[mythtv-users] rpi4 HD playback profile

[Monkey Pet]

On Sun, May 17, 2020 at 8:34 AM Mike Bibbings <mike.bibbings at gmail.com>
wrote:

> On 17/05/2020 13:31, Tim Draper wrote:
> > i give up... spent 2-3 days on getting my new rpi4 (2gb, with 256mb GPU
> ram assignment) to playback HD content smoothly and just can't. playback
> profile is setup to use V4L2 codecs, and I've upped core count to 4. Tried
> none, software, oGL and driver deinterlacers and disabled deblocking to try
> and improve things but non of them really fix the issue, just make it worse
> depending on system load.
>

1. Disable the Desktop Environment
2. Overclock it just a bit

I listed a few other things I tried in
https://forum.mythtv.org/viewtopic.php?f=46&t=3791 also the link has a bit
more details. Also see https://www.mythtv.org/wiki/Raspberry_Pi.

Good luck, i am happy with mine, but I basically use it for HDHomerun MPEG2
OTA recording playback.

The two above did it for me. Mostly it was the desktop environment.  Then a
slight overclock, now things are smooth.


> rpi4 not overheating (around 72c during playback and running the full
> 1.5ghz)
> >
> > seems like i could be dealing with multiple issues too.
> > first, any playback of HD content feels like it's dropping frames. also
> seems to jump every few seconds. almost like a rpi3 does with HD content
> with 'ondemand' governor.
> >
> > second is HD deinterlacer. LiveTV seems to correctly detect HD content
> as interlaced (correct; UK is 1080i broadcast). Recorded program gets
> detected as progressive. I'm having to change this manually every playback
> to interlaced.
> >
> > Third, very intermittent screen blanking where hdmi video&audio both cut
> out but resume again after 2-3 seconds. doesnt seem to be related to
> anything specific and seems completely random. I'll be placing an order
> later for a new HDMI cable to see if that helps but not sure this would
> have an effect on the above..
> >
> > thanks for any help on this - its driving me insane !!
> > _______________________________________________
>
> I am assuming that you are trying to get mythtv-light  31 working from
> https://www.mythtv.org/wiki/MythTV_Light on current Raspbian Buster.
>
> Pi 4 must be in console mode (not Desktop)
>
> In /boot/config.txt make sure screen resolution is correctly set and no
> higher than 1920x1080 with either 50Hz or 60Hz refresh (depends on your
> broadcast standard.
>
> For example in UK hmdi_group=1 hdmi_mode=31 gives 1920x1080 at 50Hz
>
> There maybe further complications depending on your TVs maximum
> resolution, which requires an eglfs json override file, otherwise qt
> (part of mythfrontend) will use data from EDID which is likely to cause
> incorrect resolution/fresh during playback or LiveTV. I have a 4K TV and
> playback tries to use a much higher resolution and the wrong refresh
> frequency (30Hz with Pi4 in default settings). I also have an HD TV and
> this uses 60Hz instead of 50Hz.
>
> I have a script run_mythfrontend.sh which launches mythfrontend and sets
> up the required override based on hdmi_group and hdmi_mode settings in
> /boot/config.txt.
>
> The script is available from my github repository at
> https://github.com/MikeB2013/pi-utils
>
>
> Mike
>
>
>
>
>
>
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://lists.mythtv.org/mailman/listinfo/mythtv-users
> http://wiki.mythtv.org/Mailing_List_etiquette
> MythTV Forums: https://forum.mythtv.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mythtv.org/pipermail/mythtv-users/attachments/20200517/cd1035af/attachment.htm>