Splitter is a command line tool for cutting video files into equal length or fixed length segments using FFmpeg.
It supports multi threaded splitting, ETA and speed reporting, flexible duration formats, and a simple terminal user interface.

This tool is intended for creators, archivists, and automation workflows that need fast and predictable video segmentation.

Features

Multi threaded splitting for high performance
Equal length segments (default)
Fixed length segments with the --force option
Flexible duration formats (Ns, NmMs, or plain seconds)
Estimate only mode (--estimate)
Terminal progress display with ETA and speed
Custom output filename masks
FFmpeg passthrough for advanced users
Cross platform (.NET 10)

Requirements

FFmpeg and FFprobe installed and available in the system PATH
.NET 10 SDK or newer

Note: You must download YuNet ONNX model: https://github.com/opencv/opencv_zoo/tree/master/models/face_detection_yunet (github.com in Bing)

Usage

splitter <input.mp4> <output_folder> [options] [--] <ffmpeg passthrough>

Options

--duration=

Overrides the default 60 second target chunk size.

Accepted formats:

Format	Meaning
Ns	N seconds
NmMs	N minutes and M seconds
N	N seconds (plain number)

Examples:

--duration=90s
--duration=2m30s
--duration=45

Without --force, the program adjusts the segment length so that all segments are equal.

--force

Uses the duration exactly as provided.
The last segment may be shorter.

Example:

--duration=45 --force

--estimate

Prints calculated segment information and exits.
No splitting is performed.

Example:

splitter video.mp4 out/ --duration=2m30s --estimate

--mask=

Custom output filename pattern.

Default:

<OriginalName>_Seg%03d.mp4

Supports:

%03d for zero padded index
%d for plain index

Example:

--mask="Part_%03d.mp4"

FFmpeg passthrough

Anything after -- is passed directly to FFmpeg.

Example:

splitter video.mp4 out/ -- -an -sn

How It Works

Reads total duration using ffprobe
Parses the target duration (default 60 seconds or from --duration=)
Computes the number of segments
If not forced, adjusts segment length so all segments are equal
Runs multiple FFmpeg processes in parallel
Displays progress, ETA, and speed in the terminal

Examples

Split into equal 60 second segments:

splitter video.mp4 out/

Split into equal 90 second segments:

splitter video.mp4 out/ --duration=90s

Split into fixed 45 second segments:

splitter video.mp4 out/ --duration=45 --force

Estimate only:

splitter video.mp4 out/ --duration=2m30s --estimate

Custom output names:

splitter video.mp4 out/ --mask="Clip_%03d.mp4"

Pass extra flags to FFmpeg:

splitter video.mp4 out/ -- -an -sn

Building

dotnet build

Or run directly:

dotnet run -- video.mp4 out/