FFV1, Matroska, LPCM (And More)
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Nix on SHARCNET
Nix on SHARCNET Tyson Whitehead May 14, 2015 Nix Overview An enterprise approach to package management I a package is a specific piece of code compiled in a specific way I each package is entirely self contained and does not change I each users select what packages they want and gets a custom enviornment https://nixos.org/nix Ships with several thousand packages already created https://nixos.org/nixos/packages.html SHARCNET What this adds to SHARCNET I each user can have their own custom environments I environments should work everywhere (closed with no external dependencies) I several thousand new and newer packages Current issues (first is permanent, second will likely be resolved) I newer glibc requires kernel 2.6.32 so no requin I package can be used but not installed/removed on viz/vdi https: //sourceware.org/ml/libc-alpha/2014-01/msg00511.html Enabling Nix Nix is installed under /home/nixbld on SHARCNET. Enable for a single sessiong by running source /home/nixbld/profile.d/nix-profile.sh To always enable add this to the end of ~/.bash_profile echo source /home/nixbld/profile.d/nix-profile.sh \ >> ~/.bash_profile Reseting Nix A basic reset is done by removing all .nix* files from your home directory rm -fr ~/.nix* A complete reset done by remove your Nix per-user directories rm -fr /home/nixbld/var/nix/profile/per-user/$USER rm -fr /home/nixbld/var/nix/gcroots/per-user/$USER The nix-profile.sh script will re-create these with the defaults next time it runs. Environment The nix-env commands maintains your environments I query packages (available and installed) I create a new environment from current one by adding packages I create a new environment from current one by removing packages I switching between existing environments I delete unused environements Querying Packages The nix-env {--query | -q} .. -
On Audio-Visual File Formats
On Audio-Visual File Formats Summary • digital audio and digital video • container, codec, raw data • different formats for different purposes Reto Kromer • AV Preservation by reto.ch • audio-visual data transformations Film Preservation and Restoration Hyderabad, India 8–15 December 2019 1 2 Digital Audio • sampling Digital Audio • quantisation 3 4 Sampling • 44.1 kHz • 48 kHz • 96 kHz • 192 kHz digitisation = sampling + quantisation 5 6 Quantisation • 16 bit (216 = 65 536) • 24 bit (224 = 16 777 216) • 32 bit (232 = 4 294 967 296) Digital Video 7 8 Digital Video Resolution • resolution • SD 480i / SD 576i • bit depth • HD 720p / HD 1080i • linear, power, logarithmic • 2K / HD 1080p • colour model • 4K / UHD-1 • chroma subsampling • 8K / UHD-2 • illuminant 9 10 Bit Depth Linear, Power, Logarithmic • 8 bit (28 = 256) «medium grey» • 10 bit (210 = 1 024) • linear: 18% • 12 bit (212 = 4 096) • power: 50% • 16 bit (216 = 65 536) • logarithmic: 50% • 24 bit (224 = 16 777 216) 11 12 Colour Model • XYZ, L*a*b* • RGB / R′G′B′ / CMY / C′M′Y′ • Y′IQ / Y′UV / Y′DBDR • Y′CBCR / Y′COCG • Y′PBPR 13 14 15 16 17 18 RGB24 00000000 11111111 00000000 00000000 00000000 00000000 11111111 00000000 00000000 00000000 00000000 11111111 00000000 11111111 11111111 11111111 11111111 00000000 11111111 11111111 11111111 11111111 00000000 11111111 19 20 Compression Uncompressed • uncompressed + data simpler to process • lossless compression + software runs faster • lossy compression – bigger files • chroma subsampling – slower writing, transmission and reading • born -
Downloads." the Open Information Security Foundation
Performance Testing Suricata The Effect of Configuration Variables On Offline Suricata Performance A Project Completed for CS 6266 Under Jonathon T. Giffin, Assistant Professor, Georgia Institute of Technology by Winston H Messer Project Advisor: Matt Jonkman, President, Open Information Security Foundation December 2011 Messer ii Abstract The Suricata IDS/IPS engine, a viable alternative to Snort, has a multitude of potential configurations. A simplified automated testing system was devised for the purpose of performance testing Suricata in an offline environment. Of the available configuration variables, seventeen were analyzed independently by testing in fifty-six configurations. Of these, three variables were found to have a statistically significant effect on performance: Detect Engine Profile, Multi Pattern Algorithm, and CPU affinity. Acknowledgements In writing the final report on this endeavor, I would like to start by thanking four people who made this project possible: Matt Jonkman, President, Open Information Security Foundation: For allowing me the opportunity to carry out this project under his supervision. Victor Julien, Lead Programmer, Open Information Security Foundation and Anne-Fleur Koolstra, Documentation Specialist, Open Information Security Foundation: For their willingness to share their wisdom and experience of Suricata via email for the past four months. John M. Weathersby, Jr., Executive Director, Open Source Software Institute: For allowing me the use of Institute equipment for the creation of a suitable testing -
Opus, a Free, High-Quality Speech and Audio Codec
