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US 6,665,646 B1Granted
Predictive balanced multiple description coder for data compression
AssigneeAT&T Corp.
InventorsSam John, Vinay A. Vaishampayan
Life of this patent
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Abstract
A balanced multiple descriptive coder codes data in streams so that an acceptable replica of source data can be generated if either stream is lost. The balanced multiple descriptive coder may include a pair of coding branches, each branch including a coding chain and a prediction chain.
Claims34
A balanced multiple descriptive coder, comprising:
- a plurality of coding branches, each coding branch coupled to a common data sources each branch comprising:
- 1) an encoding circuit comprising:
- a) a quantizer, and
- b) a mapping unit coupled to the quantizer and responsive to a data value from the common data source, the mapping unit generating a respective one of a plurality of index values representative of the data value with reference to an index assignment scheme having uniform spread;
- 2) a prediction circuit coupled to an output of the encoding circuit, and
- 3) a subtractor having an input for source data and a second input coupled to the prediction circuit, an output of the subtractor being input to the encoding circuit.
3 more elements
A method of coding a source data signal comprising in each of a pair of coding branches:
- generating a respective differential signal representing a difference between the source data signal and a respective predicted source signal,
- quantizing the respective differential source signal,
- generating a respective bin index signal accordingly to a mutually refinable index assignment scheme,
- predicting the respective source signal from the respective bin index signals, and
- outputting each bin index signal to respective channels.
2 more elements
A balanced multiple descriptive coder, comprising:
- a plurality of coding branches, each coding branch comprising:
- 1) an encoding circuit, comprising:
- a) a source transform,
- b) a quantizer coupled to the source transform, and
- c) a mapping unit coupled toe quantizer and operating in accordance with an index assignment scheme having uniform spread;
- 2) a prediction circuit, comprising:
- a) an inverse mapping unit,
- b) a scalar coupled to the inverse mapping unit,
- c) an adder having inputs coupled to an input of the encoding circuit and to the scalar,
- d) a predictor coupled to the scalar, and
- e) an inverse source transform coupled to the predictor and
- 3) a subtractor having an input for source data and a second input coupled to the prediction circuit, an output of the subtractor being coupled to the encoder circuit.
9 more elements
A balanced multiple descriptive coder, comprising:
- a plurality of coding branches, each coding branch comprising:
- 1) an encoding circuit comprising;
- a) a quantizer,
- b) a mapping unit coupled to the quantizer and operating in accordance with an index assignment scheme having uniform spread, the mapping unit having a pair of outputs, and
- c) a selection switch coupled the two outputs of the mapping unit,
- 2) a prediction circuit, comprising:
- a) an inverse mapping unit,
- b) a scalar coupled to the inverse mapping unit,
- c) an adder having inputs coupled to an input of the encoding circuit and to the scalar,
- d) a predictor coupled to the scalar, and
- e) a prediction analyzer coupled to a control input of the encoding circuit;
- and
- 3) a subtractor having an input for source data and a second input coupled to the prediction circuit, an output of the subtractor being coupled to the encoding circuit.
10 more elements
A balanced multiple descriptive coder, comprising:
- a plurality of coding branches, each coding branch comprising:
- 1) an encoding circuits comprising:
- a) a quantizer, and
- b) a mapping unit coupled to the quantizer and operating in accordance with an index assignment scheme having uniform spread;
- 2) a prediction circuit, comprising:
- a) an inverse mapping unit,
- b) a scalar coupled to the inverse mapping unit,
- c) an adder having inputs coupled to an input of the encoding circuit and to the scalar, and
- d) a motion compensated predictor coupled to the adder;
- and a subtractor having an input for source data and a second input coupled to the prediction circuit, an output of the subtractor being coupled to the encoding circuit.
