Blog de François Becker

Aller au contenu | Aller au menu | Aller à la recherche

mercredi 30 septembre 2015

Compress a MP4 video using ffmpeg

This is the two-pass command, using a 2048k video bitrate:

ffmpeg -y -i <input>.mp4 -c:v libx264 -preset medium -b:v 2048k -pass 1 -c:a libfdk_aac -b:a 128k -f mp4 /dev/null && ffmpeg -i <input>.mp4 -c:v libx264 -preset medium -b:v 2048k -pass 2 -c:a libfdk_aac -b:a 128k <output>.mp4

dimanche 13 septembre 2015

Notes on The World Set Free by H. G. Wells

This book was written in 1913-1914 — that's one CENTURY ago! — even before the two World Wars — but some excerpts are nonetheless either premonitory or still valid nowadays. It predicts the age of atomic bombs and, though in the fiction it works differently in its consequences on the battlefield, it tackles the brand new impact of this strategic weapon as of its deterrence and its proliferation.

Here are some quotes, a list of vocabulary which can has usefulness for non-native English readers, and finally resources for further reading.


If there was a vast development of production there was also a huge destruction of values.

Between these high lights accumulated disaster, social catastrophe. The coal mines were manifestly doomed to closure at no very distant date, the vast amount of capital invested in oil was becoming unsaleable, millions of coal miners, steel workers upon the old lines, vast swarms of unskilled or under-skilled labourers in innumerable occupations, were being flung out of employment by the superior efficiency of the new machinery

The world in these days was not really governed at all, in the sense in which government came to be understood in subsequent years. Government was a treaty, not a design; it was forensic, conservative, disputatious, unseeing, unthinking, uncreative; throughout the world, except where the vestiges of absolutism still sheltered the court favourite and the trusted servant, it was in the hands of the predominant caste of lawyers, who had an enormous advantage in being the only trained caste. Their professional education and every circumstance in the manipulation of the fantastically naive electoral methods by which they clambered to power, conspired to keep them contemptuous of facts, conscientiously unimaginative, alert to claim and seize advantages and suspicious of every generosity.

For more than a century the French system exhausted its vitality in belligerent convulsions, and then the infection passed to the German-speaking peoples who were the heart and centre of Europe, and from them onward to the Slavs.

the ultimate aim of art, religion, philosophy, and science alike was to simplify.

A population map of the world in 1950 would have followed seashore and river course so closely in its darker shading as to give an impression that homo sapiens was an amphibious animal.

Man who is ceasing to be an agricultural animal becomes more and more a builder, a traveller, and a maker.

And the chemists' triumphs of synthesis, which could now give us an entirely artificial food, remain largely in abeyance because it is so much more pleasant and interesting to eat natural produce and to grow such things upon the soil. Each year adds to the variety of our fruits and the delightfulness of our flowers.

Membership of the government, it was decided, must be for life, save in the exceptional case of a recall; but the elections, which were held quinquenially, were arranged to add fifty members on each occasion. The method of proportional representation with one transferable vote was adopted, and the voter might also write upon his voting paper in a specially marked space, the name of any of his representatives that he wished to recall. A ruler was recallable by as many votes as the quota by which he had been elected, and the original members by as many votes in any constituency as the returning quotas in the first election.

In that age they seem to have been perpetually making laws when we should alter regulations.

This phase of history, which has been not inaptly termed the 'Efflorescence,' is still, to a large extent, with us. The majority of our population consists of artists, and the bulk of activity in the world lies no longer with necessities but with their elaboration, decoration, and refinement.

The earlier novelists tried to show 'life as it is,' the latter showed life as it changes.

'We have so many men working now,' said Fowler. 'I suppose at present there must be at least a thousand thinking hard, observing, experimenting, for one who did so in nineteen hundred.'

Here—I must show you it to-day, because it will interest you—we have our copy of the encyclopaedic index—every week sheets are taken out and replaced by fresh sheets with new results that are brought to us by the aeroplanes of the Research Department. It is an index of knowledge that grows continually, an index that becomes continually truer. There was never anything like it before.'

