Topaz Video AI (Upscale & Frame Interpolation)

Let's get the framing right first, because it matters more than the sliders: this node doesn't ship an upscaling model. It doesn't call an API either. It shells out to the copy of Topaz Video AI already installed and logged in on your machine, running your ComfyUI frames through Topaz's own ffmpeg with Topaz's proprietary filters attached. If you don't own a Topaz license, this node does nothing for you - full stop. If you do, it saves you the export-to-Topaz-GUI-reimport dance every time you want to polish an AI-generated clip.

That's worth knowing up front, because Topaz is the paid benchmark the rest of the open-source video-upscaling world measures itself against, and there's a real, growing crowd figuring out they don't need the subscription anymore thanks to free options like SeedVR2 and NVIDIA's RTX video nodes. This node is for the other camp: you already pay for Topaz, you like its results, and you want them living inside your ComfyUI pipeline instead of a separate app you tab out to.

How it works

ComfyUI moves video around as a stack of image frames (a batch), not a video file. This node takes that batch, encodes it to a stream, runs it through Topaz's bundled ffmpeg binary using Topaz's tvai_up (upscale) and interpolation filters, then decodes the result back into a frame batch for the rest of your graph. That round trip is also why the author explicitly built this for short AI-generated clips - long footage means longer encode/decode overhead than just doing it in the Topaz GUI directly.

Inputs and outputs that matter

Two independent toggles drive it - enable_upscale and enable_interpolation - and you can run either or both in one pass:

• Upscale side: upscale_factor (1–4, default 2) and upscale_model (16 choices, default thf-4, pulled from Topaz's model library). The README is blunt about scaling: not every model has been validated at every factor, thm-2 is hard-locked to 1x, and if 4x throws an error, just drop to 2x. compression and blend are the same two secondary sliders you'd see in the Topaz desktop app - leave them at their defaults (1 and 0) for your first pass.
• Interpolation side: input_fps (your source clip's real frame rate - get this right or the timing is off) and interpolation_multiplier (1–8, default 2, doubles your frame count by default) plus interpolation_model (5 choices, default apo-8).
• Plumbing: use_gpu (leave it true), topaz_ffmpeg_path (defaults to the standard Windows install path - the most common thing to fix on a non-stock install), and force_topaz_ffmpeg (locks the node to Topaz's own ffmpeg, since only Topaz's build knows the tvai_* filters).
• Output handling: it can save the result itself (save_video, filename_prefix) since it's marked as an output node, though the README's own usage note still describes wiring it between your video source and a save node.
• previous_upscale (optional) takes an UPSCALE_PARAMS bundle from the companion TopazUpscaleParams node instead of the inline sliders - handy if you're reusing the same preset in several places.

Output is a single IMAGE - the processed frame batch, wire it straight into whatever combines your frames into a video file.

How to install it

Search TopazVideoAI in ComfyUI Manager, or clone it by hand:

cd ComfyUI/custom_nodes
git clone https://github.com/sh570655308/ComfyUI-TopazVideoAI.git

Restart ComfyUI - but you're not done. This is the part people skip and then get confused: you need a licensed, logged-in Topaz Video AI installation on the same machine. Open the Topaz app, log in, and hit Ctrl+Shift+T to auto-populate the TVAI_MODEL_DATA_DIR and TVAI_MODEL_DIR environment variables (set by hand if that fails). Then close the GUI, open a terminal in Topaz's install folder, and run .\login once to authorize it. Only after that does the node actually work. The default path being a Windows Program Files directory is a hint too - this reads as a Windows-first pack, with no Mac/Linux install path in the README.

Common issues & troubleshooting

No such filter: 'tvai_up' is the README's own named error, and it means your ffmpeg isn't Topaz's - check topaz_ffmpeg_path points at your real install directory and that force_topaz_ffmpeg is on.

Nothing happens, or it errors out on launch. Nine times out of ten this is the .\login step being skipped - the node calls Topaz's ffmpeg, but Topaz still gates it on an authorized login.

4x upscale errors. Per the README, fall back to 2x - not all models have been standardized past that.

A long video takes forever or looks wrong. This node is built and tested for short clips; the author never validated it on long footage because of the batch-encode overhead. If you're processing a multi-minute video, do it in the Topaz GUI directly instead.