[mythtv-commits] Ticket #10984: Improve closed caption performance

MythTV noreply at mythtv.org
Sat Aug 31 02:38:44 UTC 2013


#10984: Improve closed caption performance
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 Reporter:  stichnot           |          Owner:  stichnot
     Type:  Developer Task     |         Status:  new
 Priority:  minor              |      Milestone:  0.28
Component:  MythTV - Captions  |        Version:  Master Head
 Severity:  medium             |     Resolution:
 Keywords:                     |  Ticket locked:  0
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Comment (by Jim Stichnoth <jstichnoth@…>):

 In [changeset:"3325c09b2fc070179047f678a02ee6feaed5cfd7/mythtv"]:
 {{{
 #!CommitTicketReference repository="mythtv"
 revision="3325c09b2fc070179047f678a02ee6feaed5cfd7"
 Speed up drawing caption text with outlines.

 The old method of drawing text with outlines involves drawing the same
 text many times at various offsets, with the offsets based on
 traversing the perimeter square of pixels with edge length 2N+1, where
 N is the specified outlinesize.  This means drawing 8N extra copies of
 the text.  With some fonts and point sizes, this can be a very
 expensive operation, leading to video stuttering while captions are
 drawn.

 The new method draws just one extra copy, but with a pen width set to
 2N+1, which is much faster.  Beware that using a huge outlinesize may
 lead to strange artifacts in the outline (but that was already the
 case for the original outline code).

 Refs #10984.
 }}}

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Ticket URL: <http://code.mythtv.org/trac/ticket/10984#comment:4>
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