+ optional<ContentTime> pos;
+ auto f = film();
+
+ if (video && !video->ignore() && (!pos || video->position(f).get_value_or(ContentTime()) < *pos)) {
+ pos = video->position(f);
+ }
+
+ if (audio && !audio->ignore() && (!pos || audio->position(f).get_value_or(ContentTime()) < *pos)) {
+ pos = audio->position(f);
+ }
+
+ /* Only decide position based on subtitle sources if there is nothing else
+ to go on. Otherwise we can have problems with muxed sources which have
+ (for example) video, audio and a subtitle. If the subtitle data runs out
+ before the video/audio the position() call will return the position of the
+ end of the subs. This causes this file to be pass()ed in favour of others,
+ which can cause bugs like #1581.
+ */
+ if (!pos) {
+ for (auto i: text) {
+ if (!i->ignore() && (!pos || i->position(f) < *pos)) {
+ pos = i->position(f);
+ }
+ }
+ }
+
+ return pos.get_value_or(ContentTime());
+}
+
+
+void
+Decoder::seek (ContentTime, bool)
+{
+ if (video) {
+ video->seek ();
+ }
+ if (audio) {
+ audio->seek ();
+ }
+ for (auto i: text) {
+ i->seek ();
+ }