Hi Ruediger,Thanks for the info. It does sound like i7 is overkill even for HD recordings. I look forward to getting this and other users' capture agent setup/config up on a wiki!
No hurry and any further testing, but when you do, I am sure the Opencast Community would want to get the results.
Kevin Chan Operations Team Educational Technology Services UC Berkeley On 2/9/12 1:45 AM, Ruediger Rolf wrote:
Hi Kevin,we only use two i7 for capturing. One of these is a Windows PC using the Blackmagic H.264 Pro Recorder box (that's why windows) for HD-recording. But as this box is still missing the APIs that Blackmagic promissed the recording is still manual. The machine is quite over-powered (20-30% CPU load while capturing 1280x800 vga and 1080i video simultanous). The second i7 is in use for our live streaming test system, that we use for over a semester now. If we record, enable confidence monitoring and do h.264-live-streaming for 2 streams (SD-video only) with the Matterhorn Capture Agent we are getting to 40-50% CPU load. So again this machine could be slower. I production we used only single stream live-streaming, which ran at about 30% CPU load. We are using the Hauppauge PVR-150 in all our machines, so we have to do an additional decoding and re-encoding to h.264 for the streaming. Both machines are Dell Optiplex MT 980 with the cheapest quad-core i7 and 4 GB RAM.In general we use Dell Optiplex 780 as recorders with a Pentium 4 Dual Core with 2.8 Ghz and 4GB RAM. They run at 70-80% CPU load while recording 2 streams. With the optimisations in Matterhorn 1.3 these machines can do recording and live streaming at 90-100% CPU load, what may cause some frame drops if we are unfortunate. For only recordings the general CPU load will go down significantly too with 1.3. Again we are using Hauppauge PVR-150 and epiphan VGA2USB LR on all of these machines.Currently if I would need to buy new computers as recorders I would recommend a Dell Optiplex MT 790 with a i5-2400. As this would probably have enough power for reliable live-streaming at least.If you are interested I can try to check how much CPU load it will take on the i7 to capture from the epiphan device and a Blackmagic Intensity Pro HD-capture-card. This is already on my to do list, but I had no time to evaluate this yet. The capture card is lying on my desk for a a while already...Rüdiger Am 08.02.2012 18:14, schrieb Kevin Chan:Hi Nils,Thanks for your info. While I have heard of other universities running different hardware, this is the first documented case (as far as I know) of someone specifically stating that someone is running capture agents using i5/i7 cores.At UC Berkeley, we are likely to need some higher powered capture agents to do some HD camera captures (and possibly for SD camera captures) and that's why I have been trying to get the Opencast Community to share their hardware/software/config setup on this list (and even better would be on the Opencast Wiki).As such, can you share some basic information about your setup (perhaps with a note on the path that led you to your particular setup)?Even though we are still in our very early stages of testing/silent piloting, if I have a few minutes today, I will try to get a "capture agent setup page" for UC Berkeley started on the Opencast wiki so that others can benefit from this information.Kevin Chan Operations Team Educational Technology Services UC Berkeley On 2/7/12 10:46 PM, Nils Birnbaum wrote:Hi Kevin,besides Gallicaster, this is a general problem. Most Universities run i5 or i7 processor to capture sufficient framerates for 2-stream-recording. So you have a trade off between CPU-Power and framerate (and some RAM) toget a result that match with the needs of your institution. Regards NilsHi Ruben, Thanks for the info, your approach sounds reasonable to me. I am still unclear on what hardware setup you are using. I found thispage - http://wiki.teltek.es/display/Galicaster/Hardware+recommendations- so I am guessing you are probably running your captures against an Intel i3 processor with some sort of Hauppauge card. So in summary:a) using the above hardware setup, you had some video sync/dropped framerate issuesb) these issues were fixed with "a different pipeline structure with theelement 'videorate' to guarantee the video stream synchronization" In theory, adding "videorate" to the MH capture agent pipeline should also fix this issue, but the placement of this element is probably key to the whole thing! Let me know if I got any of the above wrong. Kevin Chan Operations Team Educational Technology Services UC Berkeley On 2/6/12 4:51 AM, Rubén Pérez wrote:Hi all, The pipeline we are using in Galicaster is rather different than the one used in the standard capture agent in many ways, the first one coming to my mind being the fact that Galicaster needs