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Home: Isadora: Performance: Live video, questions

trtrjyrki New User Aug 12, 2007, 11:47 PM Post #1 of 13 (4172 views) Shortcut Live video, questions Can't Post We are working on a theatre adaptation from Bulgakov's Master and Margarita and we need Isadora to play both effected live video and video clips from hard disk. We have been thinking about buying a Mac Pro 2,66GHz Quad Core, with 5GB Ram and proper video cards for minimum three outputs + monitor. With what computer and what setup you have been able to play 720x576 (PAL), or similar, live image smoothly? We might compromise with half size if we have to. Which codec suits live video the best? Which video card(s) have you been using with live video in Isadora? We have now been testing on live video with a MacBook Pro 2,66GHz Dual Core, 3GB Ram. We have now managed to get the image to work without major "jumpiness". There is still a delay close to 10 frames, due to the effects we use. To what amount can you minimize the delay? The status window shows that most of the time we are at or close to 25fps. We have some scenes where there is some audio leak from and to the stage, and we'd like to make it as easy as possible for the actors. When we run audio through Isadora as well, it seems like it is in sync. Is this possible? If it is, it might help us a bit. Thanks for your help! Jyrki Väisänen (This post was edited by trtrjyrki on Aug 13, 2007, 9:16 AM)

Mark Coniglio TroikaTronix / Moderator Aug 14, 2007, 6:42 AM Post #2 of 13 (4153 views) Shortcut Re: [trtrjyrki] Live video, questions [In reply to] Can't Post Regarding delays... if you are using a DV camera, the delays are impossible to totally remove, because the DV camera itself presents a delay when it compresses the image from analog to DV. You're going to have to move to a different type of input device to get delays down further than that, though I'm sorry to say I have no real world experience on what that device might be. (Black Magic Deck Link maybe? Anyone have experiences about that?) In terms of what codec suits live video best, you should chose the codec that's native for the capture device. For a FireWire DV camera, that would be DV-PAL (in your case.) Hope that helps, Mark - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Mark Coniglio / TroikaTronix Creator of Isadora

trtrjyrki New User Aug 14, 2007, 8:52 AM Post #3 of 13 (4150 views) Shortcut Re: [Mark Coniglio] Live video, questions [In reply to] Can't Post Thanks for your answer! The delay of the DV camera is only under two frames. The major delay comes when we take the video into the computer. I'll put a detailed description of what our system will be. If anyone has ideas they want to share, I would appreciate it. We have 3 or 4 cameras with which we record live action behind the stage. The cameras are connected to a video mixer from which we bring video signal (Composite) to DV Converter (Can anyone recommend something?) and from there we take it via FireWire to the computer and Isadora. (Maybe that Black Magic thing would be useful here?) In Isadora we put effects and mix the live video with film clutter video (we've done it with alpha mask now; do you have any better ideas how to do it?) We have also pre-recorded video of some scenes and some additional background video on hard disk that we use to illustrate some scenes. In one scene we need to do some basic blue screen stuff with live video. (Is this very computer power consuming?) In Isadora we have 1) one stage/output that we split for two screens (the projectors are not used at the same time) with a vga or dvi matrix (Is this a good idea? Should we have two stages, one for each projector?) 2) three stages/outputs for maybe 30 televisions (so that we can either have three different images in the televisions or have the same image in all the televisions) These outputs are never used all at the same time (e.g. all the televisions at one time; projector and one tv at one time). Do you think this setup could run smoothly with for example a Mac Pro Quad Core, 5GB RAM? Would Core Video thing help us? Which video cards would you recommend? Has anyone used ATI Radeon X1900 with Isadora? It has two DVI/VGA outputs and one Composite output. Is it possible that Isadora would recognise all three for different screens? How much difference anyway does it make to have a very good video/graphics card in terms of reducing delay and making the video run smoothly? I mean: How much can Isadora use all the fancy features these cards offer? If you have any information that could help us, please post. We have to try to make sure that everything will work out before we can actually start buying stuff because we have a limited budget. Thanks for your help! Jyrki Väisänen

