Image Batch Extend With RIFE

This is the fancy older sibling of Image Batch Extend With Overlap. Same job - stitch two video batches into one continuous sequence - but where the plain version blends the boundary, Image Batch Extend With RIFE can animate it. It finds the best-matching seam between source_images and new_images, builds a pyramid blend across the overlap (same as the match_gradient_mse+pyramid mode on its sibling), and then optionally replaces the center of that transition with actual RIFE-interpolated frames. The result is a seam that isn't just blended - it moves.

RIFE is the frame-interpolation model family that's been the community standard for "make fake in-between frames" since video work got serious, and this node doesn't ship it. It reaches into the ComfyUI-Frame-Interpolation pack's registered RIFE VFI node, looks up the checkpoint you name in rife_model (the dropdown lists the usual suspects: rife47, rife49, rife417, rife426, plus the sudo_rife4_269... variant), and invokes it. Crucially, the whole thing degrades gracefully: if RIFE isn't installed, it logs that refinement is unavailable and keeps the plain pyramid transition. So the node never hard-fails - it just gets less fancy without Frame-Interpolation present.

What to set

• rife_model - none keeps the pure pyramid blend; anything else requires ComfyUI-Frame-Interpolation. Start at none, add RIFE once the rest works.
• rife_transition_frames (0–4, default 3) - how many center blend frames RIFE replaces. The tooltip is blunt about the payoff: output length is unchanged, so RIFE is purely improving the in-between quality, not adding duration.
• overlap - match-search and blend window. 0 concatenates outright.
• overlap_side - both (default) scans the source tail against the new head; you can pin one side instead.
• rife_fast_mode (default on), rife_ensemble, rife_scale_factor - the RIFE performance knobs. Fast mode is a meaningful speedup; ensemble is higher quality at real cost. Leave scale at 1.

The honest take

RIFE here is polish, not a necessity. The gradient-MSE match plus pyramid blend already gives you a genuinely good seam for most loop-extension and clip-joining jobs, and it runs without any extra install. RIFE earns its place when your boundary has motion - a static crossfade of moving content looks smeared, and interpolated frames actually bridge the motion. That's the "model ramp-in freeze" problem the tooltip hints at, solved with real intermediate frames instead of a gradient.

Installing

Both packs needed for full function: ComfyUI_Eclipse (via Manager, search ComfyUI_Eclipse, or git clone https://github.com/r-vage/ComfyUI_Eclipse custom_nodes/ComfyUI_Eclipse), plus ComfyUI-Frame-Interpolation for the RIFE path. Restart after each. Standard deps; nothing heavy beyond Frame-Interpolation's own RIFE checkpoints. Eclipse targets current ComfyUI - frontend 1.51.2+ for the modern widgets, and its v4.0 cleanup means old RvTools_v2 workflows want the built-in Migration Tool.

People get tripped up by expecting the output to get longer when they add RIFE. It won't. The node's contract is "same length, better motion." If you want length, you're looking for a frame-multiplier, not a splice.