• Title/Summary/Keyword: stream transmission

Search Result 376, Processing Time 0.027 seconds

Design of Smart OTT Platform based on the Analysis of Adaptive Buffering (적응 버퍼링 성능분석 기반의 스마트 OTT 플랫폼 설계☆)

  • Kim, Inki;Kang, Mingoo
    • Journal of Internet Computing and Services
    • /
    • v.17 no.4
    • /
    • pp.19-26
    • /
    • 2016
  • In this paper, the dynamic buffering based smart OTT platform was proposed, and analyzed for adaptive bit-rate video delivery with the optimization of HLS (HTTP Live Streaming). This platform consists of the software platform between sever and client which detects the bandwidth capacity, and adjusts the quality of the streaming for multiple bit-rates resolutions. In order to apply adaptive buffering, two buffers are added to the basic HLS player, and each buffer is responsible for constantly buffering a previous and the next channels relative to the current channel. This adaptive transmitting with smart OTT platform is superior to delivering a static video file at a single buffering, because the video stream of adaptive double buffers can be switched streaming according to client's available network speed. As a result, this proposed smart OTT can be cooperated to the application of HLS server with segmented H.265 MPEG-2 TS video & m3u8 files with its information based on the optimized transmission channel state of live and VOD, and applied to PLC transmission, too.

A study of scene change detection in HEVC bit stream (HEVC 비트 스트림 상에서의 장면전환 검출 기법 연구)

  • Eom, Yumie;Yoo, Sung-Geun;Yoon, So-Jeong
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2014.06a
    • /
    • pp.258-261
    • /
    • 2014
  • The era of realistic broadcast with high fidelity has come after the wide-spread distribution of UHD display and the transmission of UHD experimental broadcast in CATV. However, UHD broadcast now has constraint because it requires much amount of bandwidth and data in broadcasting transmission and production system. Not only HEVC(High Efficiency Video Codec) which has more than two times higher compression rate but also cloud-based editing system would be the key to solve the problems above. Also, fast scene change detection of videos is needed to index and search UHD videos smoothly. In this paper, therefore, a method is proposed to index and search the scene change information of large volume UHD videos compressed with high-efficiency codec. Application usages of fast detection of scene change information in various UHD video environments are considered by using this algorithm.

  • PDF

An Transport Layer Vertical Handover Approach for Video Services in Overlay Network Environments (오버레이 네트워크 환경에서 비디오 서비스를 위한 트랜스포트 계층에서의 수직 핸드오버 방안)

  • Chang, Moon-Jeong;Lee, Mee-Jeong
    • The KIPS Transactions:PartC
    • /
    • v.14C no.2
    • /
    • pp.163-170
    • /
    • 2007
  • The next generation communication environment consists of various wireless access networks with distinct features that are configured as an overlay topology. In the network environments, the frequency of hand overs should be minimized and the error propagation should be solved in order to provide high-quality multimedia services to mobile users. Therefore, we propose an performance enhancement approach, based on mSCTP, that provides high quality multimedia services to mobile users by ameliorating the error propagation problem. We utilizes the following four functions: 1) the separation of transmission paths according to the types of frames. 2) retransmission strategy to minimize the loss rate of frames, 3) Foced vertical handover execution by utilizing bicasting, 4) using the stability period in order to reduce the effect of the ping pong phenomenon. The simulation results show that the proposed approach provides seamless multimedia service to mobile users by achieving error resilience.

Mean Response Delay Estimation for HTTP over SCTP in Wireless Internet (무선 인터넷 환경에서 HTTP over SCTP의 평군 응답 시간 추정)

  • Lee, Yong-Jin
    • The Journal of the Korea Contents Association
    • /
    • v.8 no.6
    • /
    • pp.43-53
    • /
    • 2008
  • Hyper text transfer protocol (HTTP) over transmission control protocol (TCP) is currently used to transfer objects in the Internet. Stream control transmission protocol (SCTP), an alternative to TCP, which allows for independent delivery among streams, and can thus reduce the mean response delay of web object. We present an analytical model to find the mean response delay for HTTP over SCTP, therefore, estimate the effectiveness of SCTP over TCP. Typical TCP delay models assume the wired environment. On the contrary, the proposed model in this paper assumes the multiple packet losses and wireless environment where fast retransmission is not possible due to small window. The estimated mean response time can be used the benchmark to meet quality of service (QoS) at end-user. We validate the accuracy of our model using experiments. It is shown that the differences between the results from model and those from experimental are very small below 6 % on average. We also find that the mean response delay for HTTP over SCTP is less than that for HTTP over TCP.

Robust Video Transmission System Employing Byte-Aligned Variable-Length Turbo Codes and Its Code-Rate Adaptation over Mobile Communication Channels (이동통신 환경에서 바이트 정렬 가변 길이 터보 코드의 적응 부호화율 적용을 통한 동영상 전송 시스템)

  • 이창우;김종원
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.29 no.7C
    • /
    • pp.921-930
    • /
    • 2004
  • In this paper, a robust video transmission system is proposed. To effectively prevent the corruption of video stream and its propagation in spatial and temporal domains, a version of turbo code, so-called as byte-aligned variable-length turbo code, is applied. Protection performance of the proposed turbo code is first evaluated by applying it to GOB-based variable-size ITU-T H.263+ video packets, where the protection level is statically controlled based on the joint source-channel criteria. This protection is then extended to support the adaptation of code ratio to best match the time-varying channel condition. The time-varying Rayleigh fading channel is modelled considering the correlation of the fading channel. The resulting performance comparison with the static turbo code as well as the conventional RCPC code clearly demonstrates the possibility of the proposed adaptation approach for the time-varying correlated Rayleigh-fading channel.

