...to identify if a file was normalized or not when it was ripped?

Depends on what you're trying to find out... Do you want to know about the peak level of the final file, or do you want to know what's been done to the file in the ripping process?

There are ways to determine what the peak of the song's waveform is. If the peak waveform reaches between 98% and 100%, then you can assume it's been normalized.

However, there's no way of knowing if the CD was already normalized to 98% to begin with, or if the ripping software normalized it to 98% during the ripping process.

If all you care about is the volume level of the final file, then here's what you do: Open the MP3 file in WinAmp and use its "Disk Writer" plug-in to save it as a WAV file. Then analyze that WAV file in any program that'll tell you its peak levels (SoundForge, CoolEdit, heck, even AudioCatalyst will tell you the existing peak as part of its normalization process).

Remember that normalization only increases the volume of the entire song by a fixed factor. It increases the volume so that the song's single highest peak reaches 100% (or 98% or whatever you set the normalizer to). It doesn't balance quiet/loud parts within a song, so just listening to a song doesn't necessarily tell you if it's been normalized. A song could be mostly quiet, but have one single loud peak. Normalizing such a file doesn't necessarily make it sound louder. There was an example someone gave on this BBS about a live recording of a guitarist: the loudest peaks on the recording were the sounds of him scooting his chair on the floor between songs. It could be even more subtle than that, it could be a tiny "pop" in the recording, so brief and high-frequency that you don't even hear it audibly. Or it could be the high-frequency component of a single snare drum hit that happened to be louder than the others.

Also, I've found that the vast majority of CDs are already normalized, and that the ripping software rarely needs to do anything to normalize the file. Normalization is a standard part of producing a CD.



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Tony Fabris