MP3 - VBR - Frame length in time

Florian Schulze florian.proff.schulze at gmx.net
Sat Dec 11 21:46:04 CET 2004


On Sat, 11 Dec 2004 20:32:30 +0100, Ivo Woltring <TheDolphin at ivonet.nl> 
wrote:

> mmpython will help but not always.
> Lets put it this way. I will ALWAYS read through the whole file. In that
> order I don't mind evaluating each frame. The thing I don't seem to be 
> able
> to find is the timelength-constants for frames for the different mp3
> versions, bitrates and layers. Can anybody help me?

 From http://www.oreilly.com/catalog/mp3/chapter/ch02.html#71109
"In addition, the number of samples stored in an MP3 frame is constant, at 
1,152 samples per frame."


So you only need the samplerate for each frame to calculate the duration 
of that frame.

1152 samples / 44100 samples per second ~ 0.026 seconds

I don't exactly know whether you need to include mono/stereo into the 
calculation, you would have to test that out.

Regards,
Florian Schulze




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