Sometimes when working with virtual images, R or python, I can see that the memory load is really high and then the system becomes completely unresponsive. This post will show you how to optimize memory management in linux so the system does not freeze.
Category Archives: ubuntu
Grub rescue
Codify video with ffmpeg
To recodify a video with a different codec you can use ffmpeg with the following sintaxis:
ffmpeg -i inputfile -c:v -c:a outputfile
Where and are the codecs for video and audio channel to codify the intpu file.
To see all the available codecs write:
ffmpeg -formats
For example to recodify a video into h.264 for video channel and mp3 for audio:
ffmpeg -i input.AVI -c:v h264 -c:a mp3 output.mp4
To codify in mov:
ffmpeg -i input.AVI -acodec aac -ac 1 -ar 44100 -ab 64k -strict -2 -vcodec libx264 output.mov
How to create a Debian/Ubuntu repository
Create the repository directory with a conf dir inside:
Configure your favourite webserver to publish this repository dir and all its content
$ mkdir -p repo/conf $ cd repo
Create the file conf/distributions and edit its content:
$ vi conf/distributions
Architectures: i386 amd64 source Codename: stable Components: main Description: Repo description Label: Ubuntu Origin: MyOrigin Version: 12.10 SignWith:repokey
Create the file conf/options and edit its content:
$ vi conf/options
verbose basedir .
Check if the repo is working:
$ reprepro check Checking stable...
Create a key with name repokey:
$ gpg --gen--key $ gpg --export repokey > repokey.gpg
Sign the debian packages with the new key:
$ dpkg-sig --sign repokey ~/packages/*.deb
Copy them to the stable repository:
$ reprepro includedeb stable ~/packages/*.deb
We can see that the repository has the desired packages by writing:
$ reprepro list stable
And that it’s all.
You have finished your new repository.
If you want to remove a package from the stable repository:
$ reprepro remove stable
If you want to remove all the packages from the stable repository
$ reprepro removefilter precise 'Section'