Crash when launch / freeze when stages' preferences change

  • Hi,

    Working on a 3-screens-projection, I have been exposed to a bug, that I never had before. At first I precise that I work on a windows 10 (64 bits) PC, with 2 graphic cards : the first outputs my PC monitor, the second outputs my two stages. I installed a 2.1 version of Isadora that is running in demo mode for now. At the beginnins I had no problem. The problem has first occured when I changed - while the computer was off - the pluging order between my two videoprojectors. Isadora couldn't launch, it always crashed. The bug temporary disappeared when I unplugged the 2 videoprojectors and that Isadora lost my "stages preferences". I could then run isadora, set the "place on" items of the preferences menu on "none", then close isadora, plug the two videoprojectors and detect them, and finally open my isadora's file at new and set the new stage preferences...
    It's been working for a while, but as soon as I changed the pluging order of my two VPs, the bug occured again. It's not practical when you're on a the road with your show.
    But the problem is getting worse now : It's occuring more and more often, even if I don't change the configuration of my screens plugged.
    Another detail : When I tape on "Ctrl + G" to show stages, then goes in the preference menu, checks my stages' preferences and clicks "ok", it sometimes close my stges and freezes Isadora's activities. The cycles and the Ips freezes, and I can't regain my stages. I just have to close isadora and try again....

    Last info : I've installed the version 1.3.0f24 and tries to do the same things, to check my preferences and everything else, and it doesn't crash.

    Could you tell me if you have ideas about this bug ?
    I'm trying to get a RJ45 connexion to internet to edit a report bug file, because the computer I'm working on with isadora doesn't have wifi connexion...


  • Tech Staff

    Please do enter a bug report. I think this sounds like an issue between your 2 video cards and the resolutions supported by each. Deleting your preferences file will probably correct it for relaunch, but I would like to investigate further the issue of changing preferences while the stages are shown.

  • I think I have found the cause of the issue I had when I opened this post.

    In the Preferences, I have disabled "Shared OpenGL Resources", and after a relaunch the bugs have disappeared. I am not sure to understand what was the exact meaning of this option, but Isadora now works correctly. There's just something else : sometimes when I close Isadora, it tells me after some seconds that Isadora has crashed... It doesn't occure everytime and it is not a problem during the show but I'd like to know if it may happen because of a too big patch ?


  • Dear @loulight,

    This is an ongoing issue that I will be focusing on the coming week. Being forced to turn off "Shared OpenGL Resources" is not optimum, but there is an issue (depending on configuration) with multiple video cards and Isadora under Windows. This issue doesn't affect users with laptops, because there is only ever one video card there. But when you have two, especially when they are of different makes/models, there are problems.
    The workaround as you discovered is turning off "Shared OpenGL Resources." The reason this isn't optimum is that you must specify the destination stage at the beginning of a video chain, e.g., in the Movie Player. The reason? When you have multiple cards, Isadora needs to know which physical GPU will host the video, and you need to know this at the source.
    I am making this our highest priority bug now, so you can expect some better answers in the coming days.
    Thanks your patience as we address this issue.
    Best Wishes,

  • To loulight.

    I had almost same trouble on PC when i use 3 output stages. When I start Isadora with 3 stages at same time, it freezes. But in my case disabling of Shared Resources, doesn't help(after restart Isadora still Freezes). Only checking "Disable vertical sync" helped me. 
    To [mark]( unfortunately problem still exists on Isadora 2.2(I use Isadora with "disable vertical sync" option checked).

  • @Mikhail,

    When you say Isadora 2.2, do you men 2.2.2 which is the latest version? There were fixes since the original v2.2 release that may affect things.
    For some people who have laptops with both integrated and discrete graphics cards in their laptops, there is a setting that allows you specify that Isadora requires the discrete GPU. Open this [NVIDIA Article]( for more information. Use the Program Settings feature to add Isadora and set it to use the discrete (high-performance) GPU.
    Finally, update your video card drivers. I had a user here in Berlin where Isadora was crashing on startup, but as soon as she updated her video drivers, the problem went away.
    Best Wishes,

  • Hi,

    Coming back, because I have some new developpements about the issue I had at the beginning of this topic.
    The computer on which I fixed the problem of crashing Isadora was brought to me in order to improve the way of mapping with the new Isa tools like "Output Setup" and the new "projector" objects that I hadn't been using until now.
    During these five last days, I had some new issues that are a bit scary.

