US 8,428,124 B2 · Moving picture encoding apparatus and distribution system

Abstract

A moving picture encoding apparatus divides a moving picture signal into key frames and non-key frames, encodes the key frames, predicts the non-key frames from the encoded key frames, determines an encoding rate for each non-key frame, encodes each non-key frame, and outputs an error-correcting code at the encoding rate as encoded data of the non-key frame. To determine the encoding rate, parameters related to the likelihood of prediction errors are calculated by at least two different methods for each non-key frame, the parameters are compared, one of the parameters is selected, and the encoding rate is calculated from the selected parameter. The selective use of differently calculated parameters enables an efficient encoding rate to be calculated for each non-key frame and reduces the transmission of encoded data that the decoder does not need or cannot decode.

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Drawings

Claims18

Dependent claims

A moving picture encoding apparatus for encoding a moving picture signal including a sequence of frames, the moving picture encoding apparatus comprising:

a frame classifier for designating each frame in the sequence as a key frame or a non-key frame;
a key frame encoder for encoding the designated key frames in the sequence to generate encoded key frame data;
a side information generator for using the encoded key frame data to generate a predicted image for each designated non-key frame in the sequence;
an encoding rate estimator for determining an encoding rate for said each designated non-key frame by estimating a number of error-correcting bits needed to correct prediction errors in the predicted image generated for said each designated non-key frame;
and
a non-key frame encoder for encoding said each designated non-key frame to obtain an error-correcting code at the encoding rate determined by the encoding rate estimator, and outputting the error-correcting code as encoded data of said each designated non-key frame;
wherein the encoding rate estimator includes
a distribution model entropy calculator configured to calculate a distribution model entropy value from a model that approximates a relation between said each designated non-key frame and the predicted image,
a bit error entropy calculator configured to compare said each designated non-key frame with the predicted image to determine a difference therebetween, and to calculate a bit error entropy value from the difference,
a selector configured to select one of the bit error entropy value and the distribution model entropy value as a selected entropy value, the bit error entropy value being selected when it is larger than the distribution model entropy value, and
an encoding rate calculator configured to calculate the encoding rate from the selected entropy value.

8 more elements

A moving picture encoding apparatus for encoding a moving picture signal including a sequence of frames, the moving picture encoding apparatus comprising:

a frame classifier for designating each frame in the sequence as a key frame or a non-key frame;
a key frame encoder for encoding the designated key frames in the sequence to generate encoded key frame data;
a side information generator for using the encoded key frame data to generate a predicted image for each designated non-key frame in the sequence;
an encoding rate estimator for determining an encoding rate for said each designated non-key frame by estimating a number of error-correcting bits needed to correct prediction errors in the predicted image generated for said each designated non-key frame;
and
a non-key frame encoder for encoding said each designated non-key frame to obtain an error-correcting code at the encoding rate determined by the encoding rate estimator, and outputting the error-correcting code as encoded data of said each designated non-key frame;
wherein the encoding rate estimator includes
a distribution model error calculator configured to calculate a distribution model error rate from a model that approximates a relation between said each designated non-key frame and the predicted image,
a bit error calculator configured to compare said each designated non-key frame with the predicted image to determine a difference therebetween and to calculate a bit error rate from the difference,
a selector configured to select one of the bit error rate and the distribution model error rate as a selected error rate, and to calculate an entropy value from the selected error rate, the bit error rate being selected when it is larger than the distribution model error rate, and
an encoding rate calculator configured to calculate the encoding rate from the entropy value calculated by the selector.

8 more elements

A moving picture encoding apparatus for encoding a moving picture signal including a sequence of frames, the moving picture encoding apparatus comprising:

a frame classifier for designating each frame in the sequence as a key frame or a non-key frame;
a key frame encoder for encoding the designated key frames in the sequence to generate encoded key frame data;
a side information generator for using the encoded key frame data to generate a predicted image for each designated non-key frame in the sequence;
an encoding rate estimator for determining an encoding rate for said each designated non-key frame by estimating a number of error-correcting bits needed to correct prediction errors in the predicted image generated for said each designated non-key frame;
and
a non-key frame encoder for encoding said each designated non-key frame to obtain an error-correcting code at the encoding rate determined by the encoding rate estimator, and outputting the error-correcting code as encoded data of said each designated non-key frame;
wherein the encoding rate estimator includes
a distribution model entropy calculator configured to calculate a distribution model entropy value from a model that approximates a relation between said each designated non-key frame and the predicted image,
a bit error calculator configured to compare said each designated non-key frame with the predicted image to determine a difference therebetween and to calculate a bit error entropy value from the difference,
a decision table configured to store information indicating which one of the distribution model entropy value and the bit error entropy value is to be selected as a selected entropy value, the bit error entropy value being to be selected when it is larger than the distribution model entropy value,
a selector configured to select the selected entropy value according to the information stored by the decision table, and
an encoding rate calculator configured to calculate the encoding rate from the selected entropy value selected by the selector.

