公开(公告)号：KR1020030006641A

公开(公告)日：2003-01-23

申请号：KR1020010042486

申请日：2001-07-13

Applicant: 전자부품연구원

Inventor： 김제우 ,  정혁구 ,  최병호 ,  백종호 ,  송혁 ,  백준기 ,  황인경

IPC: H04N7/24

CPC classification number: H04N19/60 ,  H04N19/124 ,  H04N19/184 ,  H04N19/51 ,  H04N19/91

Abstract: PURPOSE: A transcoder and a method for transcoding thereof are provided to prevent deterioration of picture quality although video frames are consecutively transcoded. CONSTITUTION: A transcoder includes a VLD(Variable Length Decoder)(111) receiving R1 bit rate video bit stream for entropy decoding, thereby outputting a quantized DCT(Discrete Cosine Transform) coefficient and parameters for motion compensation; a first inverse quantizing part(112) receiving the quantized DCT coefficient for executing an inverse quantization using a quantizing table, and outputting a DCT coefficient including a quantizing error; a first MCD(Motion Compensation Decision)(114) generating a compensation image at a DCT area by executing motion compensation and half pixel motion compensation for the current image at the DCT area by using the motion vector of the VLD and a reference image; an adder(113) generating a restored image at the DCT area by adding the DCT coefficient including the quantizing error and the compensation image; a decoder(110) including a frame memory(115) receiving the restored image to be stored as the reference image to be provided to the first MCD; and an encoder(120) receiving the restored image of the decoder for generating image bit stream having R2 bit rate video bit stream.

Abstract translation: 目的：提供代码转换器及其代码转换方法，以防止图像质量的劣化，尽管视频帧被连续转码。 构成：代码转换器包括接收用于熵解码的R1比特率视频比特流的VLD（可变长度解码器）（111），从而输出用于运动补偿的量化DCT（离散余弦变换）系数和参数; 接收用于使用量化表执行逆量化的量化DCT系数并输出包括量化误差的DCT系数的第一逆量化部分（112） 第一MCD（运动补偿判定）（114），通过使用VLD的运动矢量和参考图像对DCT区域执行运动补偿和当前图像的半像素运动补偿，在DCT区域产生补偿图像; 加法器（113），通过将包括量化误差和补偿图像的DCT系数相加，在DCT区域生成恢复图像; 解码器（110），包括接收要存储的恢复图像作为要提供给第一MCD的参考图像的帧存储器（115）; 以及编码器（120），接收用于产生具有R2比特率视频比特流的图像比特流的解码器的恢复图像。