    I am working on the same station as before : Win10 64bits / i7 / 16Go Ram / SSD 250Go / with two identical Graphic cards "Sapphire Radeon R7 360 series" : I have my interface monitor + one videoprojector on the first Card, and two HD LCD screens on the second one. Each physical output of the graphic card is connected to its screen or projector in VGA with "DVI-I/VGA adaptaters" or "DisplayPort/VGA adaptaters". I've been working on Isadora 2.1.
    At first when I started the computer I did some updates : mainly the graphic cards' drivers and Radeon software : "AMD Radeon Software Crimson Edition Display Driver version 16.30.2311"

    Now the problems :

    • First issue I had : After all of that when I launched Isadora it refused to open it because "MSCVP100.dll" was missing. I fixed it by installing Microsoft Visual C++ 2010 x86 & x64 so it's not a problem anymore.

    - The second is the beginning of the real issue : Sometimes the videoprojector seemed to lose the projection. It projects a black screen, it says that it is computing and it changes its resolution by its own and projects my movie in a bad ratio. So my mapping isn't good anymore. Normally it's in 800x600px and it suddenly switchs to 524x768. I suppose that this is linked to the fact I was using a 1024x576px frame, that I was scaling into 1024x768px and then using two "chopper pixel" to split it into 2 x 564x768 frames - to perform a soft edge between both projections. For the records, the both HD LCD screens didn't encounter any problem. Only the videoprojector (DVI-I / VGA output on the graphic card) was concerned.
    I first replace my two "chopper pixels" by two "panner" in order to keep a 1024x768 resolution but I stall had sometimes the same issue.
    Into the Radeon software, I disabled the EDID option. This is an option that allows the soft to automatically choose the best resolution for the videoprojector. And I tried to activate / deactivate other options of the soft like "GPU scaling" - in French it is "mise à l'échelle GPU".
    I thought it would fix the problem, but at first when I launched Isadora and the projections I had a big flickering bug on all of my screens. Even my control screen was concerned.
    I reset the computer and everything seemed to be ok. I played the entire show and it looked good.

    • But on the next morning, when I launched the patch to check it, it started with flickering bug again. When I looked at the projection of the VP it looked like it was switching at a high speed rate between the different outputs of the scene, as if it was projecting in loop its output, then the output of one of both lcd screens. I checked the "windows display settings" and "Radeon settings" to see if the resolutions of my screens were not too big, and everything looked fine. I could open new windows in each screen, when it was not in isadora everythings looked fine.
      I tried to open Isa again but the same problem occured. I reset the computer but no changes. I also saw that when I launched the projection in Isadora, the "cycles" sign was falling at 30 instead of 230 like it is usually... I tried to activate or deactivate the options in the Radeon settings (like "Super resolution", "GPU scalling", "Scalling mode") and it became worse ! When I tried to launch Isadora again after that it was immediately freezing. Precisely it was not freezing but the "cyles" sign was immediately at 30 which made the launch of isadora real slow (even if I just opened a new patch).
      I've been trying many things :
           - in the stages preferences of Isadora, I tried to remove the displays one by one and it looked like the cycles stopped falling as soon as the videoprojector was removed. When I launched Isadora after removing the videoprojector from the stage preferences I could launch Isadora with no lag.
           - I tried to exchange the physical outputs of the graphic cards, but it was not the fact of the output of the graphic card it was always linked to the videoprojector itself, as if Isa could recognize it which looks strange to me...
           - I installed Isadora V2.2.2 but no changes.
      I can't manage to be sure that the problem stops when the videoprojector is removed from the stage displays or just as soon as there are just two displays and not three. Sometimes when I add the three displays in the stage preferences the "cycles" sign stays at 230, but as soon as I project my images it starts falling again...
           - I tried removing the soft and the drivers of the graphic cards, then installing older drivers and soft, or just installing the drivers without the soft, but as far as I tried, I can't put my finger on the source of the problem.
           - I tried something interesting : opening a Isadora V1 (1.3f24 I guess) and it's not concerned at all by this issue. I can configure the stage preferences as I want there's no problem.

