Hydrogenaudio Forums

Lossy Audio Compression => MP3 => MP3 - General => Topic started by: swayzak on 03 February, 2007, 07:49:31 AM

Title: Any quality loss decoding MP3 to CD?
Post by: swayzak on 03 February, 2007, 07:49:31 AM
Forgive me for my ignorance here...

Is there any perceivable quality difference between an mp3 file (say, Lame extreme compression) and then the same file converted to cda track (ie. expanded 10x) ?

thanks

swayzak
Title: Any quality loss decoding MP3 to CD?
Post by: db1989 on 03 February, 2007, 07:51:33 AM
Unless your MP3 playback mechanism or decoder are flawed, no.
Title: Any quality loss decoding MP3 to CD?
Post by: swayzak on 03 February, 2007, 07:54:48 AM
Unless your MP3 playback mechanism or decoder are flawed, no.


thankyou

So now I just need to get an mp3 playing car stereo instead having to burn the bloody mp3s to cda cd's..... 

The stereo in my Honda Accord is quite nice though, and is integral to the dash / display unit....just doesn't play mp3 discs 
Title: Any quality loss decoding MP3 to CD?
Post by: Firon on 03 February, 2007, 01:21:21 PM
Edit: ugh, can't read.
Title: Any quality loss decoding MP3 to CD?
Post by: evereux on 03 February, 2007, 01:31:28 PM
On a few problem tracks, sure. On 99.9% of real music? Probably not.

What is your definition of problem track? A broken MP3?
Title: Any quality loss decoding MP3 to CD?
Post by: pdq on 03 February, 2007, 01:40:46 PM

Unless your MP3 playback mechanism or decoder are flawed, no.

On a few problem tracks, sure. On 99.9% of real music? Probably not.


He was asking about any difference between an MP3 and a CD burned from the MP3, not between the MP3 and the original CD.
Title: Any quality loss decoding MP3 to CD?
Post by: Firon on 03 February, 2007, 01:41:08 PM
Ugh, nevermind what I said, my brain is broken today.

To answer the correct question, no, there shouldn't be any difference at all. You might have slight gaps that weren't there before (depending on what you used to decode the MP3), but that's about it.
Title: Any quality loss decoding MP3 to CD?
Post by: aLii on 03 February, 2007, 05:59:08 PM
You might have slight gaps that weren't there before (depending on what you used to decode the MP3), but that's about it.

If you burn with iTunes7 and set the gap between tracks to 0s (default is 2s) it should burn gapless CDAs perfectly
Title: Any quality loss decoding MP3 to CD?
Post by: Firon on 03 February, 2007, 06:13:28 PM
I meant gaps resulting from a decoder that doesn't use the enc_delay and enc_padding flags properly.
Title: Any quality loss decoding MP3 to CD?
Post by: Martin F. on 04 February, 2007, 04:15:25 AM
What happens if the MP3 file's sample count isn't a multiple of 588? Will there be a gap?
Title: Any quality loss decoding MP3 to CD?
Post by: Firon on 04 February, 2007, 02:16:31 PM
If it supports enc_delay and enc_padding properly (such as foobar2000), there will be no gap. The length should be exactly the same.
Title: Any quality loss decoding MP3 to CD?
Post by: Martin F. on 04 February, 2007, 07:11:34 PM
But won't there be a gap because CDDA has sectors with 588 samples (1/75 sec)? I don't know if CDDA has a way to specify the exact length …
Title: Any quality loss decoding MP3 to CD?
Post by: db1989 on 04 February, 2007, 07:27:36 PM
Not all MP3 files come from CDDA.

Either way, there isn't a "standard" way to store gapless information within MP3 files. However, as Firon said, LAME and compatible decoders can store and use such information. As such, they will store all samples (well, the corresponding psycho-acoustically compressed equivalents!) of the source audio - whether it is from a CD or not.

Anyway, 588 samples is surely not noticable . . . although I'm sure there'll be some exceptional case to prove me wrong.