GarciaPL Notes - Java and Others

I would like to present you some showcase of using PHP SDK to integrate with Facebook which was developed by Naitik Shah one of the Facebook employee. Appropriate reference to this very powerful SDK you can find in reference below.

So, I have created some small showcase which aims to show how to retrieve Facebook profile (not person, but some organisation or business) and print entries which was published on it's wall. Every entry is described by Name, Image (if was uploaded), Creation time, Title and Description as on screenshot below.

FB Profile list of entries

FB Profile Manager

Let's assume that you use FFmpeg distribution in your application. One of your function is for instance saving some HLS stream (HTTP Live Streaming) into file. I suppose you are using python subprocess module to create process in Linux OS to obtain this stream to your hard disk.

In normal way if you would like to stop saving this content using FFmpeg on your storage, you will just press 'q' button while you are in terminal. Due to this FFmpeg will be able to finish saving content and do not damage the file at the end.

There is some kind of problem if you would like to kill this FFmpeg process in smooth way without damaging the file while you do not have access to the terminal.

You can use below solution written in Python to kill this FFmpeg process from your application. Only input which you need to ensure is PID (Process IDentifier) which describes your  process. You can use below shell code in Linux :

ps -ef | grep ffmpeg | awk '{print $2}'

import psutil
import os
import signal

pids = psutil.get_pid_list()

for pid in pids:
      if (pid == <your_PID>):
            os.kill(pid,signal.SIGINT)

Have you ever thought how receive the bitrate of your video/audio file using ffmpeg in command line ? Before I will show you a solution of this problem I would like to paste below some example output of video file which can be obtained using ffmpeg :

ffmpeg version git-2013-10-30-94a80e3 Copyright (c) 2000-2013 the FFmpeg developers
  built on Oct 30 2013 15:46:23 with gcc 4.8 (Ubuntu/Linaro 4.8.1-10ubuntu8)
  configuration: --prefix=/home/user/ffmpeg_build --extra-cflags=-I/home/user/ffmpeg_build/include --extra-ldflags=-L/home/luszcwoj/ffmpeg_build/lib --bindir=/home/luszcwoj/bin --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-x11grab
  libavutil      52. 48.100 / 52. 48.100
  libavcodec     55. 39.100 / 55. 39.100
  libavformat    55. 19.104 / 55. 19.104
  libavdevice    55.  5.100 / 55.  5.100
  libavfilter     3. 90.100 /  3. 90.100
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'aquarium.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 0
    compatible_brands: isom3gp4
    creation_time   : 2013-09-08 23:38:41
  Duration: 00:00:03.44, start: 0.000000, bitrate: 3933 kb/s
    Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuvj420p(pc), 640x480 [SAR 1:1 DAR 4:3], 2250 kb/s, 29.70 fps, 29.67 tbr, 90k tbn, 30 tbc (default)
    Metadata:
      creation_time   : 2013-09-08 23:38:41
      handler_name    : VideoHandle
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 123 kb/s (default)
    Metadata:
      creation_time   : 2013-09-08 23:38:41
      handler_name    : SoundHandle

ffmpeg -i aquarium.mp4 2>&1 | grep bitrate: | awk '{print $6}'

A few days ago I found very useful solution (thanks for Biomathematicus!) for deleting tables from a MySQL schema. I know that it could be quite difficult for some developers (also for me) to manually remove every table from schema without removing this schema itself. So, there is a two-step solution which is going to help you removing a lot of tables from SQL database.

1) List all tables in the MySQL schema :

SELECT CONCAT('drop table ',table_name,'; ')
FROM information_schema.tables
WHERE table_schema = 'yourDatabaseName';

drop table table1; 
drop table table2;

I really really would like to share with a video of my participation on conference called "Confitura" in the year 2013.

Confitura is the largest free conference for Java developers in Europe and even the largest event of its kind in Poland. 6 July this year on the campus of the University of Warsaw will be the next edition of our conference. From year to year we develop and we host a growing number of enthusiasts programming, a year ago there were more than 800. This year we expect nearly 1,000 people, for whom we have prepared five parallel tracks of almost 30 lectures.

More information you can find on : http://2013.confitura.pl/

Video : http://www.youtube.com/watch?v=HAuVAgeBqyQ



You can see when I am talking a lot of about many interesting and clever things starting from 0:34 second of this video ;) Enjoy.

I used to have a problem while I was developing some application using Django (Python Web Framework). This problem occurs when I received some data from some kind of source using for example JSON notation. When this data contains some custom characters which should be saved in Unicode notation, I received and error like this one :