how does soundcloud.com generate the waveform for their excellent mp3 player?

Question

i would like to make a similar application but am struggling on how to generate the image of a waveform - are there any php libararies i can use, or perhaps something i can run from in linux to generate waveforms from an mp3?

thanks :)

Answer 1

SoundCloud's waveform is Flash, which does have native MP3 support which is where they probably started. To recreate this in PHP will NOT be easy, but there is a PHP project that draws waveforms from WAV files, so you could convert them on the backend and use his code.

PS: If anybody wants to see the SoundCloud waveform in action check out: http://colortheory.com/the-album-so-far

Answer 2

They are definitely not generating the wavform from flash. Even if it is possible to do it in flash, it would require downloading and decoding the entire file first, and those waveforms pop up instantly.