void emit_bitmap_start (ContentBitmapText const& bitmap);
void emit_bitmap (dcpomatic::ContentTimePeriod period, std::shared_ptr<const Image> image, dcpomatic::Rect<double> rect);
void emit_bitmap_start (ContentBitmapText const& bitmap);
void emit_bitmap (dcpomatic::ContentTimePeriod period, std::shared_ptr<const Image> image, dcpomatic::Rect<double> rect);