US6493386B1
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Object based bitstream transcoder
Assignee: Mitsubishi Electric Research Laboratories Inc
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Filing: 2000-02-14
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Granted: 2002-12-10
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Expires: 2020-02-14
Abstract
Abstract A compressed bitstream is scaled down to a reduced rate bitstream by first demultiplexing a compressed input bitstream to extract video objects as elementary input bitstreams having a first bit rate. A transcoder converts each elementary input bitstream to an elementary output bitstream having a second bit rate. The first bit rate is less than the second bit rate. A transcoding control unit, coupled to the transcoder, supplies control information for the transcoder. A multiplexer composes the elementary output bitstreams into a compressed output bitstream having the second bit rate.
Inventors
- 👤 Anthony Vetro
- 👤 Huifang Sun
- 👤 Yao Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:13
CPC Classifications
H; H04; H04N; H04N21/00; H04N21/80; H04N21/83; H04N21/84; G; G06; G06T; G06T9/00; G06T9/20; H04L; H04L47/00; H04L47/10; H04L65/00; H04L65/1066; H04L65/1101; H04L65/60; H04L65/75; H04L65/752; H04L65/765; H04L65/80; H04L67/00; H04L67/50; H04L67/56; H04L67/565; H04L69/00; H04L69/04; H04L9/00; H04L9/40; H04N19/00; H04N19/10; H04N19/102; H04N19/124; H04N19/134; H04N19/146; H04N19/147; H04N19/152; H04N19/169; H04N19/17; H04N19/172; H04N19/189; H04N19/19; H04N19/20; H04N19/25; H04N19/29; H04N19/30; H04N19/33; H04N19/40; H04N19/42; H04N19/436; H04N19/60; H04N19/61; H04L67/564; H04L69/30; H04L69/32; H04L69/322; H04L69/329
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
87 words
An apparatus for converting a compressed bitstream, comprising: a demultiplexer to extract each of a plurality of video objects from a compressed input bitstream as an elementary input bitstream having a first bit rate; a transcoder to convert each elementary input bitstream to an elementary output bitstream having a second bit rate; a transcoding control unit, coupled to the transcoder, to generate control information for the transcoder; and a multiplexer configured to compose the elementary output bitstreams into a compressed output bitstream having the second bit rate.
Claim 2
Independent Claim
87 words
An apparatus for converting a compressed bitstream, comprising: a demultiplexer to extract each of a plurality of video objects from a compressed input bitstream as an elementary input bitstream having a first bit rate; a transcoder to convert each elementary input bitstream to an elementary output bitstream having a second bit rate; a transcoding control unit, coupled to the transcoder, to generate control information for the transcoder; and a multiplexer configured to compose the elementary output bitstreams into a compressed output bitstream having the second bit rate.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 wherein the second bit rate is less than the first bit rate.
Claim 4
Dependent Claim
24 words
The apparatus of claim 1 further comprising: an output buffer, coupled to the multiplexer, to generate rate feedback information for the transcoding control unit.
Claim 5
Dependent Claim
15 words
The apparatus of claim 1 wherein the transcoder converts multiple elementary bit streams in parallel.
Claim 6
Dependent Claim
37 words
The apparatus of claim 1 wherein the transcoding control unit further comprises a shape analyzer, a texture analyzer, a temporal analyzer, and a spatial analyzer to generate the control information from object data generated by the transcoder.
Claim 7
Dependent Claim
66 words
The apparatus of claim 5 wherein the texture analyzer uses a texture model R = S · ( X 1 Q + X 2 Q 2 ) where R represents a number of texture bits spent for a particular video object (VO), Q represents a quantization parameter QP, X 1 and X 2 represent the first and second-order model parameters, and S represent a encoding complexity.
Claim 8
Dependent Claim
20 words
The apparatus of claim 6 wherein the texture model is updated by linear regression using results from previous n frames.
Claim 9
Dependent Claim
96 words
The apparatus of claim 6 wherein the encoding complexity S is defined by a discrete cosine transform-based complexity measure {tilde over (S)}: S ~ = 1 M C ∑ m ∈ M ∑ i = 1 63 ρ ( i ) · B m ( i ) 2 where B m (i) are AC coefficients of a block, m is a block index in a set M of coded blocks, M C is the number of blocks in the set M, and ρ(i) is a frequency dependent weighting.
Claim 10
Dependent Claim
19 words
The apparatus of claim 6 wherein the texture model is updated before and after converting a particular video object.
Claim 11
Dependent Claim
39 words
The apparatus of claim 1 wherein a first temporal quality of a first video object at a given instant in time is different than a second temporal quality of a second video object at the given instant in time.
