Isadora movie player performances with respect to VLC

  • Dear Mark, dear all,
    I have recently run basic tests between Isadora 1.3.0f24 and VLC to understand what was going on when we were simply playing movies - we want to do much more but this drastically limit our possibilities. To make it short and simple, please find attached a series of screen captures that are self explained :

    • HPZ820 workstation configuration
    • Isadora General preferences
    • Isadora Video preferences
    • 6 played full HD movies with Isadora and the corresponding CPU and GPU loads
    • 6 played full HD movies with VLC and the corresponding CPU and GPU loads
      It is striking to see that the CPU load is concentrated on the first16 cores with a total of 35% CPU usage for Isadora whereas it is limited to a total of 3% CPU usage for VLC. How such a discrepancy can be explained? The 10 fold CPU added load prevents us from doing what we need.

    As anyone encounter such limitations? I still might be doing something wrong and help would be most welcome.

    Thanks a lot.


    P.S.: Also attached is the specification of the on of the six movies - basic wild life by microsoft. The hardrive is SSD.
    P.S.: A multi-threaded 64bits Isadora version would be such a great thing as we often saturate the core to which Isadora sticks so the application freezes for a while and we lose real time and video projection.
    a1ae8c-hpz820_workstation_configuration.jpg f47e44-isadora_general_preferences.jpg abb28c-isadora_video_preferences.jpg bd2615-6_full_hd_6on.jpg adc92c-vlc_6_full_hd_6on.jpg d69dde-wild_life_1.wmv_0.txt

  • Hi,

    What's your codec ?
    Would you give a try with threaded movie playback disabled ?
    Would you give a try playing back all the movies on only one single stage ( using zoom & position inputs of the projector to but them side by side ) ?
    Thank you.

  • Dear ikse,

    Just to be clear -- these are WMV or AVI movies, yes?
    Best Wishes,

  • Dear Keftaparty, dear Mark,

    These were WMV movies with basic Windows VC1 codec. Please find attached a more detailed description of the video and audio formats.

    The codec is not really an issue for me as it is a native Windows codec and as VLC reads it smoothly. Some time ago, I did run rather extensive tests on the best codec to be played with Isadora - I should have posted it but I was still struggling with CPU issues. In summary, as codecs are concerned, I installed the ffmpeg library and found out that VC1 competes fairly well with other available codecs when the latter were performed natively by windows (through ffmpeg). Of course, checking the Plays Windows Movies Formats natively was essential. Otherwise decoding was not carried as a multithreaded process and Isadora freezes. I did try mp4 but I could not have them decoded by ffmpeg. Quicktime take care of them - not really efficiently on Windows. So I had to have h264 codec embededded in avi containers, which worked fine. Last week-end, to make things plain, I fully reinstalled Windows then I only installed Quicktime, Isadora, and VLC to run the late tests - a very clean bench test, I believe.

    I have run the tests, Keftaparty, you suggested. Please find attached the corresponding screenshots. In summary, the "threaded movie playback disabled" and the "all movies on one stage" did not change anything I could notice. I did try while hidding the stages: It really frees the core Isadora loads. I guess it does represent the work Isadora has to handle to send the video data to the GPU. Any suggestion to reduce the load would be welcome.

    What still remains is the cpu load difference between Isadora and VLC while handling video fluxes. I would be happy to understand where the issue is and if it can be solved. I would be happy to hear that I am doing things the wrong way.

