US5588029A
Expired / Lapsed
US
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MPEG audio synchronization system using subframe skip and repeat
Assignee: Avago Technologies International Sales Pte Ltd
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Filing: 1995-01-20
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Granted: 1996-12-24
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Expires: 2015-01-20
Abstract
Abstract A Motion Picture Experts Group (MPEG) video/audio data bitstream comprises frames of encoded audio data, each of which includes a plurality of integrally encoded subframes, which are decoded by an audio decoder for presentation. A synchronization unit controls the decoder to skip a subframe if a predetermined decoding time for the subframe is earlier than a current time, and to repeat the subframe if the predetermined decoding time is later than the current time. A typical MPEG audio frame includes 12 subframes, such that skipping or repeating a subframe is 1/12 as noticeable as skipping or repeating an entire frame. A buffer memory stores one or more subframes prior to decoding, such that the subframes can be skipped or repeated by manipulation of a read pointer for the memory.
Inventors
- 👤 Greg Maturi
- 👤 Gregg Dierke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:54
CPC Classifications
H; H04; H04N; H04N21/00; H04N21/40; H04N21/43; H04N21/434; H04N21/4341; H04N21/4302; H04N21/4305; H04N21/4307; H04N21/43072
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
73 words
A decoding system for decoding a data stream including frames of encoded data, each frame including a plurality of subframes of integrally encoded data, comprising: decoding means for decoding said subframes; and synchronization means for controlling the decoding means to skip a subframe if a predetermined decoding time for said subframe is earlier than a current time; and to repeat said subframe if said predetermined decoding time is later than said current time.
Claim 2
Dependent Claim
73 words
A decoding system for decoding a data stream including frames of encoded data, each frame including a plurality of subframes of integrally encoded data, comprising: decoding means for decoding said subframes; and synchronization means for controlling the decoding means to skip a subframe if a predetermined decoding time for said subframe is earlier than a current time; and to repeat said subframe if said predetermined decoding time is later than said current time.
Claim 3
Dependent Claim
36 words
A system as in claim 1, in which the synchronization means controls the decoding means to repeat said subframe by causing the decoding means to pause for a length of time required to decode said subframe.
Claim 4
Dependent Claim
50 words
A system as in claim 1, in which the synchronization means controls the decoding means to skip said subframe by preventing said subframe from being input to the decoding means, and causing a subframe following said subframe to be input to the decoding means at substantially said predetermined decoding time.
Claim 5
Dependent Claim
49 words
A system as in claim 1, in which: said data stream further includes a time stamp for indicating said predetermined decoding time; the system further comprises clock means for maintaining said current time; and the synchronization means comprises comparator means for comparing said time stamp with said current time.
Claim 6
Dependent Claim
24 words
A system as in claim 1, in which said subframes are the smallest units of said integrally encoded data that can be decoded independently.
Claim 7
Dependent Claim
87 words
A decoding system for decoding a data stream including frames of encoded data, each frame including a plurality of subframes of integrally encoded data, comprising: decoding means for decoding said subframes; memory means for storing said subframes prior to decoding thereof by the decoding means; and synchronization means for controlling the decoding means to skip a subframe if a predetermined decoding time for said subframe is earlier than a current time; and to repeat said subframe if said predetermined decoding time is later than said current time.
Claim 8
Dependent Claim
87 words
A decoding system for decoding a data stream including frames of encoded data, each frame including a plurality of subframes of integrally encoded data, comprising: decoding means for decoding said subframes; memory means for storing said subframes prior to decoding thereof by the decoding means; and synchronization means for controlling the decoding means to skip a subframe if a predetermined decoding time for said subframe is earlier than a current time; and to repeat said subframe if said predetermined decoding time is later than said current time.
Claim 9
Dependent Claim
35 words
A system as in claim 6, in which the synchronization means controls the decoding means to repeat said subframe by causing the decoding means to read and decode said subframe from the memory means twice.
Claim 10
Dependent Claim
54 words
A system as in claim 6, in which the synchronization means controls the decoding means to skip said subframe by preventing the decoding means from reading said subframe from the memory means, and causing the decoding means to read a subframe following said subframe from the memory means at substantially said predetermined decoding time.
Claim 11
Dependent Claim
34 words
A system as in claim 6, in which: the memory means has a read pointer; and the synchronization means controls the decoding means to repeat said subframe by inhibiting incrementation of said read pointer.
Claim 12
Dependent Claim
33 words
A system as in claim 6, in which: the memory means has a read pointer; and the synchronization means controls the decoding means to skip said subframe by incrementating said read pointer twice.
Claim 13
Dependent Claim
20 words
A system as in claim 6, in which said memory means has a capacity for storing one of said subframes.
Claim 14
Independent Claim
81 words
A method of synchronizing a decoder for decoding a data stream including frames of encoded data, each frame including a plurality of subframes of integrally encoded data, comprising the steps of: (a) determining a decoding time for a subframe; (b) sensing a current time; (c) controlling the decoder to skip said subframe if said decoding time is earlier than said current time; and (d) controlling the decoder to repeat said subframe if said decoding time is later than said current time.
Claim 15
Independent Claim
81 words
A method of synchronizing a decoder for decoding a data stream including frames of encoded data, each frame including a plurality of subframes of integrally encoded data, comprising the steps of: (a) determining a decoding time for a subframe; (b) sensing a current time; (c) controlling the decoder to skip said subframe if said decoding time is earlier than said current time; and (d) controlling the decoder to repeat said subframe if said decoding time is later than said current time.
Claim 16
Dependent Claim
26 words
A method as in claim 12, in which step (d) comprises causing the decoder to pause for a length of time required to decode said subframe.
Claim 17
Dependent Claim
38 words
A method as in claim 12, in which step (c) comprises preventing said subframe from being input to the decoder, and causing a subframe following said subframe to be input to the decoder at substantially said decoding time.
Claim 18
Dependent Claim
35 words
A method as in claim 12, in which: said data stream further includes a time stamp for indicating said decoding time; steps (c) and (d) each comprise comparing said time stamp with said current time.
Claim 19
Dependent Claim
24 words
A method as in claim 12, in which said subframes are the smallest units of said integrally encoded data that can be decoded independently.
Claim 20
Dependent Claim
25 words
A method as in claim 12, further comprising the step, performed prior to steps (c) and (d), of: (e) storing said subframes in a memory.
Claim 21
Dependent Claim
24 words
A method as in claim 17, in which step (d) comprises causing the decoder to read and decode said subframe from the memory twice.
Claim 22
Dependent Claim
40 words
A method as in claim 17, in which step (c) comprises preventing the decoder from reading said subframe from the memory, and causing the decoder to read a subframe following said subframe from the memory at substantially said decoding time.
Claim 23
Dependent Claim
24 words
A method as in claim 17, in which: the memory has a read pointer; and step (d) comprises inhibiting incrementation of said read pointer.
Claim 24
Dependent Claim
23 words
A method as in claim 17, in which: the memory has a read pointer; and step (c) comprises incrementating said read pointer twice.
Claim 25
Dependent Claim
29 words
A method as in claim 17, further comprising the step, performed prior to step (a), of: providing the memory as having a capacity for storing one of said subframes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-12-24 | 2000-06-24 | 2000-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-24 | 2004-06-24 | 2004-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-24 | 2008-06-24 | 2008-12-24 | $7700.00 | Window Closed / Lapsed |