计算机工程与应用 ›› 2012, Vol. 48 ›› Issue (23): 191-195.

• 图形、图像、模式识别 • 上一篇    下一篇

H.264帧内预测快速模式选择

李世平,郑文彬   

  1. 东北大学 信息科学与工程学院,沈阳 110004
  • 出版日期:2012-08-11 发布日期:2012-08-21

Fast intra mode decision for H.264/AVC encoding

LI Shiping, ZHENG Wenbin   

  1. School of Information Science and Engineering, Northeastern University, Shenyang 110004, China
  • Online:2012-08-11 Published:2012-08-21

摘要: H.264/AVC视频编码标准中用率失真优化(RDO)方法为一个宏块(MB)判决最佳编码模式来提高编码效果,加大了算法复杂度并且计算冗余大。为了克服这一缺点,一种快速帧内预测模式选择算法被提出。在色度预测中,根据宏块的色度纹理复杂度,把原先的4种模式降到1或2种;在亮度16×16块模式判决中,根据最小哈达玛变换的绝对误差和(SATD)来选择最佳模式;在亮度4×4块模式判决中,该算法在9种模式中选择3种可能模式作为候选模式。通过比较16个4×4块总代价与1个16×16块的代价来选择最佳块选择模式,实验表明,该算法能在节省69%左右编码时间的情况下,比特率与峰值信噪比(PSNR)保持不变。

关键词: H.264/AVC, 帧内预测, 模式选择

Abstract: H.264/AVC uses the rate distortion optimization method to determine the best mode for a macroblock (MB) to improve coding efficiency. But it increases computational complexity. To overcome this shortcoming, a fast intra mode decision algorithm for H.264 is raised. In chroma prediction, four prediction modes can be reduced into one or two modes according to the textural features of a MB. In luma 16×16 prediction, the mode which has lowest Sum of Absolute Transformed Difference(SATD) can be selected as the best prediction mode. In luma 4×4 prediction, the algorithm chooses three probable modes from nine modes as the candidate modes. Comparing the total cost of sixteen 4×4 blocks and one 16×16 block, the best block size can be determined. Experimental results show that the coding time of the propose method is decrease about 68% while maintaining similar PSNR and bit rate performance of H.264 intra encoding.

Key words: H.264/AVC, intra prediction, mode select