Set-top boxes are very similar to mobile devices when it comes to developing and testing Flash content; speed, performance, memory issues, choosing between vectors and raster images; they all exists.

I had some hands on experience with an older version of Flash for set-top boxes, also known as Flash Lite for Digital Home, and also managed some testing with AIR on TVs.

Had a couple of takeaways while working with FLDH on set-top boxes and televisions –

1. Flash content is universal. You could have a game or application that has been developed for a non-TV platform, and you could manage to run it successfully on a television set.
2. You should not have complex code written in Flash, for instance complex 3D renderings, or extensive use of vectors can cause lag in performance.
3. Content can be published as Flash Lite 2.1+ or Flash 8, but fscommands will not work. For instance, a command such as “Fullscreen” will be overlooked by the runtime.
4. Most television content have something known as a “safe viewing area”. This refers to the visual with a 5-7% margin cut around the content edges during display. Most newer televisions may not have this overscan area, but it is always best to design content keeping the overscan area in mind i.e avoid placing any art or media in the corners.
5. Mapping keys to the remote can be a challenge from the UI perspective. A good design is one where a user uses less keys and still manages to navigate without any help. In case of a TV, we have limited keys which a user may be familiar with for interactive content, i.e  the left/right/top/bottom and enter keys; ( no soft keys like mobiles). So if an application or game has a UI with several buttons, it should be visually displayed to the user.
6. Managing memory and maintaining quality. This is a big challenge, especially when dealing with sounds, images and videos. With TV resolutions of 720p and 1080p, the quality of display can’t be compromised. Media of high quality should go through a good process of loading and unloading at frequent intervals for the platform to remain stable.
7. While a well architectured code with OOP is a good programming practice, it can sometimes take a toll on performance and design.
8. There is no community support for Flash Lite for digital homes. Most of it is trial based if you are developing content. Having a device connected to the television set is the best way to move forward.