[mythtv-users] rpi3 & v31 mythtv-light deb package

[Tim Draper]

 ---- On Sun, 26 Apr 2020 09:20:16 +0100 Tim Draper <veehexx at zoho.com> wrote ----
 > 
 > 
 > 
 >  ---- On Sun, 26 Apr 2020 08:00:55 +0100 Mike Bibbings <mike.bibbings at gmail.com> wrote ----
 >  >         On 26/04/2020 00:27, Peter Bennett      wrote:
 >  >                     
 >  >       
 >  >       On 4/25/20 11:57 AM, Tim Draper        wrote:
 >  >                     i've upgraded my mythtv deployment to v31 (from v30), BE first, then my Shield primary FE, and now the rpi3's.rpi3's are having major performance issues both in the menu and video playback. menu you can see the fade transitions stutter through and it's generally slow&laggy response. htop shows low CPU usage. Video playback is running maybe 1-2fps and maxes out all 4 cores. v30 was via https://www.mythtv.org/wiki/MythTV_Light. since there isnt an rpi3 specific build for v31 (and rpi specific codec has been depreciated in favour of v4l2, so i assume we're using a generic package now) i've installed the mythtv-light deb package: https://dl.bintray.com/bennettpeter/deb/pool/myth31/m/mythtv-light/:mythtv-light_31.0-16-ga465f1b03d-0_armhf_buster.deb which is where i currently am.the playback profile has been updated to use v4l2 codec and both my rpi3's are codec licensed. is there a current v31 guide on rpi(3) deployment i've not found yet, or can anyone help out with suggestions on fixing this? _______________________________________________            
 >  >       There are some v31 specific notes in the wiki, see this URL.
 >  >       
 >  >       https://www.mythtv.org/wiki/Raspberry_Pi
 >  >       
 >  >       If you do a find on the page (ctrl-f) for v31 you can see the v31      differences
 >  >       
 >  >       The main thing is, openmax is dead and you have to use v4l2. also      you have to change your raspbian setup to use "Fake KMS". And you      have to change raspbian to boot to the command line, and from      command line run 
 >  >       
 >  >       QT_QPA_PLATFORM=eglfs mythfrontend
 >  >       
 >  >       to start up the frontend.
 >  >       
 >  >       
 >  >         I have a script which invokes mythfrontend on Raspberry Pi (2,3      or 4) from console.
 >  >     See      https://github.com/MikeB2013/pi-utils/blob/master/run_mythfrontend.sh
 >  >     The script, in brief:
 >  >     
 >  >     takes account of which model Pi it is running on
 >  >     sets performance mode
 >  >     limits screen resolution (qt sets highest possible resolution for      connected hdmi device, which can be wrong
 >  >     restores console operation after exit from mythfrontend (there is      a bug in qt which breaks console) 
 >  >     
 >  >     
 >  >     
 >  >     In mythfrontend setup when using v4l2 Codecs profiles make sure      CPU is set to 4. 
 >  >     
 >  >     
 >  >     Mike
 > 
 > ah, i see now. i was putting too much faith in "This page is up-to-date as of MythTV version 30, the current release is 31.0" at the top of the page. i got as far as seeing the v4l2 change assumed that was all based on the playback/codec changes and didnt read any further. I didnt get as far as seeing the Fake KMS or cmdline launch string requirements.
 > i'll take another look later this morning, along with your script
 > 

I've done whats needed and thats fixed the menu performance, but still something  wrong with the video playback side with the rpi3. to clarify my setup:
256MB gpu, dist-upgrade ,raspi-config updated to Fake KMS, playback profile updated to v4l2. Profile updated to use 4 CPUs. console login doesnt seem to make any performance difference over GUI login.  'QT_QPA_PLATFORM=eglfs mythfrontend' used to start the FE. governor set to performance.

SD content performs ok but seeing blocky lines almost like the tearing you see with vsync but i'm saying maybe 1/2" of the picture torn.
HD content is still jerky and while i'm seeing all cores used to varying degrees, one of them is being maxed out so i'm attributing the jerkyness to that. I'm also seeing slight pink/purple colour distortion/ghosting a little bit like anaglyph 3d.

the Video playback data shows a reasonably solid 25FPS but visually it doesn't appear to be running at that fps.
i've tried the other v4l2 playback profiles (oGL & oGL decode-only) but those have no difference.

the rpi was fine with v30 mythtv-light so i dont think it's anything hardware