[mythtv-commits] Ticket #6130: Experimental VDPAU optimisations

[MythTV]

#6130: Experimental VDPAU optimisations
-------------------------------------+--------------------------------------
 Reporter:  markk                    |        Owner:  markk   
     Type:  patch                    |       Status:  accepted
 Priority:  minor                    |    Milestone:  0.22    
Component:  MythTV - Video Playback  |      Version:  head    
 Severity:  medium                   |   Resolution:          
  Mlocked:  0                        |  
-------------------------------------+--------------------------------------

Comment(by markk):

 (In [22132]) VDPAU video buffering improvements.

 Firstly, tweak the video buffers setup to fix the playback of certain
 h.264 streams (most notably, the infamous Wimbledon clip). I've tested
 extensively with my
 library of VDPAU 'special' clips on 2 setups and this does not seem to
 have an adverse impact anywhere and it does reduce the overall buffer size
 needed for some streams with 4 or more reference frames.

 Secondly, add an option for the user to specify the number of VDPAU video
 buffers to use. It is enabled by adding vdpaubuffersize=X to the filters
 section of the video display profile. Valid values for X are in the range
 6-50, 6 being the minimum that seems to work with most mpeg2 and h264
 interlaced streams (with 2 reference frames).

 The lowest setting can save over 80Mb of video memory for 1080i/p streams
 compared to the default buffer size of 17 frames. This may be enough for
 VDPAU playback on video cards with 256Mb of memory (though certainly no
 guarantee).

 Increasing the video buffer size should fix playback for problematic
 streams with more than 2 reference frames. For example, the well known
 'killa.sampla' h.264 clip needs around 32 video buffers for decent
 playback (16 reference frames) and most broken streams with 4 reference
 frames seem to need around 22 buffers.

 This a stop gap fix for 0.22 and *should* be replaced by a more
 robust/intelligent/automatic solution for 0.23 - I just haven't worked out
 the magic formula yet...

 Refs #7138, #6130.

-- 
Ticket URL: <http://svn.mythtv.org/trac/ticket/6130#comment:10>
MythTV <http://www.mythtv.org/>
MythTV