Why

To learn rust!

Usage

This is ID3 read and write library.

• Add dependency
• Reding: How to read ID3 information
• Writing: How to write ID3 information
• Rewrite: How to rewrite all ID3 information to version 4
• Getting information of a frame body without property name.

other usecases See tests.

Add dependency

This can be used by adding rtag to your dependencies in your project's Cargo.toml

toml [dependencies] rtag = "0.3" and this to your crate root:

rust extern crate rtag;

Reding: How to read ID3 information

To read a ID3 metadata, you use a MetadataReader and a Unit enum.

and the MetadataReader is implementing the std::iter::Iterator trait, you can use filter, map, fold.. and so on.

Example

```rust // read a frame1 for m in MetadataReader::new("./test-resources/v1-v2.mp3").unwrap() { match m { Unit::FrameV1(frame) => { debug!("v1: {:?}", frame); asserteq!("Artist", frame.artist); asserteq!("!@#$", frame.comment); asserteq!("1", frame.track); asserteq!("137", frame.genre); } _ => (), } }

// filter a frame v3 having compression flag let mut i = MetadataReader::new(path).unwrap().filter(|m| match m { &Unit::FrameV2(FrameHeader::V23(ref header), ) => { header.hasflag(FrameHeaderFlag::Compression) } _ => false, });

// fold a frame v2 let newdata = MetadataReader::new(path) .unwrap() .fold(Vec::new(), |mut vec, unit| { if let Unit::FrameV2(framehead, framebody) = unit { let newframebody = if let FrameBody::TALB(ref frame) = framebody { let mut newframe = frame.clone(); newframe.text = "Album!".tostring(); FrameBody::TALB(newframe) } else { frame_body.clone() };

        vec.push(Unit::FrameV2(frame_head, new_frame_body));
    } else {
        vec.push(unit);
    }

    vec
});

```

Writing: How to write ID3 information

To write a ID3 metadata, you pass FrameHeader and FrameBody to MetadataWriter via std::vec::Vec.

Example

```rust let newdata = MetadataReader::new(path) .unwrap() .fold(Vec::new(), |mut vec, unit| { if let Unit::FrameV2(framehead, framebody) = unit { let newframebody = ... vec.push(Unit::FrameV2(framehead, newframebody)); }

    vec
});

let _ = MetadataWriter::new(path).unwrap().write(new_data, false); ```

Rewrite: How to rewrite a ID3 information to version 4

To rewrite all the frames to version 4, it is same to above example but second parameter is true.

Note: the frame v1 information is ignored and some frames that are ignored. - In 2.2 'CRM', 'PIC'. - In 2.3 'EQUA', 'IPLS', 'RVAD', 'TDAT', 'TIME', 'TORY', 'TRDA', 'TSIZ', 'TYER'

rust // collect frames having version 2 let frames = MetadataReader::new(path).unwrap().collect::<Vec<Unit>>(); // rewrite to version 4 let _ = MetadataWriter::new(path).unwrap().write(frames, true); // read a version 4 for unit in MetadataReader::new(path).unwrap() { match unit { Unit::FrameV2(FrameHeader::V24(head), frame_body) => { ... }, _ => (), } }

Getting information of a frame body without property name.

To read value of frame without property name, FrameBody support to_map and inside.

Example

```rust for unit in MetadataReader::new(path).unwrap() { match unit { Unit::FrameV2(, ref framebody) => {

        // 1. using to_map();
        let map = frame_body.to_map();
        //{
        //    <key1:&str>: <value1:String>
        //    ...
        //}

        // 2. using inside
        frame_body.inside(|key, value| {
            // key<&str>, value<String>
            ...

            true // if true, look inside next.
        })

    },
    _ => (),
}

} ```