H.264编码器参考帧内存优化方法

提出了一种优化参考帧内存的新方法：每个参考帧的亮度参考图像仅包含了图像内的整数像素和扩展边界中的整数像素;在运动矢量搜索时先利用亮度参考图像找到整数运动矢量,而后由整数运动矢量搜索分数运动矢量,在每一次的搜索过程中根据搜索位置的分数运动矢量在亮度参考图像上找到对应的整数像素子块,对该子块进行插值运算获取所需的参考子块并进一步处理而获取对应代价,最后根据代价最小准则获取最佳运动矢量.试验证明这种优化方法能大大减小内存,且保证图像质量和码率几乎没有变化.

Effective Memory Reduction Scheme Used for Reference Frames in H.264/AVC Encoder

An effective memory reduction scheme used for reference frames in H.264 encoder is proposed in this paper. The samples of luma component of reference frame are only composed of integer samples in the image and the integer samples in the extended region of the image. During the process of searching for motion vector, integer vector is searched for by use of the reference frame, and then fractional motion vector is searched according to integer motion vector. During each course of searching for motion vector, the corresponding block in reference frame is found, and the reference block is acquired by interpolation from the corresponding block. The best motion vector is acquired according to cost derived during each search. Experimental results show that the scheme can greatly reduce memory used for reference frame with negligible loss of PSNR and little increase of bite-rate.