How hard can it be? (Or why you don’t have custom per contact ringtones on Maemo)

Often in blogs, forums or IRC you can find people complaining of missing features in some programs (and some of them are very rude). While they can be right sometimes, other times they just make me angry because they don’t know how difficult writing software can be, and they don’t understand the difference between a semi-working prototype and a proper stable application written by professional developers, designed by professional UI designers and tested by professional testers.

Implementing some features can actually be quite difficult and it could be better to skip those from your product and focus on other things; on the N900 one of these missing features is the ability to set customised ringtones for specific contacts.
Several people wondered how hard it can be, after all a lot of old phones do it. What they don’t consider is that, in many ways, the N900 is not a traditional phone and is more similar to a small computer. On the other hand, the N900 still needs to be reliable to be certified as a phone; for ringtones this means that the ringtone should be played as soon as the phone call is received, or the user could miss it.
Now suppose your N900 is under heavy load due to multitasking (real multitasking, like on a normal computer) and you receive a phone call from a friend; being a close friend that often calls you, you have an MP3 ringtone set just for him. The phone has to look up for the contact corresponding to the phone number, load the file from the (slow) memory card, load the libraries for playing the ringtone, uncompress the file, and finally play it. All of this on a phone under heavy load with most programs swapped out of memory!
To workaround this problem the N900 seems to do some tricks: the ringtone is uncompressed into a (big) WAV file and saved on the faster (but small) internal memory, and the component playing the ringtone is memlocked (i.e. never removed from memory). Of course, you cannot do this for all the possible ringtones or the already small disk space would be used immediately. Choosing not to uncompress the files, on the other hand, would mean keeping loaded in memory all the possible codecs.

Does this mean that it’s impossible to have a different ringtone for a specific contact on Maemo? No, it just means that if you want it you have to be ready to accept that the ringtone could start playing a couple of seconds later in some uncommon heavy load conditions. When you are ready to do that you just have to wait a couple of days, so that I can polish and publish the program I wrote to have custom ringtones :D

In other news, I’m going to GUADEC for the whole week: see you there!

I'm going to GUADEC