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A.S.
09-05-2011, 10:04 AM
BBC Radio 3, the British Broadcasting Corporation's 24 hour classical music service, is now available as a continuous 320kb AAC high-quality stream. This is as close to the ex-studio feed as you can get.

As I have the free VLC Media Player installed on my W7 PC, clicking this link starts the streamed audio decoder and recognises the format.

BBC Radio 3 stream is here: http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

VLC player, if necessary is available here: http://www.videolan.org/vlc/

This really is as good as it gets on-line. If you listen closely to the presenter's voices, you can clearly hear the whirr of equipment and the acoustic of the studio from which they are talking - and the characteristics of their microphones. I assume that there is no equalisation or signal processing, and that the 15kHz low pass filter that applies to all (BBC) broadcasting has been applied but this can easily be checked with a spectral analysis plot.

Drdennis
09-05-2011, 12:53 PM
Absolutely wonderful! It is available on iTunes for apple users.
Thank you for the tip.

Concerti
09-05-2011, 01:17 PM
Thanks Allan,
GREATLY appreciated from us down under.
Cheers
C

Labarum
09-05-2011, 05:00 PM
The BBC Radio 3 HD stream is indeed extremely good.

Would users outside the UK confirm that they are actually accessing that 320kb/s stream? I think they may be hearing a less high bit stream. In Cyprus I can get the 320kb/s stream using a Virtual Private Network (VPN) tunnelling me back to a UK IP address. If I switch the VPN off my Squeezeboxes will only get the lower quality international stream.

If members have just been clicking the BBC webpage to listen outside UK they might be surprised how low the bitrate is. I would be pleased to hear the contrary.

I believe the best Radio 3 stream available outside UK is this, and it will beat what you get outside UK from iPlayer.

Here it is, send as "Code" to cut and paste.


http://www.bbc.co.uk/radio/listen/live/r3.asx

192kb/s WMA

---

German "Radio 3" (WDR 3) is also excellent at 256kb/s MP3, and has no territorial limits.

This stream:


http://www.wdr.de/wdrlive/media/wdr3_hq.m3u

http://www.wdr3.de/

---

There is an East European Classical Radio Station that offers a higher bitrate than BBC HD - three times higher using FLAC (FLAC in an OGG container)

Try D-DUR http://www.rozhlas.cz/d-dur/portal/

This stream


http://radio.cesnet.cz:8000/cro-d-dur.flac

and compare it to the same programme at about 256kb/s with OGG compression


http://www.rozhlas.cz/audio/download/ddur_maxogg.m3u

Watch your internet usage if streaming the FLAC - the bitrate hovers around 800kb/s and can exceed 1000kb/s. It will eat your bandwidth!

Foobar on a PC and VLC player on most platforms will handle both these streams.

The technical quality is superb, but BBC Radio Three may have the edge on musical content.

------------------------------------------

For those interested in VPN, I use

https://www.my-private-network.co.uk/

and it costs me UKú5 per month on top of my ISP charges. With it I can use BBC iPlayer and the other UK streaming sites. I can watch UK TV almost as easily as in UK. An HD TV download from iPlayer is superb. I have sufficient speed to watch normal quality real time streams, and, as said, it gives me access to the higher quality BBC Radio streams.

Supersnake
09-05-2011, 09:31 PM
Would users outside the UK confirm that they are actually accessing that 320kb/s stream? I think they may be hearing a less high bit stream.
Alan's link accessed in the United States
AAC 320kbps 44100Hz


There is an East European Classical Radio Station that offers a higher bitrate than BBC HD - three times higher using FLAC (FLAC in an OGG container)
Try D-DUR http://www.rozhlas.cz/d-dur/portal/


Use this URL and the entire web site - not just the first page - will be in English language:

--> http://translate.google.com/translate?js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&sl=cs&tl=en&u=http%3A%2F%2Fwww.rozhlas.cz%2Fd-dur%2Fportal%2F




Thanks to you and Alan for the references.

A.S.
09-05-2011, 11:41 PM
BBC Radio 3 stream is here: http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

VLC player, if necessary is available here: http://www.videolan.org/vlc/

This really is as good as it gets on-line.... I assume that there is no equalisation or signal processing, and that the 15kHz low pass filter that applies to all (BBC) broadcasting has been applied but this can easily be checked with a spectral analysis plot.Attached is a spectral analysis of a studio conversation this evening (the excellent Night Waves, speech only). As you can see the audio extends right out to 20kHz and beyond so there is no 15kHz filter as there is on FM radio.

This really seems to be an extremely good source of (mainly) classical music, and with the BBC's recent commitment to more live concert recordings could be the best audio source available to the serious hifi listener.

