iTunes versus CD Bit Rates

[Ringmaster]

CD Sample & Bit rate is 44.100 kHz, 16-Bit. Why does iTunes rip at 1411 kbps. I am using the custom setting for iTunes ripping @ 44.100 kHz, 16-bit.

Can I copy the iTunes @ 44.100 kHz -1411 kbpx, and Paste to Diamond Cut Live/Forensics 7.5, and process, or do I have to convert to 16-bit before I do any processing?

If I have to convert to 16-bit, what do I need to do to cut/paste, back to iTunes?

[zarat]

I was hoping someone else would jump in here so that I could learn also. Since no-one has, I'll offer what I can.

Personally, I am not a fan of iTunes or of any compressed audio file formats. I don't own an iPod, but do have a cheap mp3 player for dictation. The only experience I have of iTunes is to convert AAC encoded files (.m4a) to wav for further manipulation.

The 1411kbps is the data rate for CD playback in real time, not necessarily the rip speed. http://www.mediatechnics.com/cdaudio.htm

To get 44/16 wav from iTunes, the only way that I have found is to burn a CD from the playlist that you create with the tracks that you want from the library. Then rip the CD tracks in DC to wav. From there you can proceed as you wish.

To get back into iTunes, "add files to library" (leaves files in original location) or "import" (copies files to iTunes folder - recommended). Once in the library, the wav files can be converted to AAC by right clicking on the file/s and "convert selection to AAC". I presume this last step may be needed to get the files back into an iPod, but here I have no experience!

Hope this helps. If anyone can add to this or correct me if I am wrong...

Bill

[Craig Maier]

Ringmaster - - -

I wish that I could bring something to the table here, but I know very little about ipods or itunes other than to say that I have heard of folks using Diamond Cut to clean up so dirty ipod files. So, I will be learning by following this thread as are you!

[Dan McDonald]

Of four kids, two use Itunes and like it, 1 hates it and refused to use it, and one doesn't like it but uses it anyway, so I have a little experience with Itunes.

Like Zarat said, the easiest way to convert from Itunes to Wav seems to be to burn a CD and then rip the CD.

There used to be an option to download 16/44.1 songs from Itunes directly, and when I got a $25 gift card for Itunes for myself, I configured it so that what I downloaded was supposed to be in that format. It was in that format, but I don't know whether it had been compressed before conversion or not; my suspicion was that it had, but they called it "CD quality." In any event, they soon after changed that option so that it cost more for the 16/44.1 and now I don't know if they even have that as a possibility.

To answer Ringmaster's original question, I don't think you can copy the files and open them with Diamond Cut.

If you have a lot of files and want to convert them, there are freeware and shareware prorams to convert Itunes into wav, but I don't know how good they are or if they're even legal.

Dan

[sus4chord]

If I remember correctly, the CD quality files you download from iTunes are actually MP3 files ripped at I believe 320. That's something fairly new; it used to be all files were ripped at 128. iTunes and iPod really prefer to use the AAC format (since it's an Apple format), but also work fine with MP3 format.

And remember, if you create a CD from either MP3 or AAC (both of which are compressed files) to ultimately create WAV files from, when you convert them back to either MP3 or AAC, you are re-compressing compressed files. So you lose fidelity each time.

[Dan McDonald]

The ones that I got were about 3-4 years ago. Then, there was an option when you set up Itunes as to how you wanted the files, and one option was 16 bit, 44.1 wav files.

I suspect they may have been compressed slightly, but on the other hand, Itunes was fairly new, and I can also imagine they were ripping wavs off of CD as they built up their database, and simply kept the wav file as an option in the process.

I know they had stopped giving it as an option when I tried to set up one of my sons' accounts the way I had set mine up about a year later.

Also echo John's caution about re-compressing and data losss. At one point, I had a multifilter where I tried to "innoculate" files before converting them to mp3 (emphasizing the areas that would get compressed), and that worked pretty well, but it took a lot of time for each song to set it up correctly.

Just checked and it was Christmas time 2004 when I got the gift card, so about 4 years ago.

Dan



Dan

[Craig Maier]

Dan,

How did the "innoculation" process work? I assume it used the VVA and/or the Punch and Crunch or something similar (maybe the EZ Enhancer).

Craig

[Dan McDonald]

Hey Craig -

Yes - I looked at a group of wavs and mp3 conversions of them, to see what was taken out in the process, then I used the VVA and a little punch and crunch to overemphasize what was going to be taken out, so that what was left sounded better. I think I used the pargraphic EQ also. I got to the point where it was pretty good, but I eventually just decided it was too much work/time spent for each song. I can check the multifilter preset out if you want to know what I had in it, but that was just a starting point. It did sound pretty good, though, after I figured it out.

Dan

[cromag]

My wife and kids all have Ipods, and the Ipod/Itunes combination works very well. It is compressed, but not too bad (especially for a portable player in potentially noisy environments). The biggest advantage is ease of use.

I have non-Ipod MP3 players, so I don't use Itunes for much music by choice. Family and friends know that I'm into music, so I often get an Itunes gift card for my birthday or holidays. I burn them to CDs as quick as I get them and then rip them to MP3 (assuming they don't have the non-DRM option on the songs I'm interested in). Again, not too bad for a portable player in less than ideal listening locations. And once they're on a CD (which I would do for archiving purposes, anyway) you can import them into DC7.

