[libbluray-devel] main title selection: improve chapter rule

[hpi1]

libbluray | branch: master | hpi1 <hpi1 at anonymous.org> | Fri Mar  4 11:52:31 2016 +0200| [a1a23c3d45dbc00648e5968efd44ac4d3dc932c7] | committer: hpi1

main title selection: improve chapter rule

Prefer playlist with many chapters over playlist with no chapters.
(was select playlist with more chapters)

Fixes ex.:
Nick & Norah's Infinite Playlist/
   index:   1 duration: 01:29:33 chapters: 189 angles:  1 clips:   1 (playlist: 00004.mpls) V:1 A:5  PG:16 IG:0  SV:0 SA:0
   index:   2 duration: 01:29:33 chapters:  16 angles:  1 clips:   1 (playlist: 00040.mpls) V:1 A:5  PG:16 IG:0  SV:0 SA:0

> http://git.videolan.org/gitweb.cgi/libbluray.git/?a=commit;h=a1a23c3d45dbc00648e5968efd44ac4d3dc932c7
---

 src/libbluray/bdnav/navigation.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/libbluray/bdnav/navigation.c b/src/libbluray/bdnav/navigation.c
index a5995e5..6840188 100644
--- a/src/libbluray/bdnav/navigation.c
+++ b/src/libbluray/bdnav/navigation.c
@@ -249,10 +249,12 @@ static int _pl_guess_main_title(MPLS_PL *p1, MPLS_PL *p2)
     /* if both longer than 30 min */
     if (d1 > 30*60*45000 && d2 > 30*60*45000) {
 
-        /* prefer many chapters over few chapters */
-        int chap_diff = _pl_chapter_count(p2) - _pl_chapter_count(p1);
-        if (chap_diff < -3 || chap_diff > 3) {
-            /* chapter count differs by more than 3 */
+        /* prefer many chapters over no chapters */
+        int chap1 = _pl_chapter_count(p1);
+        int chap2 = _pl_chapter_count(p2);
+        int chap_diff = chap2 - chap1;
+        if ((chap1 < 2 || chap2 < 2) && (chap_diff < -5 || chap_diff > 5)) {
+            /* chapter count differs by more than 5 */
             BD_DEBUG(DBG_MAIN_PL, "main title: chapter count difference %d\n", chap_diff);
             return chap_diff;
         }