针对MPEG-4（Moving Picture Experts Group-4）视频编码器每个宏块在传送过程中Cache严重缺失，视频序列帧率低等问题，提出了运动估计算法的优化、Cache使用优化、SAD（Sum of Absolute Difference）和像素插值优化以及利用EDMA（Exte...针对MPEG-4（Moving Picture Experts Group-4）视频编码器每个宏块在传送过程中Cache严重缺失，视频序列帧率低等问题，提出了运动估计算法的优化、Cache使用优化、SAD（Sum of Absolute Difference）和像素插值优化以及利用EDMA（Extended Direct Memony Access）进行数据搬移等方法，提高存储速度，并在TMS320DM642 DSP（Digital Signal Processors）平台上实现了MPEG-4视频编码器的优化。实验结果表明，优化后比优化前，图像和视频处理函数的计算速度提高了1．18—97.5倍。视频序列帧率提高了6倍以上，达到了25帧／s的实时性要求。展开更多
For a very long time video processing dealt exclusively with fixed-rate sequences of rectangular shaped images. However, interest has been recently moving toward a more flexible concept in which the subject of the pro...For a very long time video processing dealt exclusively with fixed-rate sequences of rectangular shaped images. However, interest has been recently moving toward a more flexible concept in which the subject of the processing and encoding operations is a set of visual elements organized in both time and space in a flexible and arbitrarily complex way. The moving picture experts group (MPEG- 4) standard supports this concept and its verification model (VM) encoder has adopted scalable rate control (SRC) as the rate control scheme, which is based on the spatial domain and compatible with constant bit rate (CBR) and variable bit rate (VBR). In this paper,a new rate control algorithm based on the DCT domain instead of the pixel domain is presented. More-(over), macroblock level rate control scheme to compute the quantization step for each macroblock has been adopted. The experimental results show that the new algorithm can achieve a much better result than the original one in both peak signal-to-noise ratio (PSNR) and the coding bits, and that the new algorithm is more flexible than test model 5 (TM5) rate control algorithm.展开更多
文摘针对MPEG-4（Moving Picture Experts Group-4）视频编码器每个宏块在传送过程中Cache严重缺失，视频序列帧率低等问题，提出了运动估计算法的优化、Cache使用优化、SAD（Sum of Absolute Difference）和像素插值优化以及利用EDMA（Extended Direct Memony Access）进行数据搬移等方法，提高存储速度，并在TMS320DM642 DSP（Digital Signal Processors）平台上实现了MPEG-4视频编码器的优化。实验结果表明，优化后比优化前，图像和视频处理函数的计算速度提高了1．18—97.5倍。视频序列帧率提高了6倍以上，达到了25帧／s的实时性要求。
文摘For a very long time video processing dealt exclusively with fixed-rate sequences of rectangular shaped images. However, interest has been recently moving toward a more flexible concept in which the subject of the processing and encoding operations is a set of visual elements organized in both time and space in a flexible and arbitrarily complex way. The moving picture experts group (MPEG- 4) standard supports this concept and its verification model (VM) encoder has adopted scalable rate control (SRC) as the rate control scheme, which is based on the spatial domain and compatible with constant bit rate (CBR) and variable bit rate (VBR). In this paper,a new rate control algorithm based on the DCT domain instead of the pixel domain is presented. More-(over), macroblock level rate control scheme to compute the quantization step for each macroblock has been adopted. The experimental results show that the new algorithm can achieve a much better result than the original one in both peak signal-to-noise ratio (PSNR) and the coding bits, and that the new algorithm is more flexible than test model 5 (TM5) rate control algorithm.
