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Mike Izquierdo

Mike Izquierdo's Public Library

  • We note that the signal is first convoluted with the filter bank and then subsampled. In other words, only half the samples are kept, with the other half of the filtered samples thrown away. Clearly this is not efficient, and it would be better to do the subsampling before the filtering operation. This leads to an alternative implementation of the wavelet transform termed lifting approach. It turns out that all FIR wavelet filters can be factored into lifting step.

  • Industry insiders have told HD Guru that the specification-setting process has dragged on through much of the year, in part, because of disagreements over HDR brightness ranges between LED LCD TV manufacturers and LG and OLED component suppliers, which are championing the needs of OLED TV technology.

  • <script type="text/javascript">GA_googleFillSlot("top_of_the_page_2nd_728x90");</script>

    UHD Alliance Sets 4K Specs For CES Unveiling

    December 8th, 2015 · 2 Comments · LCD Flat Panel, Blu-ray Players, OLED, News, LED LCD Flat Panels, Connected TVs, 4K Front Projection, 4K Flat Panel, 4K LED LCD, OLED, UHDTV, Streaming Services, Curved Screen, 4K Curved Screeen, HDR, UHD 4K OLED, 2160p, Full Array LED Backlit with Local Dimming

    uhd alliance 580The UHD Alliance (UHDA), an inter-industry group working on achieving consensus on standards involved in the display of 4K Ultra HD video in the home, said Tuesday that it has completed specifications for 4K Ultra HD displays, content and distribution and will formally announce them at CES 2016.

    The UHDA, which is represented by key members of the consumer electronics, content production and content distribution industries, said it will also be unveiling a new consumer-facing certification logo to help shoppers quickly identify 4K UHD products that adhere to the specifications “and can deliver the ultimate UHD experience.”

    Although many of the 4K Ultra HD specifications have already been published in the Ultra HD Blu-ray specifications announced last summer, a few major points have remained unanswered, including minimum and maximum brightness levels needed to help display makers define sets supporting high dynamic range (HDR).

    More on the UHDA specification announcement after the jump:

    Industry insiders have told HD Guru that the specification-setting process has dragged on through much of the year, in part, because of disagreements over HDR brightness ranges between LED LCD TV manufacturers and LG and OLED component suppliers, which are championing the needs of OLED TV tec

  • Therefore, the two technologies come at HDR from different directions. OLED starts at black and works up 14 to 15 camera f-stops of light (steps of increasing brightness) in the HDR spectrum. LED TVs start at maximum brightness they can generate and work down the 15 stops to the lowest level of black they can achieve.

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  • HEVC Advance no longer plans to levy usage fees on any free-to-air (FTA) broadcast content, from both commercial and non-commercial channels. Freely distributed HEVC-encoded content on the Internet will also be free from licensing fees.
  • It is further understood that FTA broadcaster content delivered via HEVC to cable or other redistributors, but then transcoded by the redistributor to another codec for delivery to end users, will not be subject to any HEVC Advance usage royalty assessed to the FTA broadcaster or the redistributor.
  • For device royalties, the HEVC Main, Main Still and Main 10 profiles are included in the basic royalty rate, but advanced profiles (including the scalable variant technology known as SHVC) and optional features (such as SEI messages) are subject to additional assessments.

  • It features a proprietary IP-based network topology, which allows it to operate as a standalone system, transmitting the HDMI signal to distances up to 120 meters over a single Ethernet cable*.

  • 1.8   Can an AVB device just use IEEE 1588v2 (PTP) instead of 802.1AS?

     

    No, IEEE 802.1AS is required to maintain the required synchronization compatibility and accuracy.

     
     
     

    1.9   My device's ethernet port says it supports IEEE 1588. Can it do AVB?

     

    IEEE 1588v2 is a framework for time synchronization.

     

    Profiles of 1588v2 are not necessarily compatible or even require the same hardware.

     

    For instance, once profile of IEEE 1588v2 is used for synchronization of Cellular Telephone towers and that profile has very different hardware and protocol requirements compared to the default 1588v2 profile seen in generic switches, and is different again compared to the profile used in industrial switches.

     

    So there is no clear definition of what “1588-2008 capable hardware” means. I have seen one ethernet chip that says that but only timestamps incoming packets, not outgoing packets.

     

    802.1AS has no options like that. If your device supports 802.1AS then it will provide AVB quality synchronization better than the default 1588v2 profile. You need to have the support in the ethernet hardware to provide timestamps of specific types of both incoming and outgoing packets. These timestamps need to represent the time that the packet hit the wire. Many ethernet hardware systems provide timestamps instead at the MAC level which means your software needs to compensate for the PHY latencies for your specific PHY. The PHY latencies are typically different for 100baseT and GigE and different for TX and RX.

     

    802.1AS needs timestamping of Pdelay, PdelayFollowUp, PdelayRequest, PdelayRequestFollowUp, Sync, and FollowUp messages for both directions.

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