Fix DCP playback when an incorrect KDM is added, followed by

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

diff --git a/src/lib/dcp_decoder.cc b/src/lib/dcp_decoder.cc
index 90b730f5b5d921fb58a8d5535f230d6bb8e3e6f4..ab724cd6c75bbb7a5f02326e15b92f3a964a0322 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 +28,8 @@
 #include "ffmpeg_image_proxy.h"
 #include "image.h"
 #include "config.h"
+#include "digester.h"
+#include "frame_interval_checker.h"
 #include <dcp/dcp.h>
 #include <dcp/cpl.h>
 #include <dcp/reel.h>
@@ -44,6 +46,7 @@
 #include <dcp/sound_frame.h>
 #include <dcp/sound_asset_reader.h>
 #include <dcp/subtitle_image.h>
+#include <dcp/decrypted_kdm.h>
 #include <boost/foreach.hpp>
 #include <iostream>
 
@@ -51,6 +54,7 @@
 
 using std::list;
 using std::cout;
+using std::string;
 using boost::shared_ptr;
 using boost::dynamic_pointer_cast;
 using boost::optional;
@@ -74,7 +78,17 @@ DCPDecoder::DCPDecoder (shared_ptr<const Film> film, shared_ptr<const DCPContent
                }
        }
 
-       if (old) {
+       /* 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 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 {
 
@@ -112,7 +126,14 @@ DCPDecoder::DCPDecoder (shared_ptr<const Film> film, shared_ptr<const DCPContent
 bool
 DCPDecoder::pass ()
 {
-       if (_reel == _reels.end () || !_dcp_content->can_be_played ()) {
+       if (!_dcp_content->can_be_played()) {
+               return true;
+       }
+
+       if (_reel == _reels.end()) {
+               if (audio) {
+                       audio->flush ();
+               }
                return true;
        }
 
@@ -210,8 +231,14 @@ void
 DCPDecoder::pass_texts (ContentTime next, dcp::Size size)
 {
        list<shared_ptr<TextDecoder> >::const_iterator decoder = text.begin ();
+       if (decoder == text.end()) {
+               /* It's possible that there is now a main subtitle but no TextDecoders, for example if
+                  the CPL has just changed but the TextContent's texts have not been recreated yet.
+               */
+               return;
+       }
+
        if ((*_reel)->main_subtitle()) {
-               DCPOMATIC_ASSERT (decoder != text.end ());
                pass_texts (
                        next,
                        (*_reel)->main_subtitle()->asset(),
@@ -222,8 +249,8 @@ DCPDecoder::pass_texts (ContentTime next, dcp::Size size)
                        );
                ++decoder;
        }
+
        BOOST_FOREACH (shared_ptr<dcp::ReelClosedCaptionAsset> i, (*_reel)->closed_captions()) {
-               DCPOMATIC_ASSERT (decoder != text.end ());
                pass_texts (
                        next, i->asset(), _dcp_content->reference_text(TEXT_CLOSED_CAPTION), i->entry_point().get_value_or(0), *decoder, size
                        );
@@ -416,3 +443,26 @@ 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());
+       }
+       if (_dcp_content->kdm()) {
+               d.add(_dcp_content->kdm()->id());
+       }
+       d.add (static_cast<bool>(c->cpl()));
+       if (c->cpl()) {
+               d.add (c->cpl().get());
+       }
+       return d.get ();
+}
+
+ContentTime
+DCPDecoder::position () const
+{
+       return ContentTime::from_frames(_offset, _dcp_content->active_video_frame_rate(film())) + _next;
+}