HDX Enhanced ThinWire Compatibility Mode 1.0

Transcription

1 HDX Enhanced ThinWire Compatibility Mode 1.0 Technology Preview Administrator's Guide For Citrix administrators who want to understand, install, configure, and deploy the features in this release.

2 HDX Enhanced ThinWire Compatibility Mode Administrator s Guide Table of contents About this release... 3 What makes the new encoder different?... 3 System requirements... 3 Limitations of this release... 3 Installation... 4 Configuration... 4 Visual quality... 5 Maximum allowed color depth... 5 Registry overrides... 5 Recommendations... 6 Known issues... 6 citrix.com

3 About this release This release consists of an enhanced ThinWire compatibility mode, an alternative to the H.264- enhanced SuperCodec (also known as DeepCompressionV2) that was released with XenApp and XenDesktop 7.x. For workloads involving server-rendered video, the SuperCodec offers the best tradeoff in image quality against network data usage but requires sufficient server and client CPU. In contrast, the enhanced ThinWire compatibility mode uses a new encoder that improves the display performance (for example, when users scroll) in environments where H.264 is not practical, because of the added cost, or is not required, because the use of server-rendered video is limited. Such environments include those with: Lower powered endpoint devices Older thin clients that do not support the SuperCodec Low bandwidth networks used to deliver Office applications Installing the new encoder does not replace the SuperCodec, which is still suitable for other environments. What makes the new encoder different? Windows Server 2012 makes use of the DirectX API from Microsoft, which improves on the earlier GDI and GDI+ APIs. Before the new encoder was available, maintaining the bandwidth, and server and endpoint CPU in Windows Server 2012 environments (with DirectX) was a challenge compared with earlier versions of Windows Server. The new encoder includes significant enhancements to the ThinWire virtual channel allowing this challenge to be overcome. System requirements This release is fully supported in environments running XenApp and XenDesktop 7.6 that deliver applications from Windows Server 2012 R2 with Remote Desktop Services enabled. Limitations of this release Be aware of the following limitations: The new encoder distinguishes areas of the screen as transient (containing moving images) and non-transient (containing still images). Only a single transient area is detected at a time. Multiple areas are not processed correctly. For example, two separate YouTube videos playing in the session do not play smoothly. The new encoder does not include Adaptive Display (an HDX technology). citrix.com 3

4 Installation To install the new encoder: 1. Install hotfix ICATS760WX64010 which includes fix LC2177, the supporting components for this release. See the enclosed readme for additional information regarding the hotfix package. 2. If you are installing the encoder on a master image, follow the instructions for updating master images located at 3. On the master image running the Virtual Delivery Agent, replace Twencode.dll with the version of this file in this release. The library file is located on the master image at C:\Program Files (x86)\citrix\system If you are installing the encoder on a master image, update it again, as described in an earlier step. Important: If you apply future hotfixes, ensure that they contain LC2177. If Twencode.dll is included in a hotfix it will overwrite the version in this release and the functionality in this release will be lost. In these situations, do not reapply Twencode.dll without first confirming with Citrix that it is safe to do so. Configuration No configuration is required to enable the new encoder. However, the following information may be useful in understanding how it treats the different XenApp and XenDesktop policy settings that may be present in your environment. The encoder is used when the system decides that the SuperCodec should not be, that is if: You have one of the following versions of Receiver that do not support the SuperCodec: o Receiver for Windows Enterprise 3.3 or earlier o Receiver for Linux 12.1 or earlier o Receiver for Mac 11.7 or earlier o Receiver for Android 3.3 or earlier You have enabled Always lossless or Build to lossless and have not enabled Visually lossless. (You generally enable Visually lossless to maximize the precision of highly detailed image data in medical applications, for example. This setting is supported in Receiver for Windows 4.2.) You override the encoder using the Windows registry as described in Registry override. The encoder responds directly to the Visual quality and Maximum allowed color depth policies as follows. citrix.com 4