to provide video feedback and the CA doesn't. Still, I will take a look and see if we can commit some changes to improve the synchronization quality. I cannot guarantee though. The pipeline used is in the code of Galicaster, available at www.galicaster.org<http://www.galicaster.org> .Sorry I cannot be more specific right now. When I have some spare timeI'll try to document myself on this topic and try to apply a patch based on our research in Galicaster, if that's feasible withoutaltering the current CA pipeline too much. Does this sound reasonable?Regards 2012/2/2 Kevin Chan<[email protected] <mailto:[email protected]>> Hi Ruben,Was this "fix" done against the referenced MH capture hardware orsome other hardware setup? In any case, thanks for the info, it would be great if you can provide this info for the MH developers in: http://opencast.jira.com/browse/MH-8505 Also, if you can provide the full pipeline structure, that would be great (for novice pipeline constructors like me). Kevin Chan Operations Team Educational Technology Services UC Berkeley On 1/30/12 5:38 AM, Tobias Wunden wrote:Hi Ruben,any chance that fix will make it back into trunk anytime soon? It would have been great to have this in for 1.3 as well, given thatyou seem to have sorted out that issue a while ago. Tobias On 30.01.2012, at 09:15, Rubén Pérez<[email protected] <mailto:[email protected]>> wrote:Hi Kevin, I can also confirm that we experienced the same frame drop/out of sync problem in long recordings, both in the capture agent and also in Galicaster's development stages. Finally, wediscovered that the key was a different pipeline structure withthe element 'videorate' to guarantee the video stream synchronization. Maybe you could try and add this element to the CA's standard pipeline, and see what happens. Of course, you can also try Galicaster :) Good luck Rubén On 25 Xan, 2012 07:18, "Kevin Chan"<[email protected] <mailto:[email protected]>> wrote: Hi all, During preliminary testing of a 2h 15m capture (which weintend to post produce for YouTube), UC Berkeley discovered that the capture files for video and screen were off by 15m (with the screen capture via Epiphan being 15m short), whichis more or less unacceptable to our post production folks (as it is very difficult for them to stitch this back together). This is likely to be due to dropped frame rate, but it is a bit difficult to confirm. I am wondering if anyone else (besides Saskatchewan folks, who confirmed this issue) has encounter this issue and how they are working around it. I imagine that lowering framerates and bitrates would work, though some initialtesting using various capture agent configurations seems tosuggest that the capture files are still off by a few minutes even with the CPUs being not fully taxed. We are using the reference capture agent hardware and very basic capture agent settings. This issue has been filed in MH Jira if anyone is interested: http://opencast.jira.com/browse/MH-8505 Finally, we have heard that there are various hardware and configuration setups for Matterhorn Capture Agents in production. I think it would be great if that we, as a community, can share this information (via the MH wiki) to help each other understand and learn about the various use cases and setups that are employed. Thanks, -- Kevin Chan Operations Team Educational Technology Services UC Berkeley _______________________________________________ Matterhorn-users mailing list [email protected] <mailto:[email protected]>http://lists.opencastproject.org/mailman/listinfo/matterhorn-users_______________________________________________ Matterhorn-users mailing list [email protected] <mailto:[email protected]>http://lists.opencastproject.org/mailman/listinfo/matterhorn-users_______________________________________________ Matterhorn-users mailing list [email protected] <mailto:[email protected]>http://lists.opencastproject.org/mailman/listinfo/matterhorn-users_______________________________________________ Matterhorn-users mailing list [email protected] <mailto:[email protected]>http://lists.opencastproject.org/mailman/listinfo/matterhorn-users_______________________________________________ Matterhorn-users mailing list [email protected] http://lists.opencastproject.org/mailman/listinfo/matterhorn-users_______________________________________________ Matterhorn-users mailing list [email protected] http://lists.opencastproject.org/mailman/listinfo/matterhorn-users_______________________________________________ Matterhorn-users mailing list [email protected] http://lists.opencastproject.org/mailman/listinfo/matterhorn-users_______________________________________________ Matterhorn-users mailing list [email protected] http://lists.opencastproject.org/mailman/listinfo/matterhorn-users
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