hoi there
im interested in some technical details about satellite radio in the U.S. and A, XM The Move in particular.
I have already found out, that XM uses the CT's HE-AAC encoder.
Since im from germany, i dont have the chance to test it for myself so my simple question is:
What settings would be recommended to transcode the XM The Move stream to a mp3?
Are more than 192kbps necessary? can it be said in general, regarding to the signal of XM Radio,
what the smartest settings are?
im looking forward for your replies
is it the wrong place to ask?
If I'm not mistaken, I believe that that Sirius and XM satellite radio (they will be one in the same in a few months/years) use a audio bitrate of 48kbps with HE-AAC. It is either 48kbps or 64kbps, I am leaning heavily towards 48kbps though.
If that is the case, you probably won't benefit recording the audio to anything higher than 192kbps since your source (ie the satellite radio) already has a low bitrate. I guess you could conduct a test to determine what mp3 bitrate is needed. You could record the radio to a wav file, then encode that wav file to various mp3 bitrates and conduct some blind ABX tests. But, as you said, you can't test it out. Then again, if you can't test it out, then why even bother having the knowledge of recording it (unless it is for a project or paper)?
If that is the case, you probably won't benefit recording the audio to anything higher than 192kbps since your source (ie the satellite radio) already has a low bitrate. I guess you could conduct a test to determine what mp3 bitrate is needed. You could record the radio to a wav file, then encode that wav file to various mp3 bitrates and conduct some blind ABX tests. But, as you said, you can't test it out. Then again, if you can't test it out, then why even bother having the knowledge of recording it (unless it is for a project or paper)?
A few possibly useful links (each is several years old, so there may be more recent info available):
http://www.xmfan.com/viewtopic.php?t=10886
http://www.hydrogenaudio.org/forums/index....showtopic=52056
http://www.siriusbackstage.com/forum/archi...hp/t-54321.html
- M.
http://www.xmfan.com/viewtopic.php?t=10886
http://www.hydrogenaudio.org/forums/index....showtopic=52056
http://www.siriusbackstage.com/forum/archi...hp/t-54321.html
- M.
It doesn't sound like 48kbps. It sounds like 24/32, because I can CLEARLY hear parametric stereo's unique artifacts ("robotic" sound, sorta). Some channels don't, but a lot I've heard do.
Then again, they could be using parametric stereo at 48kbps... But that'd be stupid.
Why would you want to transcode it to MP3? It's such a poor quality source. Anyway, I'd suggest using -V2 --vbr-new, should probably avoid introducing more artifacts on most music.
Then again, they could be using parametric stereo at 48kbps... But that'd be stupid.
Why would you want to transcode it to MP3? It's such a poor quality source. Anyway, I'd suggest using -V2 --vbr-new, should probably avoid introducing more artifacts on most music.
QUOTE(Firon @ Mar 10 2007, 21:50) 
Then again, they could be using parametric stereo at 48kbps... But that'd be stupid.
Last I checked, CT uses PS by default at 48kbps.
it's about 32kbps w/no PS on the majority of channels, 40 on a few, and 70kbps on the XMHD channels
so what to say about a strategy that means:
recording the XM80 channel via a PCM digital and encode it @202 kbps VBR with aac from nero digital.
any opinions?
recording the XM80 channel via a PCM digital and encode it @202 kbps VBR with aac from nero digital.
any opinions?
Cheez...
You guys are so far off!
Perhaps there's confusion because AOL provides low quality feeds of XM to the unwashed masses across the internet.
But, AOL subscribers get, via internet, the same 64 kbps CT AAC+ (HE-AAC v2) that comes down from the satellite. However, XM's talk channels use 32 kbps, I've read (dunno, I subscribe so as not to hear talk). Of course, AOL's own stations are also in CT AAC+.
You can confirm that AOL's internet feed of XM to AOL's paying subscribers is at 64kbps because the Mac OS X Radio@AOL player shows that information. But, not every channel on XM or Sirius comes from their own studios; I suppose there's room for signal degradation when content comes from Worldspace Satellite Radio or somewhere else.
Sirius doesn't use CT's HE-AAC, I have read. When I listened, Sirius music quality seemed below XM's. I listen both via satellite and AOL premium internet and consider audio quality very good.
Somebody very clever might be able to directly capture the 64 kbps AOL AAC+ stream, but not in Windows.
You guys are so far off!
Perhaps there's confusion because AOL provides low quality feeds of XM to the unwashed masses across the internet.
But, AOL subscribers get, via internet, the same 64 kbps CT AAC+ (HE-AAC v2) that comes down from the satellite. However, XM's talk channels use 32 kbps, I've read (dunno, I subscribe so as not to hear talk). Of course, AOL's own stations are also in CT AAC+.
You can confirm that AOL's internet feed of XM to AOL's paying subscribers is at 64kbps because the Mac OS X Radio@AOL player shows that information. But, not every channel on XM or Sirius comes from their own studios; I suppose there's room for signal degradation when content comes from Worldspace Satellite Radio or somewhere else.
Sirius doesn't use CT's HE-AAC, I have read. When I listened, Sirius music quality seemed below XM's. I listen both via satellite and AOL premium internet and consider audio quality very good.
Somebody very clever might be able to directly capture the 64 kbps AOL AAC+ stream, but not in Windows.
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