Mark Coniglio TroikaTronix / Moderator Aug 16, 2007, 6:07 AM Post #4 of 13 (4132 views) Shortcut Re: [trtrjyrki] Live video, questions [In reply to] Can't Post There is an unavoidable delay when the computer decompresses the DV signal. I don't know of any way around that if you are using standard DV input from the camera. There is this device however: http://www.theimagingsource.com/.../dfg13941e/overview/ and it's accompanying drivers http://www.outcastsoft.com/ASCDFG1394.html which some people have indicated reduces the delay. I have no personal experience with this device... perhaps others can comment. I don't think the video cards themselves introduce much delay. Furthermore, you may want to experiment with the CoreVideo version of Isadora for Mac OS X. Running the stuff through these modules gives significant performance improvements. Best, Mark - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Mark Coniglio / TroikaTronix Creator of Isadora

william User Aug 18, 2007, 10:15 PM Post #5 of 13 (4089 views) Shortcut Re: [trtrjyrki] Live video, questions [In reply to] Can't Post If you can afford it, the MacPro 8-Core is best performance available for live video processing and playback. We just used one in a similar configuration with great success, though with only 1 live feed, not 4. The lag of the video was imperceptible, if there was any lag whatsoever. We were also running 4 other videos at the same time out to 5 stages. A few notes regarding the video cards with the new MacPros - Apple's DVI to RCA/S-Video adapters are NOT compatible with the current nVidia 7300GT cards (which come standard on the machine). They are only compatible with the ATIx1900 cards, so if you are outputting to RCA and not VGA, you might want to seriously consider using the ATI cards (which already have the composite signal built in - why these need adapters... who knows). However, one can probably assume Apple will release DVI to RCA adapters that are compatible with the 7300 cards soon enough (but then again... who knows). We solved this using an AV-Toolbox scan converter for $120 (a hundred bucks more than a standard Apple adapter). Also, (this is half-statement and half-question) the Display Preferences on the Mac are such that when you plug in 8 outputs from the cards, the numbering on the displays seems arbitrary. Even if you plug everything into the computer in a certain order, the computer will number the displays in a seemingly random order. Apple tech-support could not tell me how to renumber the displays and this caused a problem, since Isadora will currently only see up to 6 Stage outputs. If anyone knows the answer to renumbering displays, let us know. I'm not talking about re-arranging them, that's a simple click and drag operation. In terms of live feed, if you are using DV cameras, you should run Firewire signals. I must recommend using firewire instead of down-converting via the composite video out into a switcher and then converting again to Firewire. This is likely where your lag is entering into your signal path. There is one Firewire mixer available on the market - the Focus Enhancements MX-4DV, which I have used and which is reliable. Just be sure to upgrade to the latest firmware as soon as you open the box. This mixer takes in 4 Firewire signals audio included OR 4 composite signals and sends out 1 dv signal as well as 1 S-Video and 1 RCA output all simultanously. Get one before they disappear, since Focus is upgrading the line to outrageously priced HD switchers. Regarding Stage Outputs - I recommend dedicating stage outputs to each output regardless of whether or not they are all used simultaneously, if you can afford the extra video cards. This helps to keep a consistency to the programming workflow and will allow you the option to later change your minds about when the projector is used. Why limit yourself if you can avoid it? For the 3 outputs to the TV's - I assume you are using multiple matrixes, yes? I might suggest you DO NOT go with any low-end matrix switcher, as the low-end Comprehensive/Kramer 16x16 switchers CANNOT receive a string of serial, but instead must receive it one hexidecimal set at a time, which forces you to pre-program settings manually on the front panel and then trigger them with serial. The cheap matrixes are sluggish in their response and will not allow for fast changes via Isadora or any other serial control for that matter. I can't comment on the CoreVideo version of Izzy as we haven't used it yet in our work. Hopefully soon, tho. In terms of delay and lag, it really starts with the processing power of the machine, I think. The 8-Core MacPro had some unbelievable results in my experience with Izzy and we were running the latest update of 1.2.8. It is also a matter of compressing everything to the 320x240 PhotoJpeg compression. If you are doing CoreVideo work, then the video card may be more important and you may want to go with the ATI card. For now, we have sworn off ATI cards for any live performance event. For editing in AE7, they are supposedly outstanding... Hope this helps...!

trtrjyrki New User Aug 20, 2007, 6:55 AM Post #6 of 13 (4074 views) Shortcut Re: [boys&murderers] Live video, questions [In reply to] Can't Post Thank you for your answer! I'm afraid we can't use Firewire for two reasons. First is expense. We are trying to get all this done with a quite limited budget, so we can't really buy both Firewire mixer AND a powerful computer. We have a composite mixer and we can buy a good DV interface box (e.g. DFG/1394-1e). Second is that we need to move the cameras a lot and I'm afraid Firewire couldn't stand the treatment for 50 nights. And still if it did we need close to 200 metres of cable, so having that much Firewire would be very expensive and complicated. Anyway when we have been testing with MacBook Pro we have been bringing the signal through Firewire and through a mixer and a cheap DV interface, and experienced quite similar lag both times. We are now trying to negotiate a deal with a store to have a very good computer (8-core with ATI 1900's) sponsored for us. Still we are worried about the delay. We are getting a test computer (probably 4-core macpro with two ATI Radeon 1900's, so we are going to be wiser after this week. How much did you manage to reduce the lag? Was it like 1 frame? 3 frames? Our director is showing signals that if we can't get the lag down we will just have to settle for black and white with no real-time film-like-fx. We have scenes where people are talking in the doorway of the stage so that the audience will see them at the same time on screen and on stage. Of course we those film clips where we can do proper fx, but it would be interesting to have a new approach to live video too. Jyrki

