[mythtv] State of Raspberry Pi 2 build

Peter Bennett pgbennett at comcast.net
Fri Jan 29 00:39:34 UTC 2016


On 01/28/2016 04:56 PM, Piotr Oniszczuk wrote:
>> Wiadomość napisana przez Peter Bennett <pgbennett at comcast.net> w dniu 28.01.2016, o godz. 22:14:
>>
>> I have been trying to build mythtv master (pre-0.28) from github for the
>> raspberry pi 2  version over the past few days, using the cross compile
>> script created by Lawrence Rust.
>>
>> The build is a little different because
>> 1. It is a cross compile from x64 to Raspberry Pi
>> 2. It uses QT version 5.4.0, while Raspberry Pi Jessie comes with QT 5.3
>> 3. I has to build for openmax video output.
>>
>> Lawrence has supplied three patches for QT 5.4.0. QT 5.4.0 has to be
>> downloaded and built as there is no download of object code QT 5.4.0 for
>> raspberry pi. It builds ok with the patches.
>>
>> Lawrence has also supplied 295 patches to mythtv.
>>
>> By default the script he supplied does not apply the mythtv patches. It
>> is possible to run the resulting 0.28 frontend on the raspberry pi but
>> many things do not work, including audio and video. It is also popping
>> up a message every few seconds asking whether to use images, video or
>> audio for the gallery.
>>
>> I attempted applying the patches (by enabling an option in Lawrence's
>> script). 16 patches were rejected, and several others complained that
>> they could not patch a binary file (png file). The build script carries
>> on regardless and then fails quite soon with messages "#else without
>> #if" and "#endif without #if". I believe the rejected patches are
>> causing this failure.
>>
>> I can go through the patches and attempt to fix them. I started looking
>> at them. The first rejection is fine - the change is already present in
>> the code. The second is simple, one of the match lines has had a small
>> change which causes a mismatch. The patch actually adds about 3000 lines
>> of code if it is successful and the description is "UPNP MediaRenderer
>> support".
>>
>> Is there any plan for this? I have been watching mythtv on raspberry pi
>> with great success using Lawrence's 0.27 pre built version, but we will
>> need a way to build the raspberry pi version in future, and the more
>> changes go into the code, the more these patches will fail.
>>
>> Should I attempt to fix the patches and see what the result is, or is
>> there a better plan?
>>
>> Peter
>>
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> Peter,
>
> Just my 0.02$:
>
> I’m building vanilla current master for RPI2 and it works no problem (in functional sense).
> I’m doing this on custom ArchLinux ARM with Qt5.5.1. 
> In my case NO single patch is needed to get compiling and working current master.
>
> What is show stopper for me is video playback.
> Generally: playback is jumpy albeit CPU load is 10-20%.
> RPI2 OC changes nothing.
>
> MythTV devs are suggesting me that issue is within A/V sync and decode areas as frames decoded are occasionally dropping to 0, and the async varies wildly. The data to feed the decoder is there so the issue all lies in the decode/sync part of myth.
> I’m seeing this in the logs as FE it’s dropping frames (which causes jerky playback)
> „Video is 3.52113 frames behind audio (too slow), dropping frame to catch up.”
> This is all with EGLFS.
> Tomorrow I’ll do tests with xcb.
>
> To judge is my playback issue of my OS (custom Archlinux) or MythTV itself - it will be good to try other OS (like Raspbian) on my RPI2 with my backend and with my recordings and see how it goes.
>
> Do we have current master available as package for current Raspbian ?
>
> I’m Arch guy and Debian is learning curve for me.
>
> 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)
>
> br
>
I have downloaded your mimimyth2. The download is quite fast, much
faster than the download from Lawrence Rust system. I will try minimyth2
and let you know.

Video playback - works better in xcb (with the raspbian build for 0.27).
I have had jerkiness in eglfs when I tested that, and eglfs outputs
errors about video being behind.

I have TV sets with overscan. I can correct that with xcb but not with
eglfs, so eglfs is no good for me.

There is no mythtv package for Raspbian, only zipped tar file that you
can untar and run from that. On Lawrence Rust's web site
(http://softsystem.co.uk/download/mythtv/) there are 0.27 and 0.28-pre
(master) tar files. I am using the 0.27 and it works well. The 0.28 I
have not tried yet, I would like to be able to build it myself but that
has not been very successful.

Peter



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