Editing MP3 Files

[isabel95]

MP3 is a compressed file.

If one takes an mp3 file into Audacity to edit it, let's say to add some more silence to the beginning of the file, when it is resaved it is going to be compressed again when the altered file is resaved as mp3, resulting in loss of sound quality.

Am I incorrect?

Would there be any merit in saving the editing mp3 file in wav format and then resaving to mp3 hoping to retain the best sound quality?

Isabel

[davegee]

This has been covered MANY times and different opinions exist.

My method is to start with the original WAV (if you have downloaded an MP3 save it as WAV immediately for storage).

After doing your edits, fades etc save as an mp3 and try it in PTE. If you have to edit again go back to the original WAV.

For complicated edits saving intermediate WAV files is a good idea - that way you don't always have to start again from the beginning.

You are correct that there is a quality loss if you open an mp3, edit it and save again. Some will say that the loss is not enough to worry about.

If, like me, you care about quality you don't take that chance.

[Ken Cox]

This has been covered MANY times and different opinions exist.

My method is to start with the original WAV (if you have downloaded an MP3 save it as WAV immediately for storage).

After doing your edits, fades etc save as an mp3 and try it in PTE. If you have to edit again go back to the original WAV.

For complicated edits saving intermediate WAV files is a good idea - that way you don't always have to start again from the beginning.

You are correct that there is a quality loss if you open an mp3, edit it and save again. Some will say that the loss is not enough to worry about.

If, like me, you care about quality you don't take that chance.

Isabel

some background theory for you

http://en.wikipedia.org/wiki/MP3

ken

[fh1805]

Isabel,

For a simple "add a bit more silence to the ends" one-time edit, you will not notice any sound quality degradation by opening the original mp3 file in Audacity, doing the edit and then exporting to a new mp3 file.

For a more complicated multi-track sound-track built up over a period of days, with frequent exports and re-opens, you probably would hear a noticeable degradation. But this where the Audacity project file comes into play. As you build up that complex soundtrack, save the work as an Audacity project file (File...Save Project As...). This file holds within it the expanded mp3 file. The uncompress is done once, when you import the mp3 file into your Audacity project. And the compress will take place only at the end of your work when you finally export to mp3 format.

regards,

Peter

[isabel95]

Saving mp3s as wav is what I've been doing.

Thanks for the confirmation (I hope!) about quality being retained!

Isabel

This has been covered MANY times and different opinions exist.

My method is to start with the original WAV (if you have downloaded an MP3 save it as WAV immediately for storage).

After doing your edits, fades etc save as an mp3 and try it in PTE. If you have to edit again go back to the original WAV.

For complicated edits saving intermediate WAV files is a good idea - that way you don't always have to start again from the beginning.

You are correct that there is a quality loss if you open an mp3, edit it and save again. Some will say that the loss is not enough to worry about.

If, like me, you care about quality you don't take that chance.