• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.835-849
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• 2013

Joint Collaborative Team on Video Coding (JCT-VC), which have founded ISO/IEC MPEG and ITU-T VCEG, has standardized High Efficiency Video Coding (HEVC). Standardization of HEVC has started with purpose of twice or more coding performance compared to H.264/AVC. However, flexible and hierarchical coding block and recursive coding structure are problems to overcome of HEVC standard. Many fast encoding algorithms for reducing computational complexity of HEVC encoder have been proposed. However, it is hard to implement a real-time HEVC encoder only with those fast encoding algorithms. In this paper, for implementation of software-based real-time HEVC encoder, data-level parallelism using SIMD instructions and CPU/GPU multi-threading methods are proposed. And we also proposed appropriate operations and functional modules to apply the proposed methods on HM 10.0 software. Evaluation of the proposed methods implemented on HM 10.0 software showed 20-30fps for $832{\times}480$ sequences and 5-10fps for $1920{\times}1080$ sequences, respectively.

• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.28-41
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• 2017

In this paper, the fast encoding algorithm in High Efficiency Video Coding (HEVC) encoder was studied. For the encoding efficiency, the current HEVC reference software is divided the input image into Coding Tree Unit (CTU). then, it should be re-divided into CU up to maximum depth in form of quad-tree for RDO (Rate-Distortion Optimization) in encoding precess. But, it is one of the reason why complexity is high in the encoding precess. In this paper, to reduce the high complexity in the encoding process, it proposed the method by determining the maximum depth of the CU using a hierarchical clustering at the pre-processing. The hierarchical clustering results represented an average combination of motion vectors (MV) on neighboring blocks. Experimental results showed that the proposed method could achieve an average of 16% time saving with minimal BD-rate loss at 1080p video resolution. When combined the previous fast algorithm, the proposed method could achieve an average 45.13% time saving with 1.84% BD-rate loss.

• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.1-14
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• 2017

This paper proposes adaptive reference structure decision method to improve the performance of HEVC (High Efficiency Video Coding) encoder. When an event occurs in the input sequence, such as scene change, scene rotation, fade in/out, or light on/off, the proposed algorithm changes the reference structure to improve the inter prediction performance. The proposed algorithm divides GOP (Group Of Pictures) into two sub-groups based on the picture that has such event and decides the reference pictures in the divided sub-groups. Also, this paper proposes fast encoding method which changes the picture type of first encoded picture in the GOP that has such event to CRA (Clean Random Access). With the statistical feature that intra prediction is selected by high probability for the first encoded picture in the GOP carrying such event, the proposed fast encoding method does not operate inter prediction. The experimental result shows that the proposed adaptive reference structure decision method improves the BD-rate 0.3% and reduces encoding time 4.9% on average under the CTC (Common Test Condition) for standardization. In addition, the proposed reference structure decision method with the picture type change reduces the average encoding time 12.2% with 0.11% BD-rate loss.

• Journal of Broadcast Engineering
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• v.22 no.3
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• pp.282-294
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• 2017

In this paper, we propose a novel intelligent headlight control (IHC) system which is durable to various road lights and camera movement caused by vehicle driving. For detecting candidate light blobs, the region of interest (ROI) is decided as front ROI (FROI) and back ROI (BROI) by considering the camera geometry based on perspective range estimation model. Then, light blobs such as headlights, taillights of vehicles, reflection light as well as the surrounding road lighting are segmented using two different adaptive thresholding. From the number of segmented blobs, taillights are first detected using the redness checking and random forest classifier based on Haar-like feature. For the headlight and taillight classification, we use the random forest instead of popular support vector machine or convolutional neural networks for supporting fast learning and testing in real-life applications. Pairing is performed by using the predefined geometric rules, such as vertical coordinate similarity and association check between blobs. The proposed algorithm was successfully applied to various driving sequences in night-time, and the results show that the performance of the proposed algorithms is better than that of recent related works.

• Journal of Broadcast Engineering
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• v.22 no.3
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• pp.295-312
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• 2017

Digital video content is the most information-intensive and high-value content. Therefore, it is necessary to protect the intellectual property rights of these contents, and this paper also proposes a watermarking method of digital image for this purpose. The proposed method uses the frequency characteristics of 2-Dimensional Discrete Wavelet Transform (2D-DWT) for digital images and digital watermark on global data without using local or specific data of the image for watermark embedding. The method to insert digital watermark data uses a simple Quantization Index Modulation (QIM) and a multiple watermarking method that inserts the same watermark data in multiple. When extracting a watermark, multiple watermarks are extracted and the final watermark data is determined by a simple statistical method. This method is an empirical method for experimentally determining the parameters in the watermark embedding process. The proposed method performs experiments on various images against various attacks and shows the superiority of the proposed method by comparing the performance with the representative existing methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.914-923
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• 2015

Recently, as the number of smart devices (such as smart TV or Web based IPTV) increases, the way of digital broadcast contents is changed. This change leads that conventional broadcast media accepts Web platform and its services to provide more quality contents. Based on this change, in education field, education broadcasting also follows the trend. The traditional education broadcasting platforms, which just delivered the lecture in one-way, are utilized the Web technology to make interaction between teacher and student. Current education platforms, however, are insufficient to satisfy users' demands for two-way interactions. This paper proposes a new remote collaborative learning platform which able to provide high interactivity among users. Based on new functional requirements from original use case, the platform provides collaborative contents sharing and collaborative video streaming techniques by utilizing WebRTC (Web Real-Time Communication) technology. The implementation demonstrates the operability of proposed system.

