Minutes

BLUG MEET - 26th September 2003

This meet mostly dedicated to Graphics and Multimedia on Linux was attended by 48 members.

SDL in Linux
The first presentation of the day was by Arun Raghavan and Vibhu Rishi and they dealt specifically with Simple Direct Media Layer(SDL). This application developed by Sam Lantinga has been written in 'C', works with C++ natively,and bindings to Java Perl are also available. It is used extensively by people who are on to 'Gaming on Linux' such as Loki Games who ported MsWindows games into Linux. SDL is used by popular games such as Tux Racer and Chromium. It is light-weight,simple, has a clean API, and is able to abstract the native graphics. They demonstrated with dexterity the full scale sound effects created by them.

The SDL sub-systems such as audio,video,cdrom etc. are initialised by running SDL_initsubsystem. After init, the video modes could be set manually. It uses a concept known as "blitting" wherein images are loaded into memory and a few things are blitted, i.e, copied to other systems. It has a very efficient way of handling inputs by having SDL events polled or waited for. It is a graphics library and is also able to provide background music and special effects for games. It can also provide the necessary infrastructure to be used in X-ray imaging etc.

The SDL graphics library provides a few utilities which act as wrappers around the FreeType 1.2 library(SDL_ttf).SDL_mixer enables loading sound samples in varied formats such as wav/mp3/ogg. SDL_net can be used with OpenGL for playing games across the net. For documentation on SDL you may refer to : /usr/share/doc/SDL-devel-1.2.4/html

Graphics on Linux by Mahendra M and Kartik N
Gnu Image Manipulation Program (GIMP)
The above utility which was developed as an alternative college project has come to acquire capabilities which match and even outdo full-scale commercial applications like Adobe's Photoshop. It has tile-based memory management since it loads images not as a linear array but breaks it into small tiles. Further, tile cache is also maintained to speed up the loading at a rate which is faster than Photoshop. GIMP runs as a server and has a Procedural Database(PDB) wherein plug-ins are registered. Script-Fu is the GIMP scripting extension which provides a variety of themes for buttons, logos, and web page frames.

Imagemagick
It is a graphic tool which cannot efficiently handle too big an image, but as a plug-in to GIMP it provides added capabilities and is pretty good. It has very good API support for C,C++,Perl,PHP,Java,and shell scripts as well. It is very good in converting between different formats and has a command line utility.

There was also a pretty demonstration of a 3D Graphics tool known as Blender which is available as a 2MB download from www.blender3d.org.It is one of the fastest rendering engines and is OpenSource. It has a very small file size(90KB)compared to the same image in AVI format of size 100MB.Both Mahendra and Kartik demonstrated the capabilities of blender by creating 3D animation of a rotating globe after transposing the world map onto a round object placed at the centre. It can also be used to create 3D games,and movie rendering. In fact a few of the Hollywood movies have used blender very effectively to produce some amazing graphics on the big screen.

There was also mention of other graphic tools available on Linux such as Xfig which could be used for creating Flowcharts,drawings. Povray was referred to as another 3D rendering tool which is text-based using solid geometry. Xmorph is a tool which gives the capability for morphing images.

Firebird - the Open source version of Borland's Interbase
The concluding talk of the day was from Gurunandan Bhat who spoke about the open source database system,viz.,Firebird which is based on Borland's Interbase version 6.0 whose source code was made public on July,2000.The lead developer of Firebird is Ann Harison who was one among the 82 persons who were initially with Borland/Inprise.It operates under Mozilla license and allows an application to run from a CD. Firebird is capable of running on multi platforms as its' database has a single file which can easily be transported say, from Linux to Windows and vice versa.

Firebird has rich features such as SQL92 compliance,and support for Stored Procedures,Triggers, and Concurrent Versioning. It also supports a variety of bindings for PHP,Perl,C,C++,ODBS/JDBC,Delphi 7,and Kylix DBExpress. The other important features of Firebird are as follows:

• User defined data types

• Support for Procedural Language like Oracle's Pl/SQL

• Ideal for CD based applications

• Easy replication and backup

• It has a command interface known as isql .

• Database Tuning

• Data backup without shutting down the database

• A View seen by an user at the time Live Backup was started is possible

• Supports all the SQL92 Dialects

Gurunandan Bhat concluded his illuminating talk with a demonstration of Interbase application,IBAccess which is used as a front-end for Firebird also.

On the whole the meet was as good as any other and for those who missed it, these words could at best convey in mere words a World of Graphics,Sound,and Animation rendering which was really a scintillating and eye-filling experience.

Murali P

FINAL ACCOUNTS