So long as you are alive you are just the moment, perhaps, but when you are dead then you are all your life from the first moment to the last....'

I suppose that nothing less than the violence of those bombs could have released it and made it a healthy world again.

everything seemed turning to evil in those last years of the old time. Everywhere there were obsolete organisations seizing upon all the new fine things that science was giving to the world, nationalities, all sorts of political bodies, the churches and sects, proprietorship, seizing upon those treat powers and limitless possibilities and turning them to evil uses. And they would not suffer open speech, they would not permit of education, they would let no one be educated to the needs of the new time....

'It was not only that the mass of people would not attend, would not understand, but that those who did understand lacked the power of real belief. They said the things, they saw the things, and the things meant nothing to them....

All this new region of London they are opening up now is plastered with advertisements of pills. Everybody must have been taking pills.

Everybody in those days, wise or foolish, believed that the division of the world under a multitude of governments was inevitable, and that it was going on for thousands of years more. It WAS inevitable until it was impossible. Any one who had denied that inevitability publicly would have been counted—oh! a SILLY fellow.

'You know, sir, I've a fancy—it is hard to prove such things—that civilisation was very near disaster when the atomic bombs came banging into it, that if there had been no Holsten and no induced radio-activity, the world would have—smashed—much as it did. Only instead of its being a smash that opened a way to better things, it might have been a smash without a recovery.

Mankind used up material—insanely. They had got through three-quarters of all the coal in the planet, they had used up most of the oil, they had swept away their forests, and they were running short of tin and copper. Their wheat areas were getting weary and populous, and many of the big towns had so lowered the water level of their available hills that they suffered a drought every summer. The whole system was rushing towards bankruptcy. And they were spending every year vaster and vaster amounts of power and energy upon military preparations, and continually expanding the debt of industry to capital.

And then we came, man came, and opened eyes that were a question and hands that were a demand and began a mind and memory that dies not when men die, but lives and increases for ever, an over-mind, a dominating will, a question and an aspiration that reaches to the stars....

'The key that opens the door,' said Karenin, 'is not the goal of the journey.'

'I do not care a rap about your future—as women. I do not care a rap about the future of men—as males. I want to destroy these peculiar futures. I care for your future as intelligences, as parts of and contribution to the universal mind of the race. Humanity is not only naturally over-specialised in these matters, but all its institutions, its customs, everything, exaggerate, intensify this difference. I want to unspecialise women. No new idea. Plato wanted exactly that. I do not want to go on as we go now, emphasising this natural difference; I do not deny it, but I want to reduce it and overcome it.'

'Karenin?' asked Rachel, 'do you mean that women are to become men?' 'Men and women have to become human beings.'

I want to abolish the woman whose support is jealousy and whose gift possession. I want to abolish the woman who can be won as a prize or locked up as a delicious treasure.

To think of yourselves as women is to think of yourselves in relation to men. You can't escape that consequence. You have to learn to think of yourselves—for our sakes and your own sakes—in relation to the sun and stars. You have to cease to be our adventure, Rachel, and come with us upon our adventures. ...' He waved his hand towards the dark sky above the mountain crests.

Shan't we presently take a tabloid or lie in some field of force that will enable us to do with an hour or so of slumber and rise refreshed again?'

'In a little while men who will know how to bear the strange gravitations, the altered pressures, the attenuated, unfamiliar gases and all the fearful strangenesses of space will be venturing out from this earth. This ball will be no longer enough for us; our spirit will reach out.... Cannot you see how that little argosy will go glittering up into the sky, twinkling and glittering smaller and smaller until the blue swallows it up. They may succeed out there; they may perish, but other men will follow them.... 'It is as if a great window opened,' said Karenin.


chisel claw fierce beset glimmering beget veils hewed bargaining propitiating aped amidst untrammelled hitherto warlocks covetousness heeded unwittingly timber lids swirl begotten chaps altar dismay fretted umpires opiate festoons lattice stroller ecstatic bethought reckoned unruly purposive trickling stonily heedless wards schemer diffident paraphernalia lull scanty dread blunder dropped crimson uproar craned tarpaulin ricks interspersed tussocks of corn and poppy wretch feeble preposterously meadows anointed plough thence shattering compelled alstribution contention smouldering thwarted dwindled hinder cowered self-forgetfulness misfit toiled nodded jostling lurk litter gnawing scarred peevish glimpses belittled mists quivers husks selvage unwholesome uncongenial daguerreotype stoutly riddles Helenism obstinacy winnowing cower


dimanche 19 avril 2015

Binaural microphones and dummyheads

Here is a list of binaural recording hardware, either to be worn by someone, or as standalone devices.

