43 research outputs found

    RTP Payload Format for MPEG1/MPEG2 Video

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    The QoSxLabel: a quality of service cross layer label

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    A quality of service cross layer label

    ARDUINO BASED WIFI ENABLED WIRELESS SPEAKER

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    This project is to create a system to wirelessly broadcast an audio signal from a computer to a set of speakers using Wi-Fi. This allows one to play music files from a computer and have the sound come out of any speakers that are in range of the wireless network. The ideal use case for this product would involve the ability to have a computer in one room processing music files while multiple speakers throughout the house are actually playing the music. This would be particularly useful in a party setting where one would like to keep a computer safe in a locked room while still being able to use it to play music. Additionally, if a party is there are sets of speakers in multiple rooms, they can all be synced to the same audio source. The major components of the system are the microcontroller receiver module (an ATMega 328p) and the computer program that sends the packetized audio data. This is to create a system that uses Wi-Fi to transmit audio from a source such as a laptop to a speaker system. The final product combines the use of embedded harware, low level software programming, and the IEEE 802.11 standard protocol for wireless communication (Wi-Fi) to create a polished end device. The hardware and software was developed using a combination of original work as open source code and libraries

    Virtual RTCP: A Case Study of Monitoring and Repair for UDP-based IPTV Systems

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    IPTV systems have seen widespread deployment, but often lack robust mechanisms for monitoring the quality of experience. This makes it difficult for network operators to ensure that their services match the quality of traditional broadcast TV systems, leading to consumer dissatisfaction. We present a case study of virtual RTCP, a new framework for reception quality monitoring and reporting for UDP-encapsulated MPEG video delivered over IP multicast. We show that this allows incremental deployment of reporting infrastructure, coupled with effective retransmission-based packet loss repair

    Building self-optimized communication systems based on applicative cross-layer information

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    This article proposes the Implicit Packet Meta Header(IPMH) as a standard method to compute and represent common QoS properties of the Application Data Units (ADU) of multimedia streams using legacy and proprietary streams’ headers (e.g. Real-time Transport Protocol headers). The use of IPMH by mechanisms located at different layers of the communication architecture will allow implementing fine per-packet selfoptimization of communication services regarding the actual application requirements. A case study showing how IPMH is used by error control mechanisms in the context of wireless networks is presented in order to demonstrate the feasibility and advantages of this approach

    Power to the People: Documenting Police Violence in Cleveland

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    Archivists have long recognized the inherent historical and social mandate in preserving stories of those who endured violence at the hands of the state. Examples of this responsibility include archivists who recorded public tribunals in post-apartheid South Africa, documented stories of Japanese Americans forced into internment camps during World War II, and acquired collections of 1960s civil rights activists who experienced military intervention while fighting to end segregation. These endeavors align with the historian Howard Zinn's call for archivists to "compile a whole new world of documentary material" about the lived experiences of marginalized populations and communities. Drawing upon Zinn's charge as well as scholarly literature around community archives, social justice, and human rights, this article describes the joint effort of community organizers and professional archivists who collaborated to establish a community archive for victims of police violence in Cleveland, Ohio. The archive, A People's Archive of Police Violence in Cleveland, provides a sustainable, autonomous means for Cleveland residents to share their first-hand accounts of police violence in the region. The authors will narrate the archive's conception and development as well as advance the archive as a post-custodial model for other grassroots organizations protesting various forms of state violence

    Implementation of Video Compression Standards in Digital Television

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    In this paper, a video compression standard used in digital television systems is discussed. Basic concepts of video compression and principles of lossy and lossless compression are given. Techniques of video compression (intraframe and interframe compression), the type of frames and principles of the bit rate compression are discussed. Characteristics of standard-definition television (SDTV), high-definition television (HDTV) and ultra-high-definition television (UHDTV) are given. The principles of the MPEG-2, MPEG-4 and High Efficiency Video Coding (HEVC) compression standards are analyzed. Overview of basic standards of video compression and the impact of compression on the quality of TV images and the number of TV channels in the multiplexes of terrestrial and satellite digital TV transmission are shown. This work is divided into six sections

    User-Oriented QoS in Packet Video Delivery

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    We focus on packet video delivery, with an emphasis on the quality of service perceived by the end-user. A video signal passes through several subsystems, such as the source coder, the network and the decoder. Each of these can impair the information, either by data loss or by introducing delay. We describe how each of the subsystems can be tuned to optimize the quality of the delivered signal, for a given available bit rate in the network. The assessment of end-user quality is not trivial. We present recent research results, which rely on a model of the human visual system
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