[mythtv] State of Raspberry Pi 2 build

[Piotr Oniszczuk]

> Wiadomość napisana przez Peter Bennett <pgbennett at comcast.net> w dniu 29.01.2016, o godz. 21:14:
> 
> On 01/28/2016 04:56 PM, Piotr Oniszczuk wrote:
>>> In the mean time: may You do me favor and try MinMyth2 RPI edition?
>>> I’m wonder what difference will be in playback between Your master build on Raspbian and mine in MiniMyth2….
>>> (don’t forget to do „pacman -Syu" update Minimyth2 system before tests)
>>> 
>>> 
> Hi Piotr
> 
> I tried your minimyth2. It looks good!
Oh thx. It is early alfa where I concentrated on basic stuff (QT/kernel/Brcm EGL in Qt) and skip all usability/plug-and-play aspects.
Many of Your valuable feedback is related to usability/plug-and-play aspects. 
This is good as this means basic OS stuff is working OK and is under our control :-)
> Here is my detailed feedback -
> The tar xvf needs an option added "--numeric-owner" at the end. Without
> that option the mythtv home directory and its files got owner id of 200,
> which is the id of the mythtv user on my system, and would not match 997
> which is the id of mythtv on the minimyth2 image.
Here I’m little confused.
By assumptions MM2 is standalone system so I’m a bit confused by „owner id of 200,which is the id of the mythtv user on my system, and would not match 997 which is the id of mythtv on the minimyth2 image”
Is this issue related to i.e. NFS share between Yours BE and MM2?
If Yes then I would say: design assumption is to use only myth protocol between MM2 and BE so id should be irrelevant 
> First boot up went to prompt for country and language, then it took a
> long time to come to the prompt for selecting your backend. Then it
> showed one entry in the list, named "Firewall". Why is it showing Firewall?
It suspect this is UPNP discovery of Your Firewall by MM2.
Strange that FE not discovered also BE. I think this is MythTV related thing. 
> After I selected Firewall it took a long time and then said "Unknown Error".
> After the unknown error it came back to the selection so I selected
> "Manual" instead of "Firewall".
> After i selected manual it came to black screen (which you said was
> expected).
> At black screen I killed mythfrontend, nothing happened and I killed it
> again.
> After this it came back to the Country and Language prompt. I entered
> them again, and it just came back to Country and Language, over and over.
> I rebooted, then it started up at the mythtv main menu.
Right. I don’t know why in ARM „mythfrontend-p”, after UPNP BE discovery, config.xml creation, reloads FE to black screen. 
It is only on ARM.
In x86 MM2 this works perfectly….
> I used setup and selected Mythcenter theme.
> I tried playing a recording and got "Audio Disabled" message. Video
> looked ok.
Ok. This is because MM2 ARM edition is work in progress now.
If MythTV devs resolve RPI2 playback to worthwhile state - I’ll add audio/video profiles autoconfig to MM2 RPI2 edition.
Target will be that MM2 will boot with fully configured Video/Audio settings ready to use.
> I went into audio setup and just selected the default that came up
> (Alsa:default), and hit next up to the end of the setting.
> After this I tried playing the recording again and audio works.
> Audio and video are jerky, I think the video is too slow and audio is
> stopping and starting.
I have the same issues. MM2 by default uses EGLFS.
XCB works better - albeit also not ideally. 
> Audio is scratchy unless I set maximum volume in Mythtv. I don't think
> this happens with my Raspbian setup.
This is interesting. We need to investigate this more deeply…
> I have had jerky audio and video with Raspbian and eglfs - I think that
> xcb will work better. How do I get X11 on miminyth?
For this some manual work is needed:

-disable mythfrontend autostart”
„systemctl disable mythfrontend.service”

-install X.org
„pacman -S xorg xorg-server-utils xterm xorg-twm xorg-xclock xorg-xinit libepoxy”
select mesa-libg

-create a file in /etc/X11/Xwrapper.config and add this line „allowed_users=anybody”

-edit /usr/bin/mythfrontend.sh as switch QPA from EGLFS to XCB

-reboot

-log ssh as mythtv/mythtv

-„startx”

-type in xterm „/usr/bin/mythfrontend.sh”

> I went into mythtv setup to try to reduce the picture size so that it
> could handle overscan, but the same problem exists as with eglfs on
> Raspbian - the X and Y offset are ignored and the "Use GUI size for TV
> playback" setting is ignored. All of these things work with xcb.
I think this is by design. EGLFS is drawing to full screen so I think any offset should be probably adjusted at OS level (/boot/config.txt). 
> There is a bug in my current 0.27 raspberry pi frontend - in a recording
> if the resolution changes the frontend crashes. - This bug is now fixed
> in minimyth2. Maybe this is fixed in master.
> There is no way to shut it down.
Yes. Missing is sudoers file allowing to use reboot/poweroff for user mythtv + mythfrontend config to laungh „reboot” and „poweroff”.
I’ll add this in next version.
> However I suppose raspberry pi can just
> be left on. In my own setup I use a shell script that prompts for you to
> press 22 on the remote to start up the front end. It comes back to this
> prompt every time you exit the front end. I exit the front end, which
> lets the backend shut down.
> 
> Can you explain how you built this? The one I built does not work and I
> thought it was because LVR's patches were not there. Did you do any
> patches?
No. I can build vanilla mythfrontend master on my RPI2. No any patches are needed to have basically working current master on RPI2.

> Did you cross-compile from a Linux box? I would be interested
> to try what you did, to see if it will work on Raspbian.
No. As this is proof-of-concept - I decided to go with easiest approach: native build on RPI2.
When MythTV on RPI2 will be usable (I mean playback) - then I’ll go with classical MiniMyth2 where armv7 arch execs will be cross-compiled on X86 host.