+string
+FFmpeg::subtitle_id (AVSubtitle const & sub)
+{
+ Digester digester;
+ digester.add (sub.pts);
+ for (unsigned int i = 0; i < sub.num_rects; ++i) {
+ AVSubtitleRect* rect = sub.rects[i];
+ if (rect->type == SUBTITLE_BITMAP) {
+ digester.add (rect->x);
+ digester.add (rect->y);
+ digester.add (rect->w);
+ digester.add (rect->h);
+#ifdef DCPOMATIC_HAVE_AVSUBTITLERECT_PICT
+ int const line = rect->pict.linesize[0];
+ for (int j = 0; j < rect->h; ++j) {
+ digester.add (rect->pict.data[0] + j * line, line);
+ }
+#else
+ int const line = rect->linesize[0];
+ for (int j = 0; j < rect->h; ++j) {
+ digester.add (rect->data[0] + j * line, line);
+ }
+#endif
+ } else if (rect->type == SUBTITLE_TEXT) {
+ digester.add (string (rect->text));
+ } else if (rect->type == SUBTITLE_ASS) {
+ digester.add (string (rect->ass));
+ }
+ }
+ return digester.get ();
+}
+
+/** @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;
+}
+