MVP locks up on "Live TV"

[sub]

Sub, can you explain the difference in processing between watching live TV and viewing a TV recording (both via an MVP)? What is happening where?

Watching live tv via the MVP pretty much the same as playing back an recordings, whilst recording at the same time. They are using the same file though, so there would likely be a fair bit of disk activity (so make sure disk isnt fragmented to hell etc).

If you kick off a recording, leave it for a couple of minutes, then start playing that recording while it is still in progress, does it continue to play find? even after that first couple of minutes? (ie the recording point when you started watching)

Are there different mpeg decoders available for the MVP?

No, its all done in hardware.

Is there a particular mux which is known to work well with the (std Hauppague?)

I use the Hauppauge mux v5.0.1307. It works well for me.

[mvallevand]

This thread appears to be related to my MVP playback problem; http://forums.nextpvr.com/showthread.php...pmc&page=4

Mvallevand, if you're around, can you explian more fully please? How can network speed (100M/s) be an issue? Is the MVPMC sw better or worse than the Hauppauge for playing back Live TV? Is avi an mpeg variant?

I think the problems are somewhat related. This one too, even without the mux http://forums.nextpvr.com/showthread.php?t=31156&page=3

First the mvp is not capable of 100Mb it it might be able to do sustained 10Mb depending on your network, most people get much less, but that isn't really the issue. What is happening you aren't able to get the sustained throughput required for livetv to the mvp. To fix this you have to eliminate all the bottlenecks on the server side It's not really CPU intensive either but your 25% is actually high for what the CPU has to actually do. For digital QAM through Cyberlink to the mvp, I average around 5% CPU. Moving to 100% CPU doesn't mean it can deliver data faster than it is available.

The bottlenecks are disk read and write speeds, mpeg capture strength (errors in digital stream), and the mux'ing to mpeg-ps to the stream to the mvp. If mpeg recording work ok, the network is likely not the bottleneck.

The only advantage to mvpmc for this is instead of freezing, rebooting and needing to reload the dongle, you usually will be able to just restart emulation mode. mvpmc is more lenient to the timeouts so it might even just be blocky and stutter along. Regardless it doesn't cost anything to try it.

Martin

[prouton]

Hmmm. How do you reconcile this theory with Task Manager reporting less than 25% CPU usage when viewing via the MVP?

The issue is less about the constant CPU usage percentage, than about instantaneous usage during function startup. While playback was fine for me with the Athlon 850, "LiveTV" startup and multiple jump commands (fast forward/reverse) together could sometimes be a problem -- the server had a problem keeping up and the MediaMVP would at some point stop responding to the remote commands.

Another thing to try, especially with an older computer, is to enable the network adapter's onboard processor to remove some of the workload from the system CPU: NIC tweak article.

[fausto]

Thanks for all the replies folks. It's given me a lot to think about and digest before I do more experimenting.

The bottlenecks are disk read and write speeds, mpeg capture strength (errors in digital stream), and the mux'ing to mpeg-ps to the stream to the mvp. If mpeg recording work ok, the network is likely not the bottleneck.

So an external USB disc via a NSLU2 would not be a good place to store recordings.....?

The only advantage to mvpmc for this is instead of freezing, rebooting and needing to reload the dongle, you usually will be able to just restart emulation mode. mvpmc is more lenient to the timeouts so it might even just be blocky and stutter along. Regardless it doesn't cost anything to try it.
Martin

I like the idea of being able to play Wav and FLAC so I may well give it a try sometime anyway. What sort of thing causes timeouts?

[mvallevand]

So an external USB disc via a NSLU2 would not be a good place to store recordings.....?

It's ok for video and great for music but don't expect to read and write to it and use it for Recordings. If your D drive is a NSLU2 that would explain the problems. I use mvpmc directly with a NSLU2 and have no issues reading up to about 8 Mbs.

I like the idea of being able to play Wav and FLAC so I may well give it a try sometime anyway.

I'm not suggesting using mvpmc in native mode, I'm talking about emulation mode with GBPVR which replaces the Hauppauge dongle.

What sort of thing causes timeouts?

I can't tell you why your capture cards stops feeding data but that look like it is causing your timeout.

Martin

[radioactive1]

I may be off in the weeds on this, but I'm wondering if this issue isn't about the MVP but about GBPVR itself. When I installed the new version of GBPVR for the first time the other day, I noticed that it locked up when I selected Live TV..........and that, when I tried it from the host PC (i.e. not from MVP).

I'm running a brand spankin' new Dell D630 Laptop running an Intel Dual Core 1.9ghz processor and 2gigs of RAM, so I don't think my machine is a problem. Also made sure I had upgraded my .Net runtime and my MS runtime files.

Only reason I suggest this is that I find it sort of interesting and coincidental that people are having problems with the Live TV funtion only.

Another interesting thing I noticed. After trying this a few times, I decided to click on Live TV and when it came up - do nothing. It ran just fine (it was just sitting therre of course, but it wasn't until I tried to click on the listing that it locked up.

radioactive1

[mvallevand]

I certainly can't duplicate fausto's problem, and I don't think it is GBPVR related.

Martin

[fausto]

I don't think it is GBPVR related. Martin

From my perspective, because the MVP plays back recordings and avi files fine, I can't see how it can just be a problem with the MVP. It must be something to do with how GBPVR talks to the MVP in "LiveTV" mode.

Can someone explain how to go about optimising the MVP LiveTV pre-play delay and Transcode pre-play delay setting in the Config utility.

[mvallevand]

From my perspective, because the MVP plays back recordings and avi files fine, I can't see how it can just be a problem with the MVP. It must be something to do with how GBPVR talks to the MVP in "LiveTV" mode.

Can someone explain how to go about optimising the MVP LiveTV pre-play delay and Transcode pre-play delay setting in the Config utility.

I don't think there is a problem with either the MVP or GBPVR, if you are running the PIII 1G machine in your sig. That machine is too slow for what you want to do. Alchemy not optimization is your best chance here.

Regarding the pre-play buffer that really is intended to address start up delays and not performance. Your log suggested the capture device stops providing data well into the broadcast for seconds. Maybe another capture device would help, otherwise it's looking like time for better system.

That's about it for me on this thread. Good luck.

Martin

[fausto]

I don't think there is a problem with either the MVP or GBPVR, if you are running the PIII 1G machine in your sig. That machine is too slow for what you want to do. Alchemy not optimization is your best chance here. Martin

Alchemy . Nice one. However, I still don't see how my PIII 1G PC is too slow, when I'm seeing less than 25% cpu usage and very light network traffic according to XP Task Manager. Can someone explain this to me???