[mythtv-commits] Ticket #10832: Use QtKit for playback on mac by default not VDA...

MythTV noreply at mythtv.org
Fri Jun 15 10:18:49 UTC 2012

#10832: Use QtKit for playback on mac by default not VDA...
 Reporter:  adamfowleruk@…  |           Type:  Bug Report - General
   Status:  new             |       Priority:  minor
Milestone:  0.25.1          |      Component:  MythTV - Video Playback
  Version:  0.25.1          |       Severity:  medium
 Keywords:  mac             |  Ticket locked:  0
 According to the apple developer site, QtKit should be used for H264
 playback, not VDA. Also VDA support varies by model. Apple recommend using
 QtKit for playback.

 "The Video Decode Acceleration framework only decodes video frame data and
 does not provide video playback or stream parsing capabilities. Using the
 QTKit QTMovie object with QTMovieOpenForPlaybackAttribute enabled is the
 recommended way for applications to automatically access GPU accelerated
 playback of H.264 encoded media."

 See Notes on Overview section here:
 Technical note TN2267 Video Decode Acceleration Framework Reference

 This may also resolve issues on MythFrontend on Mac with the kernel panic
 issue, and thus disabled VDA playback on 0.25, causing jittering.

 My system:
 MacbookPro 17" mid 2009 NVidia GeForce 8600M GT 512MB VRAM
 Intel Core 2 Duo 2.6GHz

 Playback CPU results (all for HD H264 interlaced stream):
 OpenGL High ~ 136%
 VDA High ~ 113%
 OpenGL Normal, Open GL Slim, VDA Normal, VDA Slim  ~ 103%
 (I'm assuming the VDA modes actually use OpenGL instead because the stream
 is interlaced, as per info on 0.25 build in mythtv trac)

 Let me know if I'm crazy / stupid / you need more information. Would have
 submitted this as a feature request but didn't see that option.

Ticket URL: <http://code.mythtv.org/trac/ticket/10832>
MythTV <http://code.mythtv.org/trac>
MythTV Media Center

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