Use MD5 digest of content file as part of the J2C directory, rather than the filename itself.

5 files changed, 49 insertions, 1 deletions

diff --git a/src/lib/film.cc b/src/lib/film.cc
index 502119db3..f11d30aba 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -193,6 +193,7 @@ Film::set_content (string c)
 	_state.audio_sample_rate = d->audio_sample_rate ();
 	_state.audio_sample_format = d->audio_sample_format ();
 
+	_state.content_digest = md5_digest (c);
 	_state.content = c;
 	
 	signal_changed (SIZE);
@@ -424,7 +425,7 @@ Film::j2k_dir () const
 	   settings.
 	*/
 	s << _state.format->nickname()
-	  << "_" << _state.content
+	  << "_" << _state.content_digest
 	  << "_" << left_crop() << "_" << right_crop() << "_" << top_crop() << "_" << bottom_crop()
 	  << "_" << f.first << "_" << f.second
 	  << "_" << _state.scaler->id();
diff --git a/src/lib/film_state.cc b/src/lib/film_state.cc
index 16378086c..369e4c986 100644
--- a/src/lib/film_state.cc
+++ b/src/lib/film_state.cc
@@ -92,6 +92,7 @@ FilmState::write_metadata (ofstream& f) const
 	f << "audio_channels " << audio_channels << "\n";
 	f << "audio_sample_rate " << audio_sample_rate << "\n";
 	f << "audio_sample_format " << audio_sample_format_to_string (audio_sample_format) << "\n";
+	f << "content_digest " << content_digest << "\n";
 }
 
 /** Read state from a key / value pair.
@@ -161,6 +162,13 @@ FilmState::read_metadata (string k, string v)
 		audio_sample_rate = atoi (v.c_str ());
 	} else if (k == "audio_sample_format") {
 		audio_sample_format = audio_sample_format_from_string (v);
+	} else if (k == "content_digest") {
+		content_digest = v;
+	}
+	
+	/* Itsy bitsy hack: compute digest here if don't have one (for backwards compatibility) */
+	if (content_digest.empty() && !content.empty()) {
+		content_digest = md5_digest (file (content));
 	}
 }
 
diff --git a/src/lib/film_state.h b/src/lib/film_state.h
index 52525ecd4..62ca76c41 100644
--- a/src/lib/film_state.h
+++ b/src/lib/film_state.h
@@ -147,6 +147,8 @@ public:
 	int audio_sample_rate;
 	/** Format of the audio samples */
 	AVSampleFormat audio_sample_format;
+	/** MD5 digest of our content file */
+	std::string content_digest;
 
 private:
 	std::string thumb_file_for_frame (int) const;
diff --git a/src/lib/util.cc b/src/lib/util.cc
index 7388539cd..799d0e54e 100644
--- a/src/lib/util.cc
+++ b/src/lib/util.cc
@@ -25,6 +25,7 @@
 #include <sstream>
 #include <iomanip>
 #include <iostream>
+#include <fstream>
 #ifdef DVDOMATIC_POSIX
 #include <execinfo.h>
 #include <cxxabi.h>
@@ -35,6 +36,7 @@
 #include <signal.h>
 #include <boost/algorithm/string.hpp>
 #include <openjpeg.h>
+#include <openssl/md5.h>
 #include <magick/MagickCore.h>
 #include <magick/version.h>
 #include <libdcp/version.h>
@@ -469,3 +471,37 @@ md5_data (string title, void const * data, int size)
 }
 #endif
 
+string
+md5_digest (string file)
+{
+	ifstream f (file.c_str(), ios::binary);
+	if (!f.good ()) {
+		throw OpenFileError (file);
+	}
+	
+	f.seekg (0, ios::end);
+	int bytes = f.tellg ();
+	f.seekg (0, ios::beg);
+
+	int const buffer_size = 64 * 1024;
+	char buffer[buffer_size];
+
+	MD5_CTX md5_context;
+	MD5_Init (&md5_context);
+	while (bytes > 0) {
+		int const t = min (bytes, buffer_size);
+		f.read (buffer, t);
+		MD5_Update (&md5_context, buffer, t);
+		bytes -= t;
+	}
+
+	unsigned char digest[MD5_DIGEST_LENGTH];
+	MD5_Final (digest, &md5_context);
+
+	stringstream s;
+	for (int i = 0; i < MD5_DIGEST_LENGTH; ++i) {
+		s << hex << setfill('0') << setw(2) << ((int) digest[i]);
+	}
+
+	return s.str ();
+}
diff --git a/src/lib/util.h b/src/lib/util.h
index 3901e7ec6..1f635677a 100644
--- a/src/lib/util.h
+++ b/src/lib/util.h
@@ -45,6 +45,7 @@ extern void socket_write (int, uint8_t const *, int);
 extern double seconds (struct timeval);
 extern void dvdomatic_setup ();
 extern std::vector<std::string> split_at_spaces_considering_quotes (std::string);
+extern std::string md5_digest (std::string);
 
 enum ContentType {
 	STILL,