Hi all,

this problem is happening in Vmix 26.0.0, so please let us no if this is no longer happening.

We have a powerful PC with Decklink Duo and Decklink 4k. The CPU is idling along at 4% in our project.
There are some kinds of inputs, but only one SDI live input. Nothing special going on.

We have a list holding a few pictures and a WAV file is being played from another input.

Only one script is running - it sleeps for 2 seconds, calls a NextItem on the list and queries the API
to see which item number is selected. That's just for a start, don't ask for the use of this. We can't
go on as we are already experiencing weird problems.

This tiny harmless script causes dropped frames in our external renderer.
We became aware of this by audio dropouts every now and then, but we can also clearly see the drops in the statistics
and see short spikes in render time in the vMix taskbar.
The problem disappears as soon as the script is stopped and re-appears when the script is started.
We double-checked and set up the same functionality in Bitfocus Companion - step through the list, query API. Dropouts.

We haven't nailed it down 100%, but it seems that the API query does no harm, but stepping through a simple list of pictures
(no videos) by API command does.

Any idea what's happening here?

Thanks Martin,

I'll look into this.
Although I don't really understand why an almost empty project (we broke everything down to a minimum to find the problem)
causes dropouts when one of the 3 remaining inputs (one being a WAV audio) has to load a still picture that might be larger than Full HD.

Here are our PC specs, maybe you see something suspicious:
i7-9700K, Windows 10 Enterprise, vMix 4K 26.0.0.44 (producing in 1080i), 48GB memory, NVidia GeForce RTX 3060,
1x Decklink 4K (Main output), 2x Decklink Duo (one for inputs, one for outputs).
GPU Mem 17%, CPU vMix around 4%, CPU total max 10%, task manager does not show any relevant spikes in diagrams that could
be related to the dropouts.

Rick

Just wanted to report that I looked into the used pictures.
We just had 6 for testing, but they were indeed of completely different sizes - smaller than FullHD, FullHD and
larger than FullHD straight from a photo camera. I resized them all to 1080 and the drops are gone.
Thank you for pointing me in the right direction!

So the problem is identified, but I would still appreciate some kind of "fix" for this in the future.
I mean vMix does automatically resize the pictures to the output resolution in realtime (as far as I can tell I can't even turn this off, can I?),
so I would expect this to happen in a way that does not make a complete (but small) vMix project unusable.
No question this would require a lot of CPU/GPU to achieve this for video files, but we are talking about still pictures.