An Efficient Smoothing Algorithm for Video Transmission at Variable Bit Rate (가변 비트율 비디오 전송을 위한 효율적인 스무딩 알고리즘)

  • Lee Myoun-Jae;Lee Junyong;Park Do-Soon
    • The KIPS Transactions:PartC
    • /
    • v.11C no.7 s.96
    • /
    • pp.1009-1022
    • /
    • 2004
  • Smoothing is a transmission plan where variable rate video data is converted to a constant bit rate stream. Among them are CHA, MCBA. MVBA, e-PCRTT and others. E-PCRTT algorithm, which was improved from PCRTT, restricts the number of rate changes with fixed-size run. This causes unnecessary rate changes and may not guarantee QoS when buffer size is small. In this paper. a smoothing algorithm is pro-posed, where the number of rate changes are not limited and the size of run can be flexible, in order to overcome the shortcomings of e-PCRTT. Experiments demonstrated that the proposed algorithm such as e-PCRTT. In order to show the performance, var-ious evaluation factors were used such as the nember of rate changes, buffer size to maintain QoS, and so on.

Hybrid Error Concealment Algorithm for Intra-Frame in H.264 (H.264의 인트라 프레임을 위한 하이브리드 에러 은닉 알고리즘)

  • Yim Chang-Hoon;Kim Won-Jung;Lim Hye-Sook
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.31 no.8C
    • /
    • pp.777-785
    • /
    • 2006
  • H.264 is the prominent video coding standard in various applications such as real-time video streaming and digital multimedia broadcasting, since it provides enhanced compression performance, error resilience tools, and network adaptation. Since compressed video stream is vulnerable to packet loss, error resilience and error concealment(EC) tools are essential for the transmission of video over the Internet. In this paper, we first propose a simple temporal EC method that improves the EC performance for intra-frame in H.264 when the amount of motion is relatively small. Then we propose a new hybrid EC method for intra-frame in H.264, which combines the spatial EC and temporal EC adaptively. The simulations are performed in packet-lossy environments, and the proposed hybrid EC method shows about 0.5-4dB PSNR improvement compared to the conventional spatial EC method that is used for intra-frame in H.264.

Traffic characteistics and effective bandwidth estimation for MPEG sources (MPEG 입력 신호원의 트래픽 특성과 효과적 대역폭 추정)

  • 유흥균
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.6
    • /
    • pp.1490-1500
    • /
    • 1996
  • One of the important issues for multimedia communications over ATM netowrks is efficient use of net-work resources since transmitting video at low cost requires high utilization of channel bandwidth. In this paper, we propose an effective bandwidth estimation scheme for MPEG sources in ATM networks. It has been known difficult to allocate effective transmission bandwidth to MPEG sources due to its bursty charactersitics. The MPEG traffic stream can bemodeled using five traffic parameters:service rate, burst load ratio, interburst load ratio, burst period, and interburst period. Using these parameters, a transmission bandwidth for each source can be estimated, and the estimated bandwidth is applied synchronously to reduce the queue size in a buffer. For a simple network modelof a high speed link that multiplexes a number of virtual-circuit connections, simulations on adaptive bandwidth allocation were performed, and the results show that the queueing delay is significantly reduced, when compared to a fixed bandwidth allocation.

  • PDF

XCP-OFDM System using Cross-handed Circular Polarization (역선회 원편파를 이용한 XCP-OFDM 시스템)

  • 김병옥;하덕호
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.13 no.3
    • /
    • pp.316-322
    • /
    • 2002
  • The Orthogonal Frequency Division Multiplexing(OFDM) is a special case of multicarrier transmission, where a single data stream is divided into many subcarriers and transferred in a parallel way. It reduces the necessary bandwidth using the orthogonality between the subcarriers. Therefore it requires the transmission channel which has stable characteristic. When the delay spread of the channel exceed the guard interval, then the orthogonality of the subcarriers cannot maintain and as a result the system performance degrade. In this paper, the XCP-OFDM(OFDM using cross-handed Circular Polarization) system is newly proposed. This system divides the channel in order to eliminate the overlapping of subcarrier's spectrum by using cross-handed circular polarization. Therefore, the proposed XCP-OFDM system can improve the performance without increasing the guard interval. Both theoretical analysis and simulation results are described.

A Study on Header Compression Algorithm for the Effective Multimedia Transmission over Wireless Network (무선망에서 효율적인 멀티미디어 전송을 위한 헤더압축 알고리즘 연구)

  • Yun, Sung-Yeol;Park, Seok-Cheon
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.14 no.2
    • /
    • pp.296-304
    • /
    • 2010
  • MoIP is technology to transmit a variety of multimedia over IP, but compared to traditional voice services require greater bandwidth and radio resources in a wireless environment has already reached the limits. Therefore, as a way to resolve this issue for header compression is a lot of research. SCTP protocol header compression using ROHC-SCTP has been research, ROHC-SCTP packet structure of the ROHC algorithm with different types and, SCTP header compression to apply the characteristics of the poor performance of many of these have drawbacks. Therefore, in this paper to solve these problems better header compression algorithm was designed. In this paper, the proposed algorithm to evaluate the NS-2 simulation environment was modeled on the header compression operation. Evaluation results, the algorithm designed in this paper compared to ROHC-SCTP algorithms determine the overhead rate was low, the data types vary a lot better when the total header size was small.