Video frame coding method during scene change, terminal and storage medium

Patent metadata

Field	Value
Publication number	US-11089305-B2
Application number	US-201916426915-A
Country	US
Kind code	B2
Filing date	May 30, 2019
Priority date	Aug 17, 2017
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

Disclosed are a video frame coding method performed at a terminal. The method includes: obtaining and coding an i th video frame in a group of pictures, and counting a quantity of actually consumed bits corresponding to the i th video frame; detecting a state of the i th video frame based on the quantity of actually consumed bits, an initial average bit rate of the group of pictures, a quantization model, and a video frame detection rule, and determining multiple quantization parameters of a (i+1) th video frame; and determining first quantities of allocated bits for compensation of first to-be-compensated video frames; updating the first coding rule according to a first quantity of allocated bits for compensation, the quantization parameters corresponding to the (i+1) th video frame, and coding the (i+1) th video frame.

First claim

What is claimed is:

1. A video frame coding method performed at a terminal having one or more processors and memory storing a plurality of programs to be executed by the one or more processors, the method comprising:
obtaining an ith video frame in a group of pictures, performing video coding on the ith video frame by using a first coding rule according to a frame type of the ith video frame, and counting a quantity of actually consumed bits corresponding to the ith video frame after coding, i being greater than or equal to 1 and less than or equal to N, and N being a total quantity of video frames in the group of pictures;
detecting whether the ith video frame is in a scene change state based on the quantity of actually consumed bits, an initial average bit rate of the group of pictures, and a video frame detection rule;
determining a first initial quantization parameter, a first maximum quantization parameter, and a first minimum quantization parameter corresponding to a (i+1)th video frame based on the quantity of actually consumed bits, the initial average bit rate of the group of pictures and a quantization model when the ith video frame is in the scene change state;
obtaining a length of a compensation window according to a ratio of the quantity of actually consumed bits of the ith video frame and the initial average bit rate of the group of pictures, and determining, based on the length of the compensation window, first to-be-compensated video frames in the compensation window and first quantities of allocated bits for compensation corresponding to the first to-be-compensated video frames respectively; and
updating the first coding rule according to a first quantity of allocated bits for compensation, the first initial quantization parameter, the first maximum quantization parameter, and the first minimum quantization parameter corresponding to the (i+1)th video frame when the (i+1)th video frame belongs to the first to-be-compensated video frames in the compensation window, and entering a video coding process of the (i+1)th video frame, until coding of an Nth video frame is finished.

2. The method according to claim 1 , wherein the video frame detection rule comprises a first video frame detection rule, and the operation of detecting whether the ith video frame is in a scene change state based on the quantity of actually consumed bits, an initial average bit rate of the group of pictures, and a video frame detection rule comprises:
detecting a frame type of the ith video frame;
obtaining a remaining average bit rate of the group of pictures when the frame type is a target frame type; and
detecting whether the ith video frame is in the scene change state according to the quantity of actually consumed bits, the initial average bit rate of the group of pictures, the remaining average bit rate of the group of pictures, and the first video frame detection rule.

3. The method according to claim 2 , wherein the video frame detection rule further comprises a second video frame detection rule, and the method further comprises:
detecting whether the ith video frame is in the scene change state according to the quantity of actually consumed bits, the initial average bit rate of the group of pictures, and the second video frame detection rule when the frame type is not the target frame type.

4. The method according to claim 1 , wherein the operation of performing video coding on the ith video frame by using a first coding rule comprises:
obtaining a second quantity of allocated bits for compensation corresponding to the ith video frame from second quantities of allocated bits for compensation corresponding to second to-be-compensated video frames respectively when the ith video frame belongs to the second to-be-compensated video frames, the second to-be-compensated video frames being determined after video coding is performed on a video frame prior to the ith video frame;
calculating a second quantization parameter of the ith video frame based on the second quantity of allocated bits for compensation corresponding to the ith video frame;
obtaining a second initial quantization parameter, a second maximum quantization parameter, and a second minimum quantization parameter, the second initial quantization parameter, the second maximum quantization parameter, and the second minimum quantization parameter being determined after a (i−1)th video frame is coded;
coding the ith video frame according to the second quantization parameter, the second initial quantization parameter, the second maximum quantization parameter, and the second minimum quantization parameter, an upper limit value of the second quantization parameter being the second maximum quantization parameter, and a lower limit value being the second minimum quantization parameter.

5. The method according to claim 4 , wherein the operation of performing video coding on the ith video frame by using a first coding rule comprises:
calculating a third quantization parameter of the ith video frame according to a target bit quantity when the ith video frame does not belong to the second to-be-compensated video frames, the target bit quantity being a quantity of bits pre-allocated for the ith video frame; and
performing video coding on the ith video frame according to the third quantization parameter.

6. The method according to claim 1 , further comprising:
adjusting the first initial quantization parameter, the first maximum quantization parameter, and the first minimum quantization parameter according to a quantization adjustment model, to obtain a first adjustment initial quantization parameter, a first adjustment maximum quantization parameter, and a first adjustment minimum quantization parameter, when the quantity of actually consumed bits and a target bit quantity meet a ratio condition.

7. The method according to claim 6 , wherein the operation of updating the first coding rule according to the first quantity of allocated bits for compensation, the first initial quantization parameter, the first maximum quantization parameter, and the first minimum quantization parameter comprises:
updating the first coding rule according to the first quantity of allocated bits for compensation, the first adjustment initial quantization parameter, the first adjustment maximum quantization parameter, and the first adjustment minimum quantization parameter.

8. The method according to claim 1 , further comprising:
entering the video coding process of the (i+1)th video frame when the ith video frame is not in the scene change state, until coding of the Nth video frame is finished.

9. A terminal, comprising memory, one or more processors, and a plurality of computer readable instructions stored in the memory that, when executed by the one or more processors, cause the terminal to perform a plurality of operations including:
obtaining an ith video frame in a group of pictures, performing video coding on the ith video frame by using a first coding rule according to a frame type of the ith video frame, and counting a quantity of actually consumed bits corresponding to the ith video frame after coding, i being greater than or equal to 1 and less than or equal to N, and N being a total quantity of video frames in the group of pictures;
detecting whether the ith video frame is in a scene change state based on the quantity of actually consumed bits, an initial average bit rate of the group of pictures, and a video frame detection rule;
determining a first initial quantization parameter, a first maximum quantization parameter, and a first minimum quantization parameter corresponding to a (i+1)th video frame based on the quantity of actually consumed bits, the initial average bit rate of the group of p

Assignees

• Tencent Tech Shenzhen Co Ltd

Inventors

• Guo Yaoyao
• Mao Xunan
• Gu Chenchen
• Gao Xinwei
• Lv Jing

Classifications

• H04N19/142

  Detection of scene cut or scene change · CPC title

• H04N19/172 Primary

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

• H04N19/146

  Data rate or code amount at the encoder output · CPC title

• H04N19/124 Primary

  Quantisation · CPC title

• H04N19/00

  Methods or arrangements for coding, decoding, compressing or decompressing digital video signals · CPC title