    Last info that may be useful : in every steps of my tests, when I've been clicking on "Output Setup", it often told me that Isa encountered an error, but I could click on "quiet" and I use it anyways. But often the previsualisation of the stages in the "output setup" window remained white. It didn't prevent me from working so I don't care but it thought it may be linked at the bigger problem...

    I don't know what to do. I need Isadora V2 for two reasons :

    • an input live stream in HD, that I can't have in Isa V1 (if it is possible tell me but in the "input live settings I can't switch on a HD resolution...
    • the tools that make the mapping easier than in Isa V1

    To Mark :
    In one answer you made to me on the 31th of march, you told something about the "shared open GL ressources" :
    "The reason this isn't optimum is that you must specify the destination stage at the beginning of a video chain, e.g., in the Movie Player. The reason? When you have multiple cards, Isadora needs to know which physical GPU will host the video, and you need to know this at the source."
    Can it be linked to the problem ? I can't stop thinking about the fact that this is all linked to the multiple cards configuration... I don't know how to identify the real source of the bug. It just occurs on Isadora.

    The show is playing in october so I've got some time. Can you give me some help ?
    Best regards
    Nicolas Comte

  • Tech Staff


    As mark has mentioned, this seems like an issue related to the "shared open GL resources" feature.
    I would suggest opening a new Isadora file, and setting this setting unchecked. It is found in the Isadora preferences in the OpenGL section of the Video tab.
    Then create a patch that is using all the outputs. As noted you will have to set the output stage at the beginning of the patch (eg: MoviePlayer)
    Additionally, you are not able to mix video streams with different destinations set (stage 1 VS stage 2)
    This setup/test file should allow you to determine if this setting is the cause of your troubles. 
    If you have further trouble, please submit a support request, and one of us will be happy to work with you to get the best possible performance from your system.
    The link for submitting a support request is available in my forum signature below.

  • Thanks for these informations !

    I can't believe it's not possible to adress one movie player to different stages ; how is it possible ? My movie player has to send the left half of the picture to stage 1 and the right half to stage 2 which are two separate videoprojectors. How can I do so ?

    Yes the first bug I had was linked to "shared open GL ressources" but I have unchecked it a long time ago.
    Now the problem is this : only the fact of launching Isadora with stage 1, stage 2 and stage 3 all active ("place on" set on display 1, 2 and 3) makes it crash (more precisely it makes it real slow, cycles fall at 30).

    I was told by someone else it could be linked to the fact that the videoproject that I suspect being the problem loses its numerical adress (it is linked to the computer by an DVI-I / VGA adapter and a VGA jack). Can it be this ?
    Are there any device to not fail on this ?

    I am looking for your answer, but if you don't see the problem, I'm going to create a support request, that's ok.
    Thanks for your attention

