System for just-in-time retrieval of multimedia files over computer networks by transmitting data packets at transmission rate determined by frame size
First Claim
1. A method of transmitting data packets of bytes derived from a compressed video file which is stored in a server computer, the transmission being over a computer network to a client computer connected onto the network, in which the client computer decompresses the video file as a sequence of video frames;
- characterized in that the server computer transmits the data packets at a transmission rate determined by the number of bytes (frame size) of each individual video frame, at least 10 frames per second, and not by a rate determined by the number of bytes per second to be transmitted.
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Accused Products
Abstract
A method in computer networks in which a client machine (playback client computer) requests multimedia files, such as compressed video clips, from a server (storage server computer). The transmission uses digital data packets. In the case of video files, the packet headers identify the video frame and the sequence number of each packet derived from the frame. The transmission timing is not based on a steady byte stream or an average of bytes to be transmitted. Instead, in the case of video, the frame rate determines normal transmission and a frame is transmitted during each frame time. The client agent has a normal packet buffer, normally holding 1-5 video frames. The transmission rate is adjusted to keep that buffer filled within its normal range. The timing information required for transmission, in one embodiment, is stored in a separate index file associated with each multimedia file.
326 Citations
42 Claims
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1. A method of transmitting data packets of bytes derived from a compressed video file which is stored in a server computer, the transmission being over a computer network to a client computer connected onto the network, in which the client computer decompresses the video file as a sequence of video frames;
characterized in that the server computer transmits the data packets at a transmission rate determined by the number of bytes (frame size) of each individual video frame, at least 10 frames per second, and not by a rate determined by the number of bytes per second to be transmitted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method in a computer network comprising a plurality of computers comprising a client agent in a client computer interacting with a server, a multimedia application executed by the client computer and derived from a multimedia file, including a compressed video file, stored in the server, the method being for just-in-time retrieval of the multimedia file and its transmission from the server to the client agent, the method comprising the steps of:
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(a) having the server extract timing information, including the number of bytes (frame size) of each video frame, from the multimedia file and store the timing information in a separate and accompanying index file; (b) having the server transmit the multimedia file over the network based upon the timing information, including information regarding the number of bytes (frame size) of each video frame, in the index file; and (c) having data of the multimedia file packetized and transmitted by the server to the client agent and executed by the client agent. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A computer network system comprising a plurality of computers including a plurality of client machines and a server machine, each client machine having a client agent interacting with the server machine, a multimedia application executed in the client machine and derived from a multimedia file, including a compressed video file, stored in the server machine, the system providing just-in-time retrieval of the multimedia file and its transmission from the server machine to the client machine, the system further comprising:
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(a) an index file in the server machine comprising timing information based upon the number of bytes (frame size) of each video frame in the multimedia file, the index file being separate from, and accompanying, its corresponding multimedia file; (b) server timing means to transmit the multimedia file over the network controlled by the timing information in the index file; and (c) server transmission means to packetize the data of the multimedia file and transmit the packetized data to the client machine. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A computer network system comprising a plurality of computers including a plurality of client computers each having a screen and means for decompressing compressed video files, and a server computer having transmission means for transmission of digital data files as data packets of bytes, a video application executed in the client computer and derived from a compressed video file stored in the server computer, the video file being displayed on the client computer'"'"'s screen as a sequence of video frames, the system providing just-in-time retrieval of the compressed video file and its transmission in data packets from the server computer to the client computer, the system further comprising:
server computer means for transmitting data packets at a transmission rate determined by the number of bytes (frame size) of each video frame and by the rate of at least 10 frames per second the video frames are displayed on the client computer'"'"'s screen and not by a rate determined by the number of bytes per second to be transmitted. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42)
Specification