CTX944 Dual DVB-T/DVB-S TV card

Posted on by

The CTX944 dual TV card supports analog TV, DVB-T, DVB-S and S-Video composite Video-In/Audio-In. This card is compliant with the PCI 2.2 Medion card used in the Medion MD8800 PC launched by ALDI in november 2005. The CTX948 is the single version of the CTX944.

The CTX944 and CTX484 cards are manufactured by Creatix, a german multimedia company. The main chips are Philips SAA7131E, TDA8275A and TDA8263..

The SAA7131E combines a digital global standard low IF demodulator for analog TV with a PCI audio and video decoder. The IF demodulator is an alignment-free digital multi standard vision and sound low IF signal PLL demodulator for positive and negative video modulation. It can be used worldwide for M/N, B/G/H, I, D/K and L/L’ standards.

The analog/DVB-T section is contolled by the Philips TDA8275A chip, the DVB-S section by the Philips TDA8263 chip.

The card is supported by the following software tools :

RTMP streaming for Amazon CloudFront

Posted on by

RTMP (Real Time Messaging Protocol) is a web transmission standard which allows a backend server to transfer video, audio and data to the Flash Player. It’s particularly useful for video streaming, since the Flash Player can communicate back to the server about how much video it has consumed, and how much more video the server needs to send. This is a distinct advantage over so-called progressive download video, where a web server simply begins sending bytes out to the video player over standard HTTP until there are no more bytes to send.

In addition to saving bandwidth and allowing better seeking control, RTMP is harder to steal content, allows dynamic bitrate switching and is able to stream live content.

Amazon added RTMP to the CloudFront servers in December 2009 and thus became a real CDN (Content Delivery Network), offering content providers a simple and reliable way to host, format and deliver their video content at high speeds.

CloudFront Streaming is very easy to set up with the JW Player 5.3.

Today a created the first video-distributions on Amazon CloudFront by using the AWS-Console. This process is very straightforward.

The following parameters are used to embed a streaming-videofile in a webpage using a flash-player or the HTML5 <video> tag.

  • videofile = path/filename.ext
  • streamer = rtmp://xxxxxxxxxxxxx.cloudfront.net/cfx/st/
  • provider = rtmp

The suffixes /cfx/st/ at the end of the URL are required to access the streaming-server at the CloudFront server. Videofile extensions can be mp4, flv and webm.

The Wilderness Downtown by Chris MILK and Arcade Fire

Posted on by

The Wilderness Downtown is an interactive interpretation of Arcade Fire’s song “We Used To Wait” and was built entirely with the latest open web technologies, including HTML5 video, audio, and canvas.

Choreographed windows, interactive flocking, custom rendered maps, real-time compositing, procedural drawing, 3D canvas rendering… this Chrome Experiment uses all of them.

The Wilderness Downtown is an outstanding browser-dominating Net Artwork. This experimental, interactive film by Chris Milk, is a lovely visual poem to accompany Arcade Fire’s excellent “We Used To Wait” from their album The Suburbs.

This Chrome Experiment has been done with some of Chris Milk’s friends from Google, among them the technology director Aaron Koblin.

Roles and Capabilities in WordPress Blogs

Posted on by

WordPress uses a concept of Roles, designed to give the blog owner the ability to control and assign what users can and cannot do in the blog.

WordPress has five pre-defined Roles: Administrator, Editor, Author, Contributor and Subscriber. Each Role is allowed to perform a set of tasks called Capabilities. There are many Capabilities including publish_posts, moderate_comments, and edit_users. The default Capabilities are pre-assigned to each Role.

The summary is given here :

  • Administrator –  has access to all the administration features
  • Editor -can publish and manage posts and pages as well as manage other users’ posts, etc.
  • Author – can publish and manage his own posts
  • Contributor – can write and manage his posts without uploading file,  but not publish them
  • Subscriber – can only read posts and  manage his profile

Progressive video download, pseudo streaming and realtime streaming

Posted on by

Last update : January 30, 2013
In the past, audio and video on the Web was primarily a download-and-play technology. You had to first download an entire media file before it could play. Today, streaming technologies allow watching audio and video files almost immediately, while the data is being sent, without having to wait for the whole file to download.

There are three methods of delivering streaming audio and video content over the Web.

