Framerate Converter

Version 1.0.2: conversion, remux, probe and quality-check processes now respond to ComfyUI Cancel and are stopped on timeout. Logs are captured on disk; returned diagnostics retain the last MiB. Restart ComfyUI to load the backend update.

Part of the Trope Tools suite — by TropeMedia.

Two simple ComfyUI nodes for working with video files:

• Convert Framerate — change a video's frame rate (24 → 25, 30 → 25, anything to anything).
• Remux Container — change a video's container (.mov ↔ .mp4 ↔ .mkv) without re-encoding, so no quality loss.

Both nodes use ComfyUI's standard VIDEO type, so you can chain them together or wire them into the built-in Load Video / Save Video nodes.

What they do

Convert Framerate

Converts videos between any common framerates — 24, 25, 30, 60 fps and anything in between. Useful for:

• Film → PAL (24 → 25 fps)
• NTSC film → PAL (23.976 → 25 fps)
• PAL → film (25 → 24 fps)
• NTSC → PAL (30 / 29.97 → 25 fps)
• Slowing 60 fps footage to 30 fps
• Anything else FFmpeg can do

Audio stays in sync. Quality stays high. You don't need to know any FFmpeg.

Remux Container

Swaps the container format around the same video and audio streams — no re-encoding, no quality loss, runs in seconds even on long files. Useful for:

• Putting an .mp4 inside a .mov so it imports cleanly into Final Cut / Resolve
• Moving footage out of .mkv for editors that don't read it
• Standardising deliverables to a single container

Install (the easy way)

Option 1 — ComfyUI Manager (recommended)

1. Open ComfyUI Manager.
2. Search for Trope Tools — Framerate Converter.
3. Click Install.
4. Restart ComfyUI.

Option 2 — Manual

1. Find your ComfyUI custom_nodes/ folder.
2. Drop this folder inside it.
3. Restart ComfyUI.

One thing you need separately: FFmpeg

This node uses FFmpeg under the hood — it's a free tool you install once and forget about.

Your computer	What to type / do
Mac	Open Terminal, paste brew install ffmpeg, hit enter. (Don't have Homebrew? Get it at brew.sh.)
Windows	Download the build from gyan.dev/ffmpeg/builds, unzip it, and add the bin/ folder to your PATH. (Step-by-step guide.)
Linux	sudo apt install ffmpeg (or your distro's equivalent).

If FFmpeg isn't installed, the ComfyUI console shows a clear warning when it starts up — so you'll know.

No pip install needed. This pack uses only Python's standard library.

How to use it

The simplest possible workflow:

[Load Video]  →  [Convert Framerate]  →  [Save Video]

1. Right-click the canvas → Add Node → Trope Tools → Framerate Converter → Convert Framerate.
2. Connect a Load Video node (any source) into the input slot.
3. Set target_fps (default is 25.0 — change it to whatever you need).
4. Connect output to a Save Video node.
5. Hit Queue Prompt.

That's it. The converted video saves to ~/comfyui/output/.

You can also skip Save Video — Convert Framerate already drops a converted file into ~/comfyui/input/ named <original>_<targetfps>fps.mp4.

Chaining the two nodes together

Because both nodes use the VIDEO type, you can wire them directly:

[Load Video]  →  [Convert Framerate]  →  [Remux Container]

This lets you change the framerate and the container in a single pass — for example, "take this 24 fps .mp4 and give me a 25 fps .mov."

Don't pipe Remux Container into Save Video. The built-in Save Video node ignores the input's container and re-saves as .mp4, which would undo the remux. Remux Container writes its output straight to ~/comfyui/output/ itself — set filename_prefix on the node to control the name.

The settings (only if you want to tweak)

The defaults work for most jobs. If you want to fine-tune:

method — how the conversion is done

Method	What it does	When to use it
speed_change (default)	Adjusts playback speed slightly, keeps every frame	Small fps changes like 24 ↔ 25 — gives the cleanest result
frame_drop	Drops or duplicates frames	Big jumps like 60 → 30 fps
frame_blend	Blends adjacent frames together	Smoother than frame_drop, slight ghosting
minterpolate	AI-style motion interpolation	Highest quality up-conversion, but slow

audio_mode — how the audio is handled (only matters with speed_change)

Mode	What happens
allow_shift (default)	Audio plays at the new speed; pitch shifts a tiny bit (~0.7 semitones for 24→25). Most people can't hear it.
preserve_pitch	Audio is re-pitched so it sounds the same as the original.
copy	Original audio is kept untouched (will go out of sync — only useful for tests).
no_audio	Strips audio entirely.

crf — quality dial

Number from 0 (huge file, perfect quality) to 51 (tiny file, awful quality). Default is 18, which looks essentially identical to source. Lower = better.

