Aiff

aiff is just the mac equvalent of WAV - uncompressed (although still digital so is in some ways i guess) cd quality audio. an aiff file would be exactly the same size file as a wav file.

Bec

AIFF is indeed the same as WAV... it's uncompressed music ripped straight off your CD. So whatever space it takes up on your CD, it'll take up that same space in AIFF files. Typical 128kbps MP3 compression is about a 1:12 ratio in compression.. so.. size is a consideration.

However, in a hi-fi set-up, you can hear the difference between compressed music and uncompressed. So the first criterium for iPod to be a high-end source (or at least mid-end) is to have only AIFF files on it.

The 2nd criterium is that you have to use iPod's line-out instead of its headphone output. You can get the line-out either by using the mini-jack from the back of the dock, or you can use a dock adaptor cable that has a line-out, such as the Sik Imp.

Reason being, is if you're going to be passing the signal out from the iPod into another receiver/amplifier of some sort, you need a clean signal that comes from the DAC (Digital-Analog Conversion) stage of the iPod. You don't want it to come from the headphone output, because headphone output has an "amp" behind it as well. You don't want to pass an already altered signal into another receiver to have it re-amplified again.

Satisfying these two criteriums, iPod is indeed a pretty reliable source that compares favorably against many desktop CD players. I would say even up to a $300 range (and these are dedicated, big, desktop players).

Lastly... You should choose AIFF over WAV for one reason (they're both available via iTunes for either Mac or Windows), iTunes actually store a pretty secretive metadata in the AIFF files. This is the same as ID3 tags for MP3 files. So that means when you move that AIFF file around (back-up, or moving directories), the song title, artists and such information stays with the file. Ripping to WAV files renders no metadata being attached to the file, so the as soon as you move the file to a different directory, you lose all your song information. If you ever have to restore from a back-up of WAV files, you have to re-enter all the song information manually.

Technically there's no sound differences between WAV and AIFF whatsoever.

It is an analog level line-out.. it makes more sense than a digital out, if you're only going to have one. If you need to take this line-out into a headphone amp, most of them do not have a built-in DAC. If you want to take it to a home receiver, home receiver's DAC's usually aren't all that great, not much better than iPod's built-in DAC actually. You have to have some pretty high-end receiver to get a good DAC. External DAC is expensive as well.

With the release of iTunes 4.5 and iPod firmware 2.2.. you can finally get lossless compression on iPod as well. I've just finished converting all the AIFF files I had into Apple Lossless format (which seems like a MPEG4 standard, wonder if other software will adopt it as well).

Using uncompressed format saves some processing power, since you don't have to "decode" it, but it does increase hard drive access, since you have to read more often from the hard drive into RAM. You see a 20% drop in battery life in general, but not too bad.

I'll have to see if the lossless format fares better (less hard drive access, but maybe more processor-intensive) in some real world test as the week goes on...

Why would you want them to wrap a DRM around it? In fact, AAC files you rip from your CD's doesn't have any DRM. The only DRM is those music purchased from iTMS. DRM is inconvenient and annoying.

I wonder if Apple's lossless format (which seems to be a MPEG4 standard, actually) has less impact on battery life than FLAC. Currently the only portable player supporting FLAC is the Rio Karma. Using FLAC with it decreases its rated 16 hour playing down to 10... a huge decrease. I think a part of that has to do with the decoding taxation on the processor.

So far, I noticed very little difference (if any) using ALS against AIFF on my iPod in terms of battery consumption...

Its not. Hence the name Apple Lossless and not MPEG4 Lossless. MPEG4 lossless is another format entirely. Battery loss is due to reading the HUGE files from the hardisk, not the decoder. Decoder power use is pretty negligable.

http://www.nue.tu-berlin.de/forschung/projekte/lossless/mpeg4als.html

This page talks of an eerily similar codec, doesn't it? I wouldn't be surprised that Apple Lossless is indeed MPEG4 lossless, after all, AAC is the just another MPEG4 compression spec. It also makes sense from a hardware point of view that since you can already decode MPEG4 in hardware, it's easy to implement MPEG4 lossless in hardware as well. Going to FLAC would require a new processor.

Also, people on Head-Fi has conducted testing, processor drain might not be much, but there is one. People who used to get about 7 and half hour of playing time using WAV and AIFF are now getting about 6 hours of playing time using Apple Lossless.

Originally posted by lindrone
http://www.nue.tu-berlin.de/forschung/projekte/lossless/mpeg4als.html

This page talks of an eerily similar codec, doesn't it? I wouldn't be surprised that Apple Lossless is indeed MPEG4 lossless, after all, AAC is the just another MPEG4 compression spec. It also makes sense from a hardware point of view that since you can already decode MPEG4 in hardware, it's easy to implement MPEG4 lossless in hardware as well. Going to FLAC would require a new processor.

Also, people on Head-Fi has conducted testing, processor drain might not be much, but there is one. People who used to get about 7 and half hour of playing time using WAV and AIFF are now getting about 6 hours of playing time using Apple Lossless.

Once again the are not the same format.