A video file transcoding method

Abstract

The invention discloses a video file transcoding method. The video file transcoding method comprises the following steps of using a first constant quantization parameter to encode a video file so as to obtain a first transcoding video file; predicting a second constant quantization parameter which is adopted when code reduction is carried out on the first transcoding video file and the code rate of the first transcoding video file is larger than a target code rate, and obtaining when the code rate of the video file is smaller than the target code rate; using the second constant quantization parameter to carry out code reduction on the first transcoding video file so as to obtain a second transcoding video file. According to the video file transcoding method, due to the fact that the constant quantization parameters for code reduction of the video file are predicted, twice code reduction needs to be carried out on the video file at most, the frequency of code reduction of the video file is reduced, on the premise that video quality is ensured, and image quality cannot have visual difference along with changes of scenes, it is ensured that the output code rate of the video file is controllable, and the transcoding time is controllable, and the overall effect of transcoding of the video file is improved.

Description

technical field [0001] The invention relates to the technical field of video processing, in particular to a video file transcoding method. Background technique [0002] With the development of network video technology, people are more and more exposed to various videos. Users can watch them through terminals such as computers, mobile phones, and tablet computers. The processing of video files is becoming more and more complicated. Users The requirements for video file transcoding are becoming more and more stringent and detailed. [0003] Generally, the transcoding of video files can be processed in a variety of ways, such as using CRF (constant ratefactor / constant quality, constant quality mode): by reducing relatively unimportant frames (such as consuming bit rate, difficult to encode frames) quality, save the bit rate and use it on relatively effective frames. CRF quantization scales range from 0 to 51 (8-bitx264 and 10-bitx264 quantization scales range from 0 to 63), w...

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Problems solved by technology

[0004] The inventors of this application found that for large files, it may take multiple downsizing to achieve the quantization ratio within the specified range, increasing the encoding time, the output bit rate is uncontrollable, and the quality of encoded files within the specified bit rate range cannot be guaranteed.

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