A long long long long long long time ago, Ali Momeni wanted to play with mp3's and mxj.

There http://www.synthesisters.com/hypermail/max-msp/Nov05/34373.html He wrote : "however, i'm having trouble setting the length of a buffer because the getFrameLength() method of an AudioInputStream seems to always return -1 (!@#$)."

And there were no answers. I wanted to give you the result of my searches about this specific subject:

1- Indeed, normal getFrameLength() does not give the length of an audiostream coming from an mp3. It exists a trick to calculate the mp3 length from the file information. However this is useless because you will anyway get problems with VBR mp3s...

2- It _seems_ (not 100% sure) the real trick is to use javazoom.jl.decoder.* ( http://www.javazoom.net/javalayer/ sources.html ) as follow :

import javazoom.jl.decoder.*; ...........

int nTotalMS = 0;

try { Bitstream m_bitstream = new Bitstream(new FileInputStream (your_file)); Header m_header = m_bitstream.readFrame();

int mediaLength = (int)encodedFile.length();

if (mediaLength != AudioSystem.NOT_SPECIFIED) { nTotalMS = Math.round(m_header.total_ms(mediaLength)); } post("Length in ms: " + nTotalMS); } catch(Exception e) { e.printStackTrace(); } }

Best, O./