9 more elements

A moving picture encoding apparatus for encoding a moving picture signal including a sequence of frames, the moving picture encoding apparatus comprising:

a frame classifier for designating each frame in the sequence as a key frame or a non-key frame;
a key frame encoder for encoding the designated key frames in the sequence to generate encoded key frame data;
a side information generator for using the encoded key frame data to generate a predicted image for each designated non-key frame in the sequence;
an encoding rate estimator for determining an encoding rate for said each designated non-key frame by estimating a number of error-correcting bits needed to correct prediction errors in the predicted image generated for said each designated non-key frame;
and
a non-key frame encoder for encoding said each designated non-key frame to obtain an error-correcting code at the encoding rate determined by the encoding rate estimator, and outputting the error-correcting code as encoded data of said each designated non-key frame;
wherein the encoding rate estimator includes
a distribution model error calculator configured to calculate a distribution model error rate from a model that approximates a relation between said each designated non-key frame and the predicted image,
a bit error calculator configured to compare said each designated non-key frame with the predicted image to determine a difference therebetween and to calculate a bit error rate from the difference,
a decision table configured to store information indicating which one of the distribution model error rate and the bit error rate is to be selected as a selected error rate, the bit error rate being to be selected when it is larger than the distribution model error rate,
a selector configured to select the selected error rate according to the information stored by the decision table, and to calculate an entropy value from the selected error rate, and
an encoding rate calculator configured to calculate the encoding rate from the entropy value calculated by the selector.

9 more elements

Dependencies are inferred from the claim text.

Description7,408 words

Summary1,118 words

#1. Field of the Invention

#The present invention relates to the encoding and decoding of moving picture sequences and is applicable in, for example, a system that uses distributed video coding techniques to distribute moving picture data.

#2. Description of the Related Art

Brief description of the drawings9 figures

#In the attached drawings:

#FIG. 1 is a block diagram illustrating the basic structure of a moving picture distribution system embodying the invention;

#FIG. 2 is a functional block diagram illustrating the structure of a moving picture encoding apparatus in a first embodiment;

Detailed description6,109 words

#Four embodiments of the invention will now be described with reference to the attached drawings, in which like elements are indicated by like reference characters.

#These embodiments concern a moving picture distribution system 1 (1A, 1B, 1C) with the basic structure shown in FIG. 1, including a moving picture distribution apparatus 10 (10A, 10B, 10C) and a moving picture receiving apparatus 20. The moving picture distribution apparatus 10 includes a moving picture encoding apparatus 100 (100A, 100B, 100C) that encodes a video signal, and a transmitter (not shown) that transmits the encoded video signal to the moving picture receiving apparatus 20. The moving picture receiving apparatus 20 includes a moving picture decoding apparatus 200 that decodes the video signal, and other apparatus (not shown) for output of the decoded signal. The type of output is not limited. Exemplary forms of output include display, writing onto a storage medium, and transmission over a communication link. The reference characters with suffixes A, B, and C are used in the second, third, and fourth embodiments.

#The video signal input to the moving picture encoding apparatus 100 may be any type of video signal, digital or analog, but it will be assumed in the following description that the signal is a digital signal organized as a sequence of frames. This is the type of signal that would be received from a video camera equipped with a charge coupled device (CCD) imager. If an analog video signal is input, the moving picture encoding apparatus 100 may include a frame grabber that captures the signal by converting it to a digitized frame sequence.

Facts

Application

12/923,510Filed 24 Sep 2010

Priority

JP 2009-22523429 Sep 2009

Published

US 2011/0075726 A131 Mar 2011

Granted

23 Apr 2013

Term ends

25 Jun 2031

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 274 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification2 codes

H04N 19/395
Using hierarchical techniques, e.g. scalability: involving distributed video coding [DVC], e.g. Wyner-Ziv video coding or Slepian-Wolf video coding
H04N
Pictorial communication

Timeline

29 Sep 2009Priority claimedJP 2009-225234
24 Sep 2010Application filedUS 12/923,510
24 Sep 2010Assigned to Oki Electric Industry Co., Ltd.assignment of assignor's interest
31 Mar 2011PublishedUS 2011/0075726 A1
23 Apr 2013GrantedUS 8,428,124 B2
12 Oct 2026TodayWithin its term
25 Jun 2031Term endsEstimated, includes 274 days of adjustment

Moving picture encoding apparatus and distribution system

Life of this patent

Moving picture encoding apparatus and distribution system

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims18

Description7,408 words

Drawings

Classification2 codes

Life of this patent

Description7,408 words