void video (boost::weak_ptr<Piece>, ContentVideo);
void audio (boost::weak_ptr<Piece>, AudioStreamPtr, ContentAudio);
void bitmap_text_start (boost::weak_ptr<Piece>, boost::weak_ptr<const TextContent>, ContentBitmapText);
void plain_text_start (boost::weak_ptr<Piece>, boost::weak_ptr<const TextContent>, ContentStringText);
void subtitle_stop (boost::weak_ptr<Piece>, boost::weak_ptr<const TextContent>, dcpomatic::ContentTime);
void video (boost::weak_ptr<Piece>, ContentVideo);
void audio (boost::weak_ptr<Piece>, AudioStreamPtr, ContentAudio);
void bitmap_text_start (boost::weak_ptr<Piece>, boost::weak_ptr<const TextContent>, ContentBitmapText);
void plain_text_start (boost::weak_ptr<Piece>, boost::weak_ptr<const TextContent>, ContentStringText);
void subtitle_stop (boost::weak_ptr<Piece>, boost::weak_ptr<const TextContent>, dcpomatic::ContentTime);