ffx

ffx is an opinionated Rust CLI wrapper around FFmpeg for common media tasks. It keeps the command surface small, applies useful defaults, and still exposes enough control for real batch workflows.

Features

• compress for H.264 MP4 output with CRF-based defaults
• to-mp4 for smart remux-or-reencode conversion
• gif with palettegen + paletteuse
• audio extraction to mp3 or m4a
• thumb extraction using FFmpeg's thumbnail filter
• cut for single or multi-segment trimming with optional merge
• Batch processing with configurable concurrency
• --dry-run support for inspecting generated FFmpeg commands
• Hardware-accelerated H.264 encoding when FFmpeg supports it (VideoToolbox on macOS, NVENC/QSV/AMF elsewhere)
• Presets for web, discord, and high-quality

Requirements

• Rust 1.85+ recommended for building
• ffmpeg and ffprobe available on PATH

Install

Pre-built binaries are on the GitHub Releases page.

macOS (Apple Silicon)

curl -LO https://github.com/guozijn/ffx/releases/download/v0.1.3/ffx-v0.1.3-aarch64-apple-darwin.tar.gz
tar -xzf ffx-v0.1.3-aarch64-apple-darwin.tar.gz
sudo install -m 755 ffx-v0.1.3-aarch64-apple-darwin/ffx /usr/local/bin/ffx
rm -rf ffx-v0.1.3-aarch64-apple-darwin ffx-v0.1.3-aarch64-apple-darwin.tar.gz
ffx --help

Linux (x86_64)

curl -LO https://github.com/guozijn/ffx/releases/download/v0.1.3/ffx-v0.1.3-x86_64-unknown-linux-gnu.tar.gz
tar -xzf ffx-v0.1.3-x86_64-unknown-linux-gnu.tar.gz
sudo install -m 755 ffx-v0.1.3-x86_64-unknown-linux-gnu/ffx /usr/local/bin/ffx
rm -rf ffx-v0.1.3-x86_64-unknown-linux-gnu ffx-v0.1.3-x86_64-unknown-linux-gnu.tar.gz
ffx --help

Windows builds are published as .zip on the releases page; extract ffx.exe and add it to your PATH.

Build from source

cargo build --release
./target/release/ffx --help

Hardware acceleration

By default, ffx probes your ffmpeg binary at startup and picks the best available H.264 hardware encoder:

Platform	Encoder	Decode acceleration
macOS	h264_videotoolbox	videotoolbox
NVIDIA	h264_nvenc	cuda / nvdec
Intel	h264_qsv	qsv
AMD (Windows)	h264_amf	d3d11va / dxva2

If no hardware encoder is available, ffx falls back to libx264. Use --no-hwaccel to force software encoding.

macOS

If macOS shows "ffx" Not Opened because the binary is not notarized, remove the quarantine attribute manually:

xattr -d com.apple.quarantine /usr/local/bin/ffx
ffx --help

Command Overview

ffx compress input.mov
ffx to-mp4 clip.mkv
ffx gif clip.mp4 --from 00:00:02 --duration 3 --fps 15
ffx audio lecture.mp4 --format m4a
ffx thumb video.mp4
ffx cut input.mp4 --from 00:00:10 --to 00:00:30

Usage

Compress

Default behavior converts to H.264/AAC MP4, applies CRF 23, and scales down to a maximum height of 1080p.

ffx compress input.mov
ffx compress *.mov --preset discord -j 4
ffx compress demo.mov --target-size-mb 20
ffx compress input.mov --output exports/final.mp4

Example generated command:

ffmpeg -hide_banner -y -i input.mov \
  -c:v libx264 -preset medium -crf 23 \
  -vf "scale='if(gt(ih,1080),trunc(iw*1080/ih/2)*2,iw)':'if(gt(ih,1080),1080,ih)'" \
  -c:a aac -b:a 128k -movflags +faststart input_compressed.mp4

To MP4

to-mp4 probes codecs first. If the input streams are MP4-compatible it remuxes with -c copy; otherwise it falls back to H.264/AAC re-encoding.

ffx to-mp4 clip.mkv
ffx to-mp4 clip.webm --reencode --preset high-quality

GIF

gif uses FFmpeg's palette workflow for better quality than a naive one-pass GIF export.

ffx gif clip.mp4
ffx gif clip.mp4 --from 12 --duration 2.5 --fps 15 --width 640

Example generated command:

ffmpeg -hide_banner -y -ss 12 -i clip.mp4 -t 2.5 \
  -vf "fps=15,scale=640:-1:flags=lanczos,split[s0][s1],[s0]palettegen=stats_mode=full[p],[s1][p]paletteuse=dither=sierra2_4a" \
  clip.gif

Audio

ffx audio video.mp4
ffx audio video.mp4 --format m4a --bitrate 256k

Thumbnail

ffx thumb video.mp4
ffx thumb video.mp4 --at 00:00:05 --width 1920

Cut

Single trim:

ffx cut input.mp4 --from 00:00:10 --to 00:00:20

Multi-segment merge:

ffx cut input.mp4 \
  --segment 00:00:10-00:00:20 \
  --segment 00:01:00-00:01:30

Split output instead of merge:

ffx cut input.mp4 \
  --segment 10-20 \
  --segment 60-90 \
  --split

When using multiple segments, ffx:

1. Extracts each range into a temporary directory.
2. Writes a concat list file.
3. Merges the parts with ffmpeg -f concat.
4. Falls back to re-encoding if stream copy fails and fallback is enabled.

Dry Run

Inspect the FFmpeg commands without executing them:

ffx --dry-run compress input.mov
ffx --dry-run cut input.mp4 --segment 10-20 --segment 30-40
ffx --no-hwaccel compress input.mov

Development

cargo fmt
cargo test