Frame rate very high for a muxer not efficiently supporting it

I had a 1h video, with about 400Mb…
My batch was taking HOURS (with a 8 core CPU) and creating a 5Gb mp4 file of the encoding….. wtf?

13442 www-data 22 2 1426m 361m 3884 R 614 4.5 2180:37 ffmpeg 
14462 www-data 22 2 1773m 966m 3660 R 100 12.1 293:07.12 ffmpeg

I had to run the command manually and figure out the issue.

 creation_time : 2014-04-19 19:19:31
File 'video.mp4' already exists. Overwrite ? [y/N] y
[mp4 @ 0x26a8ae0] Frame rate very high for a muxer not efficiently supporting it.
Please consider specifying a lower framerate, a different muxer or -vsync 2
[libx264 @ 0x26c6ce0] using SAR=1/1
[libx264 @ 0x26c6ce0] MB rate (108000000) > level limit (2073600)

I had to add -vsync 2 to solve this.

/usr/bin/ffmpeg -i 14-18-14.mp4 -c:v libx264 -vsync 2 -threads 4 video.mp4


Redis Autocomplete – 8 millions of entries

This is a demo of the new ZRANGEBYLEX Redis command. It autocompletes the query field using all the 8 millions of unique lines of the Linux kernel source code as autocompletion dictionary. 

Every time the user types something, the page sends a request to a small PHP snippet called search.php which sends a query to Redis, and returns the result to the web page as a JSON array.
As you type in the input field below, you’ll see the list of suggestions appearing.

Virtualization hardware requirements?

The Host Server is the physical computer that will host your virtual machines. The host server can be a machine you’ve rented from one of our partners or one of your own in-house machines. This guide shows how to use one of your own machines as a host server.


  • 64 bit x86 processor with Intel® VT or AMD-V™ technology.

  • CD/DVD-ROM reader or USB port.

  • Minimum 1 GB of RAM.

  • Hard drive (min 20 GB) or NFS storage.



Tails, the OS used by Edward Snowden

When NSA whistle-blower Edward Snowden first emailed Glenn Greenwald, he insisted on using email encryption software called PGP for all communications. But this month, we learned that Snowden used another technology to keep his communications out of the NSA’s prying eyes. It’s called Tails. And naturally, nobody knows exactly who created it.

Tails is a kind of computer-in-a-box. You install it on a DVD or USB drive, boot up the computer from the drive and, voila, you’re pretty close to anonymous on the internet. At its heart, Tails is a version of the Linux operating system optimized for anonymity. It comes with several privacy and encryption tools, most notably Tor, an application that anonymizes a user’s internet traffic by routing it through a network of computers run by volunteers around the world.

Read more at:



Tails is a live operating system, that you can start on almost any computer from a DVD, USB stick, or SD card. It aims at preserving your privacy and anonymity, and helps you to:

  • use the Internet anonymously and circumvent censorship;
    all connections to the Internet are forced to go through the Tor network;
  • leave no trace on the computer you are using unless you ask it explicitly;
  • use state-of-the-art cryptographic tools to encrypt your files, emails and instant messaging.

KVM – Witsbits

Witsbits enables you to set up your servers with virtualization and deploy virtual machines faster than ever before. It’s a complete virtualization solution with a self-upgrading hypervisor and cloud-based centralized management, reducing time spent on maintenance to a fraction of what other solutions require. The self-configuring hypervisor comes as a Live CD, delivering the fastest time-to-deployment by removing the need for spending time on installation and configuration.



Your bare-metal servers will be ready to host virtual machines within 10 minutes. You will never have to upgrade your servers. You don’t have to install centralized management.

Hardware Requirements


You can use any 64bit x86 PC with 2GB of RAM and a CPU with virtualization extensions (Intel® VT-x or AMD-V™).

Info: Most CPUs has virtualization extensions, for details see Intel‘s and AMD‘s respective lists of virtualization capable processors.

Info: You may successfully use a CPU that lacks virtualization extensions with Witsbits to host Linux VMs. It will work, but with reduced performance. Windows VMs will however not work without enabled virtualization extensions.


For local storage devices you need a hard drive of at least 20GB. Alternatively you may use NFS for completely diskless servers. Or any combination of the two.


The following network ports are required to be open in firewall for outgoing traffic: 443/TCP and 873/TCP.

The world’s greatest Azure demo


All the awesome wrapped up into a one hour superdemo