5 Visual quality Policy setting Content of display Treatment by encoder Low Static text, simple images, solid color Lossless Medium (default) Static text, simple images, solid color JPEG quality 45 with subsampling JPEG quality 25 with subsampling Lossless JPEG quality 90 with subsampling JPEG quality 60 with subsampling High Static text, simple images, solid color Lossless JPEG quality 90 without subsampling JPEG quality 70 with subsampling Always lossless Static text, simple images, solid color Lossless Lossless Disabled Build to lossless Static text, simple images, solid color Lossless Lossless JPEG Quality 60 with subsampling Maximum allowed color depth When the Maximum allowed color depth policy is applied to a session with a value of 16-bit color (or lower), the encoder enters a 16-bit color-optimized mode of operation. This is a new feature, which helps greatly to reduce the bandwidth used in the session. This mode does not make the session itself operate in 16-bit color. Only the encoder is affected, as follows: Static text, simple images, solid color, and photographic images are converted to 16-bit objects The processing of moving images is unchanged Registry overrides Caution: Editing the registry incorrectly can cause serious problems that may require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it. citrix.com 5

6 Two registry entries can be used with this release: To force the new encoder to always be used, set the following registry entry to 0: HKLM\Software\Citrix\Graphics\encoder [REG_DWORD] To disable JPEG subsampling, set the following registry entry to 0: HLKM\Software\Citrix\Thinwire\UseJPEGSubsampling [REG_DWORD] This can remove bleeding or remnant lines and edges in static images, which occur when the Visual quality policy is set to Medium or Low. Disabling subsampling may result in a small increase in CPU on the endpoint. Recommendations Follow the advice in this section to ensure the encoder performs at its best. To optimize the user experience when application windows are moved across the desktop background in a session: 1. Check that the Show window contents while dragging setting in Windows is enabled. Disabling this setting has been previous best practice for XenApp and XenDesktop, but it is no longer required with the new encoder. 2. Use a solid (or mostly solid) color for the desktop background. To save 10-15% of bandwidth for sessions composed largely of text (such as Microsoft Word or Outlook), specify 16-bit color for the sessions. This saving does not apply to sessions composed largely of photographic images. To reduce bandwidth when scrolling web pages in Internet browsers, ensure that the Use smooth scrolling setting is disabled. Known issues Blank areas are left when you drag a local window slowly over the desktop session window. This occurs in XenDesktop 7.6 running Windows Server 2012 if the LVB has been disabled on the endpoint. Some older Receivers, such as Receiver for Linux 12.1, are configured this way by default. To work around this issue, check that the LVB is enabled. With Linux Receiver 12.1, use the setting ForceLVBMode=1. [#547491] Receiver for HTML5 does not support 16-bit lossless or JPEG-encoded ThinWire bitmaps. Any bandwidth savings by switching the Maximum allowed color depth policy to 16-bit color (for example, to process server-rendered video) are lost and result in excessive bandwidth usage and poor performance. Instead, the session is rendered lossless. There is no workaround for this issue. [#547930] citrix.com 6

7 About Citrix Citrix (NASDAQ:CTXS) is leading the transition to software-defining the workplace, uniting virtualization, mobility management, networking and SaaS solutions to enable new ways for businesses and people to work better. Citrix solutions power business mobility through secure, mobile workspaces that provide people with instant access to apps, desktops, data and communications on any device, over any network and cloud. With annual revenue in 2014 of $3.14 billion, Citrix solutions are in use at more than 330,000 organizations and by over 100 million users globally. Learn more at Copyright 2015 Citrix Systems, Inc. All rights reserved. Citrix, Citrix Receiver, and StoreFront are trademarks of Citrix Systems, Inc. and/or one of its subsidiaries, and may be registered in the U.S. and other countries. Other product and company names mentioned herein may be trademarks of their respective companies. citrix.com 7