Posts

How to stream rtsp videos or mp4 files throught python/flask + opencv

Image
First, you need to download the code to generate your site with flask. To do this, you can use the following @miguelgrinberg project to stream your webcam or image files with flask.

git clone https://github.com/miguelgrinberg/flask-video-streaming

In app.py you need replace:

from camera import Camera
by
from camera_opencv import Camera

Now, you must edit your video source from camera_opencv.py.
video_source = 0, means that you want to stream your webcam (/dev/video0)
You can edit it, by a file or a rstp url

If you replace 0 by 'video.mp4' you will probably get the following error:

Starting camera thread.
Exception in thread Thread-4:
Traceback (most recent call last):
File "/usr/lib/python3.5/threading.py", line 914, in _bootstrap_inner
self.run()
File "/usr/lib/python3.5/threading.py", line 862, in run
self._target(*self._args, **self._kwargs)
File "/home/nboettcher/Downloads/rtsp/flask-video-streaming/base_camera.py", line 93, in _thread
for frame in frames_i…

How to install Matlab from iso files in Ubuntu Linux

Image
If you try mount the iso files, maybe you can't change the permissions to execute (read-only files).
Try to extract both isos with:

7z x namefileDVD1.iso
7z x namefileDVD2.iso

To run matlab installer you must change the permissions from two files:

chmod +x install
chmod +x bin/glnxa64/install_unix

If you execute "sudo ./install" probably you will get this message:

Preparing installation files ...
Installing ...
Finished.

That means that you may have problem with your jre environment.
Give the JRE path to the executable to run it:

sudo ./install -javadir "/usr/lib/jvm/java-8-openjdk-amd64/jre" 

If you don't know where is your JRE path, just find jre folders with:

locate jre

Enjoy it!















How to install Freeplane 1.6.x from github in Ubuntu 16.04

First, you need to clone the project form github:

git clone https://github.com/freeplane/freeplane.git

Now, to build it, you need to install grandle to create BIN folder where will be freeplane:

sudo apt-get install gradle
cd freeplane
gradle dist test
cd BIN
./freeplane.sh

Enjoy it!

How to configure a Matlab cluster in your lan

Image
First, you need to run admincenter to mange your cluster. It route should be there:

/usr/local/MATLAB/R2016a/toolbox/distcomp/bin/admincenter

Now, you must run mdce on each member node of your cluster

cd /usr/local/MATLAB/R2016a/toolbox/distcomp/bin
sudo ./mdce start    

WARNING: The mdce script detected that the number of processes allowed
is limited by ulimit. Be sure that the limit of processes for the ROOT user
(or the user running the mdce service) is set to either "unlimited"
or at least 128 * W, where W is the maximum number of MATLAB Distributed
Computing Server workers that will run on this machine.

Creating LOGBASE directory (/var/log/mdce).
Creating CHECKPOINTBASE directory (/var/lib/mdce).
Creating SECURITY_DIR directory (/var/lib/mdce/security).
Starting the MATLAB Distributed Computing Server in the background.

To choice who is the jobmanger or workers you need run each command by separate:

sudo ./startjobmanager
or
sudo ./startworker

Now, press Add or Find to add your clust…

IOError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/protobuf-3.2.0-py2.7.egg/EGG-INFO/namespace_packages.txt'

If you try to execute a python script and you get this error:

File "~/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3017, in <module>
    @_call_aside
  File "~/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3003, in _call_aside
    f(*args, **kwargs)
  File "~/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3045, in _initialize_master_working_set
    dist.activate(replace=False)
  File "~/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2575, in activate
    for pkg in self._get_metadata('namespace_packages.txt'):
  File "~/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2565, in _get_metadata
    for line in self.get_metadata_lines(name):
  File "~/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1471, in get_metadata_lines
    return yield_lines(self.get_metadata(name))
  File "~/.local/lib/python2…

How to install wine on Ubuntu 16.04 64 bits

If you try to install wine, maybe you will see the following error:

The following packages have unmet dependencies:
 wine1.6 : Depends: wine1.6-i386 (= 1:1.6.2-0ubuntu14)
           Recommends: fonts-droid but it is not installable
E: Unable to correct problems, you have held broken packages.

I tried installing these fonts but without solution.
To avoid it, you can download the source code and compile it:

wget https://dl.winehq.org/wine/source/2.0/wine-2.0.tar.bz2
tar xjvf wine-2.0.tar.bz2
cd wine2.0
./configure

checking whether gcc -m32 works... no
configure: error: Cannot build a 32-bit program, you need to install 32-bit development libraries.

This happend because you must be explicit if you want to install on a 64-bits platform.

./configure --enable-win64
make -j8
sudo make install

Enjoy it!

How to broke the pdf security to edit it

If you think the protection of pdf is enough for nobody can edit it, you are wrong.
Just execute the follow sentence to broke it:

sudo apt-get install qpdf
qpdf --decrypt encrypted.pdf decrypted.pdf

Enjoy it!