Backend on Pi 4

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MikeB2013
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Re: Backend on Pi 4

Post by MikeB2013 » Thu Apr 02, 2020 7:00 pm

MikeB2013 wrote:
Tue Mar 24, 2020 5:52 pm
knappster wrote:
Tue Mar 24, 2020 12:05 pm
MikeB2013 wrote:
Sat Mar 21, 2020 1:40 pm
For commercial flagging there is an open ticket https://code.mythtv.org/trac/ticket/13476

Mike
Thanks for the heads up. Out of curiosity is this because the pi4 doesn't have hardware mpeg2 decoding? I have a pi3 with the mpeg2 license, so if I configure it as a slave backend, would it be able to run the commercial flagging or is it broken across the board on pis?
As far as I know it affects all Pi's. The trac ticket includes pi3 on mythtv-light 30 (I am not aware of any significant changes to commercial flagging between mythtv 30 and 31)

Mike
The above ticket is now closed as commercial flagging is no longer giving error code 140 on Pi4 for mythtv fixes/31 and master branches.

knappster
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Re: Backend on Pi 4

Post by knappster » Thu Apr 02, 2020 7:30 pm

Thanks for the update. Would it be silly of me to consider trying to upgrade to v31 a "slave backend" using mythjobqueue instead of mythbackend while leaving the master backend v30? I use kodi on a shield as my main frontend and I'm not certain of compatibility with v31 yet...

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jfabernathy
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Re: Backend on Pi 4

Post by jfabernathy » Thu Apr 02, 2020 9:41 pm

In my playing with RPi4 4GB on v31 I found that using it as just a backend and using either the Shield TV or FireTV 4K was just fine. No issues for me but I didn't test commercial Flagging.

Now that my production backend is on V31 and not causing any issues, I've got time to do more RPi4 testing. Certainly can't go to a bar/pub for a while.

If however you need as I do for my camper as combo FE/BE I'd stay with V30 until V31 is more mature on RPi4. But then again I don't use Commercial flagging very often.

If I setup the RPi4 as a backend only with Commercial flagging and h.264 transcoding from MPEG2 that would be a good test. I can test the frontend part with Kodi, Leanfront, or Mythfrontend on Shield.

Jim A

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Re: Backend on Pi 4

Post by knappster » Sat Apr 04, 2020 11:54 am

I went ahead and decided to test whether or not it would be silly for me to run mythjobqueue on rpi3 mythtv-light v31 while my pi4 runs mythbackend on mythtv-light v30. I just ran a test for a commercial detection job on the rpi3 and it seemed to work fine. My concern at the moment is that the passively cooled cpu temp went from an idle of maybe 50C to 81+C. While it has built-in protection to prevent overheating, I think I'll rest better at night if I get a fan cooled case...

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jfabernathy
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Re: Backend on Pi 4

Post by jfabernathy » Sat Apr 04, 2020 1:33 pm

jfabernathy wrote:
Thu Apr 02, 2020 9:41 pm
In my playing with RPi4 4GB on v31 I found that using it as just a backend and using either the Shield TV or FireTV 4K was just fine. No issues for me but I didn't test commercial Flagging.

Now that my production backend is on V31 and not causing any issues, I've got time to do more RPi4 testing. Certainly can't go to a bar/pub for a while.

If however you need as I do for my camper as combo FE/BE I'd stay with V30 until V31 is more mature on RPi4. But then again I don't use Commercial flagging very often.

If I setup the RPi4 as a backend only with Commercial flagging and h.264 transcoding from MPEG2 that would be a good test. I can test the frontend part with Kodi, Leanfront, or Mythfrontend on Shield.

Jim A
So I setup my RPi4 with V31 built from source. I kept the number of background jobs at 1 using low priority. I had overlapping recordings so three were recording at the same time and 2 ended and I assume metadata lookup and commercial flagging started sequentially on those while the 3rd continue recording. This morning I checked out the resulting recordings. They all looked good and had some commercials detected. I watch the recording, carefully, that was being recorded while the first 2 were being processed in background and there were no issues with the quality of the recording that I could see. I used an RP3B+ running LibreELEC with Kodi-pvr-mythtv to watch the programs.

So RPi4 as a backend with commercial detection works fine. However, I have not gotten transcoding working yet and I tried running Handbrake to convert an MPEG2 OTA recording to .m4v. It worked but forget it. Took 4 hours for a 20 minute segment of a program. I don't do this much so won't miss it.

