[mythtv-users] Recommendations for Myth Frontend on Raspberry Pi?

Peter Bennett cats22 at comcast.net
Thu Mar 16 17:20:34 UTC 2017

On 03/16/2017 03:41 AM, Simon Hobson wrote:
> Not that surprising.
> Without the UI showing, once the video is playing then the CPU is basically shovelling data from the network to the GPU and the GPU is doing all the work.
> Once you add the UI, then I suspect the CPU has to decode the video so it can overlay the UI on it before feeding the decoded & modified video to the GPU.
Not true. Video is decoded by the GPU whether the OSD is visible or not.
If you select OpenGL for the OSD, the GPU does the work of overlaying it 
on the video. If you select "softblend" then MythTV code is using the 
CPU to merge the OSD into each frame.
OpenGL is the better option, but it may require more memory allocated to 
the GPU.
>   If there's any way to see the processor load in the GPU then I suspect you'd see a corresponding drop.
> The ideal would be to be able to keep shovelling the raw data at the GPU and have that overlay the UI as it decodes the video - but I suspect the architecture of Mythfrontend would need some major remodelling to support that.
Unfortunately it does a lot more than shovel data at the GPU. There is 
actually a lot of processing done between frames, regardless of whether 
the OSD is displayed.


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