Help - Search - Members - Calendar
Full Version: Transcoding ... Sort Of?
Hydrogenaudio Forums > Lossy Audio Compression > MP3 > MP3 - Tech
56Nomad
We all know transcoding / re-encoding is bad. What happens when you edit an MP3? Suppose you have Cool Edit (substitute your favourite editor). You can open and edit an MP3 directly, and it saves using an FhG codec. What if the source file wasn't created with FhG, but with Lame or something else? Or the original was 'stereo' but the editor saves it as joint stereo?

I'm wondering if there's any theoretical problem with going from one encoder to another, even if you retain the same bitrate and such. Aren't you re-encoding, in a sense?

No, I haven't tried a blind taste test. Yes, I suppose I could. I'm thinking more thoretical than actual. Any thoughts?
smz
Saving your edits in mp3 (whatever) and re-editing them, possibly many times is a very-bad-bad-thing, as at every new save you'll have a transcoded version of the previous one. Use straight PCM WAV or a lossles format, WavPack being probably the very best choice for CoolEdit/Adobe Audition, to save the files you're working on.

Sergio
Digga
QUOTE(56Nomad @ Jan 25 2005, 02:55 AM)
What happens when you edit an MP3?
there are ways of editing compressed music in a lossless way, but most professional editors don't make use of this.
basicly if you open a MP3-file and edit it somehow, all the changes are memorized and applied at the the end when you save these changes. this process involves transcoding, as it is decoded and again saved to e.g. MP3.
QUOTE
You can open and edit an MP3 directly, and it saves using an FhG codec.
=transcoding
QUOTE
What if the source file wasn't created with FhG, but with Lame or something else? Or the original was 'stereo' but the editor saves it as joint stereo?
yeah, what? what is your question?
QUOTE
I'm wondering if there's any theoretical problem with going from one encoder to another, even if you retain the same bitrate and such. Aren't you re-encoding, in a sense?
yes. not only in a sense but simply yes.

you may want to do some basic reading on this smile.gif

edit: spelling
56Nomad
My question is, if you are saving a Lame file with an FhG codec (in this case), isn't that transcoding? So, maybe trying to edit MP3 files is a lost cause, if you're just re-encoding an encoded file? Or is there some process that I don't know that overcomes the problem?
dev0
Non-destructive MP3 editing software:
http://www.hydrogenaudio.org/forums/index....showtopic=30049
upNorth
QUOTE(56Nomad @ Jan 25 2005, 04:38 AM)
My question is, if you are saving a Lame file with an FhG codec (in this case), isn't that transcoding?
*
Even if you went from Lame to Lame, FhG to FhG or [encoder of choice] to [encoder of choice], it would still be transcoding.
Encoder, bitrate, preset and such, doesn't change the fact that it's transcoding.

So, do as others have told you. Either avoid it, save to lossless or use the tools dev0 linked to.

Edit: Now that you're aware of the quality reduction, you can of course also choose to live with it.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2008 Invision Power Services, Inc.