A Fast Transcoding Technique From MPEG-2 To MPEG-1 in the DCT Domain with Downsampling
Cai An-ni · Microelectronics & Computer · 2006
In this papar,we proposed a fast transcoding algorithm from MPEG-2 to MPEG-1 with 2:1 quasi-convuluted downsampling in the DCT domain. During MPEG-1 transcoding processing, the head information obtained from the incoming MPEG-2 video stream are kept unchanged, The motion vector, macroblock type, quantiztion parameter are directly obtained from the corresponding four macroblocks available in the incoming MPEG-2 bitstream information according to maximizing and minimizing distance,the simple Majority rule and quantiztion parameter weighted average respectively. In addition, the source of transcoding distortion for reduced spatial resolution reduction transcoding was analyzed.The experimental results show that our method not only achieves decrease by 67.6 per cent in the computational complexity and and improvement with 0.1dB peak signal-to-noise ratio(PNSR) but also yields a much smaller bit control error. when compared with the Cascaded Pixel-Domain Transcoding Methods with TM5 rate control algorithm.