• Journal of Broadcast Engineering
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• v.9 no.4 s.25
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• pp.424-433
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• 2004

Jing(gong) is one of the most well known Korean traditional Samulnori instruments to the general public. Samulnori is consisted of four instruments, them being : the jingo the janggu (hour-glass drum). the kkwaenggwari, and the buk(drum). Of the four instruments, the jing with its deep, and yet soft and beautiful long lingering sound embraces the sounds of the other three. The jing is a brassware instrument, a compound of $70{\%}\;copper\;and\;22{\%}\;tin.$\;A high quality brassware is used when the jing is made. The jing is shaped with a 39-40cm circular plate and a rim that gives 7.0-7.5cm of depth to the instrument. Even with its most simple structure, when the circular plate is hit during performance, the rim which supports the circular plate gives resonance to the sound making low-frequency sounds. Therefore the range of the representative frequency of the full rim jing is between $118.4{\~}366.0[Hz],$\;the lingering sound lasts for more than 20 seconds afterwards. When the jing with half of its rim cut off is hit the basic frequency is $139.9{\~}387.5[Hz].$\;And the sound lasted for ten more seconds. The jing of its rimless frequencies are distributed between $990.5{\~}1,372[Hz].$\;And the lingering sound lasts for 5seconds afterwards. Therefore, different thickness and depth of the rim may give new resonance frequencies and alter the longing time of the sound. This thesis paper will try to reveal the relationship between the thickness or depth of the rim (which holds the bending circular plate) and the frequency or the lasting time of the sound.

• Journal of Broadcast Engineering
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• v.10 no.3
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• pp.413-421
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• 2005

As the population of HDTV is growing, among many useful features of modern set top boxes (STBs) or digital video recorders (DVRs), video browsing, visual bookmark, and picture-in-picture capabilities are very frequently required. These features typically employ reduced-size versions of video frames, or thumbnail images. Most thumbnail generation approaches generate DC images directly from a compressed video stream. A discrete cosine transform (DCT) coefficient for which the frequency is zero in both dimensions in a compressed block is called a DC coefficient and is simply used to construct a DC image. If a block has been encoded with field DCT, a few AC coefficients are needed to generate the DC image in addition to a DC coefficient. However, the bit length of a codeword coded with variable length coding (VLC) cannot be determined until the previous VLC codeword has been decoded, thus it is required that all codewords should be fully decoded regardless of their necessary for DC image generation. In this paper, we propose a method especially for fast DC image generation from an I-frame using multiple-symbol lookup table (mLUT). The experimental results show that the method using the mLUT improves the performance greatly by reducing LUT count by 50$\%$.

• Journal of Broadcast Engineering
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• v.6 no.3
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• pp.246-259
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• 2001

Due to recent rapid deployment of Internet streaming service and digital broadcasting service, the issue of how to efficiently support streaming workload in so called "Internet Home Appliance" receives prime interests from industry as well as academia. The underlying dilemma is that it may not be feasible to put cutting edge CPU, boards, disks and other peripherals into that type of device. The primary reason is its cost. Usually, Internet Home Appliances has its dedicated usage, e.g. Internet Radio, and thus it does not require high-end CPU nor high-end Va subsystem. The same reasoning applies to I/O subsystem. In Internet Home Appliances dedicated to handle compressed moving picture, it is not equipped with high end SCSI disk with fast rotational speed. Thus, it is mandatory to devise elaborate software algorithm to exploit the available hardware resources and maximize the efficiency of the system. This paper presents our experiences in the design and implementation of a new multimedia file system which can efficiently deliver the required disk bandwidth for a periodic I/O workload. We have implemented the file system on the Linux operating system, and examined itsperformance under streaming I/O workload. The results of the study show that the proposed file system exhibits superior performance than the Linux Ext2 file system under streaming I/O workload. The result of this work not only contribute to advance the state f art file system technology for multimedia streaming but also put forth the software which is readily available and can be deployed. deployed.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.410-426
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• 2003

MPEG-21 defines a digital item as an atomic unit lot creation, delivery and consumption in order to provide an integrated multimedia framework in networked environments. It is expected that MPEG-21 standardization makes it Possible for users to universally access user's preferred contents in their own way they want. In order to achieve this goal, MPEG-21 has standardized the specifications for the Digital Item Declaration (DID). Digital Identification (DII), Rights Expression Language (REL), Right Data Dictionary (RDD) and Digital Item Adaptation (DIA), and is standardizing the specifications for the Digital Item Processing (DIP), Persistent Association Technology (PAT) and Intellectual Property Management and Protection (IPMP) tot transparent and secured usage of multimedia. In this paper, we design an MPEG-21 terminal architecture based one the MPEG-21 standard with DID, DIA and DIP, and implement with the MPEG-21 terminal. We make a video summarization service scenario in order to validate ow proposed MPEG-21 terminal for the feasibility to of DID, DIA and DIP. Then we present a series of experimental results that digital items are processed as a specific form after adaptation fit for the characteristics of MPEG-21 terminal and are consumed with interoperability based on a PC and a PDA platform. It is believed that this paper has n important significance in the sense that we, for the first time, implement an MPEG-21 terminal which allows for a video summarization service application in an interoperable way for digital item adaptation and processing nth experimental results.