What are the factors for channel changing speeds? (1 Viewer)

[Nightmare77]

I'm just wondering what affects the speeds for channel changes? I have a dvb-t card and i'm just wondering what seems to be slowing down the speed in which it takes to change channels, the fusion software that the card comes with seems to change channels quite quickly with timeshifting enabled, however with the TV server version 3 it seems to take maybe 3-4 seconds longer . Any ideas on the factors.
From what i can tell it doesn't seem to like not having full signal strength in MP but seems to cope with it in the fusion software , do you think this is the main reason behind the slower changes ? or is it because its over the network?

 

[tourettes]

Are you using latest SVN of MediaPortal & TV Engine? There have been some fixes that improve the channel zapping time. For me the zapping between two DVB-T channels is less than one second.

Also check what version of TSFileSource.ax filter your system has. You can see that info when adding a filter in GraphEdit. The version should be 2.2.0.9 beta9 (or newer, but that's the current version.)

 

[shred444]

subscribed to this thread. seems interesting.


i've also noticed that different TVs with built in tuners tune differently. some zap immediatly, others show a black screen for a half a second, then change. Is this all due to the quality of the tuner?

 

[knutinh]

For digital tv you at least have to wait for the next non-predicted frame (I-frame). Analog tv does not have to take that consideration.

I suspect that the reason why different programs have different speed is due to how optimised the code is. Perhaps a program written for one specific card can make some assumptions and skip redundant stuff?

-k

 

[tourettes]

I suspect that the reason why different programs have different speed is due to how optimised the code is. Perhaps a program written for one specific card can make some assumptions and skip redundant stuff?

Most propably the delay is coming from card's tuner and BDA drivers itself.

 

[knutinh]

Most propably the delay is coming from card's tuner and BDA drivers itself.

If two different applications have very different delays using the same card and the same drivers, I cant see how this delay can be attributed to tuner and drivers?

On the other hand, programs delivered with the card may or may not use the BDA drivers. If they use proprietary drivers then I agree, those could be faster than what MP ever sees.

-k

 

[tourettes]

The new MP TV client (actually the tsfilesource filter) had bug that caused single cpu systems to have approx 5 second additional delay when changing channel. So that might have been contributed to the long zapping delays

 

[Nightmare77]

hmmm perhaps thats my problem, the odd thing tho was that previously on day one when the tv server was released it was quick , and probably quicker than the old version, i would say around 2-3 seconds max, but laterly it just seems to say around 9-10 seconds and the screen is just black. perhaps it is that problem tourettes, is that in mantis , nice to see some info on it

 

[tourettes]

I think that's not in mantins, but it should be fixed in current SVN builds.