william User Aug 24, 2007, 5:46 PM Post #7 of 13 (4003 views) Shortcut Re: [trtrjyrki] Live video, questions [In reply to] Can't Post What sort of live effects? Your best bet to cut the lag is to use switcher and to cut the computer out of the equation entirely. I worked on a production years ago which was a real-time film concept and the director/designer did a brilliant job green-screening live actors with no lag whatsoever by keeping everything analog. In our production, the performers moved quite slowly and as I said, the lag was imperceptible. It must have been a mere 1 or 2 frames. I understand the firewire situation completely and you're making the right choice to stick with composite in terms of the physical installation. However, perhaps you should invest in a decent production switcher...? Tell me more about your desired effect and maybe I can help point you toward a piece of hardware.

trukske Novice Jan 20, 2008, 7:47 AM Post #8 of 13 (3207 views) Shortcut Re: [boys&murderers] Live video, questions [In reply to] Can't Post Hello, I want to buy an internal PCI video capture card. We work with composite video in 640x480 from a cctv cam. Does anyone now which one is the best choice? The most important is that it has no visible lag... I was thinking to buy one of the blackmagic cards.Does anyone has some experience with these? We are going to use the latest macpro with the standard graphic card. Thx, Ief.

knowtheatre New User Apr 1, 2008, 10:08 PM Post #9 of 13 (2675 views) Shortcut Re: [william] Live video, questions [In reply to] Can't Post We're running a similar setup, and experiencing the same delay. But what I don't quite get is that I'm seeing very little delay in the video input preview, only on the output to our projectors. This would lead me to believe that the delay isn't happening at the conversion back into firewire, but somewhere either within isadora, or at the output. Any ideas to speed things up on the output end?

trukske Novice Apr 2, 2008, 5:10 AM Post #10 of 13 (2660 views) Shortcut Re: [knowtheatre] Live video, questions [In reply to] Can't Post with 'projectors' you mean a real projector or the stage preview?

knowtheatre New User Apr 2, 2008, 6:58 AM Post #11 of 13 (2652 views) Shortcut Re: [trukske] Live video, questions [In reply to] Can't Post Yep, the actual projectors. I'll check the lag in the stage preview today. It might be a case of a slight delay coming into the computer, slight delay within isadora, slight delay out to projectors all add up to the rather substantial delay that I'm seeing. Thanks.

trukske Novice Apr 2, 2008, 7:17 AM Post #12 of 13 (2648 views) Shortcut Re: [knowtheatre] Live video, questions [In reply to] Can't Post You can connect a television to see whether it's the projector or isadora/the camera. Now we are using a Sony Evi-D70. It uses a Photo Jpeg compression, and that works great. MiniDV, CCD security cams, hard disk recorder cams are all causing a lot of latency. Firewire input isn't also a very good option i think. The best is to use a PCI capture card. You already have some very cheap ones. If you have some video capture software (imovie, finalcut) you can check the real latency of your camera and capture device. The latency there should be the same as in the video input preview window of isadora, NOT the stage preview. The stage preview shows the image after it 'passed' isadora. The video input preview shows the image before it comes in in isadora. Enfin, I think so... Ief

jnevin Novice Jul 21, 2008, 3:12 PM Post #13 of 13 (1501 views) Shortcut Re: [trtrjyrki] Live video, questions [In reply to] Can't Post I have the DFG/1394-1e for use with live green-screen and Izzy. It significantly reduces the lag time. The DFG/1394-1e outputs UNCOMPRESSED firewire data to your computer. It takes both composite and svideo analog inputs. I'm down to approximately a 1-second delay on my MacBook Pro 2Ghz Intel machine. Another feature is that when you go to select your video input source in Izzy (or other video software, for that matter) -- you will see 3 selectable sources coming from the DFG/1394 -- the 2 Y/C and 1 svideo connections of the DFG/1394. I am now trying to further reduce the delay by doing my greenscreen comp in Quartz Composer before the hand-off to Izzy. I haven't yet found an equivalent way of doing this using Izzy Core Image (which exposes most of the QC patches) because of current limitations in how Izzy Core Image addresses the "stage" settings.

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