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View Full Version : Can anyone explain the wiki re: flac vs apple lossless to me.



lreinstein
2008-01-07, 19:39
Like many other SB newbies, I am trying to figure out how to best rip my CD collection. I understand that lossless is the way to go. But, as some others have expressed, i am currently more comforatable using iTunes for ripping, and as well it works with my several iPods.

But, will i be losing much in terms of response time or audio quality using slimserver/SB3 into my home Audio System? The WIKI "explains" that with the Apple lossless, the file:

"Must be transcoded (automatically) to play on SlimServer"

Am I correct in assuming this means that it is converted on the fly to another (quicktime?) format? But my question is whether this makes any difference at all to sound quality, or to playback response time...or anything i would notice. ??

Thanks so much

Larry

Eric Seaberg
2008-01-07, 20:07
It may only make a difference depending on your server CPU.

I'm using a Mac Mini as a server and rip everything Apple Lossless. I've not noticed any compromises because of this.

I totally prefer iTunes for handling cataloging, tagging and everything else. Lossless = lossless, whether Apple (co-written with Dolby Labs and others) or FLAC. The biggest proponents of FLAC like it because it's FREE (hence the 'F') and open to other programmers.

There isn't a quality issue playing ALAC files as they'll be transcoded to something else on the fly.

________________

BTW, if you're using a Mac, there's a plugin available for Mac iTunes called MultiTunes allowing multiple libraries. I use this to create a library of LOSSLESS FILES for moving to SlimServer. Then I'll create another library for my iPod that is 192kAAC. I can actually open the lossless library, re-import into the iPod library and have iTunes re-encode, keeping the two separate and only encode what I really want to take with me. Rip ONCE at the highest quality, leaving the most options.

JJZolx
2008-01-07, 20:17
"Must be transcoded (automatically) to play on SlimServer"

Am I correct in assuming this means that it is converted on the fly to another (quicktime?) format? But my question is whether this makes any difference at all to sound quality, or to playback response time...or anything i would notice. ??

The audio is decoded to WAV format, which is the uncompressed format of a CD, so in theory the sound quality should be identical to that of Flac. The downsides, which may be unimportant to you:

- You cant' FFW/REW within the song when it's transcoded on the server

- Streaming will use extra bandwidth, in the range of 50% to 100%over streaming compressed Flac, depending on the compression level of the particular track. On a wired ethernet network, this extra network traffic is inconsequential. On a healty wireless network it normally won't pose a problem, but on a very marginal wireless network, it may.

- It will require a bit of additional CPU overhead to do the decoding on the machine running SlimServer. For most configurations that won't make any difference, but on an underpowered system, it could make the web or remote interfaces a bit less responsive.

Do a search in these forums for 'apple lossless' and you'll probably find a lot more information about using the format than can be found in the wiki.

lreinstein
2008-01-07, 21:19
thanks jim and thanks eric. these are very helpful replies. I have a fairly healthy wireless network and have not really noticed any delays. Also the cpu of the server is pretty robust. If i change my mind later, can apple lossless be converted to FLAC?

I am not sure why you want 2 seperate libraries. Cant iTunes be told to synch to the iPod in compressed MP3 even if the file is apple lossless? perhaps this takes too long.?

Eric Seaberg
2008-01-08, 08:18
[QUOTE=lCant iTunes be told to synch to the iPod in compressed MP3 even if the file is apple lossless? perhaps this takes too long.?[/QUOTE]

No, it will play whatever is in your iTunes library as long as it can decode it, i.e. MP3, AAC, ALAC, AIF and WAV files. The biggest disadvantage of playing lossless on your iPod is that the drive will be spinning alot more than if you just played MP3s.

Remember that AIF/WAV files are about 10MB per minute is size... a 5-minute tune will be about 50MB. Lossless will be about half and 128kMP3 will be about 1/10 or 5MB. This may also determine what goes on your iPod for size.

BTW, if you do convert everything to Apple Lossless there's no reason to re-convert it to FLAC as they are virtually the same. If Apple decides they're no longer supporting ALAC, or Slim doesn't want to deal with transcoding any longer, then you could re-convert to FLAC if necessary.

The beauty of lossless files is that you can convert it to ANYTHING ELSE and never lose quality from the original CD.