    Thanks again for your help,


    1cd951-wild_life_format.jpg 59f9c6-130417_6_full_hd_6on_shown_stages_threaded.jpg 83390b-130417_6_full_hd_6on_schown_stages_not_threaded.jpg f446cf-130417_6_full_hd_6on_hidden_stages_threaded.jpg 0d1ce8-130417_6_full_hd_6on_1_shown_stage_threaded.jpg

  • Hi Ikse,

    I personnaly never had very nice experiences with WMV ( I maybe never found the good "tunings" ).
    I use AVI files, and the blackmagic codecs ( you can get them by installing their desktop video software). I manage to handle 8 layers of 1080p in isadora ( with SSDs of course ).
    It would be interesting to compare isadora to windows media player. Because I think (hope) that it uses the native video playback of windows.
    Comparing Isadora to VLC is a bit complicated, as VLC has it's own engine to decode videos ( witch is quite powerfull ). And isadora is not using this engine.
    Also one curiosity question: with such powerfull workstations, why do you want to avoid using your CPUs ? They have to get warm !
    One more 2 cents advice: I found sometimes isadora performing better when setting the target fps to 60 ( like my monitors ).
    Also, it's really great that you provide such good and well documented tests ! Thanks.

  • Hi Mehdi,

    Thanks for your feedback. I agree it is definitely possible to run that many HD video fluxes with Isadora with blackmagic codecs, or even WVC1, or h264. I ran some initial tests before reinstalling the OS with various codecs. The issue is that, as soon as one of the cores saturates, Isadora freezes. The project is not only dealing with video streaming to six monitors but it has a lot of expected real time interactions with the passage of seven tracked people. Hence I need to spare as much CPU as I can to allow for real time to happen - mostly CPU on the core that Isadora uses.

    I know the comparison with VLC is not totally fair but I believe only one instance of Windows media player is possible. I also ran tests with the Classic media player and the comparison was not favorable to Isadora. I can rerun then. Sorry, I was just reluctant to reinstall too many things on the machine so far.

    Best from Paris,


    P.S.: Despite every things one can have against microsoft stuffs, VC1 is pretty light both in terms of filesize and cpu decoding. I guess I will reinstall every codecs, rerun and record the tests to put things down.
    P.P.S.: The nice thing with ffmpeg is that you can make sure that it is effectively ffmpeg which does the decoding job as you can allow for icons to pop out when it is working! It works well. Multi-threading is just great then.

  • I have no experience in tracking.
    Is it so process heavy ?
    What video sources and capture material do you use ? This can make a big difference.
    What about running it on a non rendering machine and send results to your rendering machine with osc ?


    Would it be possible to run multiple instances of isadora ?
    Windows should distribute the processes on the cores ( am I wrong ? ).
    For tracking etc... two instances can communicate with osc.

  • Mehdi,

    You are right again. The tracking in itself is not that heavy. It is actually confined in one of the cores of the computer and performed by a home-programmed script, which sends via osc the position (x,y,z) and velocity (Vx,Vy,Vz) of seven tracked heads using 2 kinects. The heavy part comes when the video streams must be processed according to these parameters independently and according to different scenarii: 7 local displace given by local 3D projector, which position is given by (x,y,z) , generation of associated 3D objects. So the machine we are talking is the rendering one. The first attempts with a low resolution video looked like that

    It is possible to run multiple instances of isadora but the last attempt was not very successful when dealing with high definition video streams - it crashed too quickly. I did not see any distribution over the cores. I should certainly give it another try.


  • Dear All,

    I'm in the midst of the workshop in Munich. I'll need some time to answer these questions with any level of intelligence. I've bookmarked this discussion so I can come back to it next week. Sorry for the delays.
    Best Wishes,

  • Dear Mark,

    Thanks for the forthcoming reflections on the subject - hot and burning for us!

    Enjoy the workshop in Munich!


    P.S.: If you happened to pass by Paris on your way back, I would be happy to welcome you at the neticLab

  • Hi Ikse,

    Are you manipulating the images only with the projector actors ( 3d quad distort etc... ) ?
    Are you using any other actors to manipulate the images ?
    Are you using 3d renderers ? If yes at witch resolution ?
    Can you post a screenshot of the stage tab of your isadora preferences ?
    Can you post a screenshot of your nvidia's driver screens configuration ( The "configurere Surround et PhysX" tab would be perfect for what I want to see... )?
    If you use only projector actors, you should not have any performance problems ( they are gpu based ).
    On windows, Isadora was a bit capricious when using multiple stages on multiple monitors.
    I see you have 3 x quadro cards, are they SLI or are they independant ?

