XM on DirecTV broadcast quality [Archive]

psymn

12-27-07, 05:24 PM

Does anyone know what type of compression is used to broadcast the XM feeds via DirecTV, and how does this compare to an uncompressed CD?

I'm curious to know if it is lossless or MP3, and, if it is MP3, what the bitrate is. The reason for this query are the rockin' speakers I received from my loving wife for Christmas.:D

Thanks,
psymn (aka simon not a vulgar acronym):nono2:

harsh

12-27-07, 05:44 PM

Does anyone know what type of compression is used to broadcast the XM feeds via DirecTV, and how does this compare to an uncompressed CD?The DIRECTV XM feeds are MPEG2 audio versions of what appears to be the standard XM satellite downlink. The bitrate of the XM feeds is relatively low; I'm guessing in the 60-80Kbps range for music and much less for talk. I'd be willing to wager that DIRECTV isn't doing appreciable damage to the XM signal.

CD audio by definition is aboout 1,400Kbps. http://en.wikipedia.org/wiki/Red_Book_(audio_CD_standard)

psymn

12-27-07, 05:49 PM

The DIRECTV XM feeds are MPEG2 audio versions of what appears to be the standard XM satellite downlink. The bitrate of the XM feeds is relatively low; I'm guessing in the 60-80Kbps range for music and much less for talk. I'd be willing to wager that DIRECTV isn't doing appreciable damage to the XM signal.

CD audio by definition is aboout 1,400Kbps. http://en.wikipedia.org/wiki/Red_Book_(audio_CD_standard)

So this means that the XM feed is lower quality than the mos3 in my library, which are either 192k or 320k. right?

That really stinks:mad: ...now I have to find a way to stream my lossless files to my receiver .

Is there a way to do this without buying anymore hardware. I have an xbox 360 networked to my desktop, but i'm not sure if it supports lossless formats.

homebase

12-27-07, 06:09 PM

The online XM radio feeds are either 32 or 64Kbit WMA. The XM delivered signal is noticeably better than the online feed.

Steve Mehs

12-27-07, 06:10 PM

At XMFan there is a table showing the bitrate of each channel from XM's own satellites. (Scroll 2/3s down) And remember sound quality is not dependent on bitrate but codec as well. XM 71 Watercolors streams at 41K, but it sounds a hell of a lot better then a 41K MP3.

http://www.xmfan.com/viewtopic.php?t=58631&postdays=0&postorder=asc&start=1770

(the above has nothing really to do with your question, but just for informational purposes)

The sound quality on XM via D* is much better then it is from XM themselves, if you're an audiophile you won't be satisfied with either, but I find XM to be acceptable and I found XM via D* to be better, but not as good as Sirius on Dish or Music Choice on cable. Everyone's ears are different, I'd say hook them up and see what you think.

psymn

12-27-07, 06:37 PM

I'm glad I asked this question. I was naive to think the stream was CD quality, and I guess I was horribly wrong. It was all of those "digital quality" commercials I've heard for XM and Sirius.

So, if I understand correctly, the DirecTV stream may be better than XM's, but it's still nowhere near CD quality.

I guess I'll have to get that old CD jukebox out of the attic. :lol:

Steve Mehs

12-27-07, 06:47 PM

Digital quality means nothing. Low rez flash videos on You Tube are just as digital as Finding Nemo on Blu Ray Disc at 1080p.

Sirius on Dish sounds very close to CD quality to me, XM on DirecTV is not that good, but better then from XM themselves. Again it's up to you to decide if you find it acceptable or not. Which the wealth of content on XM and Sirius, I have no problem with the audio quality. Content is king and satellite radio rocks!

Stuart Sweet

12-27-07, 08:34 PM

When I was an XM subscriber I wasn't incredibly impressed with the quality anyway... I find the DIRECTV versions to be acceptable as well.

VARTV

12-28-07, 06:45 AM

Steve Mehs

12-28-07, 09:40 AM

Yep, but it was upgrade to the processing not the bitrate and only affects XM, not XM on DirecTV.

Redlinetire

12-28-07, 10:39 AM

Again it's up to you to decide if you find it acceptable or not.

Exactly. Hook them up and let your ears decide.

ThomasM

12-28-07, 08:37 PM

At XMFan there is a table showing the bitrate of each channel from XM's own satellites. (Scroll 2/3s down) And remember sound quality is not dependent on bitrate but codec as well. XM 71 Watercolors streams at 41K, but it sounds a hell of a lot better then a 41K MP3.

The sound quality on XM via D* is much better then it is from XM themselves, if you're an audiophile you won't be satisfied with either, but I find XM to be acceptable and I found XM via D* to be better, but not as good as Sirius on Dish or Music Choice on cable. Everyone's ears are different, I'd say hook them up and see what you think.

