Method writeRecordingToWav

src/extended/RecorderNode.cpp:134–193

bool RecorderNode::writeRecordingToWav(const std::string & filenameWithWavExtension, bool mixToMono)
{
    size_t recordedChannelCount = m_data.size();
    if (!recordedChannelCount) return false;
    size_t numSamples = m_data[0].size();
    if (!numSamples) return false;

    std::unique_ptr<nqr::AudioData> fileData(new nqr::AudioData());

    std::vector<std::vector<float>> clear_data;
    for (int i = 0; i < recordedChannelCount; ++i)
        clear_data.emplace_back(std::vector<float>());

    {
        std::lock_guard<std::recursive_mutex> lock(m_mutex);
        m_data.swap(clear_data);
    }

    if (recordedChannelCount == 1)
    {
        // only one channel recorded
        fileData->samples.resize(numSamples);
        fileData->channelCount = 1;
        float* dst = fileData->samples.data();
        memcpy(dst, clear_data[0].data(), sizeof(float) * numSamples);
    }
    else if (recordedChannelCount > 1 && mixToMono)
    {
        // Mix channels to mono if requested, and there's more than one input channel.
        fileData->samples.resize(numSamples);
        fileData->channelCount = 1;
        float* dst = fileData->samples.data();
        for (size_t i = 0; i < numSamples; i++)
        {
            dst[i] = 0;
            for (size_t j = 0; j < m_channelCount; ++j)
                dst[i] += clear_data[j][i];
            dst[i] *= 1.f / static_cast<float>(m_channelCount);
        }
    }
    else
    {
        // straight through
        fileData->samples.resize(numSamples * recordedChannelCount);
        fileData->channelCount = static_cast<int>(recordedChannelCount);
        float* dst = fileData->samples.data();
        for (size_t i = 0; i < numSamples; i++)
        {
            for (size_t j = 0; j < recordedChannelCount; ++j)
                *dst++ = clear_data[j][i];
        }
    }

    fileData->sampleRate = static_cast<int>(m_sampleRate);
    fileData->sourceFormat = nqr::PCM_FLT;

    nqr::EncoderParams params = {static_cast<int>(recordedChannelCount), nqr::PCM_FLT, nqr::DITHER_NONE};
    bool result = nqr::EncoderError::NoError == nqr::encode_wav_to_disk(params, fileData.get(), filenameWithWavExtension);