Adaptive single-field/dual-field video encoding

Patent metadata

Field	Value
Publication number	US-9560361-B2
Application number	US-201213705422-A
Country	US
Kind code	B2
Filing date	Dec 5, 2012
Priority date	Dec 5, 2012
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A video processing device includes an interface to receive an input video stream and an interface to provide an encoded video stream. The input video stream includes a sequence of frames. Each frame comprises two fields. The video processing device further includes an encoder to encode the input video stream to generate the encoded video stream. The encoder is to dynamically switch between a first encoding mode and a second encoding mode responsive to a variable quantization parameter. In the first encoding mode the encoder is to encode both fields or the complete frame of a corresponding frame of the sequence. In the second encoding mode the encoder is to encode only one field of the two fields of a corresponding frame of the sequence. This approach can achieve a specified low bit rate with reduced quantization effects while keeping the horizontal resolution unchanged.

First claim

What is claimed is:

1. A method comprising:
encoding an input video stream at a video processing device based on a variable quantization parameter to generate an encoded video stream, the input video stream comprising a sequence of frames, each frame representing a single picture comprising two fields: an odd field having the odd numbered rows of the picture and an even field having the even numbered rows of the picture, wherein the encoding comprises:
encoding only one field of the two fields of each frame of a first subsequence of the sequence of frames for the encoded video stream responsive to the quantization parameter exceeding a first threshold.

2. The method of claim 1 , wherein encoding only one of the two fields of each frame of the first subsequence comprises:
encoding picture data of a first field of each frame of the first subsequence to generate encoded picture data for inclusion in the encoded video stream; and
inserting skip coding information into the encoded video stream in place of encoded picture data for a second field of each frame of the first subsequence.

3. The method of claim 2 , further comprising:
decoding the encoded video stream, wherein the decoding includes:
decoding the encoded picture data to generate a decoded representation of the first field of each frame of the first subsequence; and
replicating the decoded representation of the first field of each frame as a decoded representation of the second field of the frame.

4. The method of claim 1 , wherein the encoding further comprises:
encoding both fields of each frame of a second subsequence of the sequence of frames for the encoded video stream responsive to the quantization parameter falling below a second threshold.

5. The method of claim 4 , wherein the first threshold and the second threshold are the same threshold.

6. The method of claim 4 , wherein the first threshold is greater than the second threshold.

7. The method of claim 4 , wherein encoding both fields of each frame comprises encoding both fields using picture adaptive frame field (PAFF) encoding.

8. A method of encoding an input video stream, the method comprising:
dynamically switching between a first encoding mode and a second encoding mode at a video processing device responsive to a variable quantization parameter, wherein:
the input video stream comprises a sequence of frames, each frame representing a corresponding single picture comprising two fields: an odd field having the odd numbered rows of the picture and an even field having the even numbered rows of the picture;
the first encoding mode comprises encoding both fields of a corresponding frame of the sequence; and
the second encoding mode comprises encoding only one field of the two fields of a corresponding frame of the sequence.

9. The method of claim 8 , wherein dynamically switching between the first encoding mode and the second encoding mode comprises:
switching to the second encoding mode at the video processing device responsive to the quantization parameter exceeding a first threshold.

10. The method of claim 9 , wherein dynamically switching between the first encoding mode and the second encoding mode further comprises:
switching to the first encoding mode at the video processing device responsive to the quantization parameter falling below a second threshold.

11. The method of claim 8 , wherein the first encoding mode further comprises selecting between a frame-based encoding sub-mode and a field-based encoding sub-mode for a corresponding frame based on a motion analysis between the two fields of the corresponding frame.

12. The method of claim 8 , wherein dynamically switching between the first encoding mode and the second encoding mode comprises delaying a switch between the first encoding mode and the second encoding mode at the video processing device until a specified switch point.

13. The method of claim 12 , wherein the specified switch point comprises at least one selected from a group consisting of: a scene boundary; a group of pictures (GOP) boundary; a miniGOP boundary; and a minimum distance condition from a previous switch between the first encoding mode and the second encoding mode.

14. The method of claim 8 , further comprising:
decreasing the quantization parameter responsive to switching to the second encoding mode.

15. A video processing device comprising:
an interface to receive an input video stream, the input video stream comprising a sequence of frames, each frame representing a corresponding single picture comprising two fields: an odd field having the odd numbered rows of the picture and an even field having the even numbered rows of the picture; and
an encoder to encode the input video stream to generate an encoded video stream, wherein the encoder is to dynamically switch between a first encoding mode and a second encoding mode responsive to a variable quantization parameter, wherein:
in the first encoding mode the encoder is to encode both fields of a corresponding frame of the sequence; and
in the second encoding mode the encoder is to encode only one field of the two fields of a corresponding frame of the sequence.

16. The video processing device of claim 15 , wherein the encoder is to dynamically switch between the first encoding mode and the second encoding mode by switching to the second encoding mode responsive to the quantization parameter exceeding a first threshold.

17. The video processing device of claim 16 , wherein the encoder is to dynamically switch between the first encoding mode and the second encoding mode further by switching to the first encoding mode responsive to the quantization parameter falling below a second threshold.

18. The video processing device of claim 15 , wherein in the first encoding mode the encoder further is to select between a frame-based encoding sub-mode and a field-based encoding sub-mode for a corresponding frame based on a motion analysis between the two fields of the corresponding frame.

19. The video processing device of claim 15 , wherein the encoder is to delay a switch between the first encoding mode and the second encoding mode until a specified switch point.

20. The video processing device of claim 15 , wherein the encoder further is to decrease the quantization parameter responsive to switching to the second encoding mode.

Assignees

• Zhao Xu Gang
• Li Ying
• Vixs Systems Inc

Inventors

• Zhao Xu Gang
• Li Ying

Classifications

• H04N19/172

  the region being a picture, frame or field · CPC title

• H04N19/149

  by estimating the code amount by means of a model, e.g. mathematical model or statistical model · CPC title

• H04N19/112 Primary

  according to a given display mode, e.g. for interlaced or progressive display mode · CPC title

• H04N19/124

  Quantisation · CPC title