Video coding

• US 20010040926A1
• Filed: 05/15/2001
• Published: 11/15/2001
• Est. Priority Date: 05/15/2000
• Status: Active Grant

• Current Assignee: Sisvel International S.A. (Fineur International S.A.)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Hannuksela, Miska, Caglar, Kerem
• Granted Patent: US 7,400,684 B2
• Time in Patent Office: Days
• US Class Current: 375/240.27
• CPC Class Codes: H04N 19/527 Global motion vector estimation
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/895 in combination with error concealment
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04N 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006

Abstract

A method of encoding a video signal representing a sequence of pictures, the method comprising comparing a first picture with a second picture, calculating a measure of the similarity between the first and the second pictures, comparing the measure of similarity with a predetermined criterion of similarity and, when the measure of similarity does not meet the predetermined criterion of similarity, outputting an indicator indicating that a non-temporally predictive error concealment method should be used by a subsequent decoder and, when the measure of similarity meets the predetermined criterion of similarity, outputting an indicator indicating that a temporally predictive error concealment method should be used by a subsequent decoder.

Claims

1. A method of encoding a video signal representing a sequence of pictures, the method comprising comparing a first picture with a second picture, calculating a measure of the similarity between the first and the second pictures, comparing the measure of similarity with a predetermined criterion of similarity and, when the measure of similarity does not meet the predetermined criterion of similarity, outputting an indicator indicating that a non-temporally predictive error concealment method should be used by a subsequent decoder and, when the measure of similarity meets the predetermined criterion of similarity, outputting an indicator indicating that a temporally predictive error concealment method should be used by a subsequent decoder.

2. A method according to

claim 1

, wherein the indicator is updated when the measure of similarity does not meet the predetermined criterion of similarity.

3. A method according to

claim 1

or

2

wherein the indicator is included in a picture header.

4. A method according to

claim 3

wherein the video signal is encoded according to the H.263 standard and the indicator is included in the Supplemental Enhancement Information.

5. A method of encoding a video signal representing a sequence of pictures, the method comprising comparing a first picture with a second picture, calculating a measure of the similarity between the first and the second pictures, comparing the measure of similarity with a predetermined criterion of similarity and outputting an indicator in response to the measure of similarity wherein, when the measure of similarity does not meet the predetermined criterion, the indicator is updated and when the measure of similarity meets the predetermined criterion, the indicator is unchanged.

6. A method of decoding an encoded video signal representing a sequence of pictures, the method comprising receiving an encoded video signal, identifying for each picture to be decoded an indicator indicating the type of concealment method to be used in the decoding process and decoding the encoded video signal using a concealment method of the identified type.

7. A method of error concealment comprising receiving an encoded video signal including an indicator indicating the type of concealment method to be used in the error concealment process and concealing the error in the video signal appropriately.

8. A method of decoding an encoded video signal representing a sequence of pictures, the method comprising receiving an encoded video signal, identifying for each picture to be decoded an indicator representing the measure of similarity between a first picture and a second picture and, when the indicator is the same as that of a previously received picture, applying a temporal predictive error concealment method and, when the indicator is the different from that of a previously received picture, applying a spatial error concealment method.

9. A video encoder comprising an input for receiving a video signal representing a sequence of pictures, a calculator to calculate a measure of the similarity between a first and a second picture, and a comparator to compare the measure of similarity with a predetermined criterion of similarity and to output an indicator indicating the concealment method to be used by a subsequent decoder, the comparator being arranged to output an indicator indicating that a non-temporally predictive concealment method should be used when the measure of similarity does not meet the predetermined criterion, and, when the measure of similarity meets the predetermined criterion, to output an indicator indicating that a temporally predictive concealment method should be used by a subsequent decoder.

10. A video encoder for encoding a video signal representing a sequence of pictures, the encoder comprising a comparator for comparing a first picture with a second picture, a processor for calculating a measure of the similarity between the first and the second pictures and comparing the measure of similarity with a predetermined criterion of similarity, the processor being arranged to output an indicator in response to the measure of similarity wherein, when the measure of similarity does not meet the predetermined criterion, the indicator is updated and when the measure of similarity meets the predetermined criterion, the indicator is unchanged.

12. A portable radio communications device including an encoder according to

claim 9

or

10

and/or a decoder according to

claim 10

or

11

.

11. A video decoder comprising an input for receiving an encoded video signal representing a sequence of pictures, a controller for identifying within the video signal for each picture to be decoded an indicator indicating the type of concealment method to be used in the decoding process, and decoding the encoded video signal using a concealment method as indicated by the indicator.