FFmpegFreeUI

Project Overview

Building a working FFmpeg command usually means paging through documentation, so 3FUI arranges the parameters into readable panels and assembles them into the exact command line it runs. It ships no codecs of its own: you provide ffmpeg or add it to PATH, which means a newer ffmpeg can be dropped in at any time.

The program is written in VB.NET on WinForms, the interface is rendered by the in-house LakeUI engine over DirectX, and all data lives in a single file next to the executable.

Item	Value
Current version	6.3.0
Platform	Windows 10 1609 or later, x64 / arm64
Runtime	.NET 10 desktop runtime, installed separately
UI stack	WinForms + WPF + LakeUI over DirectX
License	MIT, with LakeUI under GPL-3.0-only

The parameter panels are only a shell; all encoding is done by the ffmpeg you provide.

Key Features

• Free parameter mixing: video, audio, subtitle and container pages can be combined freely, with raw arguments allowed anywhere
• Presets: save a parameter set to a preset file and share it through the Preset folder
• Batch queue: unlimited tasks with pause, resume and stop, plus live remaining time and size estimates
• Color management: color space, bit depth, chroma sampling and HDR options
• Subtitle burn-in: font, position, outline and shadow options for burned subtitles
• Frame server hooks: convenience entries for AviSynth and VapourSynth
• Muxing and merging: simple remuxing and multi-file merging
• Performance monitor: CPU, memory and GPU load read through LibreHardwareMonitorLib
• Quality metrics: built-in objective checks such as VMAF
• Agent assistant: connects to any OpenAI SDK compatible endpoint to read the parameter panels, manage tasks, access files and run PowerShell

Interface and Controls

The left side holds feature tabs, the middle holds parameter panels, and the bottom holds the task queue and log. Most controls name the FFmpeg parameter they map to, and the command preview refreshes as you tick options.

Area	Purpose
Parameter panels	Choose encoder, bitrate, resolution, filters and more
Command preview	Show the final ffmpeg command line
Task queue	Watch progress, pause, stop and reorder tasks
Log and monitor	Stream ffmpeg output and hardware load

The interface supports high DPI scaling with manual calibration, so monitors at different scale factors still line up.

Target Audience

• Fansub groups encoding anime in batches
• Advanced users fluent in FFmpeg flags
• People who save and reuse encoding recipes
• AviSynth veterans with preprocessing chains
• Teams encoding across a LAN

Quick Start

1. Install the .NET 10 desktop runtime, then place FFmpegFreeUI.x64.exe or FFmpegFreeUI.arm64.exe in one folder
2. Put the ffmpeg executable in that folder, or add its folder to the system PATH
3. Start the program and drop in a video, or pass a path with the -i launch argument
4. Choose encoder and quality settings on the video, audio and subtitle tabs; the command preview updates as you go
5. Click Add to queue to start the task, watch remaining time and size estimates, and pause when needed
6. Save the current settings as a preset for reuse, then call it from the Preset folder

Launch Arguments and Remote Calls

3FUI accepts ffmpeg-like launch arguments from a terminal or another program; enabling remote calls makes it listen on a UDP port for messages in the same format.

Argument	Purpose
-i	Set the input media file
-3fui_file	Set the preset file, used together with -i
-ffmpeg	Pass every following argument straight to ffmpeg
fullscreen	Start in fullscreen borderless mode
-3fuiVideoHelperInPointTime	Pass a clip in-point time

Remote calls listen on UDP port 10591 by default with the same payload as the launch arguments, so another machine on the LAN can feed tasks to the encoding box.

System Requirements

Item	Requirement
OS	Windows 10 1609 or later, x64 / arm64 only
Runtime	.NET 10 desktop runtime, not bundled
GPU	D3D11 support for LakeUI rendering
FFmpeg	Provided by you; no codecs are bundled
Package	About 11.2 MB for the x64 single file, plus an Updater

Notes

• Simplified Chinese only: there is no language switch, and other languages require maintaining the strings yourself
• Parameters are not validated for you: the panel does not judge whether a combination makes sense, and bad options show up directly in the ffmpeg log
• Plugins need a rename: change the built .dll to .3fui.dll, drop it into the Plugin folder and keep dependent assemblies at their original names
• Data lives beside the program: presets, agent sessions and settings are written next to the executable, so a read-only folder breaks saving
• Free versus paid: production features are free, while personalization such as glass backgrounds requires the SP tier