• Journal of Digital Convergence
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• v.13 no.11
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• pp.141-148
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• 2015

In this paper, for developing and implementing the HLS(Http Live Streaming) transmitter based embedded linux which is operated easily and cheap and lower power, portable in all networks and client environments compared to exist video live streaming transmitters. We design the developed HLS transmitter hardware using the Arm11 core and then porting the Embedded Linux OS(Operating System) and implementing the HLS protocol using the open source FFmpeg and Segmenter. For proving the performance of developed HLS transmitter, we make the testing environment for testing the performance of HLS transmitter including the notebook, iPhone, android Phone, Notebook and then analysis the received video in the client displayer. In this paper, we suggest the developed HLS transmitter performance data values higher than the Apple company's HLS recommended specification values and the picture of developed HLS transmitter operation in the testing environment. The application field of this paper result is that the man who works in the emergency situation take HLS and transmit the live emergency situation to the head quarter using this portable HLS.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.945-948
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• 2005

In wireless and handheld platforms area, performance, power and cost are key metrics for product success. This is driving increasing levels of on-chip integration in state-of-the-art application processors. The purpose of this project is to optimize and design the energy-efficient embedded system that properly displays video and audio in real time. The requirements are for the media player to be capable of decoding real-time streaming video and audio with the least possible energy consumption for a variety of different clips at different resolutions. We implemented this Linux based multimedia player on Intel's PXA27x platform.

• Journal of the Korea Convergence Society
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• v.2 no.1
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• pp.7-13
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• 2011

Informations of multimedia centering in the images, are combined acoustic and letter, etc. Although the network advances and the capacity of the storage media extends, these huge informations will not be able to accommodate. From meaning which is like this, International standards for the compression and a multiplexing of image, acoustic and voice H261 where admits standard, JPEG, JBIG, MPEG-l, MPEG-2, MPEG-4 and H263, G series etc, are core techniques of multimedia. At initial step of the base technique which creates the base of like this multimedia service time, we developed the real-time MPEG-4 transmission systems to provides real-time MPEG-4 multimedia services. This system means becomes the base technique which hereafter is developed and is applied various system. This system Will be able to apply from a videoconference, a building protection system and a VOD video system to use the Internet. And, They, the image sensing, embedded linux, and MPEG4 software, will become sourceful technique to develop the different system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2341-2347
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• 2016

In this paper, we implement monitoring system for grain sorting using a high-speed FPGA and embedded LINUX. The proposed system is designed by base on web server and web-based applications while existing system was designed by base on stand-alone mode.The interface the Web server with high speed hardware of FPGA is designed on the implemented monitoring system. The proposed system has the advantages of multi-tasking on Linux web server and real-time high speed on FPGA also. The control logic of a high speed rate line-scan CCD camera, the method of center of gravity, HSL decoding and the interface on the Web server are implemented in FPGA. The implemented monitoring system has the advantage of being able to control the grain monitoring, system failure and recovery remotely by web application. As a result, we can upgrade the performance of sorting quality compared by existing system.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.1
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• pp.52-62
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• 2008

As various types of embedded devices are widely used, a technology that supports reuse of applications on multiple platforms is needed in order for time-to-market development of the applications. The interface middleware is one of such technology and it hides platform dependency from application programmers. Existing interface middleware such as the MT project, Xenomai and Legacy2linux have limitation in that the APIs provided by each of these middleware are fixed to a specific operating system, and the middleware does not provide dynamic expansion of its API set. In this paper, we propose a middleware which hides operating system dependencies and enables porting of applications on various operating systems. In addition, the middleware has scalable structure so that it is suitable for resource-limited embedded systems. The overhead of the middleware, i.e., the time delay occurred by the middleware is between $0.3{\mu}sec\;and\;5{\mu}sec$ in most cases. We believe that the amount of overhead is reasonable and does not hurt the performance of applications.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.5
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• pp.271-281
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• 2007

Real-time support of embedded OS is not optional, but essential in contemporary embedded systems. In order to achieve these system#s real-time property, it is crucial that schedulability analysis for tasks having its property have been accomplished before system execution. Acquiring Worst-Case Execution Time(WCET) of task is a core part of schedulability analysis. Because traditional WCET tools analyze only its estimation of application task(i.e. program), it is not considered that application tasks are affected by scheduling primitives(e.g. scheduler, interrupt service routine, etc.) of OS when it schedules them. In this paper, we design and implement WCET analysis tool which deliberates on scheduling primitives of system using embedded Linux widely used in embedded OSes. This tool can estimate either WCET of normal application programs or corresponding primitives which have an influence on schduling property in embedded Linux kernel. Therefore, precision of estimation about schedulability analysis is improved. We develop this tool as Eclipse#s plug-in to work properly in any platform and support convenient interface or functionality for user.

• IEMEK Journal of Embedded Systems and Applications
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• v.1 no.2
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• pp.90-103
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• 2006

There are many file systems in various operating systems. Those are usually designed for server environments, where the common cases are usually 'multiple active users', 'great many small files' And they assume a big main memory to be used as buffer cache. So the existing file systems are not suitable for resource hungry embedded systems that process multimedia data streams. In this study, we designed and implemented a new file system which efficiently stores and retrieves multimedia data steams. The proposed file system has a very simple disk layout, which guarantees a quick disk initialization and file system recovery. And we introduced a new indexing-scheme, called the time-based indexing scheme, with the file system. With the indexing scheme, the file system maintains the relation between time and the location for all the multimedia streams. The scheme is useful in searching and playing the compressed multimedia streams by locating exact frame position with given time, resulting in reduction of CPU processing and power consumption. The proposed file system and its APIs utilizing the time-based indexing schemes were implemented firstly on a Linux environment, though it is operating system independent. In the performance evaluation on a real DVR system, which measured the execution time of multi-threaded reading and writing, we found the proposed file system is maximum 38.7% faster than EXT2 file system.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.231-234
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• 2002

As control programs are becoming larger and more complex, the capacity of a microprocessor in a TV set needs to have a CPU with 32 bits or more. Also the embedded system such like a digital TV set uses RTOS (Real Time Operating System)[1]. LGE Co. has developed a digital TV system that displays HD (High definition) signal with the AR7TDMI CPU and the commercial RTOS[2]. This thesis made improvements on problems caused by porting embedded LiNUX in limited size memory (2 mega byte) instead of RTOS[3]. The advantages of changing to embedded LiNUX take away running OS royalty that needed to make TV sets[4].

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.150-152
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• 2004

The battery charge/discharge process, the final step of the secondary battery production process, requires real-time precision controls for improving both lifetime and performance of the battery cell. In this paper, we present embedded system design for precision control of the secondary battery charge/discharge production process using low power embedded processor based on embedded linux. This system receive charge/discharge command from the main server through ethernet. Compared to existing charge/discharge control system, our design makes low cost and precision control system possible.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.1
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• pp.35-42
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• 2010

Guest operating systems running over the virtual machines share a variety of resources. Since CPU is allocated in a time division manner it consequently leads them to having the unknown physical time. It is not regarded as a serious problem in the server virtualization fields. However, it becomes critical in embedded systems because it prevents guest OS from executing real time tasks when it does not occupy CPU. In this paper we propose a hypercall to register a timer service to notify the timer request related real time. It enables hypervisor to schedule a virtual machine which has real time tasks to execute, and allows guest OS to take CPU on time to support real time. The following experiment shows its implementation on Xen-Arm and para-virtualized Linux. We also analyze the real time performance with response time of test application and frames per second of Mplayer.