公开(公告)号：EP0886971A2

公开(公告)日：1998-12-30

申请号：EP97913403

申请日：1997-12-08

申请人： KONINKL PHILIPS ELECTRONICS NV

发明人： KORST JOHANNES HENRICUS MARIA ,  LAWERMAN EDZER ,  PRONK SERVERIUS PETRUS PAULUS ,  VAN DOREN GIEL

IPC分类号： H04N5/00 ,  H04N7/173

CPC分类号： H04N21/2326 ,  H04N7/17336

摘要： In a system (100), such as a video-on-demand-server, a reader (180) reads data from a storage medium (110) and stores the read data in buffers (125). The data is supplied from the buffers (125) to users (130) for consumption in the form of a plurality of data streams. The data streams may be fixed rate or variable rate with an identical maximum consumption rate of Rmax data elements per second. The reader (180) is controlled by a scheduler (170). The scheduler (170) divides a predetermined period of tcycle seconds, wherein for each active data stream at least Rmax*tcycle data elements can be read from the storage medium, into n successive time intervals, each of t¿interval? seconds. For each data stream a corresponding buffer (125) is reserved for storing at least Rmax*(n+1)*t¿interval? data elements. The data is read from the storage medium (110) by repeatedly sweeping the storage medium (110) for a group of data streams. Immediately before causing the reader (180) to perform a next sweep, the scheduler (170) determines the composition of the next group of data streams to be supplied with data. At least data streams whose corresponding buffer (125) comprise less than Rmax*2*t¿interval? data elements are assigned to this group.

公开(公告)号：EP0744868A3

公开(公告)日：1997-05-28

申请号：EP96303565.4

申请日：1996-05-20

申请人： SUN MICROSYSTEMS INC.

发明人： Hanko, James ,  Kleiman, Steve

IPC分类号： H04N7/173 ,  G04F3/04

CPC分类号： H04N21/47202 ,  H04N7/17318 ,  H04N21/2326

摘要： In a video server hard disk storage unit, video layout ensures average case bandwidth and case seek time during bounded-time information transfers, to maximize access of users S. The storage unit includes D hard disks whose platters are divided into Z zones. Each movie is divided into i blocks and is striped across all D disks such that movie block i is stored on disk (i mod D). In one embodiment, movie block i is placed in zone (i/D) mod Z of disk (i mod D). User streams are organized into slots containing N=S/D streams and the number of streams in each slot accessing a zone is ≤ (N/Z). Seeking is to the nearest end of a set of accesses, where total seek time for a set of N accesses is ≤ N*seek (1.5/N). Preferably two storage buffers/stream are used. Admission policy permits stream assignment to any slot, but streams do not transfer until the needed data block is on the disk needed by the other streams in the slot, and until the block is in the proper disk zone. A second embodiment optimizes disk seeks by placing movie block i in zone (((i/D) + (i mod D)) mod Z) of disk (i mod D) to reduce buffer unit requirements. The S streams progress in order 0 to S-1 through disks 0 to D-1, all streams accessing each disk from the same zone before moving through the disk in another zone.

公开(公告)号：EP0737929A2

公开(公告)日：1996-10-16

申请号：EP96104052.4

申请日：1996-03-14

申请人： KABUSHIKI KAISHA TOSHIBA

发明人： Yao, Hiroshi ,  Kanai, Tatsunori

IPC分类号： G06F17/30 ,  H04N7/173 ,  G06F3/06

CPC分类号： H04N21/2326 ,  G06F3/0601 ,  G06F2003/0691 ,  H04N7/17318 ,  H04N7/17336

摘要： A stream scheduling system capable of lowering a probability for a response time of a real time stream server to exceed a specified time limit. A reference for transfer timing (reference time-slot) which can guarantee a continuity of a stream for the requested real time stream data is determined, and a transfer timing is determined in a prescribed relation to the reference time-slot while a reading timing is set movably within a prescribed tolerable range defined with respect to the reference time-slot. When a request for a transfer of a new real time stream data is received, a time-slot for a reading of another real time stream data is re-allocated within a prescribed tolerable range defined with respect to the reference time-slot for that another real time stream data so as to create a vacant time-slot, and a reading of that new real time stream data is allocated to the vacant time-slot created by re-allocation.

摘要翻译： 能够降低实时流服务器的响应时间的概率超过指定时间限制的流调度系统。 确定可以保证所请求的实时流数据的流的连续性的传输定时（参考时隙）的参考，并且在读取定时为指定时间时，以规定的关系确定传送定时 在相对于参考时隙定义的规定的可容许范围内可移动地设置。 当接收到对新的实时流数据传送的请求时，用于读取另一实时流数据的时隙在相对于该另一实时流数据的参考时隙定义的规定的可容忍范围内重新分配 实时流数据，以创建空闲时隙，并且将该新的实时流数据的读取分配给通过重新分配创建的空闲时隙。