[mythtv-commits] Ticket #9565: CEA-708 caption lines write one over top of the other in some programs

MythTV noreply at mythtv.org
Wed Feb 9 13:11:11 UTC 2011


#9565: CEA-708 caption lines write one over top of the other in some programs
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     Reporter:  Clayton Smith <argilo@…>          |      Owner:  danielk
         Type:  Patch - Bug Fix                   |     Status:  new
     Priority:  minor                             |  Milestone:  unknown
    Component:  MythTV - ATSC                     |    Version:  0.24-fixes
     Severity:  medium                            |   Keywords:  cea-708
Ticket locked:  0                                 |
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 In some programs with scrolling CEA-708 closed captions, all the lines of
 the captioning get written one over top of the other on a single line.  I
 had a look at the caption stream to see what was going on, and it looks
 like the following:

 DefineWindow (with 3 rows, 32 columns)
 SetPenLocation (to row 3, column 1)
 ...characters... <CR>
 DefineWindow (with 3 rows, 32 columns)
 SetPenLocation (to row 3, column 1)
 ...characters... <CR>

 The trouble is that CC708Window::DefineWindow (if the row lock is false)
 allocates one more row than was requested.  The carriage return at the end
 of each row of characters moves the pen to this extra row, but then
 SetPenLocation moves it back up and the same row gets overwritten, and no
 scrolling ever occurs.

 I have patched this by changing CC708Window::DefineWindow so that it never
 allocates more rows than requested.  This fixed the problem, and didn't
 cause any problems for the 10 or so other shows I tested with.

-- 
Ticket URL: <http://code.mythtv.org/trac/ticket/9565>
MythTV <http://code.mythtv.org/trac>
MythTV Media Center


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