APPARATUS FOR CONTROLLING BIT RATE IN REVERSE PLAYBACK OF DIGITAL VIDEO STREAM AND METHOD THEREFOR

摘要

PURPOSE: An apparatus for controlling a bit rate in the reverse playback of a digital video stream and a method therefor are provided to control the bit rate of the video stream when the digital video stream of a GOP(Group Of Pictures) unit reversely plays back. CONSTITUTION: A picture classifier(110) receives a GOP and classifies an I(Intra-coded) picture, a P(Predicted-coded) picture and a B(Bidirectionally predicted-coded) picture. A bit rate determining unit(142) receives size information of an I picture of a primary sub-GOP in the GOP from the picture classifier, discriminates a bit rate, and determines bit rates of next sub-GOPs in the GOP using the discriminated bit rate. An I-frame encoder(140) receives the P picture, and converts the received P picture into an I picture to reversely play back at the determined bit rate. An I picture memory(160) and an I picture memory(150) store the I picture, the B picture from the picture classifier and the converted I picture. A video decoder(120) receives the I picture, the B picture and the converted I picture from the I picture memory and the I picture memory, decodes a digital video stream into a reverse playback video stream, and outputs the reverse playback video stream.