EP0550197A2
Expired / Lapsed
EP
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Synchronization techniques for multimedia data systems
Assignee: International Business Machines Corp
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Filing: 1992-12-14
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Granted: —
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Expires: 2012-12-14
Abstract
Abstract A personal computer based, multimedia, data processing system includes a software solution to the problem of synchronizing two or more data streams which output data to two or more multimedia output devices. One stream is a master and each other stream is a slave. The master stream generates sync pulses that can be handled in two different synchronization methods, master-slave independent synchronization or master-driven slave synchronization. Sync pulses are generated with a predetermined granularity, and synchronization is achieved when a slave stream is out of tolerance. Adaptive resynchronization may be used to speed up or slow down a slave stream.
Inventors
- 👤 Michael J. Koval
- 👤 William W. Lawton
- 👤 George A. Mcclain
- 👤 John G. Tyler
- 👤 Scott L. Winters
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 19:34
CPC Classifications
G; G06; G06F; G06F8/00; G06F8/40; G06F8/41; G06F8/45; G06F8/458; G06F16/00; G06F16/40
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
201 words
A multimedia data processing system comprising a personal computer having a memory for storing at least one multimedia application program and a multitasking operating system, synchronization apparatus operable under said operating system for synchronizing plural data streams from source devices to target devices, said apparatus comprising: means designating one of said streams a master stream and one of said streams a slave stream; said slave stream including a slave source device, a slave target device, and slave stream handling means for controlling data flow from said slave source device to said slave target device; said master stream including a master source device, a master target device, master stream handling means for controlling data flow from said master source device to said master target device, and means for transmitting timing information from said target device to said master stream handling means; said master stream handling means being operative in response to receiving said timing information to generate sync pulse having a predetermined granularity; and means to transmit said sync pulses from said master stream handling means to said slave handling means, said slave handling means being operative in response to said sync pulses to synchronize said slave stream with said master stream.
Claim 2
Dependent Claim
39 words
A multimedia data processing system in accordance with claim 1 wherein: said transmitting means includes a synchronization manager to receives sync pulses from said target stream handling means and to send sync pulses to said slave stream handling means.
Claim 3
Dependent Claim
46 words
A multimedia data processing system in accordance with claim 2 wherein: each of said stream handling means comprises a source thread for reading data a source device and a target thread for writing data to a target device, said threads being multitasks under said operating system.
Claim 4
Dependent Claim
57 words
A multimedia data processing system in accordance with claim 2 wherein: said slave stream handling means is operative in response to receiving one of said sync pulses to determine if said slave stream is out of sync with said master stream and to speed up or slow down said slave stream if it is out of sync.
Claim 5
Dependent Claim
62 words
A multimedia data processing system in accordance with claim 4 wherein: said each sync pulse includes current time of said master stream measured from when said master stream was started; said slave handler being operative to compare said current time of said master with current time of said slave stream and make adjustments when differences between such times exceeds a predetermined value.
Claim 6
Dependent Claim
68 words
A multimedia data processing system in accordance with claim 5 wherein: said slave stream comprises means for feeding back information from said slave target device to said slave handling means for controlling said slave stream in accordance therewith; said synchronizing manager being operative to transmit a sync pulse to said slave handling means only after receiving a predetermined number of sync pulses from said master stream handling means.
Claim 7
Dependent Claim
31 words
A multimedia data processing system in accordance with claim 5 wherein: said predetermined value is zero whereby said slave stream is driven by said master stream in accordance with sync pulses.
References Cited (Backward Citations)
No citation records indexed.
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