Chapter 23. MP3 Jukebox Assignments

Chapter 23. MP3 Jukebox Assignments
	Part III. Programming Assignments

Table of Contents

23.1. Phonon/MultiMediaKit Setup
23.2. Playlist
23.3. Playlists
23.4. Source Selector
23.5. Database Playlists
23.6. Star Delegates
23.7. Sorting, Filtering, Editing Playlists

[ fromfile: homework/mp3mgr.xml id: mp3mgr ]

Abstract

In the assignments in this chapter, you will write, in stages, a main window program that serves as an MP3 playlist generator and database manager. It will generate and play selections of MP3 songs, based on what it can find on your file system and it will permit filter-queries based on data stored in ID3v2 (meta) tag information.

Prerequisites: You can start on this once you have covered the material up to Chapter 13.

The features you will implement are inspired by open source programs such as amaroK and aTunes, and commercial programs such as iTunes and MusicMatch Jukebox. These programs all provide similar features, but very different user interfaces. There is a lot of creativity that can go into a player. Few of them are equally easy to use with a keyboard or a mouse. Try to make yours work with either.

You can find an example of a media player in $QTDIR/examples/phonon/qmusicplayer and use it as a starting point. Then you can add extra components to it as you work through the following assignments. As of this writing, qmusicplayer lets you add files to a playlist and play the list of songs on your computer.

Figure 23.1. Example Screenshot

The simplest media player, shown in Figure 23.1 has two major components:

A Player view, which consists of
- A dockable that shows the user what is currently playing and provides some controls for changing volume and position of the song
- Play/Pause and Stop buttons. (Next and Previous buttons would also be nice.)
A song list view, as the central widget, for displaying a list of songs.

Each of these components is a view for displaying the data, and it is suggested you use separate classes to hold the actual data, maintaining a separation between model and view code.

Qt MultiMedia Kit

There is another library, Qt MultimediaKit, which is available as an addon to Qt. It is included in the Qt Software Development Kit (SDK), and can be downloaded from Qt Mobility.

Qt MultiMediaKit offers a higher level API for media players, including the ability to make recordings and access raw sound vector data. It provides implementations of playlists and also readers and writers for many popular playlist formats. If you want to reuse this library instead of Phonon, a better starting point is the demos/player example from Qt Mobility. Some parts of Qt Mobility only work on mobile devices such as phones, but Qt MultiMediaKit runs on all platforms.

Qt MultiMediaKit is still under development, but it is planned to replace Phonon in future versions of Qt.

As of Qt 4.6, there is a library, called libqtmultimedia, that is included in the Qt installation. This contains a subset of libqtmultimediakit, the library previously mentioned. As of Qt 4.7 this library does not include M3u playlist classes and certain other classes you might want for your media player.


Part III. Programming Assignments		23.1. Phonon/MultiMediaKit Setup