Possible to trim MP3 without Loss of Quality?

[OrlandoJetset]

Hi, I have a few samples of voiceover work that I've done which unfortunately contain 1-2 seconds of silence at the start. I don't have a WAV so I'm wondering if there's a way to trim the 320kbps MP3 inside Audition and re-export/re-save without further compression?  There seems to be a few 3rd party apps that claim to be able to trim Losslessly so I'm looking to see if Audition or Media Encoder can do this and if not, what apps would be recommended?

[emmrecs · Accepted solution]

Simple answer: No.  Whenever you open an .mp3 in Audition it is automatically converted to .wav.  Resaving the file to .mp3 is another conversion process so further compression and lossy.

I believe an app like this one is able to do what you want but I have never needed to do this so cannot say whether it might be suitable for you, or not!

[OrlandoJetset]

Thanks for confirming and for providing a link. I've also seen an audio cutter by Clideo that may work, and I've asked Paul (who created ShutterEncoder) if his app can trim mp3 files losslessly. Hopefully one of these will garantee lossless trimming of the mp3.

[SteveG_AudioMasters_]

If you want another one to look at, that I've had here for ages, then mp3DirectCut is also free.

[OrlandoJetset]

Thanks alot for that! 

I was skeptical that such an operation was even possible (possibly because a Google search returned results pre-dating this technology) but it sounds like you've used it long enough to confirm that it can trim without degrading audio quality.

The fact that I can also join tracks using this should make it quite handy for voiceover demo reels, in situations when all I can get/find are mp3 files.

I would mark your response as the Correct Answer (Part B)!

[OrlandoJetset]

Update: Paul, the developer behind the popular video app ShutterEncoder, just confirmed:

"Yes it should work using the 'Cut without re-encoding' function"

https://www.shutterencoder.com/en/

[SteveG_AudioMasters_]

mp3DirectCut has been around since 2000, and the operations involved have always been possible with MP3 files. They have to have been, because the one thing that is standard about all mp3 files is that they should all be playable on a 'standard' mp3 player, regardless of what they were encoded with.

There's a command line splitter available as well, but it's not for the fainthearted and I definitely wouldn't recommend it. If you are really desperate to try it, then it's called mp3split and it has a bewildering array of options, most of which aren't much use, but technically possible. I think that it may be the basis of one or two of the Windows splitters out there, which they skin.