Saecki / mp4ameta

A library for reading and writing iTunes style MPEG-4 audio metadata

mp4ameta

A library for reading and writing iTunes style MPEG-4 audio metadata. Most commonly this kind of metadata is found inside m4a or m4b files but basically any mp4 container supports it.

Examples

The easy way

let mut tag = mp4ameta::Tag::read_from_path("music.m4a").unwrap();

println!("{}", tag.artist().unwrap());

tag.set_artist("artist");
tag.write_to_path("music.m4a").unwrap();

The hard way

use mp4ameta::{Data, Fourcc, Tag};

let mut tag = Tag::read_from_path("music.m4a").unwrap();
let artist_ident = Fourcc(*b"\xa9ART");

let artist = tag.strings_of(&artist_ident).next().unwrap();
println!("{}", artist);

tag.set_data(artist_ident, Data::Utf8("artist".to_owned()));
tag.write_to_path("music.m4a").unwrap();

Using freeform identifiers

use mp4ameta::{Data, FreeformIdent, Tag};

let mut tag = Tag::read_from_path("music.m4a").unwrap();
let isrc_ident = FreeformIdent::new("com.apple.iTunes", "ISRC");

let isrc = tag.strings_of(&isrc_ident).next().unwrap();
println!("{}", isrc);

tag.set_data(isrc_ident, Data::Utf8("isrc".to_owned()));
tag.write_to_path("music.m4a").unwrap();

Useful Links

• QuickTime spec
  • Overview of QTFF
  • Movie Atoms
  • Metadata
• MultimediaWiki QuickTime container
• AtomicParsley docs
• Mutagen docs
• Hydrogen audio tag mapping
• MusicBrainz Picard tag mapping
• Filetype list

Testing

Run all tests:
cargo test

Test this library on your collection:
cargo test -- --nocapture collection <path>