The first method uses a standard HTTP server to deliver the audio and video data to a media player. Unlike the download-and-play client, a special streaming client embedded in the webpage starts playing the audio or video while it is downloading, after only a few seconds wait for buffering, the process of collecting the first part of a media file before playing. This streaming method is called progressive media download.

The second method is called pseudostreaming. Pseudostreaming is a protocol that can be installed on regular HTTP servers. It uses a server side script for Flash-to-server communication. The player sends a HTTP request to the server with a start time parameter in the request URL’s query string and the server script responds with the video stream so that its start position corresponds to the requested parameter. This start time parameter is usually named simply start. The video viewer skips the nondownloaded parts of the videos.

Both FLV and MP4 video can be played back with  pseudostreaming. The following scripts or tools are available :

  • The H264 streaming module for Apache, Lighttpd, IIS and NginX.
  • The mod_flv_streaming module for Lighttpd.
  • PHP/ASP scripts such as XmooV PHP.
  • Content delivery networks such as Bitgravity, Edgecast or Limelight.

There is one major advantage to streaming with a Web server rather than with a streaming media server—utilizing existing infrastructure.

The third method uses a separate streaming media server specialized to the audio/video streaming task. A streaming server offers the following advantages :

  • More efficient use of the network bandwidth
  • Better audio and video quality to the user
  • Advanced features like detailed reporting and multi-stream multimedia content
  • Supports large number of users
  • Multiple delivery options
  • Content copyright protection

The following protocols are commonly used by streaming servers :

  • UDP – this protocol provides the most efficient network throughput. The only downside to UDP is that many network administrators close their firewalls to UDP traffic, limiting the potential audience of UDP-based streams
  • TCP – this protocol provides an adequate, though not necessarily efficient, protocol for delivering streaming media content to flow through the firewalls
  • HTTP + TCP – this combination has the benefit of working with all firewalls that let Web traffic through (port 80) and provides much more control (fast forward, rewind, etc) than a standard Web server, but also adds some overhead to the raw TCP stream that decreases scalability.
  • Multicast – this protocol enables hundreds or thousands of users to play a single stream, but will only work on networks with Multicast-enabled routers. Multicast is becoming prevalent on corporate networks, but is still very rare on the Internet

Useful informations and tutorials about streaming are available at the streamingmedia.com website.

In 2009, Amazon CloudFront, the easy-to-use content delivery service, introduced the ability to stream audio and video files. Streaming with Amazon CloudFront is exceptionally easy: with only a few clicks on the AWS Management Console or a simple API call, you’ll be able to stream your content using a world-wide network of edge locations running Adobe’s Flash® Media Server. Like all AWS services, Amazon CloudFront streaming requires no up-front commitments or long-term contracts. There are no additional charges for streaming with Amazon CloudFront; you simply pay normal rates for the data that you transfer using the service.

FFmpeg : record, convert and stream audio and video

Posted on by

Last update : August 29, 2013

ffmpeg

FFmpeg Command Line Tool

FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes libavcodec – the leading audio/video codec library.

The latest version is 2.0.1 released August 11, 2013. Version 0.6.x released in 2010 featured a lot of improvements that are relevant for HTML5 video. The H.264 and Theora decoders were significantly faster, the vorbis decoder has seen important updates and the release supported Google’s newly released libvpx library for the VP8 codec and WEBM container.

FFmpeg is free software licensed under the LGPL or GPL depending on the configuration options. Companies that violate the license terms are tracked and listed on the Hall of Shame and eventually sued.

ffdshow wrapper for Windows DirectShow

FFmpeg is developed under GNU/Linux, but it can be compiled under most operating systems. Windows distributions are available at the website ffmpeg.zeranoe.com. On Windows there are however some limitations, for instance up to now it’s not possible to capture audio in realtime.

To make the libavcodec decoders available to DirectShow-based applications (a proprietary Windows technology), you can use ffdshow. This DirectShow filter is a DirectShow-wrapper around the libavcodec (ffmpeg) decoders. Non DirectShow-based applications like Avidemux use libavcodec/ffmpeg through it’s native interface. There exist a fork of the original ffdshow project called ffdshow tryouts.

Paul Glagla developed a utility Filmerit (version 3.0.8 published on May 14, 2007) to show DirectShow filters and diagnose errors. Another similar tool called InstalledCodec (version 1.30) which allows to enable/disable codec drivers and DirectShow filters is available on the NirSoft website.

