Project: Encoding with OPTAR

A project for unix/linux by Derek Girardi during the fall 2011.

This project was begun on 11/18/11 and will take a 1-2 days.

The purpose of this project is to encode your own golay code OPTAR paper. Similar to the decoding project, except you make one for someone to decode. In this i have a selected audio of my own so there is a audio file in it.

In order to successfully accomplish/perform this project, the listed resources/experiences need to be consulted/achieved:

• Manage files in unix/linux
• Run commands on the command line
• Archive handling
• Manipulate text through expressions
• Puzzle box
• Decoding with OPTAR

Optar stands for OPTical ARchiver. It's a codec for encoding data on paper or free software 2D barcode in other words. Optar fits 200kB on an A4 page, then you print it with a laser printer. If you want to read the recording, scan it with a scanner and feed into the decoder program. This can be used in many real life situations like in law, where you need to store data in a more compact way for accounting. or in media augmentation like putting data inside books, magazines and newspapers. It can also be used just for fun if you want to show it off for your friends. It does not have a man page but it can easily be downloaded and one can find help within its readme file. All you need to know for optical archiving is in there. This is similar background info from my decoding project because its the same thing just we are encoding now.

Find your own file to encode on a piece of paper. Find a way to cut it down to size, and run it through the necessary programs to encode it on a piece of paper.

State and justify the attributes you'd like to receive upon successful approval and completion of this project.

• commands:demonstration/utilization of commands/tools
• files & directories: demonstration of paths/files/directories
• The UNIX shell:utilization of UNIX shell functionality
• The UNIX development environment:demonstration of development tools

There are many things that had to happen for this to happen:

• First one must pick an audio file to be used (or any file, you can choose whatever you want).
• Depending on what you must determine what it is and how big. ( i am going to describe the file i used, mp3 file)
• First the mp3 file had to be converted to wav (raw data) to be able to process in linux.
• Then using audacity, i had to cut it down to around 30 seconds to make it around 200k. (it can be higher, you will just have more pages)
• you then save it to your home directory or where the programs are contained
• You then need to turn the wav file to a ogg (thats what the encoder will read, in ogg)
• so use oggenc and it should convert it for you. Then run it through optar

./optar nyanit2.ogg nyanfinal

• once its converted, you can run the pgm2ps command to turn it to a ps file.
• It needs to be a ps file to print.
• Then once you have it printed out (print on best quality and grayscale, i have gotten better results with this) Just scan it and do what you did in decoding, and test for irreparable bits and see if all the data is there.

this project was interesting, it was difficult to cut down the audio because it was having issues but in the end, it was fun. :)

In performing this project, the following resources were referenced:

• http://ronja.twibright.com/optar/