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Re: Backend on Pi 4

Post by knappster » Sat Apr 11, 2020 12:06 pm

knappster wrote:
Sat Apr 04, 2020 11:54 am
I went ahead and decided to test whether or not it would be silly for me to run mythjobqueue on rpi3 mythtv-light v31 while my pi4 runs mythbackend on mythtv-light v30. I just ran a test for a commercial detection job on the rpi3 and it seemed to work fine. My concern at the moment is that the passively cooled cpu temp went from an idle of maybe 50C to 81+C. While it has built-in protection to prevent overheating, I think I'll rest better at night if I get a fan cooled case...
A case with fan arrived yesterday. When hooked to 3.3v it drops the idle temp to about 43C and each commflagging job raises it about 10C. I ran one at about 53C and three got up to 73C. I think I can unplug the old athlon machine now :). This has come a long way since I first tried mythtv-light 0.27 as a frontend on rpi3.

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bonelifer
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Re: Backend on Pi 4

Post by bonelifer » Fri May 01, 2020 8:55 pm

After reading this topic, I feel good about the progress made with MythTV on RPi4. Thanks to mike and the people behind mythtv-lite. Should be fun when I'm able to order and receive a new Pi.

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Re: Backend on Pi 4

Post by jh15 » Mon Jun 08, 2020 5:58 pm

I just got my RPi 4 4gb to boot directly from a WD nvme M2 drive in a USB 3 enclosure. Once configured, it no longer depends on a microSD to be plugged in.
Soon I hope I can shut down the full-fledged computer. Been running on full sized systems since getting a pre-configured MYTHIC DRAGON HTPC around 2004 or so. Later on new systems. Just a few watts is good.
Panas 65" ZT60 plasma.
50" samsung DLP
4 attic antennas
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RPi4's

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jfabernathy
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Re: Backend on Pi 4

Post by jfabernathy » Mon Jun 08, 2020 6:18 pm

jh15 wrote:
Mon Jun 08, 2020 5:58 pm
I just got my RPi 4 4gb to boot directly from a WD nvme M2 drive in a USB 3 enclosure. Once configured, it no longer depends on a microSD to be plugged in.
So it sounds like USB3 boot is now working without the /boot on microSD and rootfs "/" on USB3 SSD?
I'll have to test this out the next time I rebuild my RPi4 4GB. Mine dates back to last fall, but I assume there must be a firmware upgrade recently.

jh15
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Re: Backend on Pi 4

Post by jh15 » Tue Jun 09, 2020 2:18 pm

It does update the on-board eeprom or whatever the nv memory is.
So you jump some hoops to modify the on-board memory to allow usb boot. Then I put the latest rpi os image (may 27, I think), on the USB3 WD nv using my usual dd string I always have in my terminal buffer.
Due to some boot anomaly maybe already fixed in the in the latest build,you have to overwrite a couple boot files in the new USB drive.
I copied the boot files over anyway.

I ordered a USB3 ssd from amazon Prime, but is taking forever to arrive, so decided to use the WD m.2 drive in some noname enclosure. Runs super hot, so for now leaving the enclosure unsealed, in front of my rpi4 case fan.
It is now a virgin install awaiting mythtv install.

It took awhile to find this post of yours I started on a year ago, so bookmarked it for good.

Besides the tech post about USB boot on rpi site, I used this guy's method: https://tynick.com/blog/05-22-2020/rasp ... -from-usb/

I hope to use your post and script to do this. I'll report back.
Panas 65" ZT60 plasma.
50" samsung DLP
4 attic antennas
4 HD Homeruns
RPi4's

aardwolf2
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Re: Backend on Pi 4

Post by aardwolf2 » Sat Jun 13, 2020 7:14 pm

Just set up a pi4 as a main backend to replace the old i3 HTPC that died, did the remote backend (pi2 with a DVB-S2 tuner) at the same time to just jump the whole system to 0.31 and used the scripts, must say far easier than doing it by hand as I did when setting up the pi2 originally, so a big thanks from this end.

One item of note is that metadata lookups on recordings failed, traced this to requiring python3-requests-cache to be installed, did that and all is good, so may need a tweak to the script.

Cheers!

MikeB2013
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Re: Backend on Pi 4

Post by MikeB2013 » Sun Jun 14, 2020 1:36 pm

aardwolf2 wrote:
Sat Jun 13, 2020 7:14 pm

One item of note is that metadata lookups on recordings failed, traced this to requiring python3-requests-cache to be installed, did that and all is good, so may need a tweak to the script.
python3-requests-cache issue is fixed in mythtv-light v31 build 31.0-54-g445cf1fe6b
This build contains quite a few fixes over the previous build, so I suggest everyone updates.

Mike

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