FFmpeg is a command-line based tool. There are however several graphical user interfaces (GUI) available :

  • SUPER from eRigthSoft
  • Avanti, a dedicated “workbench” for FFmpeg/Avisynth
  • HandBrake, an open-source, GPL-licensed, multiplatform, multithreaded video transcoder; I upgraded to version 0.9.5 in june 2011
  • WinFF, a free tool published under the GNU public license for Windows and Ubuntu

SUPER from eRigthSoft

Avanti GUI

HandBrake

FFmpeg or the libraries are also used by other video frameworks :

  • VLC from Videolan

A full list of all projects using FFmpeg is available on the official website.

A similar project as FFmpeg, using several components of this project, is MEncoder.

The following list provides some useful links about FFmpeg :

The WebM Project

Posted on by

last update : January 16, 2011
The WebM project is dedicated to developing a high-quality, open video format for the web that is freely available to everyone.

The WebM launch is supported by Mozilla, Opera, Adobe, Google and more than forty other publishers, software and hardware vendors.

WebM defines the file container structure, video and audio formats. WebM files consist of video streams compressed with the VP8 video codec and audio streams compressed with the Vorbis audio codec. The WebM file structure is based on the Matroska container.

VP8 is a highly efficient video compression technology that was developed by On2 Technologies.

A detailed description about the WebM Project is available at the FAQ section of the website.

A first WebM encoder is available from Miro, another one from PolySoft Solutions.

Some specialists are not convinced that WebM will be a success, as stated by Devon Govett on his blog. Others, like Jason Garrett-Glaser, the current primary x264 developer and ffmpeg developer, even thinks that the performance of the V8 codec is lower than the heavenly patented H.264 codec and that there will be patent issues in the future, because V8 copied too much from H.264.

How to encode to WebM is the title of a contribution posted by Jan Ozer in the Streaming Media Magazine in january 2011.

Wavatars

Posted on by

Wavatars is a wordpress plugin that will generate and assign icons to the visitors leaving comments at your site. The icons are based on email, so a given visitor will get the same icon each time they comment. It livens up comment threads and gives people memorable “faces” to aid in following conversation threads. It’s also fun.

Wavatars

Global Trade Item Number (GTIN), European Article Numbering (EAN) et GS1

Posted on by

Le Global Trade Item Number (GTIN) ou code article international en français est un code identifiant toute unité commerciale (unité consommateur ou unité standard de regroupement…) de façon internationale et unique.

GTIN est un terme général utilisé pour parler de l’ensemble des structures de données pour l’identification des articles marchands (produits et services) de GS1. Le code GTIN peut être constitué de 8, 12, 13 ou 14 chiffres, et peut être construit en utilisant quatre structure numéraires, selon l’application qui en sera faite.

GS1 est un organisme mondial actif dans le domaine de la normalisation des méthodes de codage utilisées dans la chaîne logistique. Il est issu de la fusion en juin 2003 de l’European Article Numbering (EAN, organisme européen) et de l’Uniform Code Council (UCC, organisme américain). EAN avait développé le standard EAN, alors qu’UCC avait développé la norme CUP.

GS1 a deux sièges, l’un à Bruxelles (Belgique), l’autre à Lawrenceville (New Jersey, États-Unis).

Pour obtenir un code EAN au Luxembourg, il faut devenir membre de GS1 Belgium & Luxembourg. Le code pays EAM-13 pour le Luxembourg est 54.

Un générateur en-ligne de codes barre EAN-13 pour faire des tests est disponible sur le site EAN-13 Barcode Generator.

Un calculateur pour calculer le checkdigit d’un code EAN est disponible sur le site www.barcode-us.com.

source : Wikipedia

Privacy protect for domain name owners

Posted on by

When buying a domain name you have to provide accurate contact information or else your domain registration could be terminated as it would be in violation of the registration agreement. This information has to be made publicly available to everyone via the public WHOIS database as required by ICANN, the international governing body for domain names. Everyday, this valuable source of accurate contact information is targeted and harvested by spammers and telemarketers resulting in unwanted and unsolicited contact.

Privacy Protection ensures that your private information is not published by replacing all your publicly visible contact details with alternate contact information. PrivacyProtect.org provides a WHOIS privacy service for domain name owners through partners. The only way to contact the real domain name owner is to use a webform.