq / inputFreq;
if (sampleFactor == 1.0)
return;
const size_t nbFrames = dataIn.frames();
const size_t nbChans = dataIn.channels();
if (nbChans != format_.nb_channels) {
// change channel num if needed
int err;
src_delete(src_state_);
src_state_ = src_new(SRC_LINEAR, nbChans, &err);
format_.nb_channels = nbChans;
DEBUG("SRC channel number changed.");
}
if (nbChans != dataOut.channels()) {
DEBUG("Output buffer had the wrong number of channels (in: %d, out: %d).", nbChans, dataOut.channels());
dataOut.setChannelNum(nbChans);
}
size_t inSamples = nbChans * nbFrames;
size_t outSamples = inSamples * sampleFactor;
// grow buffer if needed
floatBufferIn_.resize(inSamples);
floatBufferOut_.resize(outSamples);
scratchBuffer_.resize(outSamples);
SRC_DATA src_data;
src_data.data_in = floatBufferIn_.data();
src_data.data_out = floatBufferOut_.data();
src_data.input_frames = nbFrames;
src_data.output_frames = nbFrames * sampleFactor;
src_data.src_ratio = sampleFactor;
src_data.end_of_input = 0; // More data will come
dataIn.interleaveFloat(floatBufferIn_.data());
src_process(src_state_, &src_data);
/*
TODO: one-shot deinterleave and float-to-short conversion
*/
src_float_to_short_array(floatBufferOut_.data(), scratchBuffer_.data(), outSamples);
dataOut.deinterleave(scratchBuffer_.data(), src_data.output_frames, nbChans);
}
void
AudioSender::process()
{
auto& mainBuffer = Manager::instance().getRingBufferPool();
auto mainBuffFormat = mainBuffer.getInternalAudioFormat();
// compute nb of byte to get corresponding to 1 audio frame
const std::size_t samplesToGet = std::chrono::duration_cast<std::chrono::seconds>(mainBuffFormat.sample_rate * secondsPerPacket_).count();
if (mainBuffer.availableForGet(id_) < samplesToGet) {
const auto wait_time = std::chrono::duration_cast<std::chrono::milliseconds>(secondsPerPacket_);
if (not mainBuffer.waitForDataAvailable(id_, samplesToGet, wait_time))
return;
}
// get data
micData_.setFormat(mainBuffFormat);
micData_.resize(samplesToGet);
const auto samples = mainBuffer.getData(micData_, id_);
if (samples != samplesToGet)
return;
// down/upmix as needed
auto accountAudioCodec = std::static_pointer_cast<AccountAudioCodecInfo>(args_.codec);
micData_.setChannelNum(accountAudioCodec->audioformat.nb_channels, true);
if (mainBuffFormat.sample_rate != accountAudioCodec->audioformat.sample_rate) {
if (not resampler_) {
RING_DBG("Creating audio resampler");
resampler_.reset(new Resampler(accountAudioCodec->audioformat));
}
resampledData_.setFormat(accountAudioCodec->audioformat);
resampledData_.resize(samplesToGet);
resampler_->resample(micData_, resampledData_);
Smartools::getInstance().setLocalAudioCodec(audioEncoder_->getEncoderName());
if (audioEncoder_->encode_audio(resampledData_) < 0)
RING_ERR("encoding failed");
} else {
if (audioEncoder_->encode_audio(micData_) < 0)
RING_ERR("encoding failed");
}
}