Encoder and associated encoding method

Abstract

The present invention provides an encoding method, which includes the following steps: determining a first quantization parameter of a first super block of an image frame; determining a binary code of the first super block; determining whether binary code information of the first super block is greater than a first threshold value; and if the binary code information of the first super block is greater than the first threshold value, increasing a second quantization parameter of a second super block.

Claims

1. An encoding method comprising: determining a first quantization parameter of a first superblock of an image frame; determining a binary code of the first superblock, wherein the binary code is used to be encoded by an encoding circuit to generate encoded data of the first superblock; determining whether the binary code information of the first superblock is greater than a first threshold; and if the binary code information of the first superblock is greater than the first threshold, increasing a second quantization parameter of a second superblock of the image frame.

2. The encoding method as described in claim 1, wherein the binary code information of the first superblock is the amount of binary code data or the binary code rate of all superblocks in a column of superblocks to which the first superblock belongs that have had their binary codes determined.

3. The encoding method as described in claim 1, wherein if the binary code information of the first superblock is greater than the first threshold, the step of increasing the second quantization parameter of the second superblock includes: generating an initial second quantization parameter of the second superblock based at least on the first quantization parameter; and adding an offset value to the initial second quantization parameter to generate the second quantization parameter.

4. The encoding method as described in claim 3 further includes the steps of: generating a bit of the encoded data of the first superblock based on the binary code of the first superblock; and generating an initial second quantization parameter of the second superblock based at least on the first quantization parameter, comprising: generating the initial second quantization parameter of the second superblock based at least on the first quantization parameter and the bit of the encoded data of the first superblock.

5. The encoding method as described in claim 4, wherein the step of generating the number of bits of the encoded data of the first superblock based on the binary code of the first superblock comprises: using a lookup table to obtain an estimated number of bits based on the binary code of the first superblock, as the number of bits of the encoded data of the first superblock.

6. The encoding method as described in claim 5 further comprises: using the first quantization parameter to encode the binary code of the first superblock to generate an actual number of bits of the encoded data of the first superblock; and using the actual number of bits to update the estimated number of bits.

7. The encoding method as described in claim 5 further comprises: determining whether the binary code information of the first superblock is greater than a second threshold value, wherein the second threshold value is greater than the first threshold value; if the binary code information is not greater than the second threshold value, using the first quantization parameter to encode the binary code of the first superblock to generate an actual number of bits of the encoded data of the first superblock, and using the actual number of bits to update the estimated number of bits; and if the binary code information is greater than the second threshold value, entering a one-bit upper limit mode, and not updating the estimated number of bits.

8. The encoding method as described in claim 1, wherein the encoding method supports the AV1 video encoding format defined by the Open Media Consortium (AOMedia).

9. An encoder configured to perform the following operations: determining a first quantization parameter of a first superblock of an image frame; determining a binary code of the first superblock, wherein the binary code is used to be encoded by an encoding circuit to generate encoded data of the first superblock; determining whether the binary code information of the first superblock is greater than a first threshold; and if the binary code information of the first superblock is greater than the first threshold, increasing a second quantization parameter of a second superblock of the image frame.

10. The encoder as described in claim 9, wherein the step of increasing the second quantization parameter of the second superblock if the binary code information of the first superblock is greater than the first threshold includes: generating an initial second quantization parameter of the second superblock based at least on the first quantization parameter; and adding an offset value to the initial second quantization parameter to generate the second quantization parameter.

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