一种面向HEVC的并行码率控制算法

视频通信时通常带宽有限,为了能在规定的目标码率下获得尽可能高质量的解码图像,需要在视频编码时进行码率控制.目前针对HEVC的并行编码以及对应码率控制已成为研究热点,现有并行结构下的平均比特率控制算法受到帧间依赖性的约束,待编码帧无法及时获得与其并行编码帧的实际比特数,因此本文算法通过预测并行帧的实际比特数来进行码率控制,并在此基础提出了自适应调整帧层量化参数补偿值.仿真结果表明,相比已有算法,前者减少码率误差约为3.38％,后者可提高PSNR约为0.204 dB同时减少约0.3％的码率误差.

A parallel bit-rate control algorithm for HEVC

During the transmission process of video communication, the network bandwidth is limited, in order to achieve high quality of decoded image under the condition of a given target bitrate, a rate control regulation is required in the video codec. The parallel encoding and rate control for HEVC has become advanced research focus. The average bit rate control algorithms under existing parallel structure is restrained by the inter-dependent, so the coding frame can not timely obtain the actual bits of frames which are in parallel with it. Therefore, in this paper, it predicts the actual bits of the frame for rate control. On this basis, a new compensation algorithm is proposed in the frame layer to adjust the Quantization Parameter(QP) of the current frame. The results show that the first method reduces the rate of error by 3.38%, and the second one improves the average Peak Signal-to-Noise Ratio (PSNR) of 0.204dB and with 0.3% reduction of the rate of error simutaneously.