June 5, 2003

Of phones and polyphonics …

While I’m kept busy at work during the daytime learning my new duties and getting ready to take over from Robin, my evenings for the past few days have been busy working with my new phone – the Sony Ericsson P800 :p I’ve been installing software, trying out backgrounds, categorizing stuff, moving data over from my Compaq iPaq and so on. I’ve now come to the ringtone stage of the customizations. The P800 supports a variety of audio formats for ringtones but I didn’t like the MIDI option since the tones were too soft and couldn’t be heard over traffic while I might be travelling on the bike .. or even in a bus. The same seemed to be true of the IMY (iMelody) format and I wasn’t sure how to work with AMR format or RMF format files.

At the same time, I wanted to have some songs as ringtones but not just the instrumental part and so that let out both MIDI and IMY and I think even RMF as well though I’m not sure about that particular format. So I dropped back to the old reliable WAV format that the phone also supports. The problem was that I couldn’t find any song ringtones online at all after a lot of searching though a friend of mine does have a couple on his Sagem phone – but the problem is that there is no way to get the tones out of his phone since he can’t beam the tones and they are too big to be sent via SMS. So I decided to try and create a ringtone on my own from an MP3 file segment. My first attempt produced a 2MB+ WAV file which was around 20 seconds in stereo at 44100Hz and in 16-bit format. So I began experimenting with all the different variables – I dropped the frequency down to 8000Hz, brought the bitrate down to 8-bit and suddenly the file was only around 200k-300k! Of course, by this time the volume was so low that I had to amplify it by around 15dB but this produced a lot of distortion in the final output.

I didn’t know enough at this point to figure out how to clean up the output file to get rid of the distortion (that would come later when I went through the help files and also went online) but I did do some normalization of the output. I later realized that going from stereo to mono would save me some space as well. That was all day before yesterday. Yesterday, I got a whole bunch of MP3’s I wanted to use and processed each one of them the same way that I’d done the original ringtone that I’d created but this time I experimented with the frequency and the final amplification on some of them. These turned out slightly better but not so loud but that was probably because I amplified most of them by 10dB instead of 15dB. I learnt after I’d done all of this as to how to clean up files which had become distorted due to amplification but it was too late to do any further experimenting. So maybe today I’ll see if that method can be used to clean up the files I’d created and still be left with a clear and loud ringtone …

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Tags: Gadgets, Technology
Posted by Fahim at 6:21 am   Comments (0)