media_file_format_id
bool operator==(const media_file_format_id& a, const media_file_format_id& b);
bool operator<(const media_file_format_id& a, const media_file_format_id& b);
media_file_format_id id; // Opaque id used to construct a
operator==(const media_file_format_id& a, const media_file_format_id& b)
operator<(const media_file_format_id& a, const media_file_format_id& b)