  • Hi Mehdi,
    I have two main superactors:
    1. The first one displaces a large resolution background movie with seven 3D rect Projectors sent to a single channel to be rendered by a 3D renderer. Ideally the resolution of the seven movies and the 3D renderers should match the resolution of the background movie to keep the latter resolved (minimal targeted matrix : 2000x1600). The vertical size of 3D renderer is anyway limited to 768. It obviously freezes when approaching a decent resolution (if I remember well it saturates for something like 512x512).
    2. The second one generates seven 3D objects (sphere for now) on the same large resolution background movie with seven 3D players sent to a single stage to be rendered by a 3D renderer. It works fine until I try to play either the background movie or project movies onto the 3D objects. The target obviously is to play both at the same time.

    I would agree with you on the expected performances with projectors. However, the projectors might be gpu-based but I guess the associated movie players take over the cpu load. So it freezes even in the second case described above.

    The three Quadro cards are independant.

    I will post the screenshots and come back to you as soon as I go back to the neticLab, hopefully later today.

    Have a nice day!


  • Xavier,

    I think one problem here is the 3d renderer. It's performance eating on heavy resolutions.
    Also, when working with 3d objects, you need to take care to some facts:
    -It's "complicated" to share the same 3d object to multiple graphic cards, even on multiple "heads" of a same graphic card.
    I've had some issues with that kind of setups in the past.
    If you want we can skype ( in french ). Send me a private message with your skype name if you want.

  • Mehdi,

    I have arrived later than expected. Please find below the screenshots. I have not looked into the setting of the graphic cards. Any improvement is certainly welcome.
    However, I don't think it is an issueso far for the 3D objects as with the seven of them, it runs smoothly. It is true that there were shared between graphics cards and within a card as they travel through three videoprojectors (2x1280800+1x12801024).

    A Skype would be great to sort this out when you have some time.

    Meanwhile I will post a late series of tests on cpu loading.


    f2cdda-isadora_stage_preferences.jpg d662a3-graphic_card_topology_01.jpg 863bc1-nvidia_physx_processor.jpg

  • Mehdi, Mark,

    For a fairer comparison, I have installed K-Lite_Codec_Pack_930 for 32 and 64 bits. It comes with the Media player classic (MPC). It is then possible to run both Isadora with six movie players and six projectors and to compare it to six MPC while making sure that they both use the same decoding process (CPU or GPU hardware accelerated).
    I tried several codex configurations (still for the same WVMC1 encoded HD movie). Please find the outcomes in the series of screenshots below (the whole series is compressed in the last file).
    The file names are self-explicit. However, in summary, it appears that:
    For Isadora

    • There is a substantial gain to make use of the ffdshow decoder (the total CPU load falls from 39% down to 18%)
    • Isadora does not stand Nvidia Cuvid (GPU acceleration) but runs with DXVA2copyback but without any gain
    • Showing the stages cost quite a bit in CPU load (the total CPU load falls by half again from 18-19% down to 10-12%) which is pretty surprising for me. At the same time, the GPU load is substantially reduced (figure again)
    • Confining Isadora to 8 cores does not change the overall CPU load - as one can expect
      In summary:
    • Native codex 38-39%
    • FFv codex 18-19%
    • Nvidia Cuvid -> Crashes
    • DXVA2copyback 18-19%
    • FFv codex + Hidden stages 10-12%
      For MPC
      The overall CPU load is still much less than Isadora
    • Native codex 8%
    • FFv codex 7%
    • Nvidia Cuvid 6%
    • FFv codex + Nvidia Cuvid 6%

    As it limits our developments, I would be happy to understand why there is such a need of CPU power for playing videos with Isadora and if there are ways to go around. The critical states are obviously exemplified in the screenshots with DXVA2copyback where there is one core (the one that Isadora uses I guess) which is overloaded. It is close to saturate and Isadora, to freeze.

