HydrogenAudio

Lossy Audio Compression => AAC => AAC - General => Topic started by: jkauff on 2013-01-09 13:06:33

Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: jkauff on 2013-01-09 13:06:33
Here it is a new year, and I haven't heard any updates to last year's rumor that Apple would be adopting HD-AAC for the iTunes Store and would start to offer lossless and/or hi-res downloads. If the rumored Pandora-killer iRadio happens, would that likely be the driver for HD-AAC?

WAGs also welcome. 
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: saratoga on 2013-01-09 15:14:10
Why would you want a scalable to lossless streaming format?
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: Kohlrabi on 2013-01-09 15:54:33
Why would you want a hi-res streaming format?
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: skamp on 2013-01-09 15:56:19
Why do you guys assume anything about the OP's motivations?
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: db1989 on 2013-01-09 16:01:40
Why is it apparently so difficult to read words?
lossless and/or hi-res downloads

Edit: OK, the mention of iRadio is irrelevant, since I doubt many stations are already at the upper limits of non-‘HD’ AAC or any other contemporary streaming format. But it’s a perfectly valid question in the context of downloads.
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: jkauff on 2013-01-09 17:38:30
The advantage of HD-AAC is that you can store a song once in a hi-res (up to 24/192) compressed lossless format, similar to FLAC, ALAC, etc., and use the same file to extract lossy AAC (like the current iTunes) for downloading or streaming, or lossless standard 16/44. The advantage for the iTunes Store is that they could use the same file to satisfy all consumer uses.

The advantage for consumers like us is no more transcoding. You store the file once, and the player simply requests the slices that it is capable of playing. Same with applications. You could archive the songs on your computer, connect your iPhone/iPod, and ask iTunes to transfer the appropriate slices to your portable device in the size and quality you want to carry with you. You could say "Give me 50GB worth of my entire collection", and iTunes would do the math for you.

HD-AAC, if it became a standard, would be great for home music servers, too. You store the file on your server at its native resolution, and then any compatible device can request a stream at the highest bitrate and quality that it can handle. From what I've read, the compression ratio of HD-AAC is also higher than FLAC, so you can store more music in the same amount of space.
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: db1989 on 2013-01-09 18:21:44
Assuming the compression was still efficient despite the scalability – and, more importantly, assuming those great benefits weren’t monopolised by Apple – that would be great.
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: LithosZA on 2013-01-09 18:23:01
Question is if a bitrate peeled LC-AAC compatible file from a HD-AAC file would be comparible quality to a LC-AAC encoded file?
128Kbit/s peeled files vs 128Kbps/s normal encoded files...

EDIT: Bitrate peeling probably isn't the right term to use for HD-AAC.
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: darkbyte on 2013-01-09 18:35:36
There were some rumors about the Fraunhofer AAC encoder in Winamp which will support HD-AAC encoding. However i haven't heard anything about this since then.
Title: Anything new in the rumor mill about Apple and HD-AAC?
Post by: Kohlrabi on 2013-01-10 11:40:24
Why is it apparently so difficult to read words?
lossless and/or hi-res downloads

FWIW, my question also applies to downloads.