Opus, a free, high-quality speech and audio codec Jean-Marc Valin, Koen Vos, Timothy B. Terriberry, Gregory Maxwell 29 January 2014 Xiph.Org & Mozilla What is Opus? ● New highly-flexible speech and audio codec – Works for most audio applications ● Completely free – Royalty-free licensing – Open-source implementation ● IETF RFC 6716 (Sep. 2012) Xiph.Org & Mozilla Why a New Audio Codec? http://xkcd.com/927/ http://imgs.xkcd.com/comics/standards.png Xiph.Org & Mozilla Why Should You Care? ● Best-in-class performance within a wide range of bitrates and applications ● Adaptability to varying network conditions ● Will be deployed as part of WebRTC ● No licensing costs ● No incompatible flavours Xiph.Org & Mozilla History ● Jan. 2007: SILK project started at Skype ● Nov. 2007: CELT project started ● Mar. 2009: Skype asks IETF to create a WG ● Feb. 2010: WG created ● Jul. 2010: First prototype of SILK+CELT codec ● Dec 2011: Opus surpasses Vorbis and AAC ● Sep. 2012: Opus becomes RFC 6716 ● Dec. 2013: Version 1.1 of libopus released Xiph.Org & Mozilla Applications and Standards (2010) Application Codec VoIP with PSTN AMR-NB Wideband VoIP/videoconference AMR-WB High-quality videoconference G.719 Low-bitrate music streaming HE-AAC High-quality music streaming AAC-LC Low-delay broadcast AAC-ELD Network music performance Xiph.Org & Mozilla Applications and Standards (2013) Application Codec VoIP with PSTN Opus Wideband VoIP/videoconference Opus High-quality videoconference Opus Low-bitrate music streaming Opus High-quality music streaming Opus Low-delay -
Feature-Oriented Defect Prediction: Scenarios, Metrics, and Classifiers
1 Feature-Oriented Defect Prediction: Scenarios, Metrics, and Classifiers Mukelabai Mukelabai, Stefan Strüder, Daniel Strüber, Thorsten Berger Abstract—Software defects are a major nuisance in software development and can lead to considerable financial losses or reputation damage for companies. To this end, a large number of techniques for predicting software defects, largely based on machine learning methods, has been developed over the past decades. These techniques usually rely on code-structure and process metrics to predict defects at the granularity of typical software assets, such as subsystems, components, and files. In this paper, we systematically investigate feature-oriented defect prediction: predicting defects at the granularity of features—domain-entities that abstractly represent software functionality and often cross-cut software assets. Feature-oriented prediction can be beneficial, since: (i) particular features might be more error-prone than others, (ii) characteristics of features known as defective might be useful to predict other error-prone features, and (iii) feature-specific code might be especially prone to faults arising from feature interactions. We explore the feasibility and solution space for feature-oriented defect prediction. We design and investigate scenarios, metrics, and classifiers. Our study relies on 12 software projects from which we analyzed 13,685 bug-introducing and corrective commits, and systematically generated 62,868 training and test datasets to evaluate the designed classifiers, metrics, and scenarios. The datasets were generated based on the 13,685 commits, 81 releases, and 24, 532 permutations of our 12 projects depending on the scenario addressed. We covered scenarios, such as just-in-time (JIT) and cross-project defect prediction. -
Creating Custom Debian Live for USB FD with Encrypted Persistence
Creating Custom Debian Live for USB FD with Encrypted Persistence INTRO Debian is a free operating system (OS) for your computer. An operating system is the set of basic programs and utilities that make your computer run. Debian provides more than a pure OS: it comes with over 43000 packages, precompiled software bundled up in a nice format for easy installation on your machine. PRE-REQ * Debian distro installed * Free Disk Space (Depends on you) Recommended Free Space >20GB * Internet Connection Fast * USB Flash Drive atleast 4GB Installing Required Softwares on your distro: Open Root Terminal or use sudo: $ sudo apt-get install debootstrap syslinux squashfs-tools genisoimage memtest86+ rsync apt-cacher-ng live-build live-config live-boot live-boot-doc live-config-doc live-manual live-tools live-manual-pdf qemu-kvm qemu-utils virtualbox virtualbox-qt virtualbox-dkms p7zip-full gparted mbr dosfstools parted Configuring APT Proxy Server (to save bandwidth) Start apt-cacher-ng service if not running # service apt-cacher-ng start Edit /etc/apt/sources.list with your favorite text editor. Terminal # nano /etc/apt/sources.list Output: (depends on your APT Mirror configuration) deb http://security.debian.org/ jessie/updates main contrib non-free deb http://http.debian.org/debian jessie main contrib non-free deb http://ftp.debian.org/debian jessie main contrib non-free Add “localhost:3142” : deb http://localhost:3142/security.debian.org/ jessie/updates main contrib non-free deb http://localhost:3142/http.debian.org/debian jessie main contrib non-free deb http://localhost:3142/ftp.debian.org/debian jessie main contrib non-free Press Ctrl + X and Y to save changes Terminal # apt-get update # apt-get upgrade NOTE: BUG in Debian Live. -
Camcorder Multimedia Framework with Linux and Gstreamer