Lire la suite...

samedi 21 mars 2015

Automate Octave script execution on save on Mac OS X

Let's say the octave script you are working on is located in ~/Documents/script.m . On save, you want it to be automagically executed by octave, including persistent figures.

Let's create a watchdog script ~/Documents/

while true
  ATIME=`ls -al ~/Documents/script.m`
  if [[ "$ATIME" != "$LTIME" ]]
    echo "Running octave script"
    echo "script" > ~/Documents/OCTAVEPIPE
  sleep 1

Make it executable: chmod u+x ~/Documents/

Don't launch it yet. We are missing the OCTAVEPIPE pipe. Create it with mkpipe ~/Documents/OCTAVEPIPE

Launch the watchdog in a shell: ~/Documents/ or ./ if you are in the same directory.

In another shell, cd to /Documents/OCTAVEPIPE) | octave --interactive

Now edit and save your octave script, it shoud be executed after less than 1 second.

mardi 20 janvier 2015

Animorph design with OpenSCAD

Hi, you might already have encountered such video of amazing 3D-printed kind of "alive" sculpture:


I'll introduce basic explanation of the phenomenon which allows such performance and how to design an aniform/animorph object.

Lire la suite...

lundi 12 janvier 2015

Activer le protocole aptX sur Mac OS X

Activer le protocole aptX sur Mac OS X :

mercredi 7 janvier 2015

7 janvier 2015. Merci.


Merci car dans toutes mes lectures aujourd'hui je ne lis que compassion, tristesse, incompréhension, amour, gentillesse, solidarité, et même humour.

Nous ne sommes pas tombés dans le panneau de la revanche, de la haine, de la recherche de boucs émissaires.

Cela nous grandit, et resserre nos liens.


lundi 1 décembre 2014

Liste de films et séries

Une liste de films vus ou à voir, avec mon évaluation personnelle. Notamment une rubrique science-fiction assez étoffée, que je séparerai probablement à l'avenir dans un nouveau billet.

Lire la suite...

mercredi 3 septembre 2014

Déflation : occasion d'une politique salvatrice ?

Une question pour les économistes qui pourraient lire ce billet : la situation déflationniste ne serait-elle pas une occasion inespérée pour la création monétaire en remboursement des dettes étatiques et en stimulation de l'investissement et de la confiance par les grands projets ?

dimanche 17 août 2014

A Complementary Learning Methodology For Foreign Language Vocabulary

It can prove difficult to estimate its own vocabulary capacities in a foreign language. It can also be difficult to find which words are still missing to its own knowledge: there is a need for targeting the words which are the most useful in the foreign language.

One can find frequency analysis of text corpuses (or "corpora" for pedants) online for instance on the Wiktionary project, originating from the Project Guteberg which works on a collection of public domain books. The words are ordered by frequency, and one can browse the list in order to find the first words we don't know — yet. Once discovered, these words can be added to flashcard-type learning softwares — these flashcards could even be provided pre-built so that adding one is easier.

One can then evaluate its own vocabulary level to the number of most-used words known.

Instead of working on a student-class level, this personalized method looks like one of the best complementary method for brute-force vocabulary upgrade. Though for the classroom it can set student level targets.

lundi 11 août 2014

Node.js and Javascript for newbies like me

Node.js is very handy for prototyping, with its NPM packages allowing to create services using HTTP, websocket, TCP, UDP, Bonjour/Avahi service declaration or discovery, each of these in only tens of lines.

Here are some "must read" for newbies:

And "could read":

Streams to follow:

What can be done:

dimanche 10 août 2014

Israel, your strikes on Gaza make no sense to me. Here is why.

