Opened 9 years ago

Closed 9 years ago

#10832 closed Bug Report - General (Invalid)

Use QtKit for playback on mac by default not VDA...

Reported by: adamfowleruk@… Owned by:
Priority: minor Milestone: 0.25.1
Component: MythTV - Video Playback Version: 0.25.1
Severity: medium Keywords: mac
Cc: Ticket locked: no


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.

Change History (1)

comment:1 Changed 9 years ago by danielk

Resolution: Invalid
Status: newclosed

QtKit? is essentially just a feature poor video player. If we used that it wouldn't really be MythTV video playback, you wouldn't have time stretch for instance. The best bet if you want to use Apple hardware is to install Linux or just make sure the CPU is fast enough that you don't need GPU assistance under OSX.

Note: See TracTickets for help on using tickets.