What format is this?
Posted by: BigH47 on 12 September 2013
I seem to have a few of these on my server but I'm not sure why they are like this:-
"Low complexity" seems confusing, but the file is 5 Mb which seems small compared to my normal save in AIFF of 30+ Mb.
It's not a problem per se as I have most of the files on CD and can re-rip, but was just interested how these files got there.
TIA
Howard
http://dafx04.na.infn.it/WebProc/Proc/P_163.pdf And http://en.wikipedia.org/wiki/Advanced_Audio_Coding. Explain
"
The combination of AAC, SBR, and the parametric stereo tool presented here was included in the MPEG-4 Audio standard and is referred to as aacPlus v2. It en- ables coding of stereo signals at bit rates that are less than 50% of those required by AAC to achieve the same subjective quality and was recently adopted as recommended coder for audio streaming in Release 6 of the 3GPP standard for mobile services. "
AAC is the low res stuff you get from the iTunes store.
Thanks guys , the music sounds fine to these old ears.
What was confusing me is how they ended up in this format (I know you guys can't answer that). I'll probably re-rip to AIFF at sometime.
Where they ripped via iTunes?.. If so its determined via you imprt settings under iTunes>Preferences.. You will have it set to AAC as the desired format, it decides itself the complexity required. You can change it to lossless (alac) or whatever format you desire,takes effect at the next rip.
hth
paul
And if you want the music for both home AND portable devices, you can consider two versions of your library -- one in lossless for home, and one lossy (such as AAC) for iPhones, iPods, etc.
I don't know the details, but apparently Apple did not want to adopt .mp3 as their default format when they got into the iPod business. I think that they took a risk with aac, but it worked out ok. (And I think there is general agreement that at a given bitrate, aac sounds a little better than mp3, but I'm not sure.) And before that, was Sony's debacle with their ATRAC format. That did not work out so well.
And if you want the music for both home AND portable devices, you can consider two versions of your library -- one in lossless for home, and one lossy (such as AAC) for iPhones, iPods, etc.
...
At least for Apple devices that sync via iTunes, you do not need to maintain additional AAC versions of your library files. You can rip it all to ALAC or AIFF and have one library. When you sync with iTunes you can set it to convert to 128, 192, or 256 Kbps AAC on the fly as the audio files are copied to the device (iPhone, iPad, iPod). That is exactly what I do.