Does the quality degrade when editing MP3?

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PatrickTR
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Joined: Tue Nov 19, 2019 6:46 am

Does the quality degrade when editing MP3?

Post by PatrickTR » Tue Nov 19, 2019 6:55 am

Can someone tell me if the quality of an MP3 file is degraded by the editing process in Goldwave (I'm thinking maybe it's decoded and re-encoded or something) .... so if you edit a file and shorten it or perhaps use the censoring tool on a section say, will saving reduce the overall quality of the file?
Thanks.
Patrick.

Tristan
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Location: Southeast Michigan

Re: Does the quality degrade when editing MP3?

Post by Tristan » Tue Nov 19, 2019 10:58 am

You could conceivably degrade the quality of any audio file by editing it. It would all depend on the frequency and severity of the edits. I only edit files when they're in 24-bit .wav format, because .mp3's don't give me any headroom.
If I can read the manual, so can you.

PatrickTR
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Joined: Tue Nov 19, 2019 6:46 am

Re: Does the quality degrade when editing MP3?

Post by PatrickTR » Tue Nov 19, 2019 11:15 am

Thanks. What I'm trying to get at is if I make a small change to one small section section - say add reverb or silence or anything to a little bit less than half a second in a 4 minute track, and re-edit that small piece 3 or 4 times trying out different things, will I be reducing the quality of the source file every time I open-edit-save?

Tristan
Posts: 329
Joined: Mon Jun 01, 2009 8:20 pm
Location: Southeast Michigan

Re: Does the quality degrade when editing MP3?

Post by Tristan » Tue Nov 19, 2019 11:28 am

Website malfunction. Redundant post. Couldn't find the delete button.
Last edited by Tristan on Tue Nov 19, 2019 11:39 am, edited 1 time in total.
If I can read the manual, so can you.

Tristan
Posts: 329
Joined: Mon Jun 01, 2009 8:20 pm
Location: Southeast Michigan

Re: Does the quality degrade when editing MP3?

Post by Tristan » Tue Nov 19, 2019 11:28 am

If all you are doing is "previews" to see how something sounds, without saving the results, then, no, you won't degrade anything while doing your experiments. If you save the results, especially over and over again, you will change how the source file sounds. Degradation can happen very quickly with .mp3's, since they start out in a degraded form relative to uncompressed files.

If you're really worried about destructive editing, though, steer clear of Audacity. GoldWave doesn't have Audacity's problem.
If I can read the manual, so can you.

PatrickTR
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Joined: Tue Nov 19, 2019 6:46 am

Re: Does the quality degrade when editing MP3?

Post by PatrickTR » Tue Nov 19, 2019 12:06 pm

OK - thanks.

DougDbug
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Re: Does the quality degrade when editing MP3?

Post by DougDbug » Tue Nov 19, 2019 12:48 pm

Yes. Editing will degrade an MP3 if you re-save it as MP3 because it's getting compressed again.

If you save-as WAV (or FLAC) there will be no further degradation. (With lossy compression, data is thrown-away during compression, not during decompression and it's going to be decompressed when it's played anyway.)

GoldWave (and all "regular" audio editors) decompress the audio when you open the file. If you re-save the file in a lossy format (such as MP3) you are going through another generation of lossy compression and some "damage" DOES accumulate. You may not hear the quality loss with one decompress/re-compress cycle but it's something to be aware of and you should try to minimize the number of times it's compressed.

AAC (also lossy) was designed to be more-immune to accumulated damage. (That doesn't necessarily apply if you transcode from MP3 to AAC.)

mp3DirectCut can do limited editing without decompressing. (If you are working with large files it can also work faster since it's working directly with smaller files and it doesn't have to take the time to decode & re-encode.)

PatrickTR
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Joined: Tue Nov 19, 2019 6:46 am

Re: Does the quality degrade when editing MP3?

Post by PatrickTR » Tue Nov 19, 2019 2:00 pm

Thanks Doug - that's helpful.

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