APPARATUS FOR REFERENCE PICTURE RESAMPLING GENERATION AND METHOD THEREOF AND VIDEO DECODING SYSTEM USING THE SAME

• US 20100150231A1
• Filed: 03/12/2009
• Published: 06/17/2010
• Est. Priority Date: 12/11/2008
• Status: Active Grant

• Current Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Original Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Inventors: Huang, Yen-Ju, Huang, Tze-Sing, Huang, Chao-Tsung
• Granted Patent: US 8,644,381 B2
• Time in Patent Office: Days
• US Class Current: 375/240.120
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/182 the unit being a pixel
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

The exemplary embodiments of the present invention are direct to a method for generating a resampling reference picture and an apparatus and video decoding system using this method. The video image decoding system is used to decode a bit stream, so as to obtain a current frame. The method for generating a resampling reference picture includes following steps: (a) looking ahead specific information of next x frames of the current frame in the bit stream; (b) determining whether to generate a resampling reference picture according to the specific information of the next x frames.

Claims

1. A method for generating a resampling reference picture, executed in a video decoding system, the video decoding system being used to decode a bit stream, so as to obtain a current frame, the method for generating a resampling reference picture comprising:

looking ahead specific information of next x frames of the current frame in the bit stream, wherein x is a natural number; and

determining whether to generate the resampling reference picture according to the specific information of the next x frames.

2. The method for generating a resampling reference picture as claimed in claim 1, wherein the specific information of the next x frames comprises a start code and a related parameter corresponding to each frame of the next x frames, wherein the related parameter of each frame in the next x frames comprises resolution information or frame shape information.

3. The method for generating a resampling reference picture as claimed in claim 1, wherein when the frames contained in the bit stream are all non-B frames, x is 1, and resolution information or frame shape information contained in the specific information of a next P frame is different from that of the current frame, the method for generating the resampling reference picture further comprises:

generating the resampling reference picture according to the specific information of the current frame and the next P frame, wherein a resolution and a frame shape of the resampling reference picture is the same as those of the next P frame.

4. The method for generating a resampling reference picture as claimed in claim 1, wherein when the frames contained in the bit stream are all non-B frames, x is 1, and resolution information or frame shape information contained in the specific information of the next P frame is the same as that of the current frame, the resampling reference picture is not generated.

5. The method for generating a resampling reference picture as claimed in claim 1, wherein when the current frame is a non-B frame, the next x frames are not all B frames, a first non-B frame in the next x frames is a P frame, and resolution information or frame shape information contained in the specific information of the P frame is different from that of the current frame, the resampling reference picture is generated according to the current frame and the specific information of the P frame in the next x frames, wherein the resolution and the frame shape of the resampling reference picture are the same as those of the P frame in the next x frames.

6. The method for generating a resampling reference picture as claimed in claim 1, wherein when the current frame is a non-B frame, and the next x frames are all B frames, the method for generating the resampling reference picture further comprises:

storing a bit stream of the current frame in a storage apparatus at a specific address, and setting a value of a resampling flag to be true.

7. The method for generating a resampling reference picture as claimed in claim 1, wherein when the current frame is a B frame, and the next x frames are all B frames, the resampling reference picture is not generated, and the video decoding system decodes the bit stream according to a general decoding process.

8. The method for generating a resampling reference picture as claimed in claim 1, wherein when the current frame is a B frame, the next x frames are not all B frames, the next frame is a P frame, and when resolution information or frame shape information contained in the specific information of the P frame is different from that of the current frame, the method for generating the resampling reference picture further comprises:

determining whether a value of a resampling flag is true; and

if the value of the resampling flag is true, generating the resampling reference picture according to a previous non-B frame and the specific information of the P frame corresponding to the current frame, and setting the value of the resampling flag to be false, wherein a resolution and the frame shape of a resampling reference picture are the same as those of the P frame.

9. The method for generating a resampling reference picture as claimed in claim 1, wherein when the current frame is a B frame, the next x frames are not all B frames, and if the next frame is an I frame or the next frame is a P frame, or resolution information or frame shape information contained in the specific information of the P frame is the same as that of the current frame, the method for generating the resampling reference picture further comprises:

decoding the bit stream by the video decoding system according to the general decoding process, and setting a value of a resampling flag to be false.

