iTunes creating 192k mp3s from 128k m4as?

Deusfaux

So I had an album that was apparently in 128k m4as... and since I wanted them in mp3 format I converted.

my regular rip settings in iTunes are for 192k mp3s... and somehow I ended up with that after the conversion. This strikes me as not possible or at least... a questionable conversion. how could the bitrate go up? it's not as good as a 192k rip from a cd is it

Janin

It's easy to increase the bitrate, but the quality won't have changed in any way. You're correct to think the transcoded MP3s won't be as good as you could get from a CD rip.

Deusfaux

bah. makes me wonder how many other 192k stuff I have in here is not "true" 192k and must be re-ripped

Feral

AAC is a better encoding system than MP3. A 128k AAC M4A is vaguely comparable to a 160k MP3 - but some files will end up slightly worse or slightly better.

So, yeah, an MP3 encoded from a 128k AAC is going to have slightly lesser audio quality in general than the same MP3 encoded directly from CD, but whether the slight difference is worth the trouble of re-ripping a CD or is even audible is really debatable.

Deusfaux

well the bigger the difference in bitrate from the original m4a and the desired file, probably the more noticeable the difference



also by "better" do you mean they pack more data into a smaller filesize?

i work with mp3's because they are so universal and work with everything I have. I'd rather not have multiple files for the same songs because I need them to work with my mp3 player, my phone, winamp, xbox, who knows what else

Feral

Deusfaux wrote: »

well the bigger the difference in bitrate from the original m4a and the desired file, probably the more noticeable the difference

Well, yeah, but the point is that you're not comparing 128k vs 192k, you're comparing ~160k to 192k.

Deusfaux wrote: »

also by "better" do you mean they pack more data into a smaller filesize?

Yes, and the data they do pack is more 'relevant.' Encoding systems like AAC and MP3 work by stripping out audio data that the human ear can't discern and using psychoacoustic algorithms to approximate the rest. AAC not only results in a smaller file size but also uses superior psychoacoustic algorithms.

Deusfaux wrote: »

i work with mp3's because they are so universal and work with everything I have. I'd rather not have multiple files for the same songs because I need them to work with my mp3 player, my phone, winamp, xbox, who knows what else

Hey, work in MP3s if you want. I'm just letting you know that a 192k MP3 ripped from a CD isn't that much better from a 192K MP3 ripped from a 128k AAC, and you might not even be able tell the difference (depending on the song, your equipment, and your ears).

But for the record, AACs work in Winamp and the 360 and a lot of different phones (as long as they're not the FairPlay-encrypted type that you buy from the iTunes music store). AAC isn't an "Apple" standard, they license it. AACs will even play on the Zune, of all things.