Being a DirecTV and XM subscriber, I have noticed that things have changed since XM replaced their neural audio processors and tweaked their audio. Now, I'd much rather listen to the XM satellite audio feed than the DirecTV equivalent. The DirecTV feed actually sounds "tinny" but the satellite feed seems much better-at least on MOST of the channels. Unfortunately, I still miss Music Choice on DirecTV which sounded almost as good as CD quality on my stereo.

Steve Mehs

12-28-07, 09:00 PM

I haven't heard XM on D* in a while, but the upgrade they made to the sound last summer was great so I wouldn't doubt if it's on par with XM on D*. XM does sound much better than it used to. Right now I'm listening to Music Choice's Party Favorites on cable and it sounds excellent, cable box connected to my home theater receiver via HDMI. Sirius on E* still gets my award for the best sound quality. MC on Cable sounds cleaner and crisper, but Sirius on E* sounds richer, I know that doesn't make much sense, but that’s the best way I can describe it.

harsh

12-28-07, 11:07 PM

XM 71 Watercolors streams at 41K, but it sounds a hell of a lot better then a 41K MP3.Bitrate in MP3 terms is the bitrate of the uncompressed data. I would guess that the XM bitrate is the bandwidth allocated to the compressed signal similar to what is done on satellite video signals and cable's QAM system. In all of these cases, a perfectly good signal is trashed as necessary to fit the space available for the compressed signal.

Sirius' Internet audio is digitized at 64K for the freebie feeds and 128K for the "premium" feeds.

wmccain

12-29-07, 01:10 AM

The DIRECTV XM feeds are MPEG2 audio versions of what appears to be the standard XM satellite downlink.I have an XM tuner and DirecTV, and I have found that the XM music channels on DirecTV run slightly AHEAD of the same channels on XM itself. Which means that DirecTV is not re-encoding from an XM satellite downlink — DirecTV must be getting some kind of direct feed from XM, probably fibre optical, and encoding into MPEG2 from that. The direct feed may be compressed — or uncompressed. (XM's own downlinks are not in MPEG2, they are in a proprietary format.)

WIlliam C. McCain
Palo Alto, California

Jeremy W

12-29-07, 01:17 AM

XM's own downlinks are not in MPEG2, they are in a proprietary format.
It's aacPlus v2, which is somewhat based on MPEG4 and made by Coding Technologies. All of the audio processing to try and make the compressed signal sound better is done by Neural.

And you are correct, DirecTV's feeds come to them before XM encodes them and sends them up to the satellites. The reason DirecTV is ahead of XM is because of the very aggressive compression XM applies to the audio to get it to fit into the very tiny space it is allowed to occupy.

wilbur_the_goose

12-29-07, 06:11 AM

So this means that the XM feed is lower quality than the mos3 in my library, which are either 192k or 320k. right?

That really stinks:mad: ...now I have to find a way to stream my lossless files to my receiver .

Is there a way to do this without buying anymore hardware. I have an xbox 360 networked to my desktop, but i'm not sure if it supports lossless formats.

If you're running Vista or XP, it's easy. Just hook up your XBOX 360's media center to your PC. It's a great UI, and the sound is perfect. I've ripped 2000 CDs and am using this interface very successfully.

Slump Buster

12-29-07, 09:48 AM

If you're running Vista or XP, it's easy. Just hook up your XBOX 360's media center to your PC. It's a great UI, and the sound is perfect. I've ripped 2000 CDs and am using this interface very successfully.

Another option (I'm not saying it is better) is to use TVersity and another add-on program and stream xm stations to your HR2x. I haven't quite figured out how to make this work on the HR20-700 (channels still show up as "x") yet but I was pleasantly surprised as to the quality of sound when streaming to my Denon receiver. In a nutshell, this Tversity add-on will allow you to nagivate to any xm channel via the gui by adding a single audio feed in tversity (you can also avoid the add-on by adding each channel individually, of course).

http://forum.freeipodguide.com/about60670.html

bhelton71

12-29-07, 10:08 AM

Another option (I'm not saying it is better) is to use TVersity and another add-on program and stream xm stations to your HR2x. I haven't quite figured out how to make this work on the HR20-700 (channels still show up as "x") yet but I was pleasantly surprised as to the quality of sound when streaming to my Denon receiver. In a nutshell, this Tversity add-on will allow you to nagivate to any xm channel via the gui by adding a single audio feed in tversity (you can also avoid the add-on by adding each channel individually, of course).

http://forum.freeipodguide.com/about60670.html

I have been using the uXM proxy for a bit with the HR20 - wanted the Led channel. I use the feeds method. You will need to adjust the maxItemsPerFeed attribute in the config.xml for tversity. I set mine to 30 just to be sure. The xpath is //config/contentdirectory/@maxItemsPerFeed.