10. The method for generating a resampling reference picture as claimed in claim 1, wherein when the current frame is a B frame, the next x frames are not all B frames, and if the next frame is a B frame, the method for generating the resampling reference picture further comprises:

decoding the bit stream by the video decoding system according to the general decoding process, and maintaining a current value of a resampling flag.

11. A resampling reference picture generation apparatus, adapted to a video decoding system, the video decoding system being used to decode a bit stream, so as to obtain a current frame, the resampling reference picture generation apparatus comprising:

a header look ahead unit, for looking ahead specific information of next x frames of the current frame in the bit stream, and outputting an indication signal according to the specific information of the next x frames, wherein x is a natural number; and

a resampling reference picture processing unit, coupled to the header look ahead unit, determining whether to generate a resampling reference picture according to the indication signal.

12. The resampling reference picture generation apparatus as claimed in claimed 11, wherein the specific information of the next x frames comprises a start code and a related parameter corresponding to each frame of the next x frames, wherein the related parameter of each frame in the next x frames comprises resolution information or frame shape information.

13. The resampling reference picture generation apparatus as claimed in claimed 11, wherein when the frames contained in the bit stream are all non-B frames, x is 1, and when resolution information or frame shape information contained in the specific information of a next P frame is different from that of the current frame, the indication signal enables the resampling reference picture processing unit, and the resampling reference picture processing unit generates the resampling reference picture according to the current frame and the specific information of the next P frame, wherein a resolution and a frame shape of the resampling reference picture are the same as those of the next P frame.

14. The resampling reference picture generation apparatus as claimed in claimed 11, wherein when the frames contained in the bit stream are all non-B frames, x is 1, and when resolution information or frame shape information contained in the specific information of the next P frame is the same as that of the current frame, the indication signal disables the resampling reference picture processing unit.

15. The resampling reference picture generation apparatus as claimed in claimed 11, wherein when the current frame is a non-B frame, the next x frames are not all B frames, a first non-B frame in the next x frames is a P frame, and resolution information or frame shape information contained in the specific information of the P frame is different from that of the current frame, the indication signal enables the resampling reference picture processing unit, and the resampling reference picture processing unit generates the resampling reference picture according to the current frame and the specific information of the P frame in the next x frames, wherein a resolution and a frame shape of the resampling reference picture are the same as those of the P frame in the next x frames.

16. The resampling reference picture generation apparatus as claimed in claimed 11, wherein when the current frame is a non-B frame, and the next x frames are all B frames, the resampling reference picture processing unit stores a bit stream of the current frame in a storage apparatus a at a specific address, and sets a value of a resampling flag to be true.

17. The resampling reference picture generation apparatus as claimed in claimed 11, wherein when the current frame is a B frame, and the next x frames are all B frames, the indication signal disables the resampling reference picture processing unit, and the video decoding system decodes the bit stream according to a general decoding process.

18. The resampling reference picture generation apparatus as claimed in claimed 11, wherein when the current frame is a B frame, the next x frames are not all B frames, the next frame is a P frame, and when resolution information or frame shape information contained in the specific information of the P frame is different from that of the current frame, the indication signal enables the resampling reference picture processing unit, and the resampling reference picture processing unit determines whether a value of a resampling flag is true, and if the value of the resampling flag is true, the resampling reference picture processing unit generates the resampling reference picture according to a previous non-B frame and the specific information of the next P frame corresponding to the current frame, and sets the value of the resampling flag to be false, wherein a resolution and a frame shape of the resampling reference picture is the same as those of the next P frame.

19. The resampling reference picture generation apparatus as claimed in claimed 11, wherein when the current frame is a B frame, the next x frames are not all B frames, and if the next frame is an I frame or the next frame is a P frame, or resolution information or frame shape information contained in a specific information thereof is the same as that of the current frame, the indication signal disables the resampling reference picture processing unit, and the video decoding system decodes the bit stream according to the general decoding process, and resampling reference picture processing unit sets a value of a resampling flag to be false.

