| 摘要 |
PURPOSE: A transcoding device is provided to use video-decoded MPEG-2 parameters when converting an HD MPEG sequence over 10Mbps into an NTSC MPEG sequence below 6Mbps, thereby performing motion compensation and reducing a calculating time. CONSTITUTION: A video preprocessor(300) down-samples a macro block decoded in a decoder(103). A transcoding parameter controller(500) detects information on a picture from a previous bit stream whose variable length is decoded, and sets an encoding mode for transcoding. A re-coding unit codes differential data between down-sampled data of the video preprocessor and motion-compensated data according to the encoding mode, via a DCT(Discrete Cosine Transform) process, a quantization process, and a VLC(Variable Length Coding) process, and adds quantized data to the motion-compensated data via an IQ(Inverse Quantization) process and an IDCT(Inverse DCT) process, then stores the added data in an external memory(15). |
