libhb: Sanitize BD chapter durations

It appears some BDs have invalid chapter durations, see
https://forum.handbrake.fr/viewtopic.php?f=12&t=30479

This compares chapter start time deltas and title duration to chapter
duration to make best guess corrections.

Note that chapter events generated by libbluray are based on the chapter
start times. So the start time should be trusted more than the duration.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6292 b64f7644-9d1e-0410-96f1-a4d463321fa5

1 files changed, 43 insertions, 2 deletions

diff --git a/libhb/bd.c b/libhb/bd.c
index 75f2b138f..6cef95609 100644
--- a/libhb/bd.c
+++ b/libhb/bd.c
@@ -491,18 +491,59 @@ hb_title_t * hb_bd_title_scan( hb_bd_t * d, int tt, uint64_t min_duration )
     }
 
     /* Chapters */
-    for ( ii = 0; ii < ti->chapter_count; ii++ )
+    for ( ii = 0, jj = 0; ii < ti->chapter_count; ii++ )
     {
         char chapter_title[80];
+
+        // Sanity check start time of this chapter.
+        // If it is beyond the end of the title, drop it.
+        if (ti->chapters[ii].start > ti->duration)
+        {
+            hb_log("bd: chapter %d invalid start %ld, dropping", ii+1,
+                   ti->chapters[ii].start);
+            continue;
+        }
+
         chapter = calloc( sizeof( hb_chapter_t ), 1 );
 
-        chapter->index = ii + 1;
+        chapter->index = ++jj;
         sprintf( chapter_title, "Chapter %d", chapter->index );
         hb_chapter_set_title( chapter, chapter_title );
 
         chapter->duration = ti->chapters[ii].duration;
         chapter->block_start = ti->chapters[ii].offset;
 
+        // Sanity check chapter duration and start times
+        // Have seen some invalid durations in the wild
+        if (ii < ti->chapter_count - 1)
+        {
+            // Validate start time
+            if (ti->chapters[ii+1].start < ti->chapters[ii].start)
+            {
+                hb_log("bd: chapter %d invalid start %ld", ii+1,
+                       ti->chapters[ii+1].start);
+                ti->chapters[ii+1].start = ti->chapters[ii].start +
+                                           chapter->duration;
+            }
+            if (ti->chapters[ii+1].start - ti->chapters[ii].start !=
+                chapter->duration)
+            {
+                hb_log("bd: chapter %d invalid duration %ld", ii+1,
+                       chapter->duration);
+                chapter->duration = ti->chapters[ii+1].start -
+                                    ti->chapters[ii].start;
+            }
+        }
+        else
+        {
+            if (ti->duration - ti->chapters[ii].start != chapter->duration)
+            {
+                hb_log("bd: chapter %d invalid duration %ld", ii+1,
+                       chapter->duration);
+                chapter->duration = ti->duration - ti->chapters[ii].start;
+            }
+        }
+
         int seconds      = ( chapter->duration + 45000 ) / 90000;
         chapter->hours   = ( seconds / 3600 );
         chapter->minutes = ( seconds % 3600 ) / 60;