Module edit 

Non-destructive MP4/ISOBMFF box editing.

Editing works on a tree where unmodified boxes are references into the source file, so serialization streams untouched bytes through verbatim (an mdat is never loaded into memory) and re-serializing an unedited tree reproduces the source byte for byte. Box sizes are recomputed bottom-up during layout, so every ancestor of an edited box is correct by construction, and stco/co64 chunk offsets are remapped through the exact old-offset → new-offset extent map — data that didn’t move keeps its offsets, data that moved shifts by exactly the right amount.

use mp4box::edit::{Command, Editor};
use std::fs::File;

let mut editor = Editor::new();
editor.add_command(Command::Remove { path: "moov/udta".into() });
editor.set_tag("title", "My Movie")?;

let mut src = File::open("in.mp4")?;
let mut dst = File::create("out.mp4")?;
let stats = editor.process(&mut src, &mut dst)?;
println!("wrote {} bytes, {} chunk offsets adjusted",
    stats.bytes_written, stats.chunk_offsets_adjusted);

Fragmented (moof/sidx) and HEIF (iloc) files are refused: their internal offsets are not covered by the fixup pass yet, and editing them would corrupt the output.

Structs

EditNode

One box in the edit tree.

EditStats

Statistics from a completed edit.

EditTree

The whole file: top-level boxes plus any trailing bytes after the last box (shorter than a box header).

Editor

Applies a batch of Commands to an MP4 source and writes the result.

FixupStats

Enums

Command

A single edit operation. Paths are slash-delimited fourcc segments with optional indices for repeated boxes: "moov/trak[1]/mdia/mdhd". An omitted index means the first match.

HeaderForm

How the original box header was written, preserved on round-trip.

Payload

Payload of an edit node.