ff-remux

Stream-copy remuxing for Rust: trim a clip and replace / extract / add an audio stream, all without re-encoding.

ff-remux is a safe, ergonomic Rust wrapper over FFmpeg's stream-copy remuxing (libavformat demux + mux, no libavcodec encoding). Errors are typed and carry human-readable context (RemuxError), so a failure reads as an actionable message rather than a raw FFmpeg return code.

It is an independent crate: use it on its own, or combine it with the other ff-* crates to assemble whatever media application, or editing model, you need. The ff-* crates are purified, model-free primitives, so none imposes an editing model on you; avio is one editing engine built on top of them. Each crate is versioned independently; see crates.io for current versions.

Installation

[dependencies]
ff-remux = "0.16"

FFmpeg 7.x or 8.x development libraries must be installed on your system.

Trim (stream copy)

StreamCopyTrim copies the selected time range without re-encoding, so it is fast and lossless.

use ff_remux::StreamCopyTrim;
use std::time::Duration;

StreamCopyTrim::new("input.mp4", "clip.mp4")
    .start(Duration::from_secs(10))
    .end(Duration::from_secs(25))
    .run()?;

Audio replace / extract / add

use ff_remux::{AudioReplacement, AudioExtractor, AudioAdder};

// Replace the audio track of a video with a new audio file.
AudioReplacement::new("video.mp4", "music.aac", "out.mp4").run()?;

// Extract the audio track to its own file.
AudioExtractor::new("video.mp4", "audio.aac").run()?;

// Add an audio track to a video that has none.
AudioAdder::new("silent.mp4", "voice.aac", "out.mp4").run()?;

Error Handling

RemuxError implements ff_format::MediaError, so err.is_recoverable() / err.is_fatal() work uniformly with the other ff-* crates.

MSRV

Rust 1.93.0 (edition 2024).

License

MIT OR Apache-2.0