US 7,548,984 B2
Stream distribution system, stream server device, cache server device, stream record/playback device, related methods and computer programs
Nobukazu Kurauchi, Nagoya (Japan)
Assigned to Panasonic Corporation, Osaka (Japan)
Filed on May 23, 2003, as Appl. No. 10/444,403.
Claims priority of application No. 2002-151938 (JP), filed on May 27, 2002.
Prior Publication US 2004/0064574 A1, Apr. 01, 2004
Int. Cl. G06F 15/16 (2006.01)
U.S. Cl. 709—231  [709/203; 709/229; 709/232; 709/238; 725/44; 725/47; 725/48; 725/49; 382/232; 382/284] 40 Claims
OG exemplary drawing
 
1. A stream distribution system comprising a stream server device that transmits a stream, a plurality of terminal devices that playback a received stream, and a cache server device that mediates between the stream server device and the terminal devices via a network, the stream server device including:
a first storage unit storing a stream composed of a content and control information necessary for the playback of the content, wherein the stream cannot be played without the control information, the control information including information regarding frame height, time period different from prior VOP, and number of macroblocks;
a separating unit separating the stream into the content and the control information; and
a time acquisition unit acquiring, the cache server device, distribution request information including a preset distribution time at which the content starts being distributed;
a first stream transmitting unit transmitting the content to the cache server device before the preset distribution time indicated be the distribution request information, and to transmit the control information to the cache server device when the preset distribution time is reached, and
the cache server device including:
a time notifying unit transmitting the distribution request information to the stream server device;
a receiving unit receiving the content and the control information;
a second storage unit storing the content upon receipt thereof;
a combining unit restoring the stream by combining the content stored by the second storage unit with the control information received by the receiving unit; and
a second stream transmitting unit transmitting, when the stream has been restored by the combining unit, a stream that results from the restoration by the combining unit to one or more of the terminal devices, the transmitted stream being the same as the stream stored by the stream server device.