stef . blog

My journey through ffmpeg and php on mamp: a n00b perspective on server-side video encoding

stef blog — Mon, 18 Jan 2010 09:20:00 +0100

Yesterday I spent almost seven hours on the server-side of one of my (numerous) personal projects. It's not that I really hate server-side coding, but I'm a front-end guy, so it can be a pain to do that part. So if you're on your way to prototype the next youtube and you're not an expert on server-side stuff, this post is for you. After setting up the main class for uploading in php, the first thing you want to do is to call shell_exec($cmd). This is an amazing function in php, allowing you to call any shell command. $cmd will be in that case the ffmpeg command line. To do so, you need a binary. On mac os x, the simpliest thing is to install ffmpegx (the gui of ffmpeg), open the package and copy the ffmpeg binary into your usr/local/bin folder so it's accessible from everywhere. At this point, it's really easy. What can be more tricky is the h264 conversion to make it compatible with flash player 9 and more. What I discovered there is that the h264 codec for encoding is not efficient. I experienced lots of artifacts and bad quality encodings. After going through ALL the ffmpeg command line options - and there are a lot - deblocking, deinterlace, pixel shapes, bitrate etc, it seems that the codec itself was the problem. On some videos, most of them coming from a Canon 500D camera (which are already h264 encoded files!), it was simply not possible to convert them in any format with a good quality. The solution is to call another library called libx264. The main problem is you need to recompile your ffmpeg binary to include that lib. Once you try to do so - using ./configure --enable-libx264 - you get a nice error, saying "libx264 not found". I tried many forums, as I'm not used to that kind of coding. It's really tricky to find out the solution if you're not familiar with C programming, and the people working on that kinds of projects (I'm talking about libx264, compiling codecs etc.) are not the most sociable and gentle people on earth, from far. You must be a nerd to enter that world. I mean a proper one. I even try to compile myself libx264 and I also got errors while building, and it became more and more obvious that the solution wasn't to try to fix those low-level problems. So I finally found the solution on that website: http://24b6.net/content/ffmpeg-binary (not to be confused with http://www.27bslash6.com, which is a very interesting website for a completely different reason^^), which offers you a compiled binary for linux and mac os x. Untar the file, then run the script using the terminal. It replaces the ffmpeg binary with a new one that includes libx264 and other codecs like libfaac for audio, and many others. Then replace the video codec in the command line to libx264, and don't forget to add aac as the audio codec, so Flash player will properly handle it. All the videos I tried works, in a lot of formats and from different devices. You can use that line, it gives an average good result on everything: /usr/local/bin/ffmpeg -i yourfile.mov -vcodec libx264 -b 1200 -ar 24000 -ab 32 -acodec aac -ab 96k yourfile.mp4 /usr/local/bin/ needs to be added in order to work in php using mamp, on most of the webserver it's not needed. Oh and one last thing: don't forget to change the upload_max_size and post_max_size in your php.ini config file, so you won't be limited by the 32M default values when uploading large files.

Designing for social traction

stef blog — Thu, 15 Oct 2009 13:32:00 +0200

A very nice slideshow on how to use the social networks leverage.

View more documents from Joshua Porter.

Microsoft is back

stef blog — Thu, 24 Sep 2009 00:21:00 +0200

I know for those who knows me it's a pretty weird title, sorry for that, but I have found a few things recently that made me think that something is coming. Watch it on The Telegraph website. It's a 6 minutes video, but don't cry, just watch the first minute or whatever time you can support that.

There's something interesting in that video. Go to exactly 0:55 and listen for 10 seconds. You can clearly hear a voice over saying "call customer service if you have any questions". I can't imagine that's not made on purpose. It's too strange. Maybe not as strange as the comedians, overplaying all the time, or the fact that you can see a geek, a granny, a housewife and a black dude acting like crazy party animals (duh), but still.

The author of that article didn't liked it but its quite possible that it's exactly what Microsoft wants. Because they are used to be on the bottom of the list when it's about to be the coolest kid in town. So why not saying "yeah we used to suck, laugh at us while you can, but we are coming". Maybe I'm totally wrong there, but if that's the plan, it's very clever.

I was even more convinced of that theory when I watched the second video. It's so weird. It seems like Steve Balmer himself did it on crack. And that's exactly what geeks like. And the stats proves it : more than 700'000 views. 2nd most viewed video on sciences / technology. Only men between 24 and 55, which means obviously geeks. And if there was a need for another proof, look at how happy they are at CNET.

And even more than that: I just spend 20 minutes to write about Microsoft, and quite positively, and you also spent around the same time reading that if you watched the videos!

Rio / Paris - Sanaa / Moroni

stef blog — Thu, 02 Jul 2009 02:41:00 +0200

Marrant comme deux evenements proches peuvent être percus completement differemment. Le crash du vol Rio / Paris avait entraine de nombreux articles, et avait occupé tous les medias pendant des jours. On a vu des minutes de silence pendant les matchs de foot, les politiques s'etaient deplaces pour en parler. Aujourd'hui le vol Sanaa / Moroni qui s'est ecrasé en mer le 30 juin ne fait pas la une des journaux. On parle encore plus du Rio / Paris, meme maintenant.

Verra-t-on des minutes de silence? Un deuil national? Il y avait 66 francais a bord de cet avion, soit a peu pres le nombre de francais dans le vol Rio / Paris (72).

Evidemment, si on compare les chiffres, le crash du Rio / Paris a fait plus de victimes. C'est un des pires crash de l'histoire. Mais n'empeche. C'est peut-etre de la mauvaise fois de ma part mais je pense que le public de Roland Garros par exemple se sent plus proche des passagers d'un vol transatlantique que d'un vol interne a l'Afrique. J'espere que je me trompe et que ca viendra plus tard. Mais j'en doute. Tout ca est tres cynique et aussi tres révelateur. Voilà, ça c'était pour pisser dans un violon, ca faisait longtemps.

Sound spectrum + Papervision 2.0 + TweenMax = SOURCE CODE !

stef blog — Tue, 24 Feb 2009 01:41:00 +0100

Remember that little experiment I made last time? So now you can use it - here's the main class and the FLA. More info on the technique here

Eric Zemmour, ou comment se planter tout simplement

stef blog — Fri, 13 Feb 2009 15:16:00 +0100

Internet = minitel 2.0

stef blog — Wed, 11 Feb 2009 11:22:00 +0100

Minitel 2.0 par Benjamin Bayart from gaspard on Vimeo.

Excellente présentation de Benjamin Bayart au rencontres mondiales du logiciel libre d’Amiens, en juillet 2007. Via Korben. Plus d'infos ici.

*stef . blog*