I'd be interested in your MP3 filter line-up as well, Dan.


On the other hand, I do use Itunes to get the free podcasts of Car Talk and Wait, Wait Don't Tell Me. I'm never around when these shows are on NPR anymore, and it's a lot easier to get these at Itunes than to hunt them down on NPR's site.

[Ringmaster]

I think my original message lost something in it's translation. In reviewing my message, I think I might have caused the confusion.

Basically, I was wondering why iTunes downloads my CD's at a "1411 kbps" bit rate, and a standard CD is "16-bit"; along with this thought, I was wondering if any conversion was taking place, when the file is "imported" to the DC 7 Live/Forensics, Version 7.5 program.

What is the difference between the bit rates of "1411 kbps" and "16-bit"? Somehow, in the back of my mind, I wonder if I am going somewhere that I don't need to go.....

I keep my files strictly in the .wav domain, even in my "Back-up" files, because I feel we lose something with each "up/down" conversion. Also, I may want to retrieve a file for further processing at a later date (I know that a lot depends on the amount and type of processing that was included in the final wave file).

Dan hit on it a little bit, but I think there is something more to it. Are we, in fact, doing any "conversion"; or, am I missing something (let's not read anything personal into this!).

[Craig Maier]

Oh - - - I think I understand the question. The bit rate is just a data rate in information units per unit time. A 16 bit parameter is just the bit depth or resolution of a file. Note that 16 bits is not a ratio as in the data rate of mp3s which is a certain number of kbits per unit of time. The example that you provided states that the file is running at a data rate of 1411 thousand bits per second.

So, a 16 bit file simply means that the signal is chopped into increments of 2^15 plus sign which is 1 part in 32,000 plus sign. This is independent of bit rates. Thus, an mp3 file having 1141 kbps can have any of a number of values of resolution, including 8 bit, 16 bit and 24 bit.

In other words, I think that the data rate is mutually exclusive of the bit depth or resolution of a file.

I hope that makes sense, if it does not, ping again!

[Ringmaster]

Confused me a little bit when you referenced "MP3 file", because I am under the impression that I am ripping, using the "Wave" Codec in "iTunes".

Reading "between the lines", it looks like I am not introducing any effect on the wave file, when I Copy/Paste from "iTunes" @ 1411kbps to DC 7 @ 16-bit; or, do you think, since you mentioned "MP3 file", that "iTunes" might be converting my "Rip" to MP3, even though I have set "iTunes" to Import Using "Wav Encoder", Setting: "Custom (44,100kHz, 16-bit)"?

What made me think of this, is sometimes I need to "Copy/Paste" a track that I have ripped into iTunes, from a purchased CD; I do this primarily to "silence" intro's, etc. and for "Fade In/Outs". However, recently a friend gave me some CD's that he made from Vinyl, in the .wav format, and when I rip these to iTunes, there are some that I like to import to DC 7 to remove "Continuous Noise". This is what got me to thinking about the "Bit Rate" (I've always had a curious mind....sometimes, it gets me a little "off-track").

I think other people do this too; but, it's a "fleeting" thought, and they do not go deep enough to put it in writing....

Thanks for putting up with me.

[Craig Maier]

I should not have used the word mp3; I think that I tend to use that term to describe any form of lossy compression and that is really what I meant. I do not know what is actually happening when you copy and paste a file from iTunes to DC7 or DC7.5 directly. I have never tried to do that. Hopefully, somebody else will understand that process better to provide you with a reasonable explaination.

Craig

[Dan McDonald]

To find out, I would do this:
a. Follow your usual method and then open the file in the spectrogram or spectrum analyzer.
b. Use DC to rip from the CDs your friend gave you.
c. compare the two files. If one is lossy, you'll probably see a difference.
d. if you think there might be a difference, then you may want to make a copy of the one from a after Itunes has imported it, turn it into a wav file, import it, then make a wav copy again, and import that one. Then you're about 3 generations away. If it's not compressing it, you won't see a difference, but if it is, you're likely to see and hear a pretty big difference.

Anyway, that's what I'd do.

Dan

[Ringmaster]

Dan,

Good Idea, I'll let you know what I can figure out. I'm going to use one of my recent CD's; because I'm sure there has been some restoration process done on new CD's of re-issues, especially the older stuff.

I did get the following response from the iTunes Forum, but it's Greek to me (I told them I'm pretty good at what I do, but I don't know much about the technical stuff {bits/bytes/sample rates}; I just know good/better/best). I do wish I knew more about this stuff, but lately, it seems that I only retain what I am interested in....

"The Red Book standard is;
2 channels x 44,100 samples per second per channel ? 16 bits per sample = 1,411,200 bit/s = 1,411.2 kbit/s

Sample rate and Bit rate are not the same thing.
Audio CDs have a sample rate of 44.1 kHz and bit rate of 1411.2 kbps.
A sample rate is what is used when converting analog signal to digital.
A bit rate is how much data per second is in the data."

I am only concerned about "bits", not "sample rate". I'm sure this contains my answer, but I like your idea better!