+/** @return true if sub starts a new image subtitle */
+bool
+FFmpeg::subtitle_starts_image (AVSubtitle const & sub)
+{
+ bool image = false;
+ bool text = false;
+
+ for (unsigned int i = 0; i < sub.num_rects; ++i) {
+ switch (sub.rects[i]->type) {
+ case SUBTITLE_BITMAP:
+ image = true;
+ break;
+ case SUBTITLE_TEXT:
+ case SUBTITLE_ASS:
+ text = true;
+ break;
+ default:
+ break;
+ }
+ }
+
+ /* We can't cope with mixed image/text in one AVSubtitle */
+ DCPOMATIC_ASSERT (!image || !text);
+
+ return image;
+}
+