-/** @param f Film.
- * @param o Options.
- * @param j Job that we are running within, or 0
- */
-Decoder::Decoder (boost::shared_ptr<Film> f, boost::shared_ptr<const DecodeOptions> o, Job* j)
- : _film (f)
- , _opt (o)
- , _job (j)
+
+/** @return Earliest time of content that the next pass() will emit */
+ContentTime
+Decoder::position () const
+{
+ 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)