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US5134476A Expired / Lapsed US ⏱️ 0.0 years remaining

Video signal encoding with bit rate control

Assignee: Nokia Bell Labs
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Filing: 1990-03-30
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Granted: 1992-07-28
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Expires: 2010-03-30
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Abstract

Abstract Individual frames in a video signal are encoded using different coding techniques such as intraframe, motion compensated prediction and motion compensated interpolation coding. The encoder output, which is produced at a first highly variable rate, is applied to a channel via a buffer that outputs the encoded signal at a second, less variable rate. The rate allocated to different frame types is determined as a function of the type of frame being encoded and the coding technique being used. A second buffer may be used to eliminate almost all variations in the rate at which data is applied to the channel. Buffer fullness may control characteristics of the encoder such as quantizer step size and/or prefiltering.

Inventors

  • 👤 Rangarajan Aravind
  • 👤 Barin G. Haskell
  • 👤 Atul Puri

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 22:34
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/80; H04N19/10; H04N19/102; H04N19/124; H04N19/134; H04N19/146; H04N19/152; H04N19/157; H04N19/159; H04N19/169; H04N19/17; H04N19/172; H04N19/174; H04N19/176; H04N19/189; H04N19/192; H04N19/50; H04N19/60; H04N19/61

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 208 words
Apparatus for encoding frames in a continuous motion video signal for application to a channel having the capacity to carry information at a predetermined average bit rate, comprising: means for generating a frame type signal classifying each of said frames in accordance with an expected number of bits required to represent the information contained in each of said frames when said frames are encoded using particular coding strategies, said frame type signal being independent of the pictorial content of said frames; means jointly responsive to said video signal and said frame type signal for generating an encoded signal representing said information in each of said frames; buffering means arranged to receive said encoded signal output from said encoding means at a first bit rate and for reading out said encoded signal at a second bit rate; and means for reading out from said buffering means at a controlled rate the portion of said encoded signal representing each frame in such a way that said channel average bit rate is not exceeded, said controlled rate being a function of the expected number of bits required to represent the information in said frame relative to the expected number of bits required to represent information in other ones of said frames.
Claim 2
Dependent Claim 208 words
Apparatus for encoding frames in a continuous motion video signal for application to a channel having the capacity to carry information at a predetermined average bit rate, comprising: means for generating a frame type signal classifying each of said frames in accordance with an expected number of bits required to represent the information contained in each of said frames when said frames are encoded using particular coding strategies, said frame type signal being independent of the pictorial content of said frames; means jointly responsive to said video signal and said frame type signal for generating an encoded signal representing said information in each of said frames; buffering means arranged to receive said encoded signal output from said encoding means at a first bit rate and for reading out said encoded signal at a second bit rate; and means for reading out from said buffering means at a controlled rate the portion of said encoded signal representing each frame in such a way that said channel average bit rate is not exceeded, said controlled rate being a function of the expected number of bits required to represent the information in said frame relative to the expected number of bits required to represent information in other ones of said frames.
Claim 3
Dependent Claim 34 words
The invention defined in claim 1 wherein said last mentioned means includes a look-up table for associating values of said frame type signal with nominal rates for reading out information from said buffering means.
Claim 4
Dependent Claim 161 words
Apparatus for encoding pictorial information contained in a series of frames of a continuous motion video signal prior to application to a channel having the capacity to carry information at a predetermined average bit rate, comprising: means for classifying each of said frames independent of the pictorial content of said frames; means responsive to said classifying means for determining the bit rate required to encode information contained in said frames; variable rate coding means for generating an encoded signal containing bits representing said information in each of said frames, said encoded signal having a first bit rate; and first buffering means responsive to said encoded signal output from said encoding means for reading out bits in said encoded signal at a second bit rate that is a function of an output from said classifying means indicative of the bit rate required to encode information in the presently processed frame relative to the bit rate required to encode information in other frames.
Claim 5
Dependent Claim 161 words
Apparatus for encoding pictorial information contained in a series of frames of a continuous motion video signal prior to application to a channel having the capacity to carry information at a predetermined average bit rate, comprising: means for classifying each of said frames independent of the pictorial content of said frames; means responsive to said classifying means for determining the bit rate required to encode information contained in said frames; variable rate coding means for generating an encoded signal containing bits representing said information in each of said frames, said encoded signal having a first bit rate; and first buffering means responsive to said encoded signal output from said encoding means for reading out bits in said encoded signal at a second bit rate that is a function of an output from said classifying means indicative of the bit rate required to encode information in the presently processed frame relative to the bit rate required to encode information in other frames.
Claim 6
Dependent Claim 34 words
The invention defined in claim 3 wherein said apparatus further includes second buffering means arranged to receive bits output from said first buffering means and to read out said bits at a constant rate.
Claim 7
Dependent Claim 119 words
Apparatus for encoding pictorial information contained in a series of frames, comprising: means for generating a frame type signal, said frame type signal classifying a priori each of said frames in accordance with the bit rate required to encode information contained in said frames; variable rate coding means for generating an encoded signal representing said information in each of said frames, said encoded signal having a highly variable bit rate; and buffering means for reducing the variability of said encoded signal in response to the relationship between the expected number of bits required to represent the information in each of said frames relative to the expected number of bits required to represent information in other ones of said frames.
