Data processing: database and file management or data structures – Database design – Data structure types
Reexamination Certificate
1997-08-27
2002-05-28
Feild, Joseph H. (Department: 2176)
Data processing: database and file management or data structures
Database design
Data structure types
C709S231000, C709S247000
Reexamination Certificate
active
06397230
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to data transmission, and particularly to fast transmission of large multimedia files.
BACKGROUND OF THE INVENTION
The advent of powerful computers and large storage disks, such as CD-ROMs, in recent years, has brought with it a surge in production and use of sophisticated multimedia applications, including full length video movies, interactive sound and animation.
In recent years with the growth in Internet use, multimedia applications have been transferred to Internet web sites. However, most Internet users are connected to the web through public telephone lines, which have a slow average rate of data transfer, commonly referred to as bandwidth, typically about 1-3 Kbyte/second. Therefore, when these users connect to web sites that include large multimedia applications, they must wait long periods until they can view the contents of the site. The result is that sites must often limit their non-text contents to, at most, a few still images.
In order to reduce the amount of time required for transmission of multimedia applications, attempts are made to reduce the amount of data transmitted by the applications. Various compression methods are used to minimize the amount of data which is to be transferred.
Such compression methods include the well-known JPEG and MPEG standards, which are described, for example, in ISO/IEC WG11 N0501, July 1993, published by the International Standards Organization, and in “JPEG Still Data Compression Standard”, William B. Pennebaker and Joan L. Mitchell, Van Nostrand Reinhold, New York, which are incorporated herein by reference. However, even with these compression methods, current multimedia applications require a data transfer rate of about 50-150 Kbytes/second to provide true real-time multimedia. Also, more sophisticated compression methods may require complex decompression software packages and special-purpose CPUs, which are not available to most users.
SUMMARY OF THE INVENTION
It is an object of some aspects of the present invention to provide improved methods of multimedia data organization, to allow fast data transfer of multimedia applications.
It is another object of some aspects of the present invention to provide apparatus and methods for development of multimedia applications for Internet users.
It is yet another object of some aspects of the present invention to provide improved methods for compressing images and data for transmission and storage.
It is a further object of some aspects of the present invention to provide apparatus and methods for developing multimedia applications suitable for transfer at a predetermined bandwidth.
It is still a further object of some aspects of the present invention to provide methods for estimating the size and transfer rate of a multimedia application.
In some aspects of the present invention, multimedia information is organized in a file for transmission, such that a recipient may randomly access parts of the file, and there is no need to transmit the whole file sequentially.
In some preferred embodiments of the present invention, a transmitting computer organizes the multimedia information in frames, each frame corresponding to a portion of the information to be presented at a given point in time. A file containing the information includes a sequential listing of the data forming each frame and a direct access table, which contains an ID for each frame and one or more pointers to the data in the frame. The frames are preferably organized in the file sequentially according to the order in which the frames are likely to be displayed, and the table is preferably placed at the beginning of the file.
When the recipient accesses the file, the access table is transmitted initially, and the recipient may then request transmission of any desired frame or sequence of frames in the file. Preferably, for this purpose, as soon as the table and an initial frame in the file have been received, the recipient's computer displays an image of the initial frame including one or more “hot spots,” as are known in the art, which are linked to invoke corresponding frame IDs or pointers in the table. Each frame is preferably displayed as it arrives at the recipient's computer, without waiting for the entire file. Thus, after the initial frame has been received and displayed, the recipient will generally be able to view a continuous stream of multimedia images, without having to wait for the entire multimedia file to download to his computer as in applications known in the art.
Preferably, each received frame is stored in a memory of the recipient's computer for further access. Thus, if a frame or parts of a frame appear or are invoked by a user twice or more in an application, there is no need to transmit the frame or parts a second time. Rather, the frame is accessed in the memory according to the access table. Preferably, the frames are stored as they are received in a compressed format and are decompressed when required. Alternatively or additionally, the frames are stored in a non-compressed format, which is ready for immediate display.
Preferably, the size of the table is dynamically adjusted according to the size of the file, and the data size of the pointers in the table is chosen according to the size of the file. Preferably, in a file smaller than 256 bytes, the pointers are one byte long, in a larger file which is smaller than 64K the pointers are two bytes long, etc.
Preferably, based on the table the recipient computer does not need to continuously check for a file delimiter, but rather counts the frames received until their number matches the number of frames in the table. Alternatively, the number of frames and/or the length of the file is specifically stated in a header of the file. In addition, according to the difference between the pointers of two consecutive frames, the size of the first frame is known, and there is no need to have a delimiter after the information of each frame.
In some aspects of the present invention, the data of the frames, and/or other multimedia information, are stored in a compact form so as to reduce the size of the file. In preferred embodiments of the present invention, the size of multimedia files may be reduced in over 90%, and on the average at a ratio of about 1:80. Such compression rates allow fast transmission of the information over relatively slow communication channels.
In a preferred embodiment of the present invention, each frame comprises a number of separate layers which when displayed or otherwise actuated together form the frame. These layers include one or more media which carry visual or audio information in any suitable format, preferably in standard formats known in the art. Each of the media comprises any number of primary objects, such as vectors or bitmaps, which form the media. Preferably, the table includes pointers to each of the media in the file. Identical media which appear in more than one frame are kept in the file only in the first frame in which they appear. In the rest of the frames they are referred to by an ID code and coordinates. When reading the file, the recipient computer will refer to the table to find the addresses of the media. Alternatively, the media may be referenced directly by a pointer to their position in the file.
In preferred embodiments of the present invention, coordinates used in identifying the locations of visual elements, layers, visual media and visual objects, are dynamically sized according to the range of pixels over which the element may move. An element having positions up to 256 pixels preferably uses one byte coordinates, while elements having up to 64K possible positions use two byte coordinates. In elements having a very large range, three byte coordinates may also be employed. Alternatively or additionally, other sizes such as half bytes and 12-bit coordinates may be used for specifying coordinates in elements of appropriate size. Such adaptively-sized coordinates are useful in reducing the volume of data that must be transmi
Carmel Sharon
Daboosh Tzur
Reifman Eli
Shani Naftali
Feild Joseph H.
Geo Interactive Media Group Ltd.
Ladas & Parry
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