extern std::pair<int, int> audio_channel_types (std::list<int> mapped, int channels);
extern std::shared_ptr<AudioBuffers> remap (std::shared_ptr<const AudioBuffers> input, int output_channels, AudioMapping map);
extern size_t utf8_strlen (std::string s);
-extern void emit_subtitle_image (dcpomatic::ContentTimePeriod period, dcp::SubtitleImage sub, dcp::Size size, std::shared_ptr<TextDecoder> decoder);
+extern void emit_subtitle_image(dcpomatic::ContentTimePeriod period, dcp::SubtitleImage sub, dcp::Size parent_size, std::shared_ptr<TextDecoder> decoder);
extern void copy_in_bits (boost::filesystem::path from, boost::filesystem::path to, std::function<void (float)>);
extern dcp::Size scale_for_display (dcp::Size s, dcp::Size display_container, dcp::Size film_container, PixelQuanta quanta);
extern dcp::DecryptedKDM decrypt_kdm_with_helpful_error (dcp::EncryptedKDM kdm);