ff-preview

Real-time video preview and proxy workflow for Rust. Provides frame-accurate seek, audio-master A/V sync, a FrameSink trait for custom renderers, RGBA pixel delivery, and proxy generation with transparent auto-substitution.

Project status (as of 2026-04-13): This crate is in an early phase. The high-level API is designed and reviewed by hand; AI is used as an accelerator to implement FFmpeg bindings efficiently. Code contributions are not expected at this time — questions, bug reports, and feature requests are welcome. See the main repository for full context.

Installation

[dependencies]
ff-preview = "0.13"

# Enable async support
ff-preview = { version = "0.13", features = ["tokio"] }

# Enable proxy generation
ff-preview = { version = "0.13", features = ["proxy"] }

Quick Start

Playback with a custom RGBA sink

use ff_preview::{PreviewPlayer, RgbaSink};

fn main() -> Result<(), ff_preview::PreviewError> {
    let mut player = PreviewPlayer::open("video.mp4")?;
    player.set_sink(Box::new(RgbaSink::new()));
    player.play();
    player.run()?;
    Ok(())
}

Frame-accurate seek

use std::time::Duration;
use ff_preview::{DecodeBuffer, FrameResult};

let mut buf = DecodeBuffer::open("video.mp4").build()?;
buf.seek(Duration::from_secs(30))?;

loop {
    match buf.pop_frame() {
        FrameResult::Frame(f) => {
            println!("pts: {:?}", f.timestamp().as_duration());
            break;
        }
        FrameResult::Seeking(_) => std::thread::sleep(Duration::from_millis(5)),
        FrameResult::Eof => break,
    }
}

Proxy generation

use ff_preview::{ProxyGenerator, ProxyResolution};

let proxy_path = ProxyGenerator::new("original_1080p.mp4")?
    .resolution(ProxyResolution::Quarter)
    .output_dir("/tmp")
    .generate()?;

println!("proxy at {}", proxy_path.display());

Feature Flags

MSRV

Rust 1.93.0 (edition 2024).

License

MIT OR Apache-2.0