How to prevent Video Combine from memory OOM/system crash if I cannot use Batch Manager?

[VladanZ]

Basically I cannot use Batch Manager as it only works with Load Video node which I do not use (Workflow works with uncompressed images). I only use Video Combine 🎥🅥🅗🅢 node to save large batch of images at the end of processing. I have still some free memory left before Video Combine 🎥🅥🅗🅢 starts but when Video Combine 🎥🅥🅗🅢 starts then 120GB RAM is completely depleted including 40GB swap leading to a system crash.

Please note I cannot add more RAM and prefer not to increase the swap as this will not really help or will only help in specific scenario when data fits.

Is there a way to use Batch Manager without Load Video node and crashing the system?

I use VideoHelperSuite 1.7.4 with Comfy 3.36 but the problem is not related to specific version.

[AustinMroz]

Video Combine should do saving entirely in place. If the workflow is reaching Video Combine and Video Combine is using more than ~0.5 GB, that's a bug with VHS I'll need to look into. I would appreciate if you could share your settings for Video Combine.

Yes, options would exist, but they will be rather workflow specific and get jank fast. Can you just do smaller batch sizes? Is the increased in workflow execution time of using --cache-none as a launch option acceptable? Can you move the Video Combine inside a for loop using the execution-inversion demo nodes? As a last resort, you can Add a Load Video node that loads a small number of frames at low resolution to serve as a start point for a batch manager.

[VladanZ]

Thank you for your reply, I will try provided options. The workflow itself uses for loop to combine and blend the images. I will try the demo you mentioned and put Video Combine inside the loop.

[VladanZ]

I moved Video Combine inside a for loop using the execution-inversion demo nodes but it saves individual video files for each cycle (which I want to avoid) instead of streaming all frames into a single video file. Am I missing something?

[AustinMroz]

No mistake from you here. I just misunderstood from your original post. I assumed from "large batch of images" that you were actually saving output images. VHS has a couple of output formats for this.

If you are wanting a single output file, the execution-inversion nodes will not be helpful.

[VladanZ]

I was trying to save many (hunreds) of hires frames in a video file, but failed.

After two days of unsuccessful trial an error with Video Combine, loops and other video nodes failing multiple ways to achieve the same goal I decided to just skip ComfyUI for this last step and use ffmpeg command which does what I need fast, without memory issues, with HW acceleration and frame interpolation.

Thank you for taking the time to help.