Author Topic: AAC+ streams?  (Read 7453 times)

Offline Microchip

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AAC+ streams?
« on: February 08, 2007, 08:57:50 AM »
Hi!

First, I love the station, and have a habit of walking round listening on my 3G phone far too much. But with the network occasionally dropping out, and a bandwidth cap per month, is there any chance of you streaming in AAC+ format as well? I don't know if it's been requested already, but it has quite a few advantages:
  • The same or higher quality at 24kbps as the current 128kbps MP3 stream
  • FM to CD quality at 32kbps, superb quality at 48kbps
  • Less bandwidth used, therefore less cost, and ability to support more users
(Etc.)

It's fairly obvious why a switch would be good, and most modern players now (with the notable exception of iTunes, but a stream can easily be run in parallel) cope with AAC+ quite happily. The sound quality is much better, and it uses a lot less bandwidth. And it'll stop it jerking on my phone ;-)

I've had some expertise with shoutcast/icecast systems if you want any information on the implementation of it, if you do consider it ;)

Offline rskm1

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Re: AAC+ streams?
« Reply #1 on: February 08, 2007, 05:14:47 PM »
Quote from: "Microchip"
...is there any chance of you streaming in AAC+ format as well? I don't know if it's been requested already, but it has quite a few advantages:
  • The same or higher quality at 24kbps as the current 128kbps MP3 stream

Well THAT gets filed immediately into the "dubious claims" folder...

I'm All-For lower-bitrate streams (see my other half-dozen posts whining about this over the past year or two), but let's not get delusional about the sound quality of a stream (of predominantly electronica music) at 24kbps.

Offline Microchip

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AAC+ streams?
« Reply #2 on: February 08, 2007, 05:29:34 PM »
Yup, you're right - that should have been 32K. Although I know it's definitely higher at 48. Whoops! *hangs head* Way to make myself look stupid on my first post ;) Your point re electronica quality is well taken too.

But the rest of it does apply. Less bandwidth, more quality. And I'm happy to help if I can. Serious offer.

One thing *don't* know is what the CPU usage is like AAC+ wise though.

Offline EvilCouch

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AAC+ streams?
« Reply #3 on: February 09, 2007, 12:20:53 AM »
The latest version of Shoutcast server supports AAC+ streams. I'm skeptical of the claim that it's that much more dramatically different in quality/file size, but from what I've read it's certainly better than MP3.

However, this would require Shirow to re-rip the entire DG collection, an effort that would probably take several weeks-worth of his free time. Might be worth it, but that's an aweful lot of hassle.

Offline Microchip

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AAC+ streams?
« Reply #4 on: February 09, 2007, 06:29:53 AM »
I'm going off my own experience - after ripping into AAC+ vs MP3, the sound quality difference is dramatic - quite shockingly, in fact. 32KB generally came out better than 128KB MP3, using the Winamp AAC+ ripper. 24K generally sounds better than 96KB MP3, that I definitely can verify.

Re the re-ripping - I'm used to running live streams from the likes of SAM2/SAM4, and doing dynamic transcoding. I hadn't considered that it'd be running direct off the MP3s. And while transcoding the MP3s to AAC files would be an option, it'd lose quality of course.

The latest Shoutcast and Icecast both support AAC+, but I'm not sure which of the variants is being run (haven't looked into it).

Re-ripping would be a pain, but it'd also dramatically increase the capacity for listeners if the main streams were switched to AAC+.

Offline Horizon

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Re: AAC+ streams?
« Reply #5 on: May 25, 2007, 12:21:37 PM »
Would we be able to split up the re-ripping process, maybe?  I know I've got two or three computers in my room that aren't doing too much... one's a test machine for me to play with different linux distros that don't play nicely with Virtual Machine, and the other two are just backup/dev servers...

Of course, then Shirow needs to make  his collection available to other people, and it would be entirely understandable if that was something he was leery of.

Just an idea.
-- Horizon

Offline Shirow

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Re: AAC+ streams?
« Reply #6 on: May 25, 2007, 04:22:33 PM »
I'm actually not even done ripping my current collection into MP3.. let alone something else :p I wouldn't mind people helping rip, but that means I have to mail CDs out.. which would suck.
Simon "Shirow" Westlake
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Offline swampfeotus

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Re: AAC+ streams?
« Reply #7 on: May 25, 2007, 10:53:30 PM »
I would be scared of having to re rip Shirow's collection.

all those cd's.....

Offline Horizon

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Re: AAC+ streams?
« Reply #8 on: May 26, 2007, 02:54:58 AM »
I know you said you can't post the whole library, Shirow, but can you ballpark some figures?
-- Horizon

Offline Shirow

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Re: AAC+ streams?
« Reply #9 on: May 26, 2007, 06:14:18 AM »
I know you said you can't post the whole library, Shirow, but can you ballpark some figures?

On the new site, the entire DG library is actually searchable. I have about 1000 CDs laying around, they're not all on the stream though.
Simon "Shirow" Westlake
- www.digitalgunfire.com

Offline elfspice

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Re: AAC+ streams?
« Reply #10 on: May 26, 2007, 07:37:09 PM »
the streams are generated on the fly by the server machine, one would need to run a second shoutcast server and somehow get winamp to put out a second stream. it's not about converting the music, that's done anyway.

48kbps is the optimal bitrate for streaming HE-AAC like aacplus, the sound quality is about as good as 96kbps mp3, but when you listen to it with headphones after a while you can notice the loss resolution of stereo imaging. it's not so bad it's unbearable though. enables a very high quality stream for dialup users those who are unlucky enough to be still on dialup, or like that person using a phone thingy... i didn't know aacplus was decoded by those things though, i believe it uses a bit more processing than the standard aac. i suppose if the machine runs winamp it can do it.

 

anything