How to play Movies (as backgrounds) without Stuttering/Crashing

Question: is there a format or length (of a movie) that ManyCam likes?

When I add a movie layer (as a background), I get the ‘waiting/loading’ dots and stuttering––quite frequently. The movie format I’m using is mp4 with a 6-minute duration. I would rather use the Youtube URL option, but, it doesn’t seem to work yet—which may have more to do with youtube.

For my scenario (as example), I have a full-screen movie of dolphins swimming layer behind my talking head webcam with chroma key.

I don’t seem to have the same issues when I make long-duration Gifs as animated backgrounds.
Takes longer to find a loop…256 color palette is…well…not good…but it works and I can store them as objects…would love to do that with movies too!

Desktop Window Capture
I don’t get stuttering if I use the desktop window capture of youtube movies. That said, my CPU jumps to 90%–I have a 2016 macbook pro ( 2.8 GHz Intel Core i7 and 16 gigs of ram).
If I add an ESL app on top of that…well…will be a 2 fps teaching session.

Capture Area
The CPU is lower (at 45%), but, ManyCam crashes too frequently. I’ve included the crash log for that
crash log:

So the question becomes, how do I play movies (as backgrounds) within ManyCam?

I have no problems using videos as background for chroma while broadcasting at 720p to a couple of rtmp sources. But I had some troubles doing it when I had a HDD, now using SSD works without issues and the CPU usage is 40% lower. Usually ManyCam uses up to 45% in my broadcasts but my laptop has a Nvidia 1050ti so maybe that’s something helping too

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agreed. might be a Mac thing…I’m using SSD (as well) with 16 gigs of RAM…

Hi @Graham_Anderson,

Manycam buffers 10 video frames of a movie (you see the dots) before starts to play it. Maybe an option to reduce this value should be added to ManyCam. It is actually weird you get sluttering after initial buffering, it should run smoothly even on old hardware. I think that best performance is achieved for movies encoded in H264 as they are normally decoded on GPU. BTW are you able to share the movie that lags?

Window capture is slow on macOS and can’t work faster. Other options like Fullscreen, Custom area, Window area are hardware accelerated since 7.0. Apple don’t provide any option to accelerate Window capture. The only option to reduce CPU usage is lowering FPS, maybe 25 is enough for you?

Please try out the new version (7.0.11) with many fixes: Let us know if it still crashes.

Hi Leo :slight_smile:
HEre is the stuttering video…

Here is a stuttering screen capture…the mp4 was downloaded directly from youtube with youtube-dl from terminal.


Hi Graham,

I am curious if this particular movie has been used for some time now, or was it a recent change.

Have you experimented with a smaller size file by any chance? 1.2 gig is a healthy size, and without knowing exactly how the file is processed my Manycam myself…maybe it is just a ‘tight squeeze?’
Nice choice in video either way, I am listening now.

May joy surprize you in unexpected places,

Robert Brooker


Hello, Robert :slight_smile: Sadly, it’s the same stutter with a 15 second 1280x720 H264 movie.

Hi @Graham_Anderson!

Have you encountered with this problem in previous versions (before ManyCam 7.0.7)? Please try switching “Hardware Acceleration” in Preferences > General to OpenGL and let us know whether it improves the video playback.

Same result with OpenGL
Here is a screencast…CPU is at 40%

Also, here is the stuttering Movie (as an example)

Hi @Graham_Anderson,

I have a similar hardware and just tried to add 3 chroma keys and the movie you provided and it works fine for me: CPU usage (the one that manycam shows) is 8%. The dots for movie means that manycam can’t decode it in realtime, so something throttles your mac: maybe slow effect, big GIF, desktop capture or another apps. Can’t see all sources and effects you run, so not sure. If you are not tired with our questions, you may try to run that movie as only one source, movie + chroma key, +other sources and effects and realize at what step it starts to be slow.

I’ll try that. I have a bunch fo stuff running…with the ESL app on top of that. Strangely, Gif animated backgrounds (big and small) don’t stutter. Only movies stutter. Fixing the issue would save me a ton of time, and, I’d no no longer be shackled by that terrible 256 color limitation.
Out of curiosity, is there anything in the console log that I can send you–that would help you debug the issue? This is a typical screen scenario: