Interactive video distribution systems – User-requested video program system – Video-on-demand
Reexamination Certificate
1997-01-06
2003-03-18
Mehta, Bhavesh (Department: 2611)
Interactive video distribution systems
User-requested video program system
Video-on-demand
C725S095000, C375S240110
Reexamination Certificate
active
06536043
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to methods and systems for encoding digital multimedia data for transmission over a network.
BACKGROUND OF THE INVENTION
The following U.S. Patents have been found in a U.S. Patent Search and are believed to be generally relevant to the field of the invention:
4,897,867
1/90
Foster et al.
5,119,188
6/92
McCalley et al.
5,122,873
6/92
Golin
5,195,092
3/93
Wilson et al.
5,220,420
6/93
Hoarty et al.
5,236,199
8/93
Thompson, Jr.
5,251,209
10/93
Jurkevich et al.
5,265,248
11/93
Moulios et al.
5,283,819
1/94
Glick et al.
5,325,423
6/94
Lewis
5,351,276
9/94
Doll, Jr. et al.
5,363,482
11/94
Victor et al.
5,420,572
5/95
Dolin, Jr. et al.
5,420,801
5/95
Dockter et al.
5,438,658
8/95
Fitzpatrick et al.
5,487,167
1/96
Dinallo et al.
5,495,576
2/96
Ritchey
5,508,940
4/96
Rossmere et al.
5,519,435
5/96
Anderson
5,553,221
9/96
Reimer et al.
5,553,222
9/96
Milne et al.
5,557,538
9/96
Retter et al.
5,561,791
10/96
Mendelson et al.
5,564,001
10/96
Lewis
5,577,180
11/96
Reed
5,577,258
11/96
Cruz et al.
5,581,783
12/96
Ohashi
When using various media such as video, audio, text and images, a user generally retrieves the media from a storage device or “server” connected via a network to many computers or users. The server downloads the media to the network and transmits it to the user at the user's request.
There are two basic limitations involved in such data retrieval: delay between the time that a user requests the data and the time when the server downloads it to the network, and bandwidth limitations on data throughput and rate of data transmission. The present invention relates to the second limitation.
One example of such a system includes a CD ROM drive and personal computer which may be located at the same site. Another example includes a network connecting Internet servers and users' personal computers. Such networks are installed in order to facilitate convenient data transmission between users and data distribution from the server to the users' computers.
When a user retrieves the media from a storage device or server, typically connected via a network, the aforesaid bandwidth limitations affect the amount of time required to transmit a video frame from the server to the user, and thus limit the video frame rate. Moreover, when dealing with object movies and panoramas the files being transmitted are extremely large, so that overcoming bandwidth limitations is a critical enabling factor, even for high bandwidth networks.
Currently, two methods are employed to overcome bandwidth limitations: The first is to compress the video frame sequence, thereby speeding up transmission time at the cost of additional downstream processing to decompress the frames prior to display. The second is to copy the entire sequence to an intermediate storage device, such as a user's hard disk, to which the user has higher bandwidth access, at the cost of delaying the viewing of the video until the entire sequence has been delivered.
Known network applications involve streaming data from a server to a client computer (hereinafter also referred to as “client”). “Streaming” refers to serial or parallel transmission of digital data between two computers, by transmitting sequences of bit packets. For example, installation executables on a network server stream files to a client computer performing the installation. Servers with large amounts of memory are used to archive digital movies, which are streamed to a client computer for viewing upon demand. Digital video is broadcast from cable stations to subscribers using streaming. Internet browsers, such as Netscape and Microsoft Explorer, are used to stream data from a server on the web to a client. Internet web sites can contain enormous databases, such as phone directories for all of the cities in the U.S., photographs from art galleries and museums around the world, voluminous encyclopedias, and even copies of all patents ever issued by the U.S. Patent & Trademark Office. Clients using the Internet can search these databases and then request the server to download specific information. This request initiates a streaming event.
In view of the multitude of bandwidths present in complex client/server systems today and the large amounts of data necessary to produce compelling audio, video and imaging presentations, there is a pressing demand for scalable data representation of multimedia data, so that it can be delivered for on-line interactive playback in such a form that the transmission rate can accommodate the client bandwidth. The Internet is an example of a complex system where clients with many different bandwidth constraints demand multimedia data from server sites. There are several low bandwidth rates for modem transmission over phone lines, higher rates for frame relay lines, higher rates for ISDN lines, even higher rates for T1 lines, etc.
SUMMARY OF THE INVENTION
The present invention seeks to provide an improved method and system for transmitting digital data representing the original over plural transmission links at least some of which have limited bandwidth.
The present invention relates to scalable encoding, which enables two or more clients, connected to a server by lines having differing bandwidth, to begin playing the multimedia data on-line, and both at the same time, almost immediately after the start of streaming, but the lower bandwidth client receives lower quality media than the higher bandwidth client at first. As the media is replayed in the foreground and the bandwidth is freed, more data streams in via background, and the quality of the media is enhanced.
Without scalable encoding, a client of an Internet application must wait until the requested data arrives, at whatever rate its network line provides. A client with a 14.4 Kbs modem line, for example, would have to wait twice as long as a client with a 28.8 Kbs modem line. Moreover, if the data was encoded for 28.8 Kbs on-line playback, the 14.4 Kbs client would never be able to achieve live playback, since there would be an ever-increasing lag in the data stream. Conversely, if the data were encoded for 14.4 Kbs on-line playback, the 28.8 Kbs client would receive unnecessarily poor quality media.
On account of the progressive nature of the data representation in accordance with the present invention, the additional data block arriving in a 14.4 Kbs stream combines with the previous data block which arrived in a 14.4 Kbs stream, to produce a 28.8 Kbs streamed version; all that is being sent is the incremental data necessary for the upgrade. The progressive form of the encoding itself provides the ability to achieve scalability.
Another shortcoming of non-scalable encoding as in the prior art is the inability to preview a video sequence. Often a client would like to play a quick preview of a video clip, before deciding whether or not to download it. The scalable representation of the present invention can be used to deliver the video in a preview mode, as the first data blocks. If the client continues to download the video after previewing, the first data block already transmitted is progressively integrated with additional data blocks to create the full viewing video.
The present invention can also be applied to enhance delivery of large still images for multi-resolution gazing. Current technology transmits such images as large files, and carries out extensive computations for sub-sampling to lower resolution and zooming in to areas of interest for gazing. This makes it very time consuming to interact with large images, and as a result it is currently impractical to produce high resolution images for Internet browsing. When dealing with large images, producers simply sub-sample them to fit entirely within a computer monitor screen, and store the resulting low resolution images on web servers. Using the technology of the present invention, producers can deliver high resolution images over the Internet for rapid interactive gazing.
The present invention seeks to provide
Lonsberry Hunter
Martine & Penilla LLP
Mehta Bhavesh
Roxio, Inc.
LandOfFree
Method and systems for scalable representation of multimedia... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and systems for scalable representation of multimedia..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and systems for scalable representation of multimedia... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3028008