US6298071B1
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US
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Method and apparatus for processing variable bit rate information in an information distribution system
Assignee: Comcast IP Holdings I LLC
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Filing: 1998-09-03
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Granted: 2001-10-02
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Expires: 2018-09-03
Abstract
Abstract A method and apparatus for managing both link and disk bandwidth utilization within the context of a multiple subscriber or user information distribution system by selectively providing variable bitrate and constant low bitrate information streams to one or more subscribers.
Inventors
- 👤 Clement G. Taylor
- 👤 Jesse S. Lerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:52
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/10; H04N21/00; H04N21/20; H04N21/21; H04N21/23
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
185 words
In an information distribution system comprising an information server providing information to a communications link, a method for managing link bandwidth comprising the steps of: determining a link bandwidth utilization level; providing, via said communications link and in response to said link bandwidth utilization indicating that an overutilization condition does not exist, a first variable bitrate information stream to at least one of said plurality of subscribers, said first variable bitrate information stream having associated with it a bitrate that may vary between a nominal first lower bitrate and a nominal first upper bitrate; and providing, via said communications link and in response to said link bandwidth utilization indicating that an overutilization condition does exist, a second variable bitrate information stream to said at least one of said plurality of subscribers, said second variable bitrate information stream having associated with it a bitrate that may vary between a nominal second lower bitrate and a nominal second upper bitrate, said nominal second lower bitrate being less than said nominal first upper bitrate and said nominal second upper bitrate being less than said nominal first upper bitrate.
Claim 2
Dependent Claim
185 words
In an information distribution system comprising an information server providing information to a communications link, a method for managing link bandwidth comprising the steps of: determining a link bandwidth utilization level; providing, via said communications link and in response to said link bandwidth utilization indicating that an overutilization condition does not exist, a first variable bitrate information stream to at least one of said plurality of subscribers, said first variable bitrate information stream having associated with it a bitrate that may vary between a nominal first lower bitrate and a nominal first upper bitrate; and providing, via said communications link and in response to said link bandwidth utilization indicating that an overutilization condition does exist, a second variable bitrate information stream to said at least one of said plurality of subscribers, said second variable bitrate information stream having associated with it a bitrate that may vary between a nominal second lower bitrate and a nominal second upper bitrate, said nominal second lower bitrate being less than said nominal first upper bitrate and said nominal second upper bitrate being less than said nominal first upper bitrate.
Claim 3
Dependent Claim
43 words
The method of claim 1 , wherein: said link bandwidth utilization comprises one of a communications link bandwidth utilization indicium and a storage device access bandwidth utilization indicium, said storage device being used to store said first and second variable bitrate information streams.
Claim 4
Dependent Claim
156 words
In an information distribution system, apparatus comprising: a storage unit, for storing a plurality of programs, each of said programs being represented by a variable bit rate (VBR) encoded stream and a corresponding substantially constant low bit rate (CLBR) encoded stream; a server, for retrieving at least one of said programs from said storage unit to form a multiplexed information stream; and a communications link having a finite bandwidth, for transporting said multiplexed information stream; wherein said server preferentially multiplexing, for each retrieved program, said VBR encoded stream representing said retrieved program; said server, in response to a condition of insufficient communication link bandwidth, multiplexing, for at least one retrieved program, at least a portion of said CLBR encoded stream representing said at least one retrieved program; wherein said VBR encoded stream and said CLRB encoded stream comprise, respectively, a quality constrained encoded stream representing said program and a bitrate constrained encoded stream representing said program.
Claim 5
Dependent Claim
156 words
In an information distribution system, apparatus comprising: a storage unit, for storing a plurality of programs, each of said programs being represented by a variable bit rate (VBR) encoded stream and a corresponding substantially constant low bit rate (CLBR) encoded stream; a server, for retrieving at least one of said programs from said storage unit to form a multiplexed information stream; and a communications link having a finite bandwidth, for transporting said multiplexed information stream; wherein said server preferentially multiplexing, for each retrieved program, said VBR encoded stream representing said retrieved program; said server, in response to a condition of insufficient communication link bandwidth, multiplexing, for at least one retrieved program, at least a portion of said CLBR encoded stream representing said at least one retrieved program; wherein said VBR encoded stream and said CLRB encoded stream comprise, respectively, a quality constrained encoded stream representing said program and a bitrate constrained encoded stream representing said program.
Claim 6
Dependent Claim
49 words
The apparatus of claim 3 , wherein for each program the representative VBR encoded stream and CLRB encoded stream is divided into a corresponding plurality of temporal extents, said temporal extents defining respective stream access points suitable for transitioning between said respective VBR encoded stream and CLRB encoded stream.
Claim 7
Dependent Claim
36 words
The apparatus of claim 4 , wherein said programs comprise at least video information, and said corresponding plurality of temporal extents are defined by one of a group of pictures (GOP) boundary and a frame boundary.
Claim 8
Dependent Claim
38 words
The apparatus of claim 3 , wherein said VBR encoded stream is generated by encoding said respective program, and said CLBR encoded stream is generated by either encoding said respective program or transcoding said respective VBR encoded stream.
Claim 9
Dependent Claim
40 words
The apparatus of claim 3 , further comprising: a disk scheduler, for modeling demand for disk bandwidth, estimating when said demand will exceed available disk bandwidth and providing to said server indicium of said condition of insufficient storage unit bandwidth.
Claim 10
Dependent Claim
66 words
The method of claim 2 , wherein: said first and second variable bitrate information streams comprise, respectively, a quality constrained encoded stream representing a program and a bitrate constrained encoded stream representing said program, wherein the difference between said nominal first upper bitrate and said nominal first lower bitrate is greater than the difference between said nominal second upper bitrate and said nominal second lower bitrate.
