Fix failure to load OV after adding a VF to a project.

[dcpomatic.git] / src / lib / dcp_decoder.cc

diff --git a/src/lib/dcp_decoder.cc b/src/lib/dcp_decoder.cc
index 95cad926620ad9a4824b40e8ff1914331d3e776e..4b189189e0b61fc395e83658968a1b34cf44947b 100644 (file)
--- a/src/lib/dcp_decoder.cc
+++ b/src/lib/dcp_decoder.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2014-2018 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2014-2019 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -28,6 +28,7 @@
 #include "ffmpeg_image_proxy.h"
 #include "image.h"
 #include "config.h"
+#include "digester.h"
 #include <dcp/dcp.h>
 #include <dcp/cpl.h>
 #include <dcp/reel.h>
@@ -52,6 +53,7 @@
 
 using std::list;
 using std::cout;
+using std::string;
 using boost::shared_ptr;
 using boost::dynamic_pointer_cast;
 using boost::optional;
@@ -75,16 +77,18 @@ DCPDecoder::DCPDecoder (shared_ptr<const Film> film, shared_ptr<const DCPContent
                }
        }
 
-       if (old) {
-               _reels = old->_reels;
+       /* We try to avoid re-scanning the DCP's files every time we make a new DCPDecoder; we do this
+          by re-using the _reels list.  Before we do this we need to check that nothing too serious
+          has changed in the DCPContent.
 
-               /* We might have gained a KDM since we made the Reel objects */
-               if (_dcp_content->kdm ()) {
-                       dcp::DecryptedKDM k = decrypted_kdm ();
-                       BOOST_FOREACH (shared_ptr<dcp::Reel> i, _reels) {
-                               i->add (k);
-                       }
-               }
+          We do this by storing a digest of the important bits of the DCPContent and then checking that's
+          the same before we re-use _reels.
+       */
+
+       _lazy_digest = calculate_lazy_digest (c);
+
+       if (old && old->lazy_digest() == _lazy_digest) {
+               _reels = old->_reels;
        } else {
 
                list<shared_ptr<dcp::CPL> > cpl_list = cpls ();
@@ -425,3 +429,18 @@ DCPDecoder::set_forced_reduction (optional<int> reduction)
 {
        _forced_reduction = reduction;
 }
+
+string
+DCPDecoder::calculate_lazy_digest (shared_ptr<const DCPContent> c) const
+{
+       Digester d;
+       BOOST_FOREACH (boost::filesystem::path i, c->paths()) {
+               d.add (i.string());
+       }
+       d.add (static_cast<bool>(_dcp_content->kdm()));
+       d.add (static_cast<bool>(c->cpl()));
+       if (c->cpl()) {
+               d.add (c->cpl().get());
+       }
+       return d.get ();
+}