What storage method for your iPod?

[RABid]

Since DB has an iPod now assume these questions are acceptable on the Keyboard forum.

 

My big question, what compression scheme are members settling on for the iPod? My iPod should be here in a day or two and Im trying to get files ready. I downloaded iTunes and started comparing different compression methods but it is hard to tell much with only computer speakers to audition sound quality. File size is another matter. Right now I have my entire CD collection converted to 256 kpbs mp3s and stored on a special HD at work. This morning I decided to try the Apple lossless encoder and the resulting file size was three times that of a 256 mp3. A single CD went from 133 meg at 256 kpbs to just over 400 meg with the lossless compression. I compressed the same CD using 128 kbps AAC and it went to 66 meg. On a side note, I find it interesting that what Apple calls AAS, Windows XP reflects back as mp4.

 

Robert

[RABid]

Ok. I have been testing AAC 256 kpbs. It seemed the way to go, but after ripping a few of my CD's in this format the resulting files will not open in Windows Media Player or my version of MusicMatch (7.5). This worries me. The format was announced a few years ago but is no one but Apple supporting it? I don't want to archive my collection in a format that is locked to one developer. Where does AAC stand?

 

Robert

[MurMan]

Originally posted by Rabid:

On a side note, I find it interesting that what Apple calls AAS, Windows XP reflects back as mp4.

Robert,

 

I assume you meant AAC. Here's some background that might be useful, but I don't think I can answer your original question.

 

Each MPEG standard is really a collection of technologies for audio and video encoders and decoders. (Or codecs if you mean both.) Within the audio portion of the standards, there are multiple types of codecs. Because of this umbrella approach, it's hard for consumers like us to know what's compatible.

 

AAC, advanced audio coding, was an audio codec option that I think showed up in MPEG-2. It's used in XM satelite radio.

 

MPEG-4 brought the MPEG-2 AAC option forward and added more AAC options: LC, Scaleable, LD. Therefore, AAC is technically MPEG-4. In addition to AAC, MPEG-4 also has BSAC, CELP, HVXC, and TTSI codecs. Confused yet?

 

There are way too many audio compresssion techniques out there. Microsoft .wav files support over 300 formats. (MPEG-4 AAC is the third most recent addition.)

 

Adoption of standards into products is always left to market forces, so it's never a sure thing as to what standards become well-supported. Apple has adopted AAC into iTunes, QT, and the iPod. (This alone would make Microsoft avoid it like the plague ...) It's also going to be used in the Mondiale digital radio.

[MurMan]

I just found the following in an MSDN (Microsoft Developer Network) article. (I changed one sentence to bold.)

 

MPEG-4 (.mp4)

MPEG-4 is an International Standards Organization (ISO) specification that covers many aspects of multimedia presentation including compression, authoring and delivery. Although video compression and file container definition are two separate and independent entities of the MPEG-4 specification, many people incorrectly believe that the two are interchangeable. You can implement only portions of the MPEG-4 specification and remain compliant with the standard.

 

The MPEG-4 file format, as defined by the MPEG-4 specification, contains MPEG-4 encoded video and Advanced Audio Coding (AAC)-encoded audio content. It typically uses the .mp4 extension. Windows Media Player does not support the playback of the .mp4 file format. You can play back .mp4 media files in Windows Media Player when you install DirectShow-compatible MPEG-4 decoder packs. DirectShow-compatible MPEG-4 decoder packs include the Ligos LSX-MPEG Player and the EnvivioTV.

[dementia13]

I've read that some of the other mp3 players, such as Winamp, will also recognize AAC with the proper plug-in.