Crate muxide 

Muxide

Zero-dependency pure-Rust MP4 muxer for recording applications.

Core Invariant

Muxide guarantees that any correctly-timestamped, already-encoded audio/video stream can be turned into a standards-compliant, immediately-playable MP4 without external tooling.

What Muxide Does

• Accepts encoded H.264 (Annex B) video frames with timestamps
• Accepts encoded AAC (ADTS) audio frames with timestamps
• Outputs MP4 files with fast-start (moov before mdat) for instant web playback
• Supports B-frames via explicit PTS/DTS
• Supports fragmented MP4 (fMP4) for DASH/HLS streaming

What Muxide Does NOT Do

• ❌ Encode or decode video/audio (use openh264, x264, etc.)
• ❌ Read or demux MP4 files
• ❌ Fix bad timestamps (rejects invalid input)
• ❌ DRM, encryption, or content protection
• ❌ MKV, WebM, or other container formats

See docs/charter.md and docs/contract.md for full invariants.

Example

use muxide::api::{Muxer, MuxerConfig};
use std::fs::File;

let file = File::create("out.mp4")?;
let config = MuxerConfig::new(1920, 1080, 30.0);
let mut muxer = Muxer::new(file, config)?;

// Write frames (encoded elsewhere).
// muxer.write_video(pts_secs, annex_b_bytes, is_keyframe)?;

let _stats = muxer.finish_with_stats()?;

Modules

api

codec

Codec configuration extraction for container muxing.

fragmented

Fragmented MP4 (fMP4) support for streaming applications.

invariant_ppt

Invariant PPT Testing Framework

Macros

assert_invariant

Assert an invariant and log it for contract testing.