sagetvtranscoder on multi-core systems

[andyvr4]

I'm experiencing a problem with my dual core athlon processor when I try and watch programs recorded on either my HD-PVR or my HVR-2250 (analog side) where when I'm watching them remotely on the hd300 the sagetvtranscoder process will set at 50% load level and will not go any higher even though there's nothing else running on the server and the video is not getting trans-coded fast enough (every 2-3 minutes the program will start getting jumpy and I'll half to pause to let the buffer build back up).

I know that was a big problem in V6, but I can't find any current post on V7 and rather there have been any work arounds! The program does appear to be multithreaded as both cores are getting loaded it just appears they only get loaded to 50%!

I've also noticed that if I pause the program to try and let the trans-coder get a little ahead the sagetvtransoder process will continue running for around 15 seconds at 50% load and then it'll stop running until I press play again and start viewing the program at which point it'll start back running at 50%. Is there anyway to tell it to buffer for more than 15 seconds while I have the program paused?

Thanks for any help that you guys might have to offer!
Andy

[andyvr4]

Does anybody have any ideas. I'm 99% sure that the trancoding is my problem because with over the air recordings made by the HVR-2250 it'll placeshift perfectly (I do not need to pause to buffer at all).

It's just with the analog HVR-2250 and HD-PVR recordings that I'm experiencing problems!

[andyvr4]

One additional thing that I just noticed if it helps anybody out is that when I connect in through a pc based client I'm seeing higher CPU utilization by the sagetvtranscoder process (usually around 65-70%) vs the 50% max that the hd300 seems to be allowing. Do any of you guys know why this might be happening?

[GKusnick]

The fact that it pegs at 50% indicates that it's running single-threaded, even though both cores seem to be in use.

Think of it like moving into a new apartment in a building with two elevators. The elevators are small, and you have a truckload of stuff to get upstairs, so it's going to take a number of trips. You don't care which elevator comes when you push the call button, so on average both elevators get around 50% utilization. But it's still just you taking loads up one at a time.

Now if you get a buddy to help you (multithreading), then you can use more than one elevator at a time so that the whole job goes faster and the elevator utilization exceeds 50%.

As to why the PC client (by which I presume you mean Placeshifter, not SageTV Client) seems to do better, I don't have a good answer for that, unless you're running Placeshifter and the HD300 at the same time. Then each gets its own transcoder process limited to 50%, but together the two processes can add up to more than that (like a neighbor moving in at the same time as you, using whichever elevator you're not using).

[andyvr4]

I'm using the placeshifter client on the pc. I'm 99% sure that what you're saying is right in that the placeshifter client is running multi-threaded and hd300 is not because when I load task manager and select the performance tab with the placeshifter both cores are showing very high activity, whereas with the hd300 only one of the cores is showing a lot of activity.

I'm really puzzled as to why I'm seeing this behavior however, because I thought that both the placeshifter and the hd300 used the same sagetvtranscoder.exe to transcode the video for viewing on the remote system! I figured that application should be either multi-threaded are not (not different depending on the application using it).

[andyvr4]

According to an email that I just got from sage support the placeshifter pc software is set to allow multi-threading, but the extenders are not. This is supposedly going to be fixed in the 7.1.8 release! I'll update this thread once that release comes out as to rather it fixes my problems!