video_forge

Open-source project maintained by the community. Found a bug or want to contribute? PRs and issues are welcome.

High-performance Rust video processing engine for Flutter — hardware-accelerated transcoding, frame-accurate previews, audio mixing, and fast thumbnail generation. Powered by native FFmpeg with platform codecs (MediaCodec, VideoToolbox).

Note

This is a low-level engine — raw FFI bindings to Rust + FFmpeg. Provides hardware-accelerated transcoding, frame-accurate previews, audio mixing, and thumbnail generation.

Platform Support

Platform	Status
Android	Tested (SDK 24+, MediaCodec)
iOS	Tested (13.0+, VideoToolbox)
macOS	Tested (10.15+, VideoToolbox)
Windows	In progress
Linux	In progress
Web	Not supported

Quick Start

import 'package:video_forge/video_forge.dart';

// Call once at app startup
await initialize();

// Probe video metadata
final info = await getMediaInfo(path: '/path/to/video.mp4');
print('${info.width}x${info.height} ${info.durationMs}ms');

// Compress with progress stream
final progress = startCompress(options: CompressOptions(
  inputPath: '/path/to/video.mp4',
  outputPath: '/path/to/output.mp4',
));
await for (final event in progress) {
  print('${event.phase}: ${event.fps} fps');
}

// Extract a thumbnail
final thumbPath = await thumbnail(options: ThumbnailOptions(
  inputPath: '/path/to/video.mp4',
  positionMs: 1500,
  outputPath: '/path/to/thumb.jpg',
));

What You Can Do

Video transcoding — Async compression with hardware acceleration (MediaCodec, VideoToolbox). Phase-based progress reporting with FPS and ETA.
Metadata probing — Fast MP4 inspection (mp4parse) with FFmpeg fallback. Dimensions, duration, framerate, codecs, rotation, Dolby Vision markers.
Thumbnails & filmstrips — Frame-accurate single/batch extraction with optimized GOP seek. Output to files or in-memory byte arrays.
Frame-accurate previews — Decode frames to raw RGBA or Apple zero-copy CVPixelBuffer. No temp files.
Audio mixing — Mix external audio tracks with source video. Per-track offsets, durations, and volume.
Overlay burn-in — Composite PNG overlays (watermarks, stickers) onto video frames with fade transitions.
Playback sessions — Decoder-driven playback with seek, play/pause, and custom frame-rate ticks.
Buffer pool — Recycled byte vectors to eliminate allocations during scrub sessions.

For the full API, see the Dart API reference.

Pros & Cons

Pros	Cons
Hardware-accelerated video processing	No web support
Async jobs with progress updates	FFmpeg libraries add significant app size
Android, iOS, macOS (Windows & Linux in progress)	FFmpeg setup can be involved (especially macOS VT)
Frame-accurate previews without temp files	FFmpeg is LGPL — requires license notice in your app
Built-in audio mixing for timeline editors	Needs native build toolchain, not pure Dart
Fast thumbnail and filmstrip generation	Large binary from bundled video codecs

App Size

The package includes native Rust code plus external FFmpeg libraries:

Component	Est. Size
Rust engine (transcoding, preview, thumbnails, audio mix)	~5–8 MB
FFmpeg libraries (libavcodec, libavformat, libavfilter, libswscale)	~15–30 MB
Total	~20–38 MB

FFmpeg is the dominant cost. The Rust engine itself is modest — most of the weight comes from video/audio codec libraries. Android uses App Bundles, so users only download their device's ABI.

Installation

flutter pub add video_forge

Prerequisites:

Rust toolchain on your development machine
FFmpeg libraries (libavcodec, libavformat, libavfilter, libswscale) on your linker path
macOS with VideoToolbox: Build FFmpeg with VT support

Android: NDK configured in local.properties; install Android Rust targets:

rustup target add aarch64-linux-android armv7-linux-androideabi \
  x86_64-linux-android i686-linux-android

More Examples

Batch thumbnails (filmstrip)

final result = await batchThumbnails(options: BatchThumbnailOptions(
  inputPath: '/path/to/video.mp4',
  positionsMs: [0, 5000, 10000, 15000],
  outputDir: '/tmp/thumbs',
));

// Or in-memory for UI display
final frames = await batchThumbnailBytes(options: BatchThumbnailBytesOptions(
  inputPath: '/path/to/video.mp4',
  positionsMs: [0, 5000, 10000, 15000],
));

Frame-accurate preview decode

final frame = await decodePreviewFrameRgba(
  inputPath: '/path/to/video.mp4',
  positionMs: BigInt.from(4200),
  maxEdge: 720,
);
// frame.width, frame.height, frame.data (RGBA bytes)

Cancel a running job

final jobId = /* from startCompress */;
await cancelJob(jobId: jobId);
print('Active jobs: ${await activeJobCount()}');

Contributing

This package is part of the MediaForge monorepo. Issues and pull requests are welcome on GitHub.