• Journal of Korea Multimedia Society
• /
• v.9 no.7
• /
• pp.818-826
• /
• 2006

In this paper, we investigate the relationship of bitrate and quantization parameter needed for the trans-coding method that makes the H.264 bitstream of a particular bitrate to the other titrate. Also we propose the new method in order to transcode the titrate between H.264 video coded bitstreams. The proposed transcoding method updates the model parameters from previous picture or slice by using the approximated relationship of bitrate and quantization step-size and finds the target quantization step-size, and then generates the target titrate by simple coding processing just after requantization. Therefore, the proposed method does not need the complex bitrate control and converts to the target titrate by simple implementation. From simulation, we can see that the proposed method transcodes exactly to an assigned target bitrate for the four test sequences with different their characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05b
• /
• pp.136-139
• /
• 2004

This thesis is realization of embedded system that of MPEG-2 down conversion using IDCT. A method for down conversion of MPEG compressed video is to perform low-pass filtering and sub-sampling after full decompression. However, this method is need large memory and high computational complexity. Recent research has been focussed on the down conversion in the DCT domain. But DCT method is reduced image qualify. The embedded system is require low complexity, and high speed algorithm. When applied to embedded system that down conversion method, DCT method is played average 29 frame per second, and better 25% than spatial-domain down conversion.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.04a
• /
• pp.185-186
• /
• 2009

VOD 서비스는 초고속 인터넷을 이용하여 정보 서비스, 동영상 콘텐츠 및 방송 등을 실시간으로 제공하는 것이다. 본 연구에서 구현하는 VOD 시스템은 기존 인터넷망에 멀티캐스트 기술을 접목하여, 비트열변환 방식과 다수개 영상저장 방식을 비교한다. 이로부터 동영상을 각 가정의 PC에 고화질 주문형 비디오/영화, TV 등 다양한 고품질 서비스를 제공할 수 있을 것이다.

• Journal of KIISE:Software and Applications
• /
• v.32 no.10
• /
• pp.956-962
• /
• 2005

To improve video quality and coding efficiency, H.264/AVC adopts different half pixel calculating method compared with the previous standards. So, the transcoder requires additional works to transcode the pre-coded video contents with the previous standards to H.264/AVC in DCT domain. In this paper, we propose the first half-pixel correction method for MPEG-2 to H.264 transcoding in DCT domain. In the proposed method, MPEG-2 block is added to the correction block obtained by difference calculation of half-pixel values between two standards using DCT reference frame. Experimental results show that the proposed achieves better quality than pixel based cascaded transcoding method.