  • Dear @loulight,

    Before we go further, can you try working with the v2.5 advance beta to see if you can turn on "Shared OpenGL Resources" – I would like you to work with this version from this point forward because then – if we find a bug – I can include it in the next build and we can get you a new version quickly
    As I said previously, for Isadora to send this to two outputs, the image must be on the same GPU, i.e., the same graphics card. The problem you are experiencing is because you have two graphics cards. Isadora does what it can to share the images between two physical cards. But if the cards are, for instance, from two different manufacturers, this isn't possible. Now, I've tested this code on a machine I have back in Berlin, and it did successfully share the textures. But there are many reasons why this sharing might fail, and since not very many users try to use this possibility, it might explain why Isadora is crashing/freezing.
    Unfortunately, I am away from Berlin right now, and only have my laptop. So I will not be able to attempt tests on this until I get back next week.
    The inability to share textures is not an Isadora specific problem. If you want to see lots of references to it on the web, enter this into Google
    sharing textures multiple video cards
    or have a look at this NVIDIA article on the topic
    The simplest possible solution is upgrading to a single video card with multiple outputs. Is this something you can do? If so, then you will be able to turn on "Shared OpenGL Resources" and I feel confident all of these problems will go away. I don't think you'll have to invest a lot of money to get such a card, but I am not a PC expert. 
    @DusX – do you have a suggestion for inexpensive graphics cards that offer at least two outputs?
    Best Wishes,
  • Tech Staff

    I am not sure of the specs you require, but a graphics card that is a year or two backs model will provide a lot of power.
    I was very happily running the early Isadora beta on a nvidia gtx 640m sometime back, and found I could run 3 displays (th2go) with lots of GPU effects without a problem.
    Below are a couple cards for under $200. 
    The first is a 700 series and the second is from the 900 series (the series before the most recent from nvidia)

    note: its a Canadian site, so the prices are in CAD... they will be less in USD

    and the newer:

  • Hi,

    @mark , can you precise one thing about this shared ressource question :
    Is it a problem to have 2 stages on one graphic card displaying a "splitted movie", and the desktop & isadora control screen on an other gpu ?

  • Dear Mehdi,

    In theory, the you should be able to have the two stages on one graphics card and the Isadora main window on a second one. But, for instance, opening IzzyMap editor on that separate video card will then have the same problem, because it will want to share the textures on GPU 1 with the IzzyMap screen which will be on GPU 2.
    That being said, I haven't tried this. So you'd have to try it yourself to see how it works. (I don't have a setup handy to try it myself.)
    Best Wishes,

  • Hi,

    Was far from networks during last week but I'm back.
    Thanks for these advices, I will be able to make some tests with the entire dispositive on the 14th of September.

    *** Just one thing to precise :
    until here my config was this one :

    • first graphic card : isadora control screen (desktop) + one videoprojector
    • second graphic card : two videoprojectors

    The both graphic cards are the same (Radeon R7 360) :

    If I uncheck the "shared openGL ressources" there shouldn't be a problem isn't it ? Even if I send one movie to the VP on the first gpu and a splitted movie to the both VPs on the second gpu ?
    Until here I've been using VGA for all my outputs (through DP/VGA adapter and DVI-I/VGA adapter), but on each gpu I also have a "HDMI output". Do you think the problem could be fixed if I used this to put the videoprojector that is on my first graphic card on the second graphic card ? That would give :

    • first gpu : isadora control screen (desktop) in VGA
    • second gpu : two videoprojectors in VGA + one videoprojector in HDMI
      It looks like it could make the setup more stable for Isadora doesn't it ?


  • Just a remind to know if you have answers about my last post


  • Tech Staff


    unchecking the "shared openGL resources" should allow everything to run correctly 
    Note that the way you build a patch will change. You will define the stage number at the source, not the projector. And you can't use a source with multiple stage targets.
    As for moving the display from one card to the other, this configuration is currently untested, and may have the same limitations. (see marks note about Izzymap)

  • Hi,

    I finally could retest everything and it looks like things are going better.

    @Mark : I've tested the bêta version of Isa you sent me on August 20 - Isadora 2.4.5b04 - to see if the "Shared OpenGL Ressources" could now be activated. No it doesn't work, I've got the same problems on Isadora's launching. Half of the attempts end up by a crash...

    Concerning my problem of Isadora going really slow when I activate my three videoprojectors in Preferences/Stages : I've checked the option "Disable Vertical Retrace Sync" and the problem suddenly disappears. So my patch is working now.

    Until here, the fact of sending a splitted movie towards different stages doesn't cause troubles so I hope to be able to let my big patch as it is...

    Best regards