20. The resampling reference picture generation apparatus as claimed in claimed 11, wherein when the current frame is a B frame, the next x frames are not all B frames, and if the next frame is a B frame, the indication signal disables the resampling reference picture processing unit, and the video decoding system decodes the bit stream according to the general decoding process, and resampling reference picture processing unit maintains a current value of a resampling flag.

21. A video decoding system, comprising:

a video decoding device, decoding a bit stream to obtain a current frame; and

a resampling reference picture generation apparatus, coupled to the video decoding device, comprising;

a header look ahead unit, for looking ahead specific information of next x frames of the current frame in the bit stream, and outputting an indication signal according to specific information of the next x frames, wherein x is a natural number; and

a resampling reference picture processing unit, coupled to the header look ahead unit, determining whether to generate a resampling reference picture according to the indication signal.

22. The video decoding system as claimed in claim 21, wherein the specific information of the next x frames comprises a start code and a related parameter corresponding to each frame of the next x frames, wherein the related parameter of each frame in the next x frames comprises resolution information or frame shape information.

23. The video decoding system as claimed in claim 21, wherein when the frames contained in the bit stream are all non-B frames, x is 1, and when resolution information or frame shape information contained in the specific information of a next P frame is different from that of the current frame, the indication signal enables the resampling reference picture processing unit, and the resampling reference picture processing unit generates the resampling reference picture according to the current frame and the specific information of the next P frame, wherein a resolution and a frame shape of the resampling reference picture is the same as those of the next P frame.

24. The video decoding system as claimed in claim 21, wherein when the frames contained in the bit stream are all non-B frames, x is 1, and when the resolution information or the frame shape information contained in the specific information of the next P frame is the same as that of the current frame, the indication signal disables the resampling reference picture processing unit.

25. The video decoding system as claimed in claim 21, wherein when the current frame is a non-B frame, the next x frames are not all B frames, a first non-B frame in the next x frames is a P frame, and resolution information or frame shape information contained in the specific information of the P frame is different from that of the current frame, the indication signal enables the resampling reference picture processing unit, and the resampling reference picture processing unit generates the resampling reference picture according to the current frame and the specific information of the P frame in the next x frames, wherein a resolution and a frame shape of the resampling reference picture are the same as those of the P frame in the next x frames.

26. The video decoding system as claimed in claim 21, wherein when the current frame is a non-B frame, and the next x frames are all B frames, the resampling reference picture processing unit stores a bit stream of the current frame in a specific space address, and sets a value of a resampling flag to be true.

27. The video decoding system as claimed in claim 21, wherein when the current frame is a B frame, and the next x frames are all B frames, the indication signal disables the resampling reference picture processing unit, and the video decoding system decodes the bit stream according to a general decoding process.

28. The video decoding system as claimed in claim 21, wherein when the current frame is a B frame, the next x frames are not all B frames, the next frame is a P frame, and when resolution information or frame shape information contained in the specific information of the P frame is different from that of the current frame, the indication signal enables the resampling reference picture processing unit, and the resampling reference picture processing unit determines whether a value of a resampling flag is true, and if the value of the resampling flag is true, the resampling reference picture processing unit generates the resampling reference picture according to a previous non-B frame and the specific information of the next P frame corresponding to the current frame, and sets the value of the resampling flag to be false, wherein a resolution and a frame shape of the resampling reference picture is the same as those of the next P frame.

29. The video decoding system as claimed in claim 21, wherein when the current frame is a B frame, the next x frames are not all B frames, and if the next frame is an I frame or the next frame is a P frame, or resolution information or frame shape information contained in the specific information thereof is the same as that of the current frame, the indication signal disables the resampling reference picture processing unit, and the video decoding system decodes the bit stream according to the general decoding process, and resampling reference picture processing unit sets a value of a resampling flag to be false.

30. The video decoding system as claimed in claim 21, wherein when the current frame is a B frame, the next x frames are not all B frames, and if the next frame is a B frame, the indication signal disables the resampling reference picture processing unit, and the video decoding system decodes the bit stream according to the general decoding process, and maintains the current value of a resampling flag.