3GP Library Overview

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.

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.

Using 3GP Library

You can use the 3GP Composer to do the following:

• Create an instance of a 3GP Composer

• Initialise the 3GP Composer for writing 3GP, 3G2 or MP4 data

• Write video and audio data streams

• Commit video and audio data to an output file.

You can use the 3GP Parser to do the following:

• Create an instance of a 3GP Parser

• Initialise the 3GP Parser for reading 3GP, 3G2 or MP4 data

• Retrieve video and audio metadata

• Read video and audio data streams (synchronously and asynchronously)

• Release 3GP Parser resources.

See also

3GP Library Tutorials