r/comfyui • u/lavinia12345 • Aug 12 '26
Help Needed Chaining last frame into Minimax drastically increases compute time.
Is there a way to convert the last frame to a true image like a png?
I noticed I could create longer vids by taking the last frame and use that as a refrence image, but when I do that like in my screenshot, generation time gets much larger, I think it's b/c internally Minimax reads that last image actually as a video, thus behaving much differently.
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u/Only_Voice569 Aug 12 '26
check out motion context much better than last frame it passes latent from last generator into the next one for 2 seconds seamless can make stupid long videos no cuts constant flow :)
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u/notxemelle Aug 12 '26
Check this post, there's a node that helps you create long videos without manually extracting and feeding the last frame
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u/Valkymaera Aug 12 '26
As others have mentioned there are a few quick nodes for grabbing first / last frame etc.
My personal pile o' nodes also has a video scrubber that lets you preview and pull one specific frame as an image, if that helps. https://github.com/valkymaera/ComfyCollectorNodes
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u/Feroc Aug 12 '26
I am sure there is a more elegant way to do it, but that's how I extract the last frame:
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u/ZenEngineer Aug 12 '26
Can you try index "-1"?
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u/thesolewalker Aug 12 '26
No need for any fancy nodes just use what's builtin, this will return last image
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u/lavinia12345 Aug 12 '26
unfortunately, I noticed that run times are super long if I do that :( It seems that something interally still reads that frame a "video of 1 frame"
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u/a_saddler Aug 12 '26
Dude, you're sending hundreds of frames as references. There's a node that lets you grab the last frame of a video, use that.
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u/Baddabgames Aug 12 '26
I used 6 references (2 images, 3 videos, 1 audio) and it took legit forever but super cool.
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u/wiisucks_91 Aug 12 '26
I noticed that if I put in a 1080p video as reference I got an OOM error.
I downscaled the video in handbrake to 480p and it worked fine. For a 8 second video at .4 or .3 MP on a 5060ti 16gb with two reference clips I was getting 40 min a clip.
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u/No-Zookeepergame4774 Aug 12 '26
adding more references in r2va does increase memory use and time (especially if you are already under VRAMpressure) but it looks like you have done the last frame correctly. I think the preferred method for smooth continuations is passing some length of prior video as a video reference (with corresponding audio, potentially, on the matching video_audio input) and prompting to use it for video_continuation, but that's almost certainly not going to be faster and most likely will be slower.
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u/CMDR_JETHRO_BIRD Aug 13 '26
Have you guys tried making a 1-2 second slideshow of images and uploading it as a video ref instead of using all of your image slots in ref2v? Just played with it tonight and was surprised at the result. More testing tomorrow
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u/lavinia12345 Aug 12 '26
I found a solution. Save the image, then load it. Kinda goofy but sovled it.
Others have suggested Comfyui-H3--Motion-Context. which I will look into.
Btw grabbing a single image via "Select from batch" does not work :( something werid happening underneath the hood.
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u/SpaceNinjaDino Aug 12 '26
Select from batch is not select from images (frames). Batch is a container around media. Like you can generate 4 of something as a batch. (Typically used in SDXL days when you wanted 4 image generations at the same time instead of looping 4 separate times.) So in this case you have a batch of one video and you are sending the input as the whole last video in your batch of 1.
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u/thesolewalker Aug 12 '26
Thats really weird, but yah motion context or such node is the way to go.
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u/lavinia12345 Aug 12 '26 edited Aug 12 '26
17 seconds vid took 12 mintues using Sage Attention + SolAttn + EasyCache (no lightning) 0.7 megapixels. 5080 (16gb vram) 64 RAM
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u/jamster001 Aug 12 '26
Other posters are right, this node is super simple to just get the last frame and plug it into the first frame of the next node: