Methods and systems for combining layers in a multi-layer bitstream

• US 8,532,176 B2
• Filed: 03/31/2007
• Issued: 09/10/2013
• Est. Priority Date: 07/10/2006
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Segall, Christopher A.
• Primary Examiner(s): Zand, Kambiz
• Assistant Examiner(s): SIMS, JING F
• Application Number:
  US11/694,954
• Publication Number:
  US 20080031345A1
• Time in Patent Office: 2,355 Days
• Field of Search: 375/240, 375/240.11
• US Class Current: 375/240.11
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream

Abstract

Embodiments of the present invention comprise systems and methods for managing and combining data contained in layers in a multilayer bitstream such that one or more transform coefficients in a first layer are used to modify one or more coefficients in a second layers that in turn is reconstructed using the modified one or more coefficients.

Claims

1. A method for combining layers in a multi-layer bitstream having a first layer and a second layer, said method comprising:

a) a processor inverse quantizing a first-layer quantized transform coefficient thereby creating a first-layer transform coefficient;

b) a processor scaling said first-layer transform coefficient to match a characteristic of a second-layer thereby creating a scaled, first-layer transform coefficient, without inverse-transforming said first layer, where said characteristic is at least one of a quantization parameter and a resolution parameter;

c) a processor inverse quantizing a second-layer quantized transform coefficient thereby creating a second-layer transform coefficient;

d) a processor combining said scaled, first-layer transform coefficient with said second-layer transform coefficient to form a combined coefficient; and

(e) a processor using said combined coefficient to inverse-transform said second layer, without inverse-transforming said first layer.

2. A method as described in claim 1 wherein said first-layer is a base layer.

3. A method as described in claim 1 wherein said inverse quantizing a first-layer quantized transform coefficient comprises using a first quantization parameter and said inverse quantizing a second-layer quantized transform coefficient comprises using a second quantization parameter.

4. A method as described in claim 1 wherein said first layer and said second layer have different spatial resolutions.

5. A method as described in claim 1 wherein said second-layer is an enhancement layer.

6. A method as described in claim 1 further comprising inverse transforming said combined coefficient thereby generating a spatial-domain residual value.

7. A method as described in claim 6 further comprising combining said spatial-domain residual value with said spatial-domain prediction value.

8. A method as described in claim 1 further comprising:

a) inverse quantizing a third-layer quantized transform coefficient thereby creating a third-layer transform coefficient;

b) scaling said combined coefficient to match a characteristic of a third layer thereby creating a scaled-combined coefficient; and

c) combining said scaled-combined coefficient with said third-layer transform coefficient.

9. A method as described in claim 1 further comprising generating a combined bitstream comprising said combined coefficient.

10. A method as described in claim 9 wherein said combined bitstream further comprises an intra-prediction mode.

11. A method as described in claim 9 wherein said combined bitstream further comprises a motion vector.

12. A system for combining layers in a multi-layer bitstream having a first layer and a second layer, said system comprising:

a) a first inverse quantizer for inverse quantizing a first-layer quantized transform coefficient thereby creating a first-layer transform coefficient;

b) a scaler for scaling said first-layer transform coefficient to match a characteristic of a second-layer thereby creating a scaled, first-layer transform coefficient, without inverse-transforming said first layer, where said characteristic is at least one of a quantization parameter and a resolution parameter;

c) a second inverse quantizer for inverse quantizing a second-layer quantized transform coefficient thereby creating a second-layer transform coefficient;

d) a coefficient combiner for combining said scaled, first-layer transform coefficient with said second-layer transform coefficient to form a combined coefficient; and

(e) a decoder that uses said combined coefficient to inverse-transform said second layer, without inverse-transforming said first layer.

13. A system as described in claim 12 further comprising a bitstream generator for generating a combined bitstream comprising said combined coefficient.

14. A system as described in claim 12 further comprising an inverse transformer for inverse transforming said combined coefficient thereby generating a spatial-domain residual value and a second combiner for combining said spatial-domain residual value with said spatial-domain prediction value.

