The kids meet PODMO

I took three students with me to Adelaide to check out mobile technologies including Podmo. My thanks to the DECS Learning Technologies people, especially Paul and Karen, for their support and assistance. The information that I got about Podmo is a bit jumbled.

We met Holly and some of the key words that I recorded don’t make sense when I try and use Google to help to get to the bottom of them. ‘Champagne of the ladies’, pixel play and pixel art. That’s fine because I will be bumping into Holly again in a couple of weeks when she comes here to run a workshop with a bunch of year 9 and 10 students re making multimedia artefacts for mobile devices.

Karen wore a Podmo T-shirt. She gave us some good hints regarding multimedia design constraints for mobile phones. Some of the key points were

• - Screen sizes will increase over time


• - Wallpapers and screen savers


• - 72dpi for images


• - 3:4 image ratio although some phone screens re square


• - the Podmo server resizes images on the fly based upon the phone type it is serving – nice


• - The GIMP was recommended as a good program for manipulating images for the mobile medium


• - screen savers need to be a 3-5 frame animated gif


• - videos need to be 30sec-1minute in duration - short attention span


• - longer video stories need to be broken down into short episodes


• - videos need to be in 3gp file format


• - SUPER © was recommended as good free program for converting movies to 3gp


• - There are different video encoding settings and basically it is a process of experimentation to come up with the best settings for each video artefact. Key frame rates should be about 10-15. Bit rates make a difference to file size but basically the greater the bit rate the better the product looks. Some video does not compress well and is a result of too much colour data and too much movement in the frames.


• - Data transfer via Podmo is free so file size is really only an issue for storage on the phone.


• - Mp3 is supported for most phone ring tones

Che talked mainly about game design for mobile phones. Some of the points I noted were
Java is the programming language and the development of these games sounded complex.

• - Have graphics based on 100 x 100 pixels and then to vary the size of the background to suit the phones screen


• - We saw some sprite strips and I understood better how they were used. The key thing about a sprite strip is to base them a consistent grid size.


• - Given the smallish storage on phone devices, programming needed to be like it was in the Vic20 and C64 days – very memory conservative. Now that I can remember with great clarity


• - Use index colours – keep colours used to the 32 colours


• - Images need to be in png8 file format (I assume that PNG8 means 8 bits per pixel or a bit depth of 8 pixels)


• - Do not use semi transparent pixels as many phones do not support them


• - PNG crush can be used to compress images


• - Paint and Fireworks are two of many possible tools that can be used to create images and sprites but turn anti-aliasing off


• - Photoshop adds to much to the size of the images for this application

An important resource for validating artefacts created for mobile phones is Sun’s mobile phone emulator for PC. I need to find this. Efforts so far have been in vain.

A recommended site for checking out and comparing phone features http://www.gsmarena.com/

I also need to keep an eye out for the Podmo developers pack

I was encouraged by the fact that all presenters referred to their extensive use of FOSS and this included the GIMP. Teachers in the graphics area seem to be fixated on proprietary software usually citing ‘industry standards’ as one of the key reasons. I felt that a hacker mindset enabled the Podmo people to be very creative because they were comfortable with picking up different tools and using them in sometimes usual ways and combinations. Relating to this, today I was alerted to the release of Ubuntu Studio next month.

Ubuntu Studio. A multimedia creation derivative of Ubuntu. Ubuntu Studio is aimed at the linux audio, video and graphic enthusiast as well as professional.

The Podmo people gave me the impression of wanting to ensure a fair go for all parties involved. Where artists want to sell their artefacts via the Podmo network they will receive a huge 50% of the takings. It is good that they want to build respect and a fair go for artists into their business model.

We have some bluetooth dongles and the Podmo server software coming soon so we will be able to have a play. I am going to find out if the Podmo mob will sell me a XL Podmo T-shirt.