7 more elements
A balanced multiple descriptive coder, comprising:
- a plurality of coding branches, each coding branch comprising:
- 1an encoding circuit, comprising:
- a) a quantizer, and
- b) a mapping unit coupled to the quantizer and operating in accordance with an index assignment scheme having uniform spread;
- 2) a prediction circuit, comprising:
- a) an inverse mapping unit,
- b) a scalar coupled to the inverse mapping unit,
- c) an adder having inputs coupled to an input of the encoding circuit and to the scalar,
- d) a predictor coupled to the scalar, and
- e) a mutual refinability shifter, coupled to the predictor;
- and
- 3) a subtractor having an input for source data and a second input coupled to the prediction circuit, an output of the subtractor being coupled to the encoding circuit.
9 more elements
A balanced multiple descriptive decoder, comprising:
- 1) a pair of decoding chains, each comprising:
- a) an inverse mapping unit,
- b) a flat scalar coupled to the inverse mapping unit,
- c) a first adder coupled to the scalar,
- d) a prediction circuit having an input coupled to an output of the adder and an output coupled to an input of the adder,
- e) a second scalar coupled to the output of the prediction circuit, and
- f) a second adder having inputs coupled to an input of the inverse mapping unit and to the second scalar;
- and
- 2) an inverse mapping unit coupled to outputs of the second adders from each decoding chain.
6 more elements
A balanced multiple descriptive decoder, comprising:
- 1) a pair of decoding chains, each comprising:
- a) an inverse mapping unit,
- b) a first scalar coupled to the inverse mapping unit,
- c) a first adder coupled to the scalar,
- d) a inverse source transform coupled to the first adder,
- e) a prediction circuit having an input coupled to an output of the inverse source transform;
- f) an inverse source transform coupled to an input of the prediction circuit and having an output coupled to an input of the first adder,
- g) a second scalar coupled to the output of the prediction circuit, and
- h) a second adder having inputs coupled to an input of the inverse mapping unit and to the second scalar;
- and
- 2) an inverse mapping unit coupled to outputs of the second adders from each decoding chain.
8 more elements
A balanced multiple descriptive decoder, comprising:
- 1) a pair of decoding chains, each comprising:
- a) an inverse mapping unit,
- b) a first scalar coupled to the inverse mapping unit,
- c) a first adder coupled to the scalar,
- d) a motion compensated prediction circuit having an input coupled to an output of the first adder and an output coupled to an input of the first adder,
- e) a second scalar coupled to the output of the prediction circuit, and
- f) a second adder having inputs coupled to an input of the inverse mapping unit and to the second scalar;
- and
- 2) an inverse mapping unit coupled to outputs of the second adders from each decoding chain.
6 more elements
A balanced multiple descriptive decoder, comprising:
- 1) a pair of decoding chains, each comprising:
- a) an inverse mapping unit,
- b) a first scalar coupled to the inverse mapping unit,
- c) a first adder coupled to the scalar, and
- d) a predication circuit, comprising:
- i) a predictor, and
- ii) a mutual refinability shifter coupled to the predictor,
- e) a second scalar coupled to the output of the prediction circuit, and
- f) a second adder having inputs coupled to an input of the inverse mapping unit and to the second scalar;
- and
- 2) an inverse mapping unit coupled to outputs of the second adders from each decoding chain.
8 more elements
A balanced multiple descriptive decoder, comprising:
- 1) a pair of decoding chains, each comprising:
- a) an inverse mapping unit,
- b) a first scalar coupled to the inverse mapping unit,
- c) a first adder coupled to the scalar,
- d) a inverse source transform coupled to the adder,
- e) a prediction circuit, comprising;
- i) a predictor,
- ii) a source transform coupled to the predictor,
- iii) a mutual refinability shifter coupled to the source transform, and
- iv) an inverse source transform coupled to the shifter,
- f) a second scalar coupled to the output of the prediction circuit, and
- g) a second adder having inputs coupled to an input of the inverse mapping unit and to the second scalar;
- and
- 2) an inverse mapping unit coupled to outputs of the second adders from each decoding chain.
11 more elements
The balanced multiple descriptive coder of 1, wherein the prediction circuit of each coding branch operates independently of the prediction circuit of every other coding branch.
Dependencies are inferred from the claim text.