code/Audio/Metadata/ID3/Frames/TextFrame.cs

Go to the documentation of this file.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Sylloge.Audio.Metadata.ID3.Frames
{
    public class TextFrame : ID3.Frame
    {
        public byte Encoding { get; protected set; }
        public string Description { get; protected set; }
        public string Value { get; protected set; }

        public TextFrame() : base(ID3.Frame.Keys.UserDefinedString) { }

        public TextFrame(string id) : base(id) { }

        public TextFrame(Frame other)
            : base(other)
        {
            this.Encoding = 0x00;
            this.Description = string.Empty;
            this.Value = ID3.Frames.TextFrame.GetTextFromFrame(other.Data);
        }

        public TextFrame(TextFrame other)
            : base(other)
        {
            this.Initialize(other.Encoding, other.Description, other.Value);
        }

        public override byte[] GenerateTag()
        {
            return this.GenerateTagData();
        }

        public void SetDescription(string desc)
        {
            this.Description = desc;
            this.GenerateTag();
        }

        public void SetEncoding(System.Text.Encoding e)
        {
            if (e == null) { throw new System.ArgumentNullException("e"); }
            this.Encoding = ((e.CodePage == System.Text.Encoding.Unicode.CodePage) ? (byte)0x01 : (byte)0x00);
            this.GenerateTag();
        }

        public void SetValue(string value)
        {
            this.Value = value;
            this.GenerateTag();
        }

        protected byte[] GenerateTagData()
        {
            System.Text.Encoding enc = ID3.Helper.GetEncoding(this.Encoding);
            int dlen = enc.GetByteCount(this.Description) + 1; // upto 0x00 + 1 byte (hence + 2)
            int vlen = enc.GetByteCount(this.Value);
            this.Data = new byte[(1 + dlen + vlen)];
            this.Data[0] = this.Encoding;
            System.Buffer.BlockCopy(enc.GetBytes(this.Description), 0, this.Data, 1, (dlen - 1));
            System.Buffer.BlockCopy(enc.GetBytes(this.Value), 0, this.Data, dlen, vlen);
            return this.FullFrame;
        }

        protected byte[] GenerateTagData(byte[] pre_data)
        {
            System.Text.Encoding enc = ID3.Helper.GetEncoding(this.Encoding);
            int dlen = enc.GetByteCount(this.Description) + 1;
            int vlen = enc.GetByteCount(this.Value);
            int plen = pre_data.Length;
            this.Data = new byte[(1 + plen + dlen + vlen)];
            this.Data[0] = this.Encoding;
            System.Buffer.BlockCopy(pre_data, 0, this.Data, 1, plen);
            System.Buffer.BlockCopy(enc.GetBytes(this.Description), 0, this.Data, (plen + 1), (dlen - 1));
            System.Buffer.BlockCopy(enc.GetBytes(this.Value), 0, this.Data, (plen + 1 + dlen), vlen);
            return this.FullFrame;
        }

        protected void Initialize(byte enc, string desc, string val)
        {
            this.Encoding = enc;
            this.Description = desc;
            this.Value = val;
        }

        public static byte[] GenerateTagData(string id, string data)
        {
            return ID3.Frames.TextFrame.GenerateTagData(id, data, false);
        }

        public static byte[] GenerateTagData(string id, string data, bool isAnsi)
        {
            System.Text.Encoding e = (isAnsi ? ID3.Helper.ISO : ID3.Helper.UTF16);
            byte[] b = new byte[(e.GetByteCount(data) + 1)];
            b[0] = (isAnsi ? (byte)0x00 : (byte)0x01);
            System.Buffer.BlockCopy(e.GetBytes(data), 0, b, 1, (b.Length - 1));
            return ID3.Frame.GetFullTagData(id, b);
        }

        public static string GetTextFromFrame(byte[] data)
        {
            /* <Header for 'Text information frame', ID: "T000" - "TZZZ", excluding "TXXX" described in 4.2.2.> 
            Text encoding    $xx
            Information    <text string according to encoding>*/
            return ID3.Helper.GetEncoding(data[0]).GetString(data, 1, data.Length - 1);
        }
    }
}