15. A method for converting a scalable video coding compliant (SVC-compliant) bitstream to Advanced Video Coding compliant (AVC-compliant) data, said method comprising:

a) a processor receiving an SVC-compliant bitstream comprising prediction data, base-layer residual data and enhancement-layer residual data;

b) a processor inverse quantizing said base-layer residual data thereby creating base-layer transform coefficients;

c) a processor inverse quantizing said enhancement-layer residual data thereby creating enhancement-layer transform coefficients;

d) a processor scaling said base-layer transform coefficients to match a quantization parameter of said enhancement-layer thereby creating scaled base-layer transform coefficients, without inverse-transforming said base layer;

e) a processor combining said scaled base-layer transform coefficients with said enhancement-layer transform coefficients to form combined coefficients; and

f) a processor using said combined coefficients to inverse transform said enhancement layer, without inverse-transforming said base layer.

16. A method as described in claim 15 further comprising combining said combined coefficients with said prediction data to form an AVC-compliant bitstream.

17. A method as described in claim 15 wherein said prediction data comprises an intra-prediction mode indicator.

18. A method as described in claim 15 wherein said prediction data comprises a motion vector.

19. A method as described in claim 15 further comprising inverse transforming said combined coefficients thereby creating spatial-domain residual values.

20. A method as described in claim 19 further comprising obtaining spatial-domain prediction values and combining said spatial-domain prediction values with said spatial-domain residual values to form a decoded image.

21. A method for combining layers in a multi-layer bitstream having a first layer and a second layer, said method comprising:

a) a processor receiving a first-layer quantized transform coefficient;

b) a processor scaling said first-layer quantized transform coefficient to match a characteristic of a second-layer thereby creating a scaled, first-layer quantized transform coefficient, without inverse-transforming said first layer, where said characteristic is at least one of a quantization parameter and a resolution parameter;

c) a processor receiving a second-layer quantized transform coefficient;

d) a processor combining said scaled, first-layer transform coefficient with said second-layer quantized transform coefficient to form a combined quantized coefficient; and

e) a processor using said combined coefficient to inverse-transform said second layer, without inverse-transforming said first layer.

22. A method as described in claim 21 further comprising inverse quantizing said combined quantized coefficient to produce a combined coefficient.

23. A method as described in claim 22 further comprising inverse transforming said combined coefficient thereby producing a spatial domain residual value.

24. A method as described in claim 23 further comprising combining said spatial domain residual value with a spatial domain prediction value.

25. A method as described in claim 21 further comprising generating a combined bitstream comprising said combined quantized coefficient.

26. A method for conditionally combining layers in a multi-layer bitstream, said method comprising:

a) a processor receiving a first-layer quantized transform coefficient;

b) a processor receiving a second-layer quantized transform coefficient;

c) a processor receiving a layer combination indicator;

d) a processor scaling said first-layer quantized transform coefficient to match a characteristic of a second-layer thereby creating a scaled, first-layer quantized transform coefficient, when said layer combination indicator indicates transform domain accumulation, and without inverse-transforming said first layer, where said characteristic is at least one of a quantization parameter and a resolution parameter;

e) a processor combining said scaled, first-layer transform coefficient with said second-layer quantized transform coefficient to form a combined quantized coefficient, when said layer combination indicator indicates transform domain accumulation; and

f) a processor using said combined quantized coefficient to inverse-transform said second layer, without inverse-transforming said first layer.

27. A method as described in claim 26 wherein said layer combination indicator is derived from data in a second-layer bitstream.

28. A method as described in claim 26 further comprising disabling smoothed reference prediction, when said layer combination indicator indicates transform domain accumulation.

29. A method for reconstructing an enhancement layer from a multi-layer bitstream having a base layer, said method comprising:

a) a processor receiving a first-layer intra-prediction mode;

b) a processor receiving a second-layer bitstream prediction indicator, said indicator indicating that said first-layer prediction mode is to be used for prediction of said second layer;

c) a processor using said first-layer prediction mode to construct a second-layer prediction based on adjacent block data in said second layer;

d) a processor combining said second-layer prediction with residual information thereby creating a reconstructed second layer; and

e) a processor inverse transforming said enhancement layer without inverse-transforming said base layer.