[mythtv-commits] Ticket #8621: Add VDA support

MythTV mythtv at cvs.mythtv.org
Fri Aug 6 10:51:04 UTC 2010

#8621: Add VDA support
 Reporter:  markk                    |           Owner:  markk     
     Type:  enhancement              |          Status:  accepted  
 Priority:  minor                    |       Milestone:  0.24      
Component:  MythTV - Video Playback  |         Version:  Trunk Head
 Severity:  medium                   |      Resolution:            
 Keywords:                           |   Ticket locked:  0         

Comment (by markk):

 (In [25571]) Add support for the VideoDecodeAcceleration framework on OS

 This enables video acceleration on certain hardware when running OS X
 10.6.3 and above (see

 There are 2 outstanding issues:-

 - there is no interlaced and repeat picture detection (and hence no
 deinterlacing). This will require some additional parsing or perhaps a tie
 in into the existing H264 parser.
 - some H264 broadcast streams are broken. So far the only problem seems to
 be BBC HD.

 Implementation wise, the VDA library is loaded dynamically in order to
 simplify package management (the framework is only available on newer
 versions of OS X) and the additional privatedecoder_vda_defs file
 replicates the required elements of the framework headers as the headers
 are currently private.

 There is a clear performance improvement, though nothing approaching the
 gains seen with, for example, VDPAU on the same hardware - no doubt due to
 the additional overhead of transferring the frames back into main memory
 (and back to GPU memory again).

 The interaction with the Quartz video renderer is untested.

 Refs #8621.

Ticket URL: <http://svn.mythtv.org/trac/ticket/8621#comment:3>
MythTV <http://www.mythtv.org/>

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