added initial scaffolding for SaveImageSequence node

[Kosinkadink]

Hey, some of the remaining big features I think we need to support are:

1. Saving image sequences in a subdirectory, with the option to use a formatted timestamp as the folder name, and allowing some customization for the saved image sequence (starting number, zero padding amount, etc).
2. Allow saving videos in Combine Video node to also be put in a subdirectory.
3. A node to copy a directory from output into input folder, so that workflows could seamlessly save and then load image sequences.

I want to spend tomorrow looking into some fixes/improvements to Advanced-ControlNet and AnimateDiff, so if you'd have the time to look into this, that would be amazing!

Fizz worked on an initial version of the node for AnimateDiff repo, so that might be a good place to look for the formatted timestamp impl: Kosinkadink/ComfyUI-AnimateDiff-Evolved#11

[AustinMroz]

I've implemented the SaveImageSequence node as true to your specs as possible.

I've got date formatting hooked up and able to output dates in year first format (yyyy-MM-ddThh:mm:ss / 2023‐09‐29T12:50:27). Currently, this extra parsing functionality is only to the Video Combine node and Save Image Sequence

I'm still pondering viability of a copy node. As a potential alternative, I've added a 'search_folder' option to Load Video to let it instead load videos from the output or temp directory.

As best I can tell folders written in the filename_prefix for the Combine Video node work with no changes needed. So the issue of output management seems to come down to a question of how to expose this information to the user. I've considered implementing a filename prefix node that can be connected to nodes like Video Combine or Save Image for guided configuration, but this is somewhat dependent on me finding a way to dynamically change the number of options on a node.

I've got a short list of things I that need work/testing:

• Some inconsistencies in how nodes are marked as stale resulting in the graph reprocessing unnecessarily
• Subdirectories not being not being included in input file lists
• More js consolidations and cleanup
  but the bulk of the implementation is done and I'm probably going to prioritize looking into the existing issues

[Kosinkadink]

Awesome, I'll test later today/tomorrow and I can pick up from here

[Kosinkadink]

Hey, sorry I have not had a chance to check things out in VideoHelperSuite, I took a few days break from coding last weekend and then had my hands full with implementing HotshotXL into AnimateDiff and investigating some Mac and lowvram issues.

At some point this weekend I'll merge the PRs in and do some edits. I'll kinda use this to set some goals I think want for this repo:

1. Avoid introducing complexity to improve maintainability and consistency - in the case of something like Load Videos node, since we are changing OpenCV to be the main code path, we should make it the only code path - no need to fallback on ffmpeg at all there. That way, if we introduce a new feature (e.g. I want to support "select_every_nth" input), we don't get into the problem of having to implement it twice in two completely different ways.
2. Keep things in python code unless needed (like UI needing to be changed via javascript for something that 100% needs it). This is also on the same vibe as 1), but .js implementation should be Plan B instead of Plan A when implementing something, just to avoid falling into a hammer and nail situation.

[Kosinkadink]

What's the intended way to use the date format here?

[AustinMroz]

I agree with the mindset of both points. I shall keep them in mind in future contributions.

Regarding dates, the vanilla 'Save Image' node has a builtin plugin (web/extensions/core/saveImageExtraOutput.js) that will take a string like %date:yyyy-MM-ddThh:mm:ss% where everything between the colon and closing percent describes the desired format for the date. My best guess for the reasoning of this being done in javascript is so multiple nodes in a single workflow will have the same timestamp of when the workflow is queued instead of individual timestamps of when the node was executed. The existing plugin was hard coded to only use the saveImage node, so just the interesting part (date formatting) was reimplemented here.

This format is more complex than it should have to be for the end user (I was completely unaware that the vanilla functionality existed), so the save image sequence node also has a toggle that will lock directory_name to an appropriate format string.

My intent is to have parity with the builtin date formatting for those who are familiar (like fizzledorf) without requiring the average user understands esoteric format strings.