MP3 playing at wrong pitch/speed; How can I fix it ?

2007-10-24 02:44:47

I have an 85 minute MP3 of a concert.

It plays at the wrong pitch and speed.

MP3VAL reported 3 errors ("warnings"), and said it fixed them; but that did not alter/fix the playing in any way.


I don't have access to the original source for this concert any more; so I'd really like to fix this MP3 if possible.

Is it possible?


I posted the first megabyte of the file in the Uploads 'forum':

http://www.hydrogenaudio.org/forums/index....showtopic=58424

I used WinHEX, with mark-block and copy block to disk; so this snippet is an exact copy of the first meg of the file.

Any help would be much appreciated.

MP3 playing at wrong pitch/speed; How can I fix it ?

Reply #1 – 2007-10-24 08:17:04

You won't be able to do this in the MP3 domain.

Convert to wav, change speed and re-encode

MP3 playing at wrong pitch/speed; How can I fix it ?

Reply #2 – 2007-10-25 15:29:04

Corrupt headers can do that.  (reports the wrong sample rate to the decoder, resulting in incorrect playback).

Dump everything but the first few seconds worth to a new file.  Does it play correctly then?  If it does, then the first header(s) are corrupt.

Maybe a hex editor can fix it? 

MP3 playing at wrong pitch/speed; How can I fix it ?

Reply #3 – 2007-10-26 05:12:44

gameplay;  thanks much for the suggestion.

I'll look around for an MP3 editor.

I tried looking at it in winhex, but couldn't find anything that was obviously (text) a sample-rate parameter.

MP3 playing at wrong pitch/speed; How can I fix it ?

Reply #4 – 2007-10-26 07:41:42

I also guessed that maybe there are a couple of wrong samplerate frames at the beginning. But when I downloaded this clip, it played back ok, even in directshow which is known _not_ to change samplerate on the fly.