ENCODING DIGITAL VIDEO

• US 20110286529A1
• Filed: 08/05/2011
• Published: 11/24/2011
• Est. Priority Date: 10/02/2000
• Status: Active Grant

• Current Assignee: Nordic Interactive Technologies LLC (Tanit Ventures Inc.)
• Original Assignee: Wimaximum LLC (Intellectual Ventures LLC)
• Inventors: Meggers, Jens
• Granted Patent: US 8,971,414 B2
• Time in Patent Office: Days
• US Class Current: 375/240.24
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/15 by monitoring actual compressed data size at the memory before deciding storage at the transmission buffer
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/192 the adaptation method, adaptation tool or adaptation type being iterative or recursive
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/507 using conditional replenishment
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression

Abstract

A video encoder encodes the video stream frame by frame. An encoding process generally includes receiving a video frame, subdividing the video frame into uniform pixel blocks, comparing a selected pixel block with the corresponding pixel block in a previous decoded video frame to determine which blocks have changed, copying changed pixel blocks into a contiguous memory block, and adding a preamble block, compressing the blocks. This process may be repeated for each frame using a different size pixel block to determine and select a pixel block size that results in the smallest encoded frame.

Claims

1. An apparatus comprising:

a processor for analyzing blocks,

a tangible, non-transitory memory configured to communicate with the processor, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the processor, cause the processor to perform operations comprising determining, by the processor, which block size of multiple block sizes produces a smaller encoded frame, wherein the multiple block sizes are used to subdivide and compare a first video frame and a second video frame of a video stream to determine whether any blocks of the first video frame are sufficiently unchanged to be discarded.

2. The apparatus of claim 1, wherein the first video frame is compressed using a block size of the multiple block sizes determined to produce the smaller encoded frame.

3. The apparatus of claim 1, wherein a compressed video frame is stored in conjunction with an indication of the block size used to compress the first video frame.

4. The apparatus of claim 1, further comprising determining a luminance difference between the multiple block sizes of the first video frame and the multiple block sizes of the second video frame.

5. The apparatus of claim 4, wherein the luminance difference is associated with a threshold value.

6. The apparatus of claim 1, further comprising identifying changed blocks during the comparing of the first video frame and the second video frame of the video stream.

7. The apparatus of claim 6, further comprising associating a preamble block with the changed blocks, the preamble block identifying the changed blocks.

8. The apparatus of claim 7, wherein the preamble block indicates that the changed blocks are included in the contiguous block of memory.

9. The apparatus of claim 7, wherein the preamble block indicates the approximately uniform block size.

10. The apparatus of claim 3, further comprising associating a preamble block with the compressed video frame, the preamble block identifying the changed blocks associated with the first video frame and the unchanged blocks associated with the first video frame included in the compressed video frame.

11. The apparatus of claim 10, wherein the second video frame precedes the first video frame in the video stream.

12. The apparatus of claim 10, wherein the second video frame occurs after the first video frame in the video stream.

13. The apparatus of claim 1, wherein the video frame is configured to encode multiple video frames of the video stream using different block sizes.

14. A method comprising determining, by a computer-based system for analyzing blocks, which block size of multiple block sizes produces a smaller encoded frame, wherein the multiple block sizes are used to subdivide and compare a first video frame and a second video frame of a video stream to determine whether any blocks of the first video frame are sufficiently unchanged to be discarded.

15. The method of claim 14, wherein the first video frame is compressed using a block size of the multiple block sizes determined to produce the smaller encoded frame.

16. The method of claim 14, wherein a compressed video frame is stored in conjunction with an indication of the block size used to compress the first video frame.

17. The method of claim 14, wherein the determining comprises determining a luminance difference between the multiple block sizes of the first video frame and the multiple block sizes of the second video frame.

18. The method of claim 17, wherein the luminance difference is associated with a threshold value.

19. The method of claim 14, wherein the computer-based system is configured to encode multiple video frames of the video stream using different block sizes.

20. A computer-readable medium having stored thereon sequences of instructions, the sequences of instructions including instructions which, in response to execution by a computer-based system for analyzing blocks, cause the computer-based system to perform operations comprising determining, by the computer-based system, which block size of multiple block sizes produces a smaller encoded frame, wherein the multiple block sizes are used to subdivide and compare a first video frame and a second video frame of a video stream to determine whether any blocks of the first video frame are sufficiently unchanged to be discarded.