Filling in the fields

The two main nodes take a VIDEO wire and have no empty text fields. The building-block nodes do. Here is what goes in each one.

Convert Framerate and Remux Container

Field	Empty means	Example of a filled value
input	Required	Wire a Load Video output
target_fps	n/a	25.0 · 23.976 · 29.97 · 50.0
method	speed_change	frame_drop for 60 to 30 · minterpolate for 25 to 50
audio_mode	allow_shift	preserve_pitch for anything with dialogue
crf	18	14 near lossless · 23 web delivery
minterpolate_quality	high	fast for a quick check
target_format (Remux)	mov	mp4 · mkv
filename_prefix (Remux)	video/ComfyUI	video/promo_sh012_25fps → output/video/promo_sh012_25fps_00001.mov

Building-block nodes

Paths must be absolute, or relative to the ComfyUI working directory. On the Mac desktop app that is ~/comfyui/. Use forward slashes on every platform.

Node	Field	Empty means	Example of a filled value
Probe Video, Detect VFR, Verify FPS, Verify A/V Sync, Verify Integrity	video_path	Required. ffprobe errors on an empty path	/Users/colinbyrne/comfyui/input/beach_take3.mp4
Verify FPS	target_fps / tolerance	n/a	25.0 / 0.001
Verify A/V Sync	duration_tolerance / start_tolerance	n/a	0.05 / 0.01 (seconds)
Calc Conversion	source_fps, target_fps, method, input_duration, input_frame_count	Duration and count 0 = unknown, the node estimates	24.0, 25.0, speed_change, 12.5, 300
Calc Audio	source_fps, target_fps, audio_mode, sample_rate	n/a	24.0, 25.0, preserve_pitch, 48000
Generate Output Path	input_path	Required	/Users/colinbyrne/comfyui/input/beach_take3.mp4
Generate Output Path	output_dir	Same folder as the input	/Users/colinbyrne/comfyui/output/converted
Build FFmpeg Command	video_path / output_path	Required. Usually wired from Probe Video and Generate Output Path	/Users/colinbyrne/comfyui/input/beach_take3.mp4 / /Users/colinbyrne/comfyui/output/beach_take3_25fps.mp4
Build FFmpeg Command	video_codec	libx264	libx265 · prores_ks · h264_videotoolbox (Mac hardware)
Build FFmpeg Command	preset	medium	slow for smaller files · veryfast for a draft
Build FFmpeg Command	audio_codec / audio_bitrate	aac / 192k	aac / 320k · pcm_s24le / leave bitrate as is for ProRes masters
Run FFmpeg Conversion	expected_duration	0 = no check	12.5 to have the node verify the output length
Quality Metrics	output_path / reference_path	Required, both	The converted file and the original
Quality Metrics	include_vmaf	false	true only if your ffmpeg build has libvmaf; it is slow

A full manual chain, if you want every dial:

[Probe Video] → [Extract Media Info] → [Calc Conversion] ─┐
                                     → [Calc Audio] ──────┼→ [Build FFmpeg Command] → [Run FFmpeg Conversion] → [Verify FPS]
[Generate Output Path] ───────────────────────────────────┘

Mac users — about Full Disk Access

The ComfyUI desktop app on Mac is sandboxed. By default it can only read/write inside ~/comfyui/. If you want to convert a video sitting somewhere else on your computer:

System Settings → Privacy & Security → Full Disk Access → + → add ComfyUI.app → restart it.

If you're happy dragging files into the Load Video node (the normal way), you don't need to do this at all.

Help, something's wrong

"ffmpeg not found" warning when ComfyUI starts You haven't installed FFmpeg yet — see the install section above.

"No such file or directory" The video file path probably has weird characters in it, or it's outside ComfyUI's sandbox. Use the upload widget on Load Video instead of typing a path.

Audio is out of sync after conversion Try setting audio_mode to preserve_pitch. If it's still off, your source video might have a variable framerate (some phone recordings do this) — you'd need to convert it to a constant framerate first.

Output looks lower-quality than the source Lower the crf number. 14 is near-source quality, 0 is fully lossless (much bigger files).

More than two nodes?

This pack is built around two simple nodes — Convert Framerate and Remux Container — which is what 99% of people need. Underneath, there are 12 smaller building-block nodes (Probe Video, Calc Conversion, Run FFmpeg, Verify FPS, etc.) you can use to build custom workflows if you want fine-grained control. They're tucked away under the Trope Tools / Framerate Converter / Inspect, Configure, Process, Verify menus. Most users will never need them.

Credits

• Built around FFmpeg — the open-source video toolkit.
• Published by TropeMedia.

License

MIT — see LICENSE.