A h264 video coding rate control method

Abstract

The invention provides a code rate control method of H264 video coding, and belongs to the technical field of video coding. The method comprises the steps of: first, determining a target bit number of a current coding frame according to an image complexity factor characterized by a frame difference method; and then, calculating a quantization parameter and carrying out rate-distortion optimization. According to the method provided by the invention, a quantization adjustment coefficient is introduced, the quantization adjustment coefficient is calculated according to the filling degree of a buffer area, and then the quantization parameter of the current frame is adjusted by the quantization adjustment coefficient. Compared with the prior art, the code rate control precision is improved while a better video quality is obtained, the lower filling degree of the buffer area can be maintained, and frame skip is avoided, so that the continuity and stability of video images are improved. The method provided by the invention is simple in algorithm, easy for hardware implementation and better in application prospect.

Description

Technical field [0001] The present invention belongs to the technical field of video coding, and specifically refers to a H264 video coding rate control method. Background technique [0002] In video communication, the compressed and encoded information stream often needs to be transmitted on a network with unbalanced bandwidth. In order to make the encoded video stream well adapt to the bandwidth, especially to adapt to low-bandwidth channels or time-varying wireless channels and make full use of limited network resources, rate control has become an indispensable link in the video communication system. The main task of bit rate control is to collect information such as buffer status and image activity to allocate a certain number of bits to each image, so that the output bit rate can be controlled on a given standard and image distortion is minimized. [0003] In the rate control method of H264 (or H.264) / AVC, the quantization parameter is used in the rate control and rate distor...

AI Technical Summary

Problems solved by technology

This method does not consider the impact of the buffer fullness on the current frame rate control when adjusting the quantization parameters, and the adjustment strategy is relatively simple

When the buffer fullness is greater than the target buffer, the buffer will overflow, and frame skipping will occur during the encoding process, which will affect the encoding quality

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