• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.268-270
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• 2001

히스토그램을 이용한 장면 전환 검출 기법은 순차적으로 접근하여 모든 프레임의 히스토그램을 구하고 각 히스토그램의 차를 이용하여 장면 전환을 검출한다. 하지만, 장면 전환이 비교적 적게 나타나는 부분에서는 모든 프레임을 비교한다는 것은 비효율적이다. 본 논문에서는 모든 프레임을 순차적으로 비교하지 않고 가중치를 조절하여 장면 전환이 거의 발생하지 않는 경우는 많은 프레임을, 장면 전환이 많은 곳에서는 적은 프레임을 생략하여 히스토그램을 비교하는 방법을 제안한다. 이 방법은 생략하는 프레임 수를 조절하기 때문에 순차적으로 처리하는 것보다 빠른 처리 시간을 보일 수 있다.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.191-194
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• 2012

The split flag and the skip flag in CU syntax have high correlation on spatial domain as well as temporal domain. This paper suggests a method for enhancing coding efficiency by using not only spatial correlation but also temporal correlation when coding CU information. In the CABAC case, temporal collocated CU information is used for selecting context model of the split flag and the skip flag. In the CAVLC case, current CU information is estimated from temporal collocated CU information then encoded. As a result, a coding efficiency was increased by 0.1%~0.6% in CABAC, 0.1%~0.4% in CAVLC compared with HM 3.0. This method shows better performance on lowdelay condition which uses reference frame close to current frame.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.2
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• pp.48-56
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• 2009

We propose a fast intra mode skip decision algorithm for H.264/AVC video encoding. Although newly added MB encoding algorithms based on various prediction methods increase compression ratio, they require a significant increase in the computational complexity because we calculate rate-distortion(RD) cost for all possible MB coding modes and then choose the best one. In this paper, we propose a fast mode decision algorithm based on an adaptive motion vector map(AMVM) method for H.264/AVC video encoding to reduce the processing time for the inter frame. We verify that the proposed algorithm generates generally good performances in PSNR, bit rates, and processing time.

• Journal of Korea Multimedia Society
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• v.15 no.9
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• pp.1086-1092
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• 2012

In this paper, we propose the rate control scheme reducing frame skipping at low bit-rate. As the method considering lossy parts in the compressing process at the existing scheme, the proposed scheme is improved by subtracting the converted bits from the target bit-rate of the current frame. The converted bits are the value resulted from multiplying the ratio of the current frame MAD to the previous frame MAD by the compressed bits changed from the remaining values after compressing the previous frame.

• The KIPS Transactions:PartB
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• v.13B no.3 s.106
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• pp.245-254
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• 2006

In this work, a new rate control algorithm for transmission of H.264/AVC video bit stream through CBR(constant bit rate) channel is proposed. The proposed algorithm predicts target bit rate and MAD(mean of absolute difference) for current frame considering image complexity variance between neighboring backward and current images. In details, respective linear regression analysis for MAD and encoded bit rate against image complexity variance produce correlation parameters. Additionally, it uses frame skip technique to maintain bit stream within a manageable range and protect buffer from overflow or underflow. Implementation and experimental results show that the proposed algorithm can provide accurate bit allocation, and can effectively visual degradation after scene changes. Also our proposed algorithm encodes the video sequences with less frame skipping compared to the existing rate control for H.264/AVC.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.953-960
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• 2002

Rel-time application programs have constraints which need to be met between media-data. It is client-leading synchronization that is absorbing variable transmission delay time and that is synchronizing by feedback control and palyout control. It is the important factor for playback rate and QoS if the buffer level is normal or not. This paper, The method of maintenance buffer normal state transmits in multimedia server by appling feedback of filtering function. And synchronization method is processing adaptive playout time for smooth presentation without cut-off while media frame is skip. When audio frame which is master media is in upper threshold buffer level we decrease play out time gradually, low threshold buffer level increase it slowly.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.2
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• pp.408-427
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• 2011

Intensive computational complexity is an obstacle of enabling multiview video coding for real-time applications. In this paper, we present a fast macroblock (MB) mode selection algorithm for B frames which are based on the computational complexity analyses between the MB mode selection and reference frame selection. Three strategies are proposed to reduce the coding complexity jointly. First, the temporal correlation of MB modes between current MB and its temporal corresponding MBs is utilized to reduce computational complexity in determining the optimal MB mode. Secondly, Lagrangian cost of SKIP mode is compared with that of Inter $16{\times}16$ modes to early terminate the mode selection process. Thirdly, reference frame correlation among different Inter modes is exploited to reduce the number of reference frames. Experimental results show that the proposed algorithm can promote the encoding speed by 3.71~7.22 times with 0.08dB PSNR degradation and 2.03% bitrate increase on average compared with the joint multiview video model.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1288-1291
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• 2002

In this paper, we present a design of mpeg-4 video codec chip to reduce the power consumption using frame level clock gating and motion estimation skip scheme. It performs 30 grames/s of codec (encoding and decoding) mode with quarter-common intermediate format(QCIF) at 27MHz. A novel low-power techniques were implemented in architectural level, which is 35% of the power dissipation for a conventional CMOS design. This chip performs MPEG-4 Simple Profile Level 2(Simple@L2) and H.263 base mode. Its contains 388,885 gates, 662k bits memory, and the chip size was 9.7 mm x 9.7 mm which was fabricated using 0.35 micron 3-layers metal CMOS technology.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.257-260
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• 2002

히스토그램을 이용한 장면 전환 검출 기법은 순차적으로 접근하여 모든 프레임의 히스토그램을 구하고 각 히스토그램의 차를 이용하여 장면 전환 지정을 검출한다. 그러나, 이 방법은 장면 전환이 비교적 적게 일어나는 동영상 데이터에는 비효율적이므로 고정된 간격으로 프레임을 생략하거나, 가중치를 조절하여 가변적으로 프레임을 생략하는 히스토그램 비교법이 개발되어 왔다. 본 논문에서는 교육용 비디오를 위한 개선된 가변길이 프레임 생략법을 제안할 것이다. 이를 위해서 여러 가지 가중치를 사용하여 실험을 통한 좋은 가중치를 제시하고자 한다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.1
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• pp.72-78
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• 2003

A new self-organizing neuro-fuzzy network based rate control algorithm for MPEG-4 video encoder is proposed in this paper. Contrary to the traditional methods that construct the rate-distorion (RD) model based on experimental equations, the proposed method effectively exploits the non-stationary property of the video date with neuro-fuzzy network that self-organizes the RD model online and adaptively updates the structure. The method needs not require off-line pre-training; hence it is geared toward real-time coding. The comparative results through the experiments suggest that our proposed rate control scheme encodes the video sequences with less frame skip, providing good temporal quality and higher PSNR, compared to VM18.0.