tailieunhanh - Extracting ID3 Data From an MP3 File

Hầu hết người chơi MP3 hiện đại có thể đọc, hiển thị, và phản ứng này bao gồm dữ liệu khi đang chơi một tập tin. Rất may, ActionScript cũng cung cấp quyền truy cập vào thông tin này khi sử dụng các tập tin MP3 trong các dự án của bạn. Thực tế này cho phép bạn tạo các ứng dụng phức tạp âm thanh. Chú ý Không phải tất cả MP3 chứa các thẻ ID3 | Extracting ID3 Data From an MP3 File Do you think an MP3 file holds nothing but code for playing back an audio file Think again. Most people are unaware that hidden in most MP3 files are ID3 tags. These tags known as metadata contain information such as the following about the MP3 file Name of the song Artist Genre Year the song was recorded Album from which the song came Lyrics Comments Most modern MP3 players can read display and react to this included data when playing a file. Thankfully ActionScript also provides access to this information when using MP3 files in your projects. This fact allows you to create sophisticated audio applications. NOTE Not all MP3s contain ID3 tags. When an MP3 is loaded into or attached to a Sound object that file s ID3 tag information can be read by accessing the Sound object s ID3 property. For example the ID3 tag representing a song name is TIT2. To extract this data from the MP3 file loaded into a Sound object named music you would use the following syntax var Other common ID3 tags include TALB album TPE1 artist TYER year of recording TRCK track and COMM comment . TIP For more information about ID3 tags consult the ActionScript dictionary or visit . Many ID3 tag editors are available to help you add your own ID3 tags to MP3 files. A search on will return a number of possibilities. In the following exercise you ll create an MP3 player that loads MP3 files based on data in an XML file. The MP3 files contain ID3 tag data that will be extracted and displayed on the user interface. 1. Open in the Lesson18 Assets folder. This project contains five layers named Background Text Fields Buttons Components and Actions. Our project s static graphics are on the Background layer. There are five text fields on the Text Fields layer song_txt artist_txt year_txt URL_txt and comments_txt. These fields will eventually be used to display extracted ID3 tag data. The Buttons .