Method createByMixingToMono

src/core/AudioBus.cpp:763–806

}

std::unique_ptr<AudioBus> AudioBus::createByMixingToMono(const AudioBus * sourceBus)
{
    if (sourceBus->isSilent())
    {
        return std::unique_ptr<AudioBus>(new AudioBus(Channels::Mono, sourceBus->length()));
    }

    switch (sourceBus->numberOfChannels())
    {
        case Channels::Mono:
            // Simply create an exact copy.
            return AudioBus::createBufferFromRange(sourceBus, 0, sourceBus->length());
        default:
        {
            const int n = sourceBus->length();
            const int m = sourceBus->numberOfChannels();
            std::unique_ptr<AudioBus> destinationBus(new AudioBus(Channels::Mono, n));
            float * destination = destinationBus->channel(0)->mutableData();

            // Do the mono mixdown.
            for (int i = 0; i < n; ++i)
            {
                destination[i] = 0.0;

                for (int j = 0; j < m; ++j)
                {
                    const float * source = sourceBus->channel(j)->data();
                    destination[j] += source[j];
                }

                destination[i] /= m;
            }

            destinationBus->clearSilentFlag();
            destinationBus->setSampleRate(sourceBus->sampleRate());

            return destinationBus;
        }
    }

    ASSERT_NOT_REACHED();

    return nullptr;
}

bool AudioBus::isSilent() const
{