+/** @param size Size of picture that the subtitle will be overlaid onto */
+void
+emit_subtitle_image (ContentTimePeriod period, dcp::SubtitleImage sub, dcp::Size size, shared_ptr<TextDecoder> decoder)
+{
+ /* XXX: this is rather inefficient; decoding the image just to get its size */
+ FFmpegImageProxy proxy (sub.png_image());
+ shared_ptr<Image> image = proxy.image().first;
+ /* set up rect with height and width */
+ dcpomatic::Rect<double> rect(0, 0, image->size().width / double(size.width), image->size().height / double(size.height));
+
+ /* add in position */
+
+ switch (sub.h_align()) {
+ case dcp::HALIGN_LEFT:
+ rect.x += sub.h_position();
+ break;
+ case dcp::HALIGN_CENTER:
+ rect.x += 0.5 + sub.h_position() - rect.width / 2;
+ break;
+ case dcp::HALIGN_RIGHT:
+ rect.x += 1 - sub.h_position() - rect.width;
+ break;
+ }
+
+ switch (sub.v_align()) {
+ case dcp::VALIGN_TOP:
+ rect.y += sub.v_position();
+ break;
+ case dcp::VALIGN_CENTER:
+ rect.y += 0.5 + sub.v_position() - rect.height / 2;
+ break;
+ case dcp::VALIGN_BOTTOM:
+ rect.y += 1 - sub.v_position() - rect.height;
+ break;
+ }
+
+ decoder->emit_bitmap (period, image, rect);
+}
+