From edd2351a77223cf6c6730c7ba782f355ef027b8b Mon Sep 17 00:00:00 2001
From: Nathan Caldwell <saintdev@gmail.com>
Date: Wed, 23 Jan 2008 23:07:29 -0700
Subject: [PATCH] Use random() to create Track, Chapter, and Edition UIDs.
 Remove the no longer needed chapter_uid from mk_Writer struct.

---
 src/chapters.c | 14 +++++++++++++-
 src/matroska.h |  1 -
 src/tracks.c   | 19 ++++++++++++-------
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/src/chapters.c b/src/chapters.c
index 272c30f..2ba07ca 100644
--- a/src/chapters.c
+++ b/src/chapters.c
@@ -27,19 +27,31 @@
 int   mk_createChapterSimple(mk_Writer *w, uint64_t start, uint64_t end, char *name)
 {
   mk_Context *ca, *cd;
+  unsigned long	chapter_uid;
 
+  /*
+  * Generate a random UID for this Chapter.
+  * NOTE: This probably should be a CRC32 of some unique chapter information.
+  *		In place of being completely random.
+  */
+  chapter_uid = random();
+  
   if (w->chapters == NULL)
   {
+	unsigned long edition_uid;
+	edition_uid = random();
+	
     if ((w->chapters = mk_createContext(w, w->root, 0x1043a770)) == NULL) // Chapters
       return -1;
     if ((w->edition_entry = mk_createContext(w, w->chapters, 0x45b9)) == NULL) // EditionEntry
       return -1;
+	CHECK(mk_writeUInt(w->edition_entry, 0x45bc, edition_uid));	/* EditionUID - See note above about Chapter UID. */
     CHECK(mk_writeUInt(w->edition_entry, 0x45db, 1)); // EditionFlagDefault - Force this to be the default.
     CHECK(mk_writeUInt(w->edition_entry, 0x45dd, 0)); // EditionFlagOrdered - Force simple chapters.
   }
   if ((ca = mk_createContext(w, w->edition_entry, 0xb6)) == NULL) // ChapterAtom
     return -1;
-  CHECK(mk_writeUInt(ca, 0x73c4, ++w->chapter_uid));
+  CHECK(mk_writeUInt(ca, 0x73c4, chapter_uid));	/* ChapterUID */
   CHECK(mk_writeUInt(ca, 0x91, start)); // ChapterTimeStart
   if (end != start)                     // Just create a StartTime if chapter length would be 0.
     CHECK(mk_writeUInt(ca, 0x92, end)); // ChapterTimeEnd
diff --git a/src/matroska.h b/src/matroska.h
index 6d225f2..33924a2 100644
--- a/src/matroska.h
+++ b/src/matroska.h
@@ -85,7 +85,6 @@ struct mk_Writer_s {
     int64_t       tc_scaled;
   } cluster;
 
-  int chapter_uid;
   uint8_t vlc_compat;
 };
 
diff --git a/src/tracks.c b/src/tracks.c
index 2152261..27e012d 100644
--- a/src/tracks.c
+++ b/src/tracks.c
@@ -50,14 +50,19 @@ mk_Track *mk_createTrack(mk_Writer *w, mk_TrackConfig *tc)
     return NULL;
   if (mk_writeUInt(ti, 0xd7, track->track_id) < 0) // TrackNumber
     return NULL;
-  if (tc->trackUID)
-  {
-    if (mk_writeUInt(ti, 0x73c5, tc->trackUID) < 0) // TrackUID
+  if (tc->trackUID) {
+    if (mk_writeUInt(ti, 0x73c5, tc->trackUID) < 0) /* TrackUID  */
       return NULL;
-  }
-  else
-  {
-    if (mk_writeUInt(ti, 0x73c5, track->track_id) < 0)
+  } else {
+	/*
+	 * If we aren't given a UID, randomly generate one.
+	 * NOTE: It would probably be better to CRC32 some unique track information
+	 *		in place of something completely random.
+	 */
+	unsigned long track_uid;
+	track_uid = random();
+	
+	if (mk_writeUInt(ti, 0x73c5, track_uid) < 0) /* TrackUID  */
       return NULL;
   }
   if (mk_writeUInt(ti, 0x83, tc->trackType) < 0) // TrackType
-- 
2.11.4.GIT