I usually don't do politics on this blog, but this makes so NO sense to me that I would like to shake your mind and shape it into a "Oh, wait!". This critique is a bit naive and is probably done without knowing all the ins and the outs, but I tried to make sense of it. I address it to Israel because I think this country can have common sense.

Israel, do you really think Hamas combatants are still on their location when you make a strike on the origin of rockets? When bank robbers use human shields, do you shoot missiles on them telling the world "but they used human shields!" and "therefore they are accountable for the civil human losses"? When you add these, it's like you are bombing a bank with hostages inside and robbers already gone, telling that you had "the right to defend yourself".

What is the effect on your strikes on Gaza? Have they reduced Hamas ability to send rockets on Israel? No. Will it after many more strikes? You said that yourself: "no". I thought the military "iron dome" was specifically designed on this purpose: endure Hamas rockets with few or no casualties; it is currently proving effective, and allows Israel to avoid quasi any human losses. However, instead of simply showing to the world that you are the victim, you fall into the trap of "defending" yourself ineffectively and killing many, many civilians. This way, the Hamas obtains its goal of making Gaza the one victim, and Israel its aggressor.

Gaza Strip NASA Gaza strip, NASA (public domain)

mardi 11 février 2014

Réactionnaire de service : du piratage et de la création artistique

Je suis pour la responsabilisation des artistes vis-à-vis de leur rôle dans la création musicale et artistique, vis-à-vis d'Internet-et-ses-dangers.

Étant admis que : - le "piratage" tue la création artistique, - il est impossible d'endiguer le phénomène de "piratage" dès lors qu'une chanson est publiée,

Il devient évident que la publication ou diffusion d'une chanson, de par le piratage qui en découle, tue la création artistique.

Il est donc démontré que la diffusion de chansons de M. Pokora, Christophe Mae ou Stromae (par exemple) tue la création musicale. Ils feraient mieux de garder leurs chansons pour eux.

vendredi 7 février 2014

Du pricing

Quelques notes sur la très intéressante présentation de TheFamily à propos du pricing SAAS.

De manière générale, quelques facteurs qui peuvent avoir une influence sur un prix : le savoir-faire nécessaire, la méthode utilisée, l'exclusivité, la disponibilité, la quantité. Bien sûr, le rapport offre/demande.

Le prix distord la perception de la réalité du produit : qualité etc.

Pour trouver le bon pricing : il faut que la valeur intrinsèque soit suffisament bien perçue par le client pour que le prix annoncé ne soit pas un showstopper. Il est impossible de trouver immédiatement le bon prix car il y a initialement une incompréhension mutuelle entre le fournisseur et le client de ce en quoi consiste l'activité de l'autre. Une méthode gagnante est une stratégie agressive d'acquisition des premiers prospects, puis passer à la phase de growth hacking et de tests de prix & segmentation du marché.

Affichage du prix : présenté de la manière la plus concise possible, toujours finir par un "9". Pour la segmentation du marché, présenter trois prix ancrés dans leur contexte.

jeudi 6 février 2014

Réactionnaire de service : des cambriolages

Je suis pour la punition des victimes de cambriolages. Le cambriolage est un business qui ne survit que parce que ses victimes n'ont pas pris les précautions nécessaires afin de l'éviter. Un cambriolage en finance ainsi un autre. En responsabilisant nos concitoyens, nous pourrons rendre non rentable l'activité de vol, qui disparaîtra dès lors de nos campagnes.

Je suis certain que cet article plaira à notre très cher ministre du redressement productif national, qui verra en de telles mesures un moyen efficace de création d'emplois via le gardiennage et la surveillance privée, et à notre très cher ministre de l'intérieur un moyen innovant de réduire efficacement des chiffres qu'il peine pour l'instant à titiller.