If you do choose to add individual channels - change the url from mms:// to rtsp://.

Basically after you have setup your XM login information, just add the feed you want (in my case 'Rock') to tversity. What I have noticed is the feed seems to need to be refreshed every 24 hours - I think XM maybe changes the feed identifiers. It will show up in the HR20 as Internet Audio/Audio Feeds/Xm Rock/[each channel name].

Slump Buster

12-29-07, 10:26 AM

I have been using the uXM proxy for a bit with the HR20 - wanted the Led channel. I use the feeds method. You will need to adjust the maxItemsPerFeed attribute in the config.xml for tversity. I set mine to 30 just to be sure. The xpath is //config/contentdirectory/@maxItemsPerFeed.

If you do choose to add individual channels - change the url from mms:// to rtsp://.

Basically after you have setup your XM login information, just add the feed you want (in my case 'Rock') to tversity. What I have noticed is the feed seems to need to be refreshed every 24 hours - I think XM maybe changes the feed identifiers. It will show up in the HR20 as Internet Audio/Audio Feeds/Xm Rock/[each channel name].

Wow, that is a better option! I did not think of that.

I'm a little confused... the uXM client as I see it just passes through the channel names. How did you get it to group by content type? Are you bypassing it? Also, any idea why this feature works with my Denon without the maxItemsPerFeed set and not the HR20?

bhelton71

12-29-07, 10:35 AM

Wow, that is a better option! I did not think of that.

I'm a little confused... the uXM client as I see it just passes through the channel names. How did you get it to group by content type? Are you bypassing it? Also, any idea why this feature works with my Denon without the maxItemsPerFeed set and not the HR20?

Yes - its just passes the channel names - not the song info - so thats a bummer. Luckily I know every song in the Zeppelin catalog :p

Using the feeds options is automatically grouped - didn't have to do anything for that. I am pretty sure the Denon is connecting directly to uXM. The max items is only an issue when using the feeds option in TVersity.

Slump Buster

12-29-07, 10:47 AM

Yes - its just passes the channel names - not the song info - so thats a bummer. Luckily I know every song in the Zeppelin catalog :p

Using the feeds options is automatically grouped - didn't have to do anything for that. I am pretty sure the Denon is connecting directly to uXM. The max items is only an issue when using the feeds option in TVersity.

(laughing) as do I. I've been wearing out that channel since they added it.

Ah, that makes sense. Would you mind passing me a sample link? Apparently I've been doing it wrong.

bhelton71

12-29-07, 11:10 AM

(laughing) as do I. I've been wearing out that channel since they added it.

Ah, that makes sense. Would you mind passing me a sample link? Apparently I've been doing it wrong.

I have a feeling my urls won't work for you - the id's are probably generated per account ?

For a feed:
In uXM just open the URLs button - on the feeds tab select the category (Rock for example) - then click clipboard - then in TVersity click + and select Add Podcast/Feed> Add Audio Podcast/Feed. On the add dialog just right-click and paste and title it as you like.

For a single channel
In uXM just open the URLs button - on the channels tab select the channel (XM2- XMX for example) - then click clipboard - then in TVersity click + and select Add Internet Media> Add Audio URL. On the add dialog just right-click and paste and title it as you like. Before you save it - change the mms:// to rtsp://.

For both - make sure you select the Bandwidth: High - the low sounds like crap.

Also - another caveat - it will not work from the TVersity interface for some reason. But it is fine on the HR20.

Slump Buster

12-29-07, 11:45 AM

I have a feeling my urls won't work for you - the id's are probably generated per account ?

For a feed:
In uXM just open the URLs button - on the feeds tab select the category (Rock for example) - then click clipboard - then in TVersity click + and select Add Podcast/Feed> Add Audio Podcast/Feed. On the add dialog just right-click and paste and title it as you like.

For a single channel
In uXM just open the URLs button - on the channels tab select the channel (XM2- XMX for example) - then click clipboard - then in TVersity click + and select Add Internet Media> Add Audio URL. On the add dialog just right-click and paste and title it as you like. Before you save it - change the mms:// to rtsp://.

For both - make sure you select the Bandwidth: High - the low sounds like crap.

Also - another caveat - it will not work from the TVersity interface for some reason. But it is fine on the HR20.

Doh! I never noticed the feeds tab when I did it. I merely added the individual channels.

Ok, I see them in the hr20 menu but they still have X's next to them. I had already changed the max per feed in the gui and verified in the config.xml. I rebooted it for the heck of it and also did a rescan. Any thoughts? Here is a sample link that I got from uXM:

http://192.168.1.205:19081/feeds/lineup.xml?bandwidth=high&category=rock&r=1198953933

bhelton71

12-29-07, 11:58 AM

Doh! I never noticed the feeds tab when I did it. I merely added the individual channels.