Camcorder multimedia framework with Linux and GStreamer W. H. Lee, E. K. Kim, J. J. Lee , S. H. Kim, S. S. Park SWL, Samsung Electronics [email protected] Abstract Application Applications Layer Along with recent rapid technical advances, user expec- Multimedia Middleware Sequencer Graphics UI Connectivity DVD FS tations for multimedia devices have been changed from Layer basic functions to many intelligent features. In order to GStreamer meet such requirements, the product requires not only a OSAL HAL OS Layer powerful hardware platform, but also a software frame- Device Software Linux Kernel work based on appropriate OS, such as Linux, support- Drivers codecs Hardware Camcorder hardware platform ing many rich development features. Layer In this paper, a camcorder framework is introduced that is designed and implemented by making use of open Figure 1: Architecture diagram of camcorder multime- source middleware in Linux. Many potential develop- dia framework ers can be referred to this multimedia framework for camcorder and other similar product development. The The three software layers on any hardware platform are overall framework architecture as well as communica- application, middleware, and OS. The architecture and tion mechanisms are described in detail. Furthermore, functional operation of each layer is discussed. Addi- many methods implemented to improve the system per- tionally, some design and implementation issues are ad- formance are addressed as well. dressed from the perspective of system performance. The overall software architecture of a multimedia 1 Introduction framework is described in Section 2. The framework design and its operation are introduced in detail in Sec- It has recently become very popular to use the internet to tion 3. -
Recommended File Formats for Long-Term Archiving and for Web Dissemination in Phaidra
Recommended file formats for long-term archiving and for web dissemination in Phaidra Edited by Gianluca Drago May 2019 License: https://creativecommons.org/licenses/by-nc-sa/4.0/ Premise This document is intended to provide an overview of the file formats to be used depending on two possible destinations of the digital document: long-term archiving uploading to Phaidra and subsequent web dissemination When the document uploaded to Phaidra is also the only saved file, the two destinations end up coinciding, but in general one will probably want to produce two different files, in two different formats, so as to meet the differences in requirements and use in the final destinations. In the following tables, the recommendations for long-term archiving are distinct from those for dissemination in Phaidra. There are no absolute criteria for choosing the file format. The choice is always dependent on different evaluations that the person who is carrying out the archiving will have to make on a case by case basis and will often result in a compromise between the best achievable quality and the limits imposed by the costs of production, processing and storage of files, as well as, for the preceding, by the opportunity of a conversion to a new format. 1 This choice is particularly significant from the perspective of long-term archiving, for which a quality that respects the authenticity and integrity of the original document and a format that guarantees long-term access to data are desirable. This document should be seen more as an aid to the reasoned choice of the person carrying out the archiving than as a list of guidelines to be followed to the letter. -
White Paper November 2017
White paper November 2017 XperiaTM Z4 Tablet SGP771 White paper | Xperia™ Z4 Tablet Purpose of this document Sony product White papers are intended to give an overview of a product and provide details in relevant areas of technology. NOTE: The illustration that appears on the title page is for reference only. All screen images and elements are subject to change without prior notice. This document is published by Sony Mobile This White paper is published by: Communications Inc., without any warranty*. Improvements and changes to this text Sony Mobile Communications Inc., necessitated by typographical errors, 4-12-3 Higashi-Shinagawa, Shinagawa-ku, inaccuracies of current information or improvements to programs and/or equipment Tokyo, 140-0002 Japan may be made by Sony Mobile Communications Inc. at any time and without notice. Such www.sonymobile.com changes will, however, be incorporated into new editions of this document. Printed versions are to be regarded as temporary reference copies only. © Sony Mobile Communications Inc., 2009-2017. All rights reserved. You are hereby granted a *All implied warranties, including without license to download and/or print a copy of this limitation the implied warranties of document. merchantability or fitness for a particular Any rights not expressly granted herein are purpose, are excluded. In no event shall Sony or its licensors be liable for incidental or reserved. consequential damages of any nature, including but not limited to lost profits or commercial loss, First released version (March 2015) -
PDF Documentation
