[mythtv-users] linking mythtv with zoneminder live view

Mark Perkins perkins1724 at hotmail.com
Thu Mar 22 08:34:06 UTC 2018

On 22/03/18 01:22, Paul Harrison wrote:
> I wonder if mythzmserver can't keep up with the frame rate and large 
> frame sizes you have set and is getting out of step with what 
> ZoneMinder has in it's buffer? There is no compression used at all so 
> each frame is passed as is which can lead to fairly large chunks of 
> data being passed over to the FE.
The underlying machine is relatively powerful. With everything I run on 
my machine under normal conditions I don't usually average above 25% 
load (although mysql backups etc can cause decent spikes). At the moment 
ZoneMinder is reporting load at 1.00 and /dev/shm at 19%.
> I know ZoneMinder is working on a new API that would eventually remove 
> the need for mythzmserver and the FE will be able to access ZoneMinder 
> directly through this API which would be more efficient and less of an 
> hack reading stuff directly from ZM's shared memory buffers.
> I don't plan on updating the plugin to support this though, I will 
> when I get time before 30.0 is released be removing the plugins I 
> support from the FE, MythArchive, MythZoneminder, MythBrowser and 
> MythMusic and possibly others that rely on those since they are all 
> unsupported and EOL.
> �
>> Re aspect ratio (16:9), yes ZoneMinder seems to display the camera 
>> perfectly, correct resolution and everything. Events replay in 
>> correct ratio as well. As far as I can see ZoneMinder in a browser 
>> window is working perfectly.
> Wonder if it just uses the resolution to guess the AR. If all your 
> camera's are the same AR you could modify the theme so the images 
> either preserve the AR or change there size to a 16:9 one.
>> I am running my ZoneMinder install in a docker container. Perhaps 
>> that has something to do with it?
> I've never run it in docker but I do know you can get unexpected 
> problems sometimes when using docker for some things but I honestly 
> don't know.
> Paul H.
I've tried a lot of different things, without really getting any wiser. 
I eventually switched to the camera's substream / second stream (h264, 
640x360 15fps) and this was a massive improvement. However it still was 
not a fix. I would still get one of those "Protocol error: '��������' is 
not a valid size prefix." messages once every 10-30sec (I can't see any 
consistent pattern to them) and I still got an eventual segfault 
although it took just a little over 3min of live view to occur.

I spent a lot of time trying to scrub the stream through ffmpeg in case 
there was something odd in the format, but I couldn't find any settings 
that made a material improvement.

At this point I am pretty much completely out of idea's. Any suggestions 
greatly appreciated but otherwise I will probably configure an IPTV 
tuner and point it to the stream and just add it as another channel and 
not worry about being able to review the events through MythTV. If the 
MythZoneMinder plug-in is going to be decommissioned shortly anyway 
there is probably little to be gained in further debugging.

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