Apparatus and method for providing multimedia data

• US 5,630,104 A
• Filed: 05/18/1995
• Issued: 05/13/1997
• Est. Priority Date: 01/21/1994
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ottesen, Hal H., Smith, Gordon J., Van Leeuwen, George W.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US08/444,116
• Time in Patent Office: 726 Days
• Field of Search: 370/94.2, 364/514, 364/514 A, 395/200, 395/650, 395/154, 395/500, 348/7
• US Class Current: 703/24
• CPC Class Codes: G11B 19/20 Driving; Starting; Stopping; Control thereof
• CPC Class Codes: G11B 19/2009 Turntables, hubs and motors for disk drives; Mounting of motors in the drive means for clamping of disk to turntable G11B17/022 and subgroups
• CPC Class Codes: G11B 19/247 using electrical means
• CPC Class Codes: G11B 20/12 Formatting, e.g. arrangement of data block or words on the record carriers within interface between computers and data recorders G06F3/06
• CPC Class Codes: G11B 20/1258 where blocks are arranged within multiple radial zones, e.g. Zone Bit Recording or Constant Density Recording discs, MCAV discs, MCLV discs
• CPC Class Codes: G11B 2020/10916 Seeking data on the record carrier for preparing an access to a specific address
• CPC Class Codes: G11B 21/00 Head arrangements not specific to the method of recording or reproducing
• CPC Class Codes: G11B 21/02 Driving or moving of heads
• CPC Class Codes: G11B 21/04 Automatic feed mechanism producing a progressive transducing traverse of the head in a direction which cuts across the direction of travel of the recording medium, e.g. helical scan , e.g. by lead-screw G11B19/20, G11B21/08 and G11B21/10 take precedence
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 2220/41 Flat as opposed to hierarchical combination, e.g. library of tapes or discs, CD changer, or groups of record carriers that together store one title
• CPC Class Codes: G11B 2220/415 Redundant array of inexpensive disks [RAID] systems
• CPC Class Codes: G11B 27/002 Programmed access in sequence to a plurality of record carriers or indexed parts, e.g. tracks, thereof, e.g. for editing; transfer of record carriers from magazine G11B15/68, G11B17/10; G11B17/22
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/5521 across disk tracks spiral track following G11B5/596
• CPC Class Codes: G11B 5/5526 Control therefor; circuits, track configurations or relative disposition of servo-information transducers and servo-information tracks for control thereof G11B5/556 takes precedence
• CPC Class Codes: G11B 5/5965 Embedded servo format G11B5/59655 takes precedence
• CPC Class Codes: G11B 7/0037 with discs
• CPC Class Codes: H04N 7/17336 Handling of requests in head-ends

Abstract

A disk drive stores multimedia data in long spiral data tracks. The tracks on opposite surfaces of the disk spiral in opposite directions, so that a track on one surface can be read as the actuator sweeps in, and a track on the opposite surface can be read as the actuator sweeps out. Because the actuator only follows spiral tracks without performing long seek operations, the actuator motor can be reduced in size and stresses on actuator bearings and other parts are reduced. Additionally, due to reduced disturbances associated with seeks, it is possible to follow tracks more closely and therefore reduce the width of individual tracks. Further cost reductions are accomplished by spinning the disks at a slower speed and reducing the size of the spin motor accordingly. Finally, data density can be increased simply because multimedia data does not require the same low error rate as conventional data. Preferably, a group of disk drives optimized for multimedia data is used to form a video-on-demand system. Compressed, interleaved portions of a video presentation, such as a motion picture, are stored in blocks on the spiral tracks. The drives read the blocks on one spiral track at a time from beginning to end, placing the data from these blocks in a set of buffers corresponding to different short time intervals. Video signals are output from the buffers. Any short time interval of the presentation can be accessed on demand by switching to the appropriate buffer.

Claims

1. A method for providing multimedia presentation data, said multimedia presentation being divisible into a plurality of portions corresponding to successive time intervals, each said portion being for presentation during the respective time interval to which it corresponds, said method comprising the steps of:

reading a plurality of multimedia data segments from at least one mass storage device, each of said multimedia data segments containing multimedia data from a respective one of said portions,

wherein a plurality of multimedia data segments contain data from each said portion, and wherein successive data segments read during said step of reading a plurality of multimedia data segments contain data from different ones of said plurality of portions, the data segments containing data from a particular one of said plurality of portions being interleaved among data segments containing data from other portions;

selectively transferring each of said multimedia data segments to a selected one of a plurality of buffers, wherein each of said plurality of buffers corresponds to a respective one of said time intervals, and said step of selectively transferring each of said data segments transfers each data segment containing data from a respective portion to the buffer corresponding to the time interval to which the respective portion corresponds; and

simultaneously providing a different portion of said multimedia presentation at a respective output from each of said plurality of buffers.

2. The method of claim 1, wherein said at least one mass storage device is a rotating disk drive storage device, and said step of reading a plurality of multimedia data segments from at least one mass storage device comprises reading a plurality of data segments from at least one spiral data track on a recording surface of said rotating disk drive storage device.

3. The method of claim 2, wherein each said rotating disk drive storage device stores a plurality of data segments containing data from a repetitive sequence of at least some of said plurality of portions.

4. The method of claim 1, wherein said reading step reads said multimedia data segments from a plurality of mass storage devices.

5. The method of claim 4, wherein said multimedia data is redundantly recorded on said plurality of mass storage devices, and wherein said method further comprises the steps of:

detecting an error condition in reading data from a first of said plurality of mass storage devices; and

obtaining redundant data from at least one of said plurality of mass storage devices other than said first mass storage device.

6. The method of claim 1, wherein each said data segment is a fraction of a video frame.

7. The method of claim 1, wherein said reading step comprises reading multimedia data segments from each of said at least one mass storage device continually at a substantially constant rate.