Method and apparatus for providing a multimedia data stream

• US 20040220966A1
• Filed: 05/02/2003
• Published: 11/04/2004
• Est. Priority Date: 05/02/2003
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Ridge, Justin
• Granted Patent: US 6,895,410 B2
• Time in Patent Office: Days
• US Class Current: 707/104.1
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/752 adapting media to network capabilities
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

A method and corresponding equipment (11) for encoding different types of objects of a multimedia data stream so as to provide improved overall quality (Q), according to relationships (11b) between quality (Q_i) and encoding size/transmission rate (R_i) for each object, and according to penalties (11c) for removing objects from the multimedia data stream. A multimedia data stream is provided in which the quality of the different objects tends to be similar according to rules provided by the invention for assigning a value of quality to each of the different kinds of objects of the multimedia stream.

Claims

1. A method by which a multimedia data stream conveying a plurality of objects of different types is provided at a total data rate (R) less than or equal to a maximum allowed total data rate (R_M), characterized by:

a step (22b) in which for each object of the data stream a relationship (11b) is established between different encoded data rates (R_i) used for transmitting the object and a resulting corresponding quality (Q_i) indicating a measure of quality for the transmitted object; and

a step (33) in which, using the established relationships (11b), for an object included in the multimedia data stream and having a generally low value of quality (Q_j) based on a currently selected data rate (R_j) compared to values of quality (Q_k) for other objects of the multimedia data stream based on currently selected values of data rate values (R_k) for the other objects, a higher data rate value (R′

_j) is selected, provided that the higher data rate value (R′

_j) does not result in the total data rate (R) exceeding the maximum allowed total data rate (R_M)

2. A method as in claim 1, wherein the relationship (11b) between different encoded data rates (R_i) used for transmitting the object and a resulting corresponding quality (Q_i) assigns values for quality (Q_i) given an encoded data rate (R_i) based upon statistical characteristics of the object.

3. A method as in claim 2, wherein the quality values (Q_i) are estimated from statistical characteristics of the received object either without performing encoding or re-encoding of the object or after performing encoding or re-encoding of the object.

4. A method as in claim 1, wherein the relationship (11b) for an object assigns a quality value (Q_i) to each transmission rate (R_i) in a set of discrete transmission rate values (R_i).

5. A method as in claim 1, wherein the relationship (11b) for an object assigns a quality value (Q_i) to any transmission rate (R_i) in a range of discrete transmission rate values (R_i).

6. A method as in claim 1, wherein the relationship (11b) assigns a quality value (Q_i) to an object for a specified transmission rate (R_i) in a range common to all objects, regardless of type.

7. A method as in claim 1, wherein the relationship (11b) for an image type of object is expressible as:

8. A method as in claim 1, wherein the relationship (11b) for an image type of object is expressible as:

Q_i=α

N+β

σ

²+λ

R_L,

where N indicates the number of colors in the object and depends on the transmission rate (R_i), σ

² indicates the color variation of the object and depends on the transmission rate (R_i), R_L indicates an average run-length defining a solidity for the object and also depends on the transmission rate (R_i), and where α

,β

,λ

are weighting values.

9. A method as in claim 1, further comprising:

a step (43) in which, if the overall quality (Q) of the multimedia data stream is improved by removing an object from the multimedia data stream according to some predetermined measure (eq. (2)) for the overall quality (Q) without the object, then the object is removed.

10. A method as in claim 9, wherein the predetermined measure (eq. (2)) for the overall quality (Q) without the object takes into account a predetermined penalty for removing the object.

11. An apparatus (11a), comprising means for performing the steps of claim 1.

12. An apparatus (11a), comprising means for performing the steps of claim 2.

13. An apparatus (11a), comprising means for performing the steps of claim 6.

14. A system, comprising:

an apparatus (11a) according to claim 11 and responsive to the multimedia data stream, for providing a quality-improved multimedia data stream;

a server (12), for providing the multimedia data stream;

a radio access network (13), responsive to the quality-improved multimedia data stream, for wirelessly transmitting the quality-improved multimedia data stream to an intended wireless terminal (14); and

the wireless terminal (14), responsive to the wirelessly transmitted quality-improved multimedia data stream.

15. A system, comprising:

an apparatus (11a) according to claim 12 and responsive to the multimedia data stream, for providing a quality-improved multimedia data stream;

a server (12), for providing the multimedia data stream;

a radio access network (13), responsive to the quality-improved multimedia data stream, for wirelessly transmitting the quality-improved multimedia data stream to an intended wireless terminal (14); and

the wireless terminal (14), responsive to the wirelessly transmitted quality-improved multimedia data stream.

16. A system, comprising:

an apparatus (11a) according to claim 13 and responsive to the multimedia data stream, for providing a quality-improved multimedia data stream;

a server (12), for providing the multimedia data stream;

a radio access network (13), responsive to the quality-improved multimedia data stream, for wirelessly transmitting the quality-improved multimedia data stream to an intended wireless terminal (14); and

the wireless terminal (14), responsive to the wirelessly transmitted quality-improved multimedia data stream.

17. A computer program product comprising:

a computer readable storage structure embodying computer program code thereon for execution by a computer processor in an apparatus (11a) by which a multimedia data stream conveying a plurality of objects of different types is provided at a total data rate (R) less than or equal to a maximum allowed total data rate (R_M), with said computer program code characterized in that includes instructions for performing the steps of the method of claim 1.

18. A computer program product comprising:

a computer readable storage structure embodying computer program code thereon for execution by a computer processor in an apparatus (11a) by which a multimedia data stream conveying a plurality of objects of different types is provided at a total data rate (R) less than or equal to a maximum allowed total data rate (R_M), with said computer program code characterized in that includes instructions for performing the steps of the method of claim 2.

19. A computer program product comprising:

a computer readable storage structure embodying computer program code thereon for execution by a computer processor in an apparatus (11a) by which a multimedia data stream conveying a plurality of objects of different types is provided at a total data rate (R) less than or equal to a maximum allowed total data rate (R_M), with said computer program code characterized in that includes instructions for performing the steps of the method of claim 6.