Claim 12
Dependent Claim
39 words
The apparatus of claim 1 wherein a first spatial quality of a first video object at a given instant in time is different than a second spatial quality of a second video object at the given instant in time.
Claim 13
Dependent Claim
16 words
The apparatus of claim 1 wherein each elementary bitstream is converted independent of other elementary bitstreams.
Claim 14
Dependent Claim
40 words
The apparatus of claim 1 wherein the transcoder further comprises: a video object layer/video object plane parser, a shape scaler, a header parser, a motion parser, a texture scaler, a bitstream memory connected to each other by a bitstream bus.
Claim 15
Dependent Claim
22 words
The apparatus of claim 1 wherein the video object layer/video object plane parser determines whether a particular video object includes shape information.
Claim 16
Dependent Claim
26 words
The apparatus of claim 13 wherein the shape scaler further comprises: a shape decoder/parser, a shape down-sampler, and a shape encoder serially connected to each other.
Claim 17
Dependent Claim
17 words
The apparatus of claim 15 wherein shape information of the video objects is converted by the down-sampler.
Claim 18
Dependent Claim
40 words
The apparatus of claim 13 wherein the texture scaler further comprises: a partial texture decoder, a texture down-sampler, a coded bit pattern re-compute unit, a coefficient memory, and a quantizer to generate a variable length code for the bitstream memory.
Claim 19
Dependent Claim
33 words
The apparatus of claim 17 wherein a previous variable bit length code in a header of a particular elementary bitstream is replaced by the variable bit length code generated by the texture scaler.
Claim 20
Dependent Claim
16 words
The apparatus of claim 17 wherein the texture down-sampler operates in a discrete cosine transform domain.
Claim 21
Dependent Claim
30 words
The apparatus of claim 5 wherein the transcoder includes a texture scaler including a quantizer to quantize the video objects according to a quantization parameter generated by the texture analyzer.
Claim 22
Independent Claim
71 words
A method for converting a compressed bitstream, comprising the steps of: extracting each of a plurality of video objects as an elementary input bitstream having a first bit rate from a compressed input bitstream; converting each elementary input bitstream to an elementary output bitstream having a second bit rate; generating control information for the converting; and composing the elementary output bitstreams into a compressed output bitstream having the second bit rate.
Claim 23
Independent Claim
71 words
A method for converting a compressed bitstream, comprising the steps of: extracting each of a plurality of video objects as an elementary input bitstream having a first bit rate from a compressed input bitstream; converting each elementary input bitstream to an elementary output bitstream having a second bit rate; generating control information for the converting; and composing the elementary output bitstreams into a compressed output bitstream having the second bit rate.
Claim 24
Dependent Claim
17 words
The method of claim 21 wherein the second bit rate is less than the first bit rate.
Claim 25
Dependent Claim
17 words
The method of claim 1 further comprising the steps of: generating rate feedback from an output buffer.
Claim 26
Dependent Claim
23 words
The method of claim 1 wherein the control information is generated by analyzing shape, texture, time, and space data of the video objects.
Claim 27
Dependent Claim
66 words
The method of claim 24 wherein the texture analyzing uses a texture model R = S · ( X 1 Q + X 2 Q 2 ) where R represents a number of texture bits spent for a particular video object (VO), Q represents a quantization parameter QP, X 1 and X 2 represent the first and second-order model parameters, and S represents an encoding complexity.
Claim 28
Dependent Claim
20 words
The method of claim 25 wherein the texture model is updated by linear regression using results from previous n frames.
Claim 29
Dependent Claim
96 words
The method of claim 25 wherein the encoding complexity S is defined by a discrete cosine transform-based complexity measure {tilde over (S)}: S ~ = 1 M C ∑ m ∈ M ∑ i = 1 63 ρ ( i ) · B m ( i ) 2 where B m (i) are AC coefficients of a block, m is a block index in a set M of coded blocks, M C is the number of blocks in the set M, and ρ(i) is a frequency dependent weighting.
Claim 30
Dependent Claim
19 words
The method of claim 25 wherein the texture model is updated before and after converting a particular video object.
Claim 31
Dependent Claim
39 words
The method of claim 21 wherein a first temporal quality of a first video object at a given instant in time is different than a second temporal quality of a second video object at the given instant in time.
Claim 32
Dependent Claim
39 words
The method of claim 21 wherein a first spatial quality of a first video object at a given instant in time is different than a second spatial quality of a second video object at the given instant in time.
Claim 33
Dependent Claim
13 words
The method of claim 21 wherein multiple elementary bitstreams are converted in parallel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-12-09 | 2006-06-10 | 2006-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-12-09 | 2010-06-10 | 2010-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-12-09 | 2014-06-10 | 2014-12-10 | $7700.00 | Window Closed / Lapsed |