extern std::pair<int, int> audio_channel_types (std::list<int> mapped, int channels);
extern boost::shared_ptr<AudioBuffers> remap (boost::shared_ptr<const AudioBuffers> input, int output_channels, AudioMapping map);
extern Eyes increment_eyes (Eyes e);
extern std::pair<int, int> audio_channel_types (std::list<int> mapped, int channels);
extern boost::shared_ptr<AudioBuffers> remap (boost::shared_ptr<const AudioBuffers> input, int output_channels, AudioMapping map);
extern Eyes increment_eyes (Eyes e);