    Again, I am hopefully doing something wrong here. The system is as simple as can be with only the required softwares and codex to run the tests (+ the monitoring gadgets).

    Thanks for your feedback,

    3ee502-6_full_hd_6_isadora.jpg 555006-6_full_hd_6_isadora_ffv.jpg cf79d9-6_full_hd_6_isadora_ffv_cuvid.jpg 7fe434-6_full_hd_6_isadora_ffv_dxva2copyback.jpg a617a8-6_full_hd_6_isadora_ffv_hidden_stages.jpg 281c2b-6_full_hd_6_isadora_ffv_hidden_stages_8cores.jpg 71ef55-6_full_hd_6_isadora_ffv_hidden_stages_32cores.jpg 36dd89-6_full_hd_6_isadora_ffv_hidden_stages_again.jpg 0fb0ca-6_full_hd_6_isadora_ffv_shown_stages.jpg 867203-6_full_hd_6_mpc.jpg a77cc8-6_full_hd_6_mpc_ffv.jpg 244bf6-6_full_hd_6_mpc_ffv_cuvid.jpg bb608b-6_full_hd_6_mpc_ffv_cuvid_paused.jpg 4551be-6_full_hd_6_mpc_ffv_no_windows_codecs.jpg

  • Dear All,

    Thank you for this continued, very detailed research. I forgot to say that, after Munich, I was going to the USA, where I am now. But, my travels are almost over I return to Berlin on Monday. Then, finally, I can properly digest and look carefully at all you have to say.
    Best Wishes,
  • Tech Staff

    Did you happen to take note as to wheather or not any of these codec option allowed for looping. I have been doing a number of windows native + Qt HD test as well (not as well documented) and a big problem for me with most windows options is that the video can not be looped.

  • Dear DusX,
    Looping is not an issue with the VC1 codec. It loops indefinitely under Isadora. I did face some looping issues with lossless avi-contained codec - namely there was no end trigger, so no looping possibility. The player could not figure out that the video had reached its end, whereas, surprisingly enough, it was possible to get its time duration with Media time to percent so I did generate the trigger with a time count down... not very clean.
    As it appears more and more clearly to me now, the codec is not that an issue within Isadora. It can be circumvented by the Plays Windows movie formats natively so Isadora does perform as well as another player. At least the movie player actor does conform to this. The problem seems to lie in the projector actor.
    I'll come with additional tests on this.

  • Dear Mehdi, Mark, DusX,

    Following some Mehdi's advices, please find attached some last results that answer two questions:

    • Projecting on a full monitor screen costs more cpu load (mostly onto the core Isadora uses) than projecting on a preview screen. The gpu load is barely affected.
    • Projecting several movies on a single preview screen or on separate preview screens do not change the cpu load nor the gpu load
      One could infer from these tests that Isadora runs some additional cpu calculations on the initial image matrix whatever the targeted screen may be. The purpose of such calculations are rather unclear to me as they occur only when the movie player actor is connected to the projector actor whereas the process should be handled by the gpu only.
      I'll hopefully come with some more later today.

    Best regards from Paris,

    f34f3a-1_full_hd_1_full_screen.jpg 245f03-1_full_hd_1_preview_screen.jpg d8c222-2_full_hd_1_full_screen.jpg 210fac-2_full_hd_1_preview_screen.jpg 956c57-3_full_hd_1_full_screen.jpg f062d8-3_full_hd_1_preview_screen.jpg 4ff4e2-4_full_hd_1_full_screen.jpg c068a6-4_full_hd_1_preview_screen.jpg 111fd3-5_full_hd_1_full_screen.jpg 38bb1d-5_full_hd_1_preview_screen.jpg 736b4f-6_full_hd_1_full_screen.jpg e2b8b3-6_full_hd_6_preview_screen.jpg

  • Tech Staff