Quality degradation from copying mp3's

[SE14man]

Someone has just told me that copying mp3's from hard disk to hard disk or form anything to anything! Will lose quality? I'm not sure if i believe this.

Is that true? That if i copy one mp3 to another desination, if i keep doing it, it will degrade the quality of the mp3?

I dont see how this is possible.

Pls lemme know.

Cheers.

[jagabo]

Nonsense. The copied file is an exact copy of the original. What happens when your bank copies your financial records from one computer to another? Do you expect the records to change? One of the main features of digital data is that it can be copied ad infinitum without any losses, unlike analog data.

[Ai Haibara]

No. You can't degrade an MP3 by copying/moving it around several times (as long as the hardware you're copying it to is okay), just as you can't degrade an MP3 by listening to it multiple times.

[SE14man]

I thought so! cheers lads.. thats put me mind at rest!

[poisondeathray]

only with hardware malufunction : eg. the hard drive is corrupted , or a bad sector

[SE14man]

But then it would be noticibly bad right? Like there would be big glitches in the audio stream such as those 'underwaterry' sounds?

do u know what i mean?

Am i correct there?

[poisondeathray]

yes , or it might not play at all

[SE14man]

Fantastic.. Thanks for the help there then guys

[SE14man]

But what about this article here:

Is this saying otherwise?

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

Or is that only about if u re-encode an mp3?

Do you think this statement is true: (taken from the above article)

"Lossy compression formats suffer from generation loss: repeatedly compressing and decompressing the file will cause it to progressively lose quality. This is in contrast with lossless data compression."

Cheers.

[hech54]

Moving it from one place to another on your computer AS A DATA FILE does not change anything. Burning your MP3 back to a playable AUDIO CD changes the MP3 to a WAV file. I doubt you will notice any quality difference going from MP3 back to WAV....but the "damage" (compression, quality degradation) has already been done when you created the MP3 files in the first place. You DO NOT get that back. Once the original file has been compressed to MP3...the original quality is gone forever.

[SE14man]

I hear you..

So basically as long as i dont re encode the mp3 it will stay the same quality?

When they say compressing/decompressing do they mean re encoding to another bitrate or just re encoding to the same bitrate will loose quality?

They dont mean compressing as in zip/rar file compressing right?

If i were to fill up a DVD-R with mp3 files wirtten as 'DATA' and i copy the files back form that DVD-R (as data) to the PC then surely there would be no quality loss either? Even if i were to repeat the process 100 times there would be no quality loss right? It just seems a way of storing them that does.. But however burning a video as a video cd or an audio as an audio CD i can see that losing quality as it encodes them itself doesnt it?

But just burning as a DATA disc for videos/mp3s this wouldnt lose quality would it? Cos its just storing them surely?

[hech54]

I hear you..

So basically as long as i dont re encode the mp3 it will stay the same quality?
YES

When they say compressing/decompressing do they mean re encoding to another bitrate or just re encoding to the same bitrate will loose quality?
MP3 to WAV - No quality loss
WAV to MP3 - quality loss EVERY TIME
MP3 to MP3 - quality loss EVERY TIME

They dont mean compressing as in zip/rar file compressing right?
You won't save much space with any music type of file to Zip or similar.

If i were to fill up a DVD-R with mp3 files wirtten as 'DATA' and i copy the files back form that DVD-R (as data) to the PC then surely there would be no quality loss either? Even if i were to repeat the process 100 times there would be no quality loss right? It just seems a way of storing them that does..
You are describing a simple file transfer - NO changes are made to the file.


But however burning a video as a video cd or an audio as an audio CD i can see that losing quality as it encodes them itself doesnt it?
Audio CD is WAV - WAV is an audio CD. A WAV file from a crappy MP3 file will be a crappy WAV file.

But just burning as a DATA disc for videos/mp3s this wouldnt lose quality would it? Cos its just storing them surely?
Yes...just data storage/transfer.

....

[SE14man]

Thanks for clearing that up for me!

So compressing the same mp3 file as zip/rar 100 times will make no difference to the audio quality itself?

(Not that id do this im just finding out if rar/zip compression in the long run affects the sound quality of mp3 files?

Cheers.

[jagabo]

So compressing the same mp3 file as zip/rar 100 times will make no difference to the audio quality itself?

Correct. Zip/rar compression is lossless.