HydrogenAudio

Lossy Audio Compression => AAC => AAC - General => Topic started by: Antigen on 2012-06-13 21:39:04

Title: iTunes Store: they use the master?
Post by: Antigen on 2012-06-13 21:39:04
Hi

but the itunes store use the audio master to obtain AAC or they encode from cd?

in the first case the quality is better respect from an aac obtained from cd?
Title: iTunes Store: they use the master?
Post by: skamp on 2012-06-13 22:08:17
I'm not sure what your question is, but a sample count of several AAC files from iTunes, from different albums, reveals that many weren't sourced straight from a CD (their sample count is not a multiple of 588). In one case I also noticed the mix on the AAC file was completely different from the CD version of the same track.

As for "Mastered for iTunes" tracks, they are allegedly sourced from masters created specially for the iTunes Music Store (different from the CD masters).
Title: iTunes Store: they use the master?
Post by: Antigen on 2012-06-13 22:18:09
I'm not sure what your question is, but a sample count of several AAC files from iTunes, from different albums, reveals that many weren't sourced straight from a CD (their sample count is not a multiple of 588). In one case I also noticed the mix on the AAC file was completely different from the CD version of the same track.

As for "Mastered for iTunes" tracks, they are allegedly sourced from masters created specially for the iTunes Music Store (different from the CD masters).



Yes my question is the source of the audio, they use a master tape? they use a digital master? Or they simply encode from a CD like us when we use iTunes and import music?
Title: iTunes Store: they use the master?
Post by: Kohlrabi on 2012-06-14 00:02:17
Yes my question is the source of the audio, they use a master tape? they use a digital master? Or they simply encode from a CD like us when we use iTunes and import music?

To repeat what skamp said: You simply cannot know unless you buy the music. The sources can be all of the above. You can go and check the no. of samples, but even if the no. of samples is a multiple of 588, this is only necessity and no sufficiency for identifying a CD source. Maybe you can ask Apple about it.

As for "Mastered for iTunes" tracks, they are allegedly sourced from masters created specially for the iTunes Music Store (different from the CD masters).

"Mastered for iTunes" is an educational program to teach mastering engineers the very basics of their craft. They are invited to create new high quality masters of their records, which are then sold exclusively on iTunes. Apparently some have learned nothing so far:
(http://kohlio.de/pics/rhcp2.png)
At least Vlado and Rick can say that they reached the same fidelity as on the CD!

I know that waveforms cannot prove that the clipping is audible (which it is here, but the record is nearly pure static anyway, so who cares), but they can indicate bad craftsmanship.