P.S. : pour ceux qui pourraient croire que c'est de la pure fiction, sachez que c'est une analogie adéquate au délit de défaut de sécurisation de vos outils informatiques et de votre connexion à internet.

dimanche 5 janvier 2014

Nice personal websites

Some pretty personal websites. minimalistic & clean

jeudi 24 octobre 2013

3D HFR : mal à la tête pour la première fois

L'année dernière, j'étais allé voir pour la première fois un film en 3D HFR, c'est-à-dire que chaque œil reçoit des images à une fréquence double de la fréquence habituelle du cinéma, c'est-à-dire 48 images par seconde au lieu de 24.

J'ai peu apprécié les les premières scènes présentant des mouvements de caméra brusques, et des plans de durée extrêmement courtes. J'ai eu la sensation de voir le film en accéléré, comme on peut en avoir l'expérience dans les rayons TV des magasins devant des écrans "200Hz". Puis J'ai été un peu perturbé par la propreté des habits des acteurs, notamment lorsqu'ils rampaient contre la paroi des montagnes. A partir de la moitié du film, j'ai commencé à avoir mal à la tête, chose qui ne m'était encore jamais arrivée avec de précédents films en 3D.

Cet article de Gizmodo donne des éléments de compréhension des limites du procédé HFR.

De la startup

Quelques bonnes explications pour monter ou comprendre les startups.

samedi 8 juin 2013

Le contrôle peut être la vulnérabilité

Il est curieux d'observer que certaines des vulnérabilités de notre société sont générées par la volonté de lutter contre celles-ci.

Je vais prendre comme exemple le domaine des télécommunications. Malgré ce que l'on a dit d'Internet (son mythe originel de sa résistance à des attaques nucléaires), les télécommunications sont très centralisées, à chacun de ses niveaux (cellule radiotéléphonique, centrale téléphonique, noeuds de backbone). Cette centralisation est voulue pour plusieurs raisons : le "modèle télécom" de facturation bien sûr, mais également la volonté de contrôle de la part des états, via les écoutes. Ces écoutes servent à lutter contre le terrorisme, terme générique pour l'ensemble des menaces contre la population. Or la centralisation du réseau est également sa vulnérabilité. Le réseau de télécommunications est ainsi vulnérable aux attaques "terroristes" et non-terroristes (guerre), aux pannes de courant, et aux pannes technologiques (comme un bug majeur sur une plateforme centrale, par exemple la panne du réseau d'Orange qui a duré une demi-journée fin 2012)

On peut appliquer des raisonnements analogues à plusieurs autres systèmes qui sont critiques dans notre modèle de société : énergie, production ou logistique de denrées, centres décisionnels ou de compétence, etc. Et ces systèmes ont de très haut niveaux d'interdépendance : les centres décisionnels ont besoin de télécommunications, les télécommunications d'électricité, la production ou logistique de denrées ont besoin d'énergie et de télécommunications, etc.

We have the technology

More or less, or not. (Une autre question serait : en a-t-on vraiment envie ?)

Concernant les télécommunications, j'ai déniché un projet de télécommunications sans opérateur et sans antenne-relai : le projet Serval ; il s’agit de faire de chaque smartphone un relai pour un autre, via les domaines de fréquence actuellement utilisés pour la téléphonie ; d'autre projets se basent sur des réseaux ad-hoc dans le domaine wifi.

Au niveau infrastructurel inférieur, la création et distribution locale d'électricité, "smart grid", semble être un moyen d'éviter une panne de grande envergure, pour peu qu'il ne soit pas dépendant de noeuds principaux.

Robustesse et décroissance

On trouve une certaine quantité de réflexions connexes chez les avocats de la décroissance soutenable et les théoriciens de l'effondrement (comme Dimitri Orlov), mais pas seulement ; on trouve des travaux universitaires et d'industriels. On peut remarquer que notre société n'est pas bâtie sur un concept de "graceful degradation", voire contre ce principe (semences agricoles non réutilisables) ; certains pourraient parler de "fuite en avant".

jeudi 16 août 2012

HTML&CSS container of a maximized image

When developing a web gallery, it can be usefull to maximize the image to the screen, so that

  • the proportions are preserved
  • the whole image fits the screen.

Here is a method for that, in pure HTML & CSS.

#imagewell {
    position: absolute;
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
<div id="imagewell" style="background-image: url('');">

- page 1 de 2