Ok, I see them in the hr20 menu but they still have X's next to them. I had already changed the max per feed in the gui and verified in the config.xml. I rebooted it for the heck of it and also did a rescan. Any thoughts? Here is a sample link that I got from uXM:

http://192.168.1.205:19081/feeds/lineup.xml?bandwidth=high&category=rock&r=1198953933

Which profile did you select in TVersity ? I am using the WAV support one. If you have it on autoselect or just HR20 I don't think it will work.

Slump Buster

12-29-07, 12:31 PM

Which profile did you select in TVersity ? I am using the WAV support one. If you have it on autoselect or just HR20 I don't think it will work.

Bingo, that was it! Thanks again for your help. I think I agree with the earlier posts that said that the Directv feed was better than the online feed. Also, I believe that my Denon was in fact seeing the Tversity feed as it appeared under the Tversity server name (and the uXM doesn't appear anywhere in either box).

Any downside to using the "with wav support" setting?

bhelton71

12-29-07, 12:36 PM

Bingo, that was it! Thanks again for your help. I think I agree with the earlier posts that said that the Directv feed was better than the online feed. Also, I believe that my Denon was in fact seeing the Tversity feed as it appeared under the Tversity server name (and the uXM doesn't appear anywhere in either box).

Any downside to using the "with wav support" setting?

None that I know of - the TVersity team created a couple of profiles to support different s/w configurations of the HR20/HR21. They left the generic profile for the autodetect and the other 2 are user selectable only.

Yes - the Directv feeds are much better - just not the 'complete' station list.

Another interesting thing - from what I have read Sirius and so-called HD Radio both use the same encoding 'PAC' (aka Perceptual audio coder ). That is my next TVersity project - get some of the online HD2 streams loaded up.

edit: ok that was too easy - clearchannel has a few HD2 streams @ http://www.clearchannelmusic.com/hdradio/

Slump Buster

12-29-07, 03:52 PM

None that I know of - the TVersity team created a couple of profiles to support different s/w configurations of the HR20/HR21. They left the generic profile for the autodetect and the other 2 are user selectable only.

Yes - the Directv feeds are much better - just not the 'complete' station list.

Another interesting thing - from what I have read Sirius and so-called HD Radio both use the same encoding 'PAC' (aka Perceptual audio coder ). That is my next TVersity project - get some of the online HD2 streams loaded up.

edit: ok that was too easy - clearchannel has a few HD2 streams @ http://www.clearchannelmusic.com/hdradio/

Did you manage to add the clearchannel channels? I tried a couple of the individiual links after viewing the source html of the page - no luck.

bhelton71

12-29-07, 06:51 PM

Did you manage to add the clearchannel channels? I tried a couple of the individiual links after viewing the source html of the page - no luck.

The asx didn't work for you ?

Like this is WRZX-FM in Indianapolis:
http://mfile.akamai.com/21875/live/reflector:45925.asx

Just added as an audio url.

If that doesn't work try opening the asx file in an xml or text editor and grabbing the stream url
mms://a1926.l2187545925.c21875.g.lm.akamaistream.net/D/1926/21875/v0001/reflector:45925

Jeremy W

12-30-07, 10:21 AM

Wow, this thread really needs to get

:backtotop

Slump Buster

12-30-07, 10:29 AM

Wow, this thread really needs to get

:backtotop

I think the thread was pretty much dead as it was. There is a lot of info in here that people may find useful. Thanks so much to bhelton for all of his great information!

Steve Mehs

12-30-07, 11:17 AM

Was this thread ever off topic :confused:

Jeremy W

12-30-07, 05:34 PM

Was this thread ever off topic :confused:
A thread about the sound quality of XM on DirecTV, in the DirecTV™ Programming and Services forum, talking about how to get XMRO streaming working? I don't see how that is possibly on topic.

bhelton71

12-30-07, 06:41 PM

A thread about the sound quality of XM on DirecTV, in the DirecTV™ Programming and Services forum, talking about how to get XMRO streaming working? I don't see how that is possibly on topic.

Its not and thats my bad - I just read the last post about TVersity and started blabbing - before I knew it we were on page 2.

Anyway - directly back on topic - channel 866 XM Pops is one of the 2 5.1 channels - wonder why we don't get it in 5.1 ?

Jeremy W

12-30-07, 07:01 PM

channel 866 XM Pops is one of the 2 5.1 channels - wonder why we don't get it in 5.1 ?
It's actually purely a 2.0 channel, along with some extra information to help a special (Neural) decoder make it into 5.1. It's essentially a step above the receiver just extracting out the 5.1 audio on it's own. DirecTV would have to do the Neural decoding on their end, and then convert it to DD 5.1 for broadcast. It would end up making the channel take up a whole lot more space than it does now.