Re: very long mp3 files

[kris west <kris.west@xxxxxxxxx>]

Were it me, I'd knock together an MP3 decoder in Java (using tritonus/JLayer) and write the audio stream down as a WAV file or other PCM format. It should stream the MP3 file avoiding any memory issues (we've played days long recordings this way). There would be nothing stopping you from breaking every X minutes and starting a new WAV file. 

This piece of code:
http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/solutions/Transcode.java
Appears to transcode from one format to another and only write out the portion between the specified time indices - note you would need the Jlayer, tritonus and mp3spi Jar files on your classpath.

Alternatively if you download the JLayer source from: http://www.javazoom.net/javalayer
An example format converter class is provided: javazoom.jl.converter.Converter
A few simple tweaks to this would allow it to start a new file every N frames.

Finally the VLC media player can transcode a segment of a file. However you would have to give it the time indices of the chunk to do each time.

K

2009/1/8 Peter van Hengel <peter.vanhengel@xxxxxxxxxxxxxxxxxx>

Dear list,

We are looking for a way to split very long MP3 recordings (several
hours up to several days!) into smaller parts and/or convert them to
wav-format. We have tried various MP3-to-wav converters, but they all
hang themselves on these long recordings. The way we solve the problem
now is to use one PC as MP3 player, and take the sound output of that as
input for a second PC, which then makes shorter recordings in
wav-format. It works, but the solution is far from ideal.

Is there anyone who has any experience with this or suggestions?

All the best,
Peter van Hengel

--
---
dr. ir. Peter van Hengel
Fraunhofer Institut Digitale Medientechnologie (IDMT)
Project Group Hearing, Speech and Audio Technology
Haus de Hörens - Marie-Curie-Strasse 2 - 26129 Oldenburg - Germany
T: +49 (0) 441 2172 436
F: +49 (0) 441 2172 450
E: peter.vanhengel@xxxxxxxxxxxxxxxxxx
W: www.idmt.fraunhofer.de

-- 
Regards,

Kris West

Tel (UK): +44 (0)208 123 1709
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