Does WMA -> MP3 Conversion ruin quality?

[xist]

OK. Excuse the picture quality (blame my internet connection limiting size) making the point lose some of it's impact but i believe it shows the important changes.

This is a transcode from AAC to MP3 (V0), with the source AAC taken from a Bandcamp download (i've just done this....i can probably do a WMA to MP3 if it matters that much....although i'm not going to make a FLAC rip just to prove a point...)

Spoiler

Can you see how the spectrum is much flatter in the transcode and has been levelled at approx 19KHz (which the original hadn't been). Also lots of the higher frequency peaks are eliminated and if you look at the colour density you can see evidence of a loss of information, plus a general degradation in the wave form.

Edit- Just to add, despite all that, chances are you won't notice the difference in the files when you listen. If depends on how attentive you are and your listening set up. Quality IS lost, but it's probable you won't notice. HOWEVER, this depends mostly on your source encode and your transcode result. Transcode a 128kbps file and it'll sound like crap.

 

[Pleng]

I think the point that was trying to be made here was that going from WMA to FLAC, if your device supports FLAC, will not reduce the quality any further. Re-encoding from WMP to MP3 will. Whether or not you can tell the difference is another story entirely...

No. Re-encoding from any lossy format as a starting point to anything else will always cause a deterioration and possibly introduce artefacts (the ones which are a bit like "beeps" are those that most irritate me). If you need to have music in different formats then you need to start from a Lossless source - i.e FLAC. Going from Lossy(WMA) to Lossless (FLAC) is the most pointless transcode anyone could ever attempt and would give you a result which was inferior in every way.

Why would re-encoding from a lossy format to a lossless one cause deterioration? OK So you're not going to restore any of the original quality, but I don't see how you're going to loose anything more.

Anyway this is a moot point, the OP's files are in WMA format so he can't convert from FLAC in the first place.

 

[xist]

Why would re-encoding from a lossy format to a lossless one cause deterioration? OK So you're not going to restore any of the original quality, but I don't see how you're going to loose anything more.

Because the process of re-encoding causes a deterioration. It's not a positive change....see the picture i posted above. The transcoded format can contain more information, but it's clear that in the process of change it's actually containing less. It doesn't matter than the final format can potentially contain all the data, the reality is that it won't. Transcoding up is not a good thing.

 

[Rydian]

Different formats store data in different manners... each format has it's own ideas about which ranges are important and how things can merge but still be heard. MP3 and other lossy formats don't retain much data, so they keep it arranged in such a way that the closest thing to the original is recreated when the file is played. Taking that data and sticking it into another format is going to produce different results, no matter if the second format is lossless or lossy.

 

[chris888222]

for some reason this thread become a format wars

Actually no. Format wars would be like WMA IS A ZILLION TIMES BETTUR THAN MP3 DUHH.

Well thanks for all the help guys/gals. Enjoying all the stuff in my phone. The quality is quite decent.