lxml 2019-03-26 Contents Contents 2 I lxml 13 1 lxml 14 Introduction................................................. 14 Documentation............................................... 14 Download.................................................. 15 Mailing list................................................. 16 Bug tracker................................................. 16 License................................................... 16 Old Versions................................................. 16 2 Why lxml? 18 Motto.................................................... 18 Aims..................................................... 18 3 Installing lxml 20 Where to get it................................................ 20 Requirements................................................ 20 Installation................................................. 21 MS Windows............................................. 21 Linux................................................. 21 MacOS-X............................................... 21 Building lxml from dev sources....................................... 22 Using lxml with python-libxml2...................................... 22 Source builds on MS Windows....................................... 22 Source builds on MacOS-X......................................... 22 4 Benchmarks and Speed 23 General notes................................................ 23 How to read the timings........................................... 24 Parsing and Serialising........................................... 24 The ElementTree -
Indiana University Media Digitization and Preservation Initiative (MDPI)
Indiana University Media Digitization and Preservation Initiative (MDPI) White Paper: Encoding and Wrapper Decisions and Implementation for Video Preservation Master Files Authored by: Mike Casey, Director of Technical Operations, MDPI Reviewed by: Carla Arton, Film Digitization Specialist, IU Libraries Moving Image Archive Jon Cameron, Digital Media Service Manager, IU Libraries Jon Dunn, Assistant Dean for Library Technologies, IU Libraries Heidi Kelly, Digital Preservation Librarian, IU Libraries Brent Moberly (Appendix author), Software Developer, UITS, IU Brian Wheeler, Senior Systems Engineer, IU Libraries Special thanks to Dave Rice for astute comments and suggestions Copyright 2017 Trustees of Indiana University This document is licensed under a Creative Commons Attribution 4.0 International license (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ Release date: March 27, 2017 Indiana University Media Digitization and Preservation Initiative Encoding and Wrapper Decisions and Implementation for Video Preservation Master Files 1. Overview There is no consensus in the media preservation community on best practice for encoding and wrapping video preservation master files. Institutions engaged in long- term video preservation typically choose from three paths, each of which are currently seen as viable for this purpose: 10-bit, uncompressed, v210 codec, usually with a QuickTime wrapper JPEG 2000, mathematically lossless profile, usually with an MXF wrapper FFV1, a mathematically lossless format, with an AVI or Matroska wrapper No single path can be said to be widely adopted, in part because there are relatively few institutions engaged in digitizing video for long-term preservation, especially at scale. It appears as of this writing that institutions are roughly evenly divided between the three paths listed above. -
Using XSL and Mod Transform in Apache Applications
Using XSL and mod_transform in Apache Applications Paul Querna [email protected] What is XSL? ● Extensible Stylesheet Language (XSL) ● A family of Standards for XML by the W3C: – XSL Transformations (XSLT) – XML Path Language (Xpath) – XSL Formatting Objects (XSL-FO) XSLT Example <?xml version="1.0"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:template match="/"> <html> <head><title>A Message</title></head> <body> <h1> <xsl:value-of select="message" /> </h1> </body> </html> </xsl:template> </xsl:stylesheet> Data Source... <?xml version="1.0"?> <message>Hello World</message> Outputs... <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>A Message</title> </head> <body> <h1>Hello World</h1> </body> </html> Why is XSLT good? ● Mixing Data and Presentation is bad! – Keeps Data in a clean XML schema – Keeps the Presentation of this Data separate ● XSLT is XML ● Easy to Extend ● Put HTML or other Markups directly in the XSLT. – Easy for Web Developers to create a template Why is XSLT bad? ● XSLT is XML ● Complicated XSLT can be slow ● Yet another language to learn Where does Apache fit in this? ● Apache 2.0 has Filters! Input Handlers Client Filters (Perl, PHP, Proxy, File) Output Filters mod_include (SSI) mod_transform (XSLT) mod_deflate (gzip) mod_transform ● Uses libXML2 and libXSLT from Gnome – C API ● Doesn't depend on other Gnome Libs. – Provides: ● EXSLT ● XInclude ● XPath ● Xpointer ● ... and more Static XML Files ● AddOutputFilter XSLT .xml ● TransformSet /xsl/foo.xsl – Only if your XML does not specify a XSL File ● TransformOptions +ApacheFS – Uses Sub-Requests to find files – Makes mod_transform work like Apache AxKit Dynamic Sources ● XML Content Types: – AddOutputFilterByType XSLT application/xml ● Controlled Content Types: – AddOutputFilterByType XSLT applicain/needs- xslt ● Works for Proxied Content, PHP, mod_perl, mod_python, CGI, SSI, etc.