Itunes loseless

Post by **bdubs767** » Wed Sep 26, 2007 2:39 pm

What exactly are these files?

What kind of information does the itunes take when it imports a cd? Does it take it as and incompressed track or does it compress it?

Post by **stipud** » Wed Sep 26, 2007 2:42 pm

The audio data remains uncompressed, but the data in the file itself is compressed.

Think of it like a zip file. If you use data compression on something, but the ZIP compression was lossy... you would encode a text file, but when unzipped it would be all garbled and messed up. Obviously ZIP encoding is totally lossless as well... it only serves to reduce the filesize. Compression is a very simple concept... all it does is replace similar sections with a simple expression.

Let's take the string "ham ham ham babies ham " and compress it... you would have a table "ham "= 1 and "babies "= 2, so it would simply replace each occurrence, so that your string is now "11121". Obviously there are less characters here, so the file is much smaller. But when you decode it, you still have the exact same information as when you began.

Lossy encoding like MP3 or JPG is actually a much more complicated algorithm where it will try to find a "near match" instead of keeping all of the data intact. This means there will be more matches, so you will have even smaller files... however this comes at the cost of accuracy for very fine details.

So the information is streamed from a CD into a file, and that file is compressed so that it can still be streamed back with absolutely no loss of the original data.

Post by **bdubs767** » Wed Sep 26, 2007 2:56 pm

Okay, so itunes does this automatically I'm assuming when downloading information from a CD?

dedlyjedly · Post by **dedlyjedly** » Wed Sep 26, 2007 3:41 pm

itunes comes "out of the box" with very poor preferences for importing music. In the Edit drop-down select Preferences. Then select the Advanced tab, followed by the Importing sub-tab. Here you will be able to decide what file type to use when importing.

Post by **Francious70** » Wed Sep 26, 2007 5:21 pm

If I'm not mistaken, Apple Losless is the default, in which case, there are no settings to edit.

Post by **stipud** » Wed Sep 26, 2007 5:32 pm

Francious70 wrote:If I'm not mistaken, Apple Losless is the default, in which case, there are no settings to edit.

AFAIK the default is 128kbps mp3. I have mine set to 192kbps (minimum) VBR AAC and I can barely tell the difference on only certain albums. Not enough to care, considering how much more music I can fit.

Post by **AVICJR** » Wed Sep 26, 2007 6:33 pm

I have my import set at 228 kbps, and the quality of the song seems good. Now, I'm thinking about the 160 gig iPod and using the highest import to store music.

dedlyjedly · Post by **dedlyjedly** » Wed Sep 26, 2007 8:00 pm

yeah, my itunes was set at 128k as well. I purchased the 5g 80gig just so that I could do everything in lossless. I do have some select material in AIFF uncompressed. I was thinking about getting the 160 classic, but now I'm torn after reading some of the info tom posted.

Post by **stipud** » Wed Sep 26, 2007 8:13 pm

I wouldn't get the classic unless you only use it connected via the "dock" to a headunit or headphone amp. The headphone output on it (i.e. built in amp) is definitely not nearly as good anymore.