mkv.cpp: fix the interpretation of JumVTS_PTT (and now all 3 buttons work)

modules/demux/mkv.cpp

@@ -5481,7 +5481,7 @@ bool dvd_command_interpretor_c::Interpret( const binary * p_command, size_t i_si
         }
     case CMD_DVD_JUMPVTS_PTT:
         {
-            uint16 i_title = (p_command[4] << 8) + p_command[5];
+            uint8 i_title = p_command[5];
             uint8 i_ptt = p_command[3];
 
             msg_Dbg( &sys.demuxer, "JumpVTS Title (%d) PTT (%d)", i_title, i_ptt);
@@ -5497,7 +5497,12 @@ bool dvd_command_interpretor_c::Interpret( const binary * p_command, size_t i_si
 
                     if ( p_chapter != NULL )
                     {
-                        p_chapter = p_segment->BrowseCodecPrivate( 1, MatchChapterNumber, &i_ptt, sizeof(i_ptt) );
+                        // find the title in the VTS
+                        p_chapter = p_chapter->BrowseCodecPrivate( 1, MatchTitleNumber, &i_title, sizeof(i_title) );
+                        if ( p_chapter != NULL )
+                        {
+                            // find the chapter in the title
+                            p_chapter = p_chapter->BrowseCodecPrivate( 1, MatchChapterNumber, &i_ptt, sizeof(i_ptt) );
                             if ( p_chapter != NULL )
                             {
                                 // if the segment is not part of the current segment, select the new one
@@ -5513,6 +5518,9 @@ bool dvd_command_interpretor_c::Interpret( const binary * p_command, size_t i_si
                                 f_result = true;
                             }
                         }
+                    else
+                        msg_Dbg( &sys.demuxer, "Title (%d) does not exist in this VTS", i_title );
+                    }
                     else
                         msg_Dbg( &sys.demuxer, "DVD Domain VTS (%d) not found", i_curr_title );
                 }