Recent Articles Changed

(Authentication|Access control|Identification) - AuthN

Modified Sep 25 - 12:31

Authentication is the process that establishes the identity of a user who accesses a resource of an application (page, image,...) It's abbreviated as AuthN for authentication versus AuthZ for authorization. The process validates who you are.(Identity "...

Java - Iterator Implementation

Modified Sep 24 - 15:31

The iterator implementation in Java is just an inner class that implements the iterator interface. In order to be able to use it in a for loop construction, the iterable interface must be implemented. See also: Introduced in the Java JDK 1.2 release "...

Java - Resource

Modified Sep 24 - 15:01

A resource abstraction is implemented in Java because a resource could be: in the file system, on any place on the classpath in a jar file or otherwise Path relative path: They are the default (Resource paths are relative to the location of thec "...

(Open|Free) Data Set

Modified Sep 24 - 14:48

A page data set A data set is generally available through: one or several files and a optional metadata describing the content of the files Syntax See: Metadata format On the web: : "...

Web Service - API

Modified Sep 24 - 14:47

API A Web Api is generally a synonym for an API based on the HTTP protocol. See the List Technology: REST. A HTTP request with the API request expressed in the URL properties, HTTP header and or HTTP body . A HTTP request with theWeb Socke

Web Service - Representational State Transfer (REST|RESTful) Web services

Modified Sep 24 - 14:38

Representational State Transfer (REST) Web services, or “RESTful” Web services describes any simple interface that transmits data over a standardized interface (such as HTTP) without an additional messaging layer, such asSOAURImicro-serviceHTTP r "...

Cryptography - Base64 Cipher

Modified Sep 22 - 18:22

Base64 is a cipher (without key and reversible) that converts (encode) a data (message) in 64 characters of the ASCII string. Decoder / Encoder See also the Google encoder/decoder Usage datastore a "...

Authentication - Basic Authentication (HTTP)

Modified Sep 22 - 17:55

Basic Access Authentication is an Authentication mechanism from HTTP auth. Basic access authentication uses the easily reversible Base64 encoding making it non-secure unless used in conjunction with TLS. The basic mechanism provides no confidentialit "...

Recent Articles Created

How to set the bitrate with ffmpeg

Created Sep 14 - 10:44

The bitrate with ffmpeg is a parameter that sets the quality of your video. You can set the bitrate: directly by giving a value with b:v (if you care the exact file size) or indirectly by giving the Constant Rate Factor (CRF) of the encoding scheme...

What is a video bitrate ?

Created Sep 02 - 10:58

A video bitrate is the number of bit per unit of time that a video sends to the display buffer (and sound). It's given in: bps - bits per second kbps - kilobps mbps - megabps It may be parameter that you give to your video editing software as a ta...

Buffer Display

Created Sep 02 - 10:52

The buffer display is a buffer that contains visual data. When the display refreshes, the buffer is read and is paint on the display. If the buffer is empty, nothing is paint. The buffer may be material (ie on a screen) but it may also be software ba...

How to reduce the size of a video dramatically with ffmpeg ?

Created Aug 28 - 14:20

This article shows you how to reduce the size of video with ffmpeg. Size parameters The following parameters have an important on the size: the codec: the codec is the algorithm that encodes the picture into the video format. The better, the algorit...

How to change the video FPS (frame per second) with ffmpeg ?

Created Aug 28 - 12:44

You can change the number frame per second (FPS) of a video thanks to the fps filter Example

How to crop a video with ffmpeg

Created Aug 28 - 12:09

This article shows you how to crop a video with ffmpeg. The crop filter once you have installed it, you can use the crop filter to crop your video. the crop is a filter that accepts the parameters such as the following w, out_w: the width of the out...

How to download and convert a video from twitter, youtube, tiktok (ie m3u, m3u8 format)

Created Aug 28 - 10:07

The M3U file is a playlist file format used often to define a stream video on the Internet. Twitter (as of today) uses it as video definition format. This page shows you how to download and convert a m3u8 playlist video to mp4

WASM (Web Assembly)

Created Aug 28 - 09:55

wasm is a binary format that can be read by all browser. You can therefore create a function in any language (java, php, ...) and compile it to the wasm format to make it available in your page.

Data all the way

Always keep one hand firmly on data, Amos liked to say.

Data is what set psychology apart from philosophy, and physics from metaphysics.

Amos Tversky (The undoing project)

Data Warehouse Subsystems

Developing a data warehouse means assembling a lot of subsystems in order to create a whole and coherent data application.

Discovers the 34 Kimball Subsystems and drill down to discover them

Data Warehouse Subsystems

Data Processing

Data processing has changed a lot since 1940 :) and luckily, we are not using punch card anymore.

Stream processing is becoming the norm in data integration task while batch processing stays the king in data analysis.

Data Processing

ENIAC, 1946

The first fully electronic digital computer

Data Modeling

Data Modeling is the translation of process into the world of data. The process is tricky but not insurmountable.

Data Modeling

Dimensional Data Modeling

Dimensional Data Modeling permits you to model a (hyper)cube and analyse a process through different perspective. You define dimensions, measures and metrics.

Dimensional Data Modeling

Most programs process some input to produce some output; that’s pretty much the definition of computing.


A Function is the basic block of all reusable code component. It is also becoming the central component of any serverless architecture.


Knowledge isn't free. You have to pay attention.

Computing Division at the Department of the Treasury, mid 1920s

Table / Relation

The table format (known also as a relation) is the most important data structure used in data analysis. Did you know that its name originate from the medieval counting table ?


Education isn't something you can finish.

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