1. Field of the Invention
The present invention relates generally to a multimedia transmission system, and more particularly, to a hybrid delivery mechanism in a multimedia transmission system.
2. Description of the Related Art
An International Organization for Standardization (ISO) base file format has been proposed by the ISO/International Electrotechnical Commission ISO/IEC 14496-12 as a standard file format to be used for multimedia services. Having a flexible and extensible file structure, the ISO base file format is the basis of various multimedia file formats. The ISO base file format is designed to have an object-oriented structure so as to include various types of media resources and metadata, as a standardized file structure for packaging media resources and metadata. For example, the Joint Photographic Experts Group (JPEG) 2000, and 3rd Generation Partnership Project (3GPP) file formats are made based on the ISO base file format, and the Moving Picture Experts Group (MPEG)-4 file format is also an extension of the ISO base file format.
FIG. 1 illustrates a conventional format of an ISO base file.
The information and functions necessary for playing a plurality of media contents together are created as an object-based box. That is, the ISO base file is structured as a sequence of objects, some of which containing other objects. The sequence of objects in the ISO base file may contain a presentation metadata wrapper (a Movie Box), and the ISO base file contains one presentation metadata.
In FIG. 1, an ISO base file 101 includes a movie box ‘moov’ box 103 and a media data box ‘mdat’ box 105.
The ‘moov’ box 103 stores temporal and spatial position information and codec information for the media data stored in the media data box 105, and the ‘moov’ box's sub-boxes define the metadata for a presentation.
The ‘mdat’ box 105 contains the actual media data for a presentation. That is, the ‘mdat’ box 105 stores media data (or a media stream) such as video and audio.
In the ‘moov’ box 103, tracks ‘trak’ 107 (video, 109 (audio), and 111 (hint) include a timed sequence of related samples in the ISO base media file. The ‘trak’ 107 includes information about audio data, while ‘trak’ 109 includes information about video data and ‘trak’ 111 includes information for a streaming service.
However, the conventional art suffers from the lack of a hybrid delivery mechanism for client and server.