Deinterlacing PAL TV-OUT problem / recompiling MythTV_Plugin.so for 710

[sambuca]

Hi,

I am having a problem with MythTV_Plugin forcing the bob deinterlacing setting on all MDs on reload.

It appears that bob deinterlacing does not work correctly with PAL TV-out (which is 50Hz), live TV is VERY choppy, I would probably go mad if I watched for more that a few seconds 
Myth complains (When running mythfrontend from shell) "video sync method can't support double framerate (refresh rate too low for bob deint)". More information about this on the Internet..

I know this problem, or similar, has been discussed before, but I could not enough information to recompile my MythTV_Plugin, as it seem the only solution is. As this is a real annoyance (and a major WAF problem), I need to fix this now, in 710.

I have set up a virtual machine with a clean 710 install, and checked out the source from http://svn.linuxmce.org/pluto/branches/LinuxMCE-0710/, and followed the build instructions from the wiki http://wiki.linuxmce.org/index.php/Compiling_from_710_sources . But to no avail.

It builds the MythTV_Plugin.so fine, but when I replace the MythTV_Plugin.so (still in the VM, if it should matter), the DCERouter fails to start, it just dies, no errors, no nothing.
I noticed that the file size of the built file is larger than the original 0710 file. This makes me think that maybe the source tree is not the same as what was used to build 710. So I tried to check out the source from the date 0710 were released, but with the same result, builds but wont run. 

Could anyone please give me some pointers?
regards,
sambuca

[colinjones]

Sambuca - can't help you with the compiling issue. But have you tried the tvtime deinterlacing instead? Its pretty good - most of the recommendations are for cheap_mode=1... however I had some choppiness and experiemented. Found that cheap_mode=0 did a really good job, but also got rid of the choppiness almost completely, and at least one other person said the same. Just thought you might be interested.

Col.

[sambuca]

Colin,

Not sure I understand you completely here. Is there a deinterlacing mode in MythTV called tvtime? Can't say I remember that I saw one by that name? I have tried the kernel deinterlacing, which works well for me.

Anyway, the problem is that the MythTV_Plugin resets the deinterlacing setting at every router reload, so any changes I do to the deinterlacing options are lost.

Or am I missing your point?

Thanks anyway.
sambuca

[colinjones]

no, I missed your point, or rather didn't think it through very carefully! I use VDR and was thinking of the xineliboutput options that give you that plus many other deinterlace options. Haven't played with Myth, but was assuming that most of these deinterlace options were pretty much standard. Sorry couldn't help you...

[darrenmason]

Sambuca,

I have the same problem on my Lounge MD (which is TV Out PAL) and till now have been just changing the interlacing mode through the menus whenever I restart the MD (which I try to minimise). I keep meaning to look into the cause. I assumed it would be a script that was overriding the value rather than the plugin code.

What part of the code did you change? I will try and recompile as well as see I get any further than you did.

regards
Darren

[sambuca]

Darren,

Actually, its the MythTV_Plugin, living on the dcerouter. I got the clue from this old forum thread http://forum.linuxmce.org/index.php?topic=4496.0

The relevant code can bee seen in the charonmedia trac browser http://svn.charonmedia.org/trac.cgi/browser/trunk/src/MythTV_PlugIn/MythTV_PlugIn.cpp#L976. From what I can make of the wiki documentation about building a 0710 version, that link is not for the correct 0710 source, but I suppose the code is not that different.

Now, when looking at the source, I notice it seems that it is possible to stop the execution of the CMD_Sync_Providers_and_Cards method. Setting the Don't Auto Configure setting for the device (MythTV_Plugin I guess..) would stop the execution before any changes are done. Not sure if this would result in any other problem, as I have not checked the other code in the function. I think it would affect users having tuners in MDs, or probably after changing tuner settings.

I have not yet changed anything in the code, I just tried compiling it. Failing to manage that, it just got put off. But I am very interested in trying again to see if we can get it right :-)

regards,
sambuca

[deffcon]

Sambuca,

Did you make any progress of recompiling the Mythtv Plugin, i have the problem also in mythtv 0710 RC2, i have a pvr-500 in my core, couple md's, on these md i watch tv, or trying to watch anyway.
Everytime the router is reloaded i have to turn off deinterlacing in my case or i get the tv image twice on one screen, when i turn it off i can watch tv, but when the md is restarted or the dcrouter is reloaded i have to turn it off again, any help would be appreciated.

Kind regards,


Dave

The Netherlands

[sambuca]

Dave,

No, I did not manage to recompile the Mythtv plugin. Or rather, it did compile, but when I tried to replace it on the core, it just crashed the DCERouter. I never got any good advice on how to fix it.

As it happens, they've switched to DVB-T in my region (of Norway) now, so I haven't used Myth for a while (problems with viewing encrypted channels, H264 encoded broadcast not working in myth etc.). I didn't get around to try the "Don't auto-configure" setting either, so I can't tell you if it will work. I suppose it's worth a try, you can always change it back later.

br,
sambuca

[hari]

you have to compile against the 0710 branch or do LD_LIBRARY_PRELOAD tweaking, you cannot mix 0710/0810/charon-merge/trunk libraries/binaries.

br, Hari

[sambuca]

Hari,

To the best of my knowledge, that is what I did. I checked out the 710 branch (on a 710 hybrid) and compiled using instructions scattered around the wiki. It was not easy to find any step-by-step instructions for compiling 710, and I might have used the wrong instructions. But in short: I used the 710 branch, it compiled successfully on a 710 hybrid. The resulting .so was a different size than the original file, and crashed the router when I tried to use it. (No changes were made to the code, so I would guess the size should have been the same).

br,
sambuca