channel changing performance (2 Viewers)

[craigcurtin]

Guys,

I am a new mediaportal user and have setup 1.1.3.

I have a backend/TVserver and a front end unit.

My network infrastructure is a gigabit ethernet switch - a Netgear GSM7548s - each system is directly connected to the switch.

Both Systems are running Windows 7 32-bit with 4GB RAM

The TV server has a QUAD BRI DVB-T card which is picking up FTA channels in Sydney Australia with no problems.

The front end can tune to the channels just find but when trying to change channels there is a lag of about 5 seconds.

Is this normal and what i should expect (we previously had MythTV and did not experience this) ? Or is there something i can optimize to reduce this time ?

Craig

 

[mm1352000]

Hi Craig

I'll get straight to the point - we can't guess where the bottleneck is (if there is indeed a bottleneck) without logs because these sorts of things can easily vary from system to system. So please post logs from both the client and server showing a few (*no more than 5*) typical channel changes. If possible, be sure to include the tuner initialisation, changing between channels on the same mux, and changing between channels on different muxes.

mm

 

[craigcurtin]

:sorry: OK no worries i will get the logs. My question was initially - is this the expected/normal behaviour that everyone sees or is there indeed a problem in my system somewhere.

I will get the logs this evening and post up

Craig

 

[mm1352000]

My question was initially - is this the expected/normal behaviour that everyone sees or is there indeed a problem in my system somewhere.

The biggest determining factor in channel changing speeds is often (but not always) tuner drivers - some people have <1 second changes whereas for other people like myself it is more like 3 seconds. I know that the limitation for me is my card drivers. For you it could be the same, but my point was that we can't tell without logs. I look forward to the logs...

mm

 

[logifuse]

Try changing the Zap Delay to zero: On-Screen Display * - MediaPortal Wiki

Why the default is 2, I don't know, but essentially it waits for 2 seconds before even starting the process of changing channel.

On the combo backend/frontend, that will change the speed to the same as Media Center, on the frontend only, it will probably drop it down to 3 secs.

mm1352000 - slow channel change speed is the number one issue for most people trying MP, yet this setting is rarely (if ever) suggested as the solution. Why isn't this either set as zero by default, or at least well publicised? The description in the wiki doesn't accurately describe what it does. Infact the Zap delay & Zap timeout descriptions are reversed (at best).

Justin

 

[mm1352000]

Hi and welcome to the forum Justin

Why the default is 2, I don't know, but essentially it waits for 2 seconds before even starting the process of changing channel.

That's so that you have a chance to enter the second or third digit in a channel number that is greater than 9.

mm1352000 - slow channel change speed is the number one issue for most people trying MP...

I honestly don't see a lot of comments about this. Most people are *far* more troubled by codec configuration or other "random" problems.

...yet this setting is rarely (if ever) suggested as the solution.

It is not clear (at least to me) that this was what Craig was referring to. Without seeing the logs that I asked for, I'd be guessing if I said it was zap delay. It could be anything from hardware to virus scanners that are actually slowing things down. See -->this<-- recent thread as an example.

Why isn't this either set as zero by default, or at least well publicised?

I explained why there is a zap delay above - it is to allow you to enter multi-digit channel numbers. I do take your point that zap delay isn't talked about very often so I will keep it in mind for future slow-channel-change threads, however like I said I *really* don't see this topic come up that much (maybe it is because I'm battling other things - my focus is almost entirely on TV Server, not MP or even the TV plugin in MP).

The description in the wiki doesn't accurately describe what it does. Infact the Zap delay & Zap timeout descriptions are reversed (at best).

I'd encourage you to update the wiki if you think it is incorrect.

mm

 

[logifuse]

Hi MM,

Thanks for that.

I've only got one & two digit channel numbers here (DVB-T Australia), but even with Zap delay set to zero, I seem to have time to comfortably enter the second digit. I can even enter a 3 digit number using digits that are used for other channels & comfortably enter them before it tries to change to one of the other channels (e.g. I enter 109, not that quickly, & it doesn't change to 1 or 10 - legit channels - before I finish).

If you're coming from WMC or any terrestrial digital tuner based device (STB/TV/PVR) these days, you expect a near instant action when you press the channel +/- buttons. That's why I think the zap delay option needs to be made more obvious, otherwise a new user assumes it's a limitation of the TV server, & perhaps even gives up on MP because of that (as I've seen when promoting MP at the pcmediacenter.com.au forum).

Regarding the wiki, I just tested the 2 settings and their descriptions are reversed, so I guess I should update them.

Apologies to Craig for the semi-hijack, but hopefully it's the fix he's after.:sorry:

Justin

 

[Dadeo]

Hi Justin

Unfortunately you need to be a forum user for 10 days with at least 5 posts to edit wiki. That's why you still display as a 'New User' instead of 'Portal Member'.

At this rate you will soon be able to update Wiki for now I made the change, thanks for catching that!

 

[logifuse]

Thanks Dadeo.

 

[craigcurtin]

:sorry:Guys, I have not forgotten about this - just got waylaid along the way.

I have two issues

1) Slow channel change times - so lets say i have the TV guide on the screen and live TV playing - from the time i select a new channel in the On Screen display to when it changes channels is about 5 seconds.

2) When i first go from the main media portal screen into watching TV it takes approx 12 seconds to actually do anything and bring that module up - just sits there spinning its wheels. Everything else is nice and timely.

I will follow the thread about how to gather the logs tomorrow evening and post them up

regards

Craig