Claim 11
Dependent Claim
53 words
The method of claim 8 , wherein each of said first and second variable bitrate information streams is divided into a corresponding plurality of temporal extents, said temporal extents defining respective stream access points suitable for transitioning between a provided first variable bitrate information stream and a provided second variable bitrate information stream.
Claim 12
Dependent Claim
40 words
The method of claim 9 , wherein said first and second variable bitrate information streams comprise video streams, and said corresponding plurality of temporal extents are defined by one of a group of pictures (GOP) boundary and a frame boundary.
Claim 13
Dependent Claim
47 words
The method of claim 1 , wherein said first variable bitrate information stream comprises a variable bit rate (VBR) encoded stream representative of a program, and said second variable bitrate information stream comprises a corresponding substantially constant low bit rate (CLBR) encoded stream representative of said program.
Claim 14
Dependent Claim
23 words
The method of claim 11 , wherein said second variable bitrate information stream is generated by transcoding said first variable bitrate information stream.
Claim 15
Dependent Claim
171 words
In an information distribution system comprising a storage unit, for storing a plurality of programs, each of said programs being represented by a variable bit rate (VBR) encoded stream and a corresponding substantially constant low bit rate (CLBR) encoded stream, said VBR and CLBR streams being divided into respective pluralities of time extents, a server, for retrieving at least one of said programs from said storage to form a multiplexed information stream, and a communications link having a finite bandwidth, for transporting said multiplexed information stream, a method for managing bandwidth comprising the steps of: preferentially multiplexing, for each retrieved program, said VBR encoded time extents representing said retrieved program; and multiplexing for at least one retrieved program, in response to a condition of insufficient communication link bandwidth, at least a portion of said CLBR encoded time extents representing said at least one retrieved program; wherein said condition of insufficient communication link bandwidth is determined by calculating a bandwidth requirement of a plurality of information stream time extents to be multiplexed.
Claim 16
Dependent Claim
171 words
In an information distribution system comprising a storage unit, for storing a plurality of programs, each of said programs being represented by a variable bit rate (VBR) encoded stream and a corresponding substantially constant low bit rate (CLBR) encoded stream, said VBR and CLBR streams being divided into respective pluralities of time extents, a server, for retrieving at least one of said programs from said storage to form a multiplexed information stream, and a communications link having a finite bandwidth, for transporting said multiplexed information stream, a method for managing bandwidth comprising the steps of: preferentially multiplexing, for each retrieved program, said VBR encoded time extents representing said retrieved program; and multiplexing for at least one retrieved program, in response to a condition of insufficient communication link bandwidth, at least a portion of said CLBR encoded time extents representing said at least one retrieved program; wherein said condition of insufficient communication link bandwidth is determined by calculating a bandwidth requirement of a plurality of information stream time extents to be multiplexed.
Claim 17
Dependent Claim
52 words
The method of claim 13 , further comprising the step of: replacing a multiplexed CLBR encoded stream with a corresponding VBR encoded stream in response to a determination that said multiplexed CLBR encoded stream may be replaced by said corresponding VBR encoded stream without creating a condition of insufficient communication link bandwidth.
Claim 18
Dependent Claim
47 words
The method of claim 14 , further comprising the step of: retrieving a VBR encoded stream from said storage unit in response to a determination that said VBR encoded stream may be additionally retrieved from said storage unit without creating said condition of insufficient storage unit bandwidth.
Claim 19
Dependent Claim
65 words
The apparatus of claim 3 , wherein: said server, for each retrieved program, preferentially retrieving from said storage unit each of said VBR encoded stream and said CLBR encoded stream representing said retrieved program; said server, in response to a condition of insufficient storage unit bandwidth, retrieving, for at least one retrieved program, only said CLBR encoded stream representing said at least one retrieved program.
Claim 20
Dependent Claim
36 words
The apparatus of claim 3 , wherein: said condition of insufficient communication link bandwidth is determined by calculating a bandwidth requirement of a plurality of information stream time extents prior multiplexing said information stream time extents.
Claim 21
Dependent Claim
50 words
The apparatus of claim 17 , wherein: said server, in response to a determination that a multiplexed CLBR encoded stream may be replaced by a corresponding VBR encoded stream without creating a condition of insufficient communication link bandwidth, replacing said multiplexed CLBR encoded stream with said corresponding VBR encoded stream.
Claim 22
Dependent Claim
34 words
The apparatus of claim 16 , wherein: said condition of insufficient storage unit bandwidth is determined by calculating a bandwidth requirement of a plurality of information stream time extents prior to retrieving said programs.
Claim 23
Dependent Claim
45 words
The apparatus of claim 16 , wherein: said server, in response to a determination that a VBR encoded stream may be additionally retrieved from said storage unit without creating said condition of insufficient storage unit bandwidth, retrieving said VBR encoded stream from said storage unit.
Claim 24
Dependent Claim
44 words
The apparatus of claim 3 , wherein: said server, in response to a condition of sufficient storage unit bandwidth, determining if a relatively high bitrate information stream may be additionally retrieved from said storage unit without creating said condition of insufficient storage unit bandwidth.
Claim 25
Dependent Claim
44 words
The apparatus of claim 16 , wherein: said server, in response to a condition of sufficient storage unit bandwidth, determining if a relatively high bitrate information stream may be additionally retrieved from said storage unit without creating said condition of insufficient storage unit bandwidth.
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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) | 2004-10-01 | 2005-04-02 | 2005-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-10-01 | 2009-04-02 | 2009-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-10-01 | 2013-04-02 | 2013-10-02 | $7700.00 | Window Closed / Lapsed |