+void
+DCPDecoder::next_reel ()
+{
+ _offset += (*_reel)->main_picture()->duration();
+ ++_reel;
+ get_readers ();
+}
+
+void
+DCPDecoder::get_readers ()
+{
+ if (_reel == _reels.end() || !_dcp_content->can_be_played ()) {
+ _mono_reader.reset ();
+ _stereo_reader.reset ();
+ _sound_reader.reset ();
+ return;
+ }
+
+ if ((*_reel)->main_picture()) {
+ shared_ptr<dcp::PictureAsset> asset = (*_reel)->main_picture()->asset ();
+ shared_ptr<dcp::MonoPictureAsset> mono = dynamic_pointer_cast<dcp::MonoPictureAsset> (asset);
+ shared_ptr<dcp::StereoPictureAsset> stereo = dynamic_pointer_cast<dcp::StereoPictureAsset> (asset);
+ DCPOMATIC_ASSERT (mono || stereo);
+ if (mono) {
+ _mono_reader = mono->start_read ();
+ _stereo_reader.reset ();
+ } else {
+ _stereo_reader = stereo->start_read ();
+ _mono_reader.reset ();
+ }
+ } else {
+ _mono_reader.reset ();
+ _stereo_reader.reset ();
+ }
+
+ if ((*_reel)->main_sound()) {
+ _sound_reader = (*_reel)->main_sound()->asset()->start_read ();
+ } else {
+ _sound_reader.reset ();
+ }
+}
+