3GP Library Overview

This document describes 3GP Library.

Purpose

3GP Library lets you read (parse) and write (compose) 3GP, 3G2, and MP4 files. You can use 3GP Library to provide direct data access for applications. When you need to develop reference audio and video controllers, you can use 3GP Library.

3GP Library details

The DLL that provides the functionality and the library to which your code must link is identified below.

DLL LIB Short Description

3gplibrary.dll

3gplibrary.lib

These files are used to implement 3GP Library.

Architectural relationship

The following diagram shows the architecture of 3GP Library:

Figure 1. 3GP Library Architecture

Description

3GP Library provides two APIs to compose and parse multimedia files.

3GP Composer

The 3GP Composer accepts H.263, MPEG-4 and AVC (also known as H.264) video formats, and AMR, MPEG-4 AAC and QCELP audio formats. These formats are used to create 3GP, 3G2 or MP4 files. If QCELP audio is supplied, the file to be composed is automatically switched to a 3G2 file. To compose an MP4 file, the video source must be either of type MPEG-4 video or AVC, and the audio source must be of type MPEG-4 AAC audio, otherwise the output file type will be automatically changed to 3GP.

3GP Parser

The 3GP Parser parses 3GP, 3G2 and MP4 content containing H.263, MPEG-4 or AVC video formats, and AMR, MPEG-4 or QCELP audio formats. Content can be from a file, a Content Access Framework (CAF) object, or given through memory buffer.

Key 3GP Library classes

The key classes that make up 3GP Library are as follows:

  • C3GPCompose

    This class provides the functions for the 3GP Composer.

  • C3GPParse

    This class provides the functions for the 3GP Parser.

  • M3GPParseCallback

    An interface provided by 3GP Library for the asynchronous retrieval of video and audio frames. The client application normally implements M3GPParseCallback.