Claim 8
Dependent Claim 119 words
Apparatus for encoding pictorial information contained in a series of frames, comprising: means for generating a frame type signal, said frame type signal classifying a priori each of said frames in accordance with the bit rate required to encode information contained in said frames; variable rate coding means for generating an encoded signal representing said information in each of said frames, said encoded signal having a highly variable bit rate; and buffering means for reducing the variability of said encoded signal in response to the relationship between the expected number of bits required to represent the information in each of said frames relative to the expected number of bits required to represent information in other ones of said frames.
Claim 9
Dependent Claim 35 words
The invention defined in claim 5 wherein said buffering means includes a first buffer arranged to read out bits in each of said frames at a rate determined in accordance with said frame type signal.
Claim 10
Independent Claim 189 words
A method of encoding frames in a continuous motion video signal for application to a channel having the capacity to carry information at a predetermined average bit rate, comprising the steps of generating a frame type signal classifying each of said frames in accordance with an expected number of bits required to represent the information contained in each of said frames when said frames are encoded using particular coding strategies, said frame type signal being independent of the pictorial content of said frames; generating an encoded signal representing said information in each of said frames jointly in response to said video signal and said frame type signal; applying said encoded signal output from said encoding means to a buffer; and reading out from said buffering means at a controlled rate the portion of said encoded signal representing each frame in such a way that said channel average bit rate is not exceeded, said controlled rate being a function of the expected number of bits required to represent the information in said frame relative to the expected number of bits required to represent information in other ones of said frames.
Claim 11
Independent Claim 189 words
A method of encoding frames in a continuous motion video signal for application to a channel having the capacity to carry information at a predetermined average bit rate, comprising the steps of generating a frame type signal classifying each of said frames in accordance with an expected number of bits required to represent the information contained in each of said frames when said frames are encoded using particular coding strategies, said frame type signal being independent of the pictorial content of said frames; generating an encoded signal representing said information in each of said frames jointly in response to said video signal and said frame type signal; applying said encoded signal output from said encoding means to a buffer; and reading out from said buffering means at a controlled rate the portion of said encoded signal representing each frame in such a way that said channel average bit rate is not exceeded, said controlled rate being a function of the expected number of bits required to represent the information in said frame relative to the expected number of bits required to represent information in other ones of said frames.
Claim 12
Dependent Claim 36 words
The method defined in claim 7 wherein said last mentioned step includes the step of associating in a look-up table, values of said frame type signal with nominal rates for reading out information from said buffer.
Claim 13
Independent Claim 143 words
A method of encoding pictorial information contained in a series of frames of a continuous motion video signal prior to application to a channel having the capacity to carry information at a predetermined average bit rate, comprising the steps of classifying each of said frames independent of the pictorial content of said frames; determining, in response to said classification, the bit rate required to encode information contained in said frames; generating an encoded signal containing bits representing said information in each of said frames; inputting said encoded signal in a buffer at a first bit rate; and outputting said encoded signal from said buffer at a second rate determined as a function of said classifying step and indicative of the bit rate required to encode information in the presently processed frame relative to the bit rate required to encode information in other frames..
Claim 14
Independent Claim 143 words
A method of encoding pictorial information contained in a series of frames of a continuous motion video signal prior to application to a channel having the capacity to carry information at a predetermined average bit rate, comprising the steps of classifying each of said frames independent of the pictorial content of said frames; determining, in response to said classification, the bit rate required to encode information contained in said frames; generating an encoded signal containing bits representing said information in each of said frames; inputting said encoded signal in a buffer at a first bit rate; and outputting said encoded signal from said buffer at a second rate determined as a function of said classifying step and indicative of the bit rate required to encode information in the presently processed frame relative to the bit rate required to encode information in other frames..
Claim 15
Independent Claim 114 words
A method of encoding pictorial information contained in a series of frames, comprising the steps of generating a frame type signal, said frame type signal classifying a priori each of said frames in accordance with the bit rate required to encode information contained in said frames; generating an encoded signal representing said information in each of said frames, said encoded signal having a highly variable bit rate; and buffering said encoded signal to alter said bit rate in response to the relationship between the expected number of bits required to represent the information in each of said frames and the expected number of bits required to represent information in other ones of said frames.
Claim 16
Independent Claim 114 words
A method of encoding pictorial information contained in a series of frames, comprising the steps of generating a frame type signal, said frame type signal classifying a priori each of said frames in accordance with the bit rate required to encode information contained in said frames; generating an encoded signal representing said information in each of said frames, said encoded signal having a highly variable bit rate; and buffering said encoded signal to alter said bit rate in response to the relationship between the expected number of bits required to represent the information in each of said frames and the expected number of bits required to represent information in other ones of said frames.
Claim 17
Dependent Claim 30 words
The method defined in claim 10 wherein said buffering step includes reading out bits in each of said frames at a rate determined in accordance with said frame type signal.

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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) 1995-07-28 1996-01-27 1996-07-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-07-28 2000-01-27 2000-07-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-07-28 2004-01-27 2004-07-28 $7700.00 Window Closed / Lapsed

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