Labarum
10-05-2011, 07:42 AM
Alan's link accessed in the United States
AAC 320kbps 44100Hz



I have just tried Alan's link in Foobar Media Player in Cyprus with my VPN off. It does indeed work.

Yesterday, before posting I checked that my Squeezeboxes would only deliver the HD stream with the VPN on. All very odd, but good news that the R3 HD stream is internationally available.

I have now added Alan's link (thanks Alan) to my Squeezebox Favourites labelled "BBC Radio 3 HD (Direct)", and yes, it does work without VPN.

Yesterday I was using the Squeezebox BBC iPlayer Pluggin (not App). iPlayer does indeed switch to lower radio bit-rates when it sees an IP outside the UK, and will not stream TV at all. I will continue to use the iPlayer pluggin as it gives me access to the "listen again" service.

----
These 320kb/s streams are also worth a try

http://radio.linnrecords.com/

This is the classical stream I send as "Code" to enable cut and paste.


http://radio.linnrecords.com/cast/tunein.php/linnclassical/playlist.pls

Not a true radio station, but randomly streamed content of the Linn Catalogue.

---

I would be interested, Alan, to know how the other high definition streams measure in comparison to the BBC R3 stream.

Labarum
10-05-2011, 10:14 AM
Absolutely wonderful! It is available on iTunes for apple users.
Thank you for the tip.

I'm not an iTunes user, but I do believe there is a "Manual Tune" option in the Internet Radio section of iTunes. Cut and copy the link into the manual tune box and click go. There may be a Favourites system, if not, save the entry as a Playlist (a one track playlist) and access it that way in future.

BBC Radio 3 HD 320kb/s AAC (Mentioned earlier)

I send links as "Code" for easy cut and paste.


http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

You could also try the German Classical Station Westdeutscher Rundfunk 3 from the region (Land) of Westphalia.
This is based in Cologne and as close to BBC Radio Three as the Germans get.

WDR 3 256kb/s MP3


http://www.wdr.de/wdrlive/media/wdr3_hq.m3u

Some detail here in English

http://en.wikipedia.org/wiki/WDR_3

and you could try

Linn Radio Classical 320kb/s AAC


http://radio.linnrecords.com/cast/tunein.php/linnclassical/playlist.pls

Put them in the same or their individual playlists. iTunes will stream AAC and MP3.

---

But VLC Player is available for Mac, Windows and Linux and is worth having on any computer because it will play almost any media file.

VLC for Mac

http://www.videolan.org/vlc/download-macosx.html

Supersnake
11-05-2011, 01:03 AM
I propose that we all thank Labarum for adding those classical music streams to Alan's BBC3 stream link.

The Linn Radio Classical 320kb/s AAC stream is quite good.

Labarum
11-05-2011, 06:38 AM
Thanks for the thanks! I spent most of my listening time with these high bit radio stations even though I have a lot of my CDs ripped to my hard drive.

Try

Avro Classic 256kb/s MP3


http://opml.radiotime.com/Tune.ashx?id=s55517&Formats=mp3,wma,real&username=sampletime&PartnerId=16


Avro Baroque 256kb/s MP3


http://opml.radiotime.com/Tune.ashx?id=s55512&partnerId=16


But bitrate is not everything.

Try Radio Swiss Classic at "only" 128kb/s MP3


http://opml.radiotime.com/Tune.ashx?id=s25582&Formats=mp3,wma,real&username=sampletime&PartnerId=16

I hope these URLs work for everyone - I have just manually tuned them in Foobar on my Windows PC.

And the bad news?

"Triode", who is the programmer of the Squeexebox iPlayer Pluggin thinks the international access (or any access) to the HTTP BBC Radio 3 HD stream which Alan gave us at the top of this thread my be shortlived - so make the most of it. The BBC seems keen to have all access by iPlayer.

See

http://forums.slimdevices.com/showthread.php?t=87614


---

I would be interested to hear quality comparisons made by Alan (and others) between the BBC HD stream and the rest. Many of the stations do live broadcasts, or at least stream content that has never been committed to CD.

Mike Smith
13-05-2011, 02:22 AM
The BBC iplayer will launch on an international level this year but will not be free of charge, it will launch first as an ipad app, with a subscription fee of a few dollars a month, have a look at BBC Worldwide for more news.

I would like to ask Alan if he has tried the Radio3 home page Listen Live in HD button (I think it is WMA instead of AAC), if so have you run the spectral analysis on this stream and will it rival or equal the AAC stream?

Thanks in advance and thanks to Alan for VLC link and others for the tips.

Mike.

Labarum
13-05-2011, 05:38 AM
I would like to ask Alan if he has tried the Radio3 home page Listen Live in HD button (I think it is WMA instead of AAC), if so have you run the spectral analysis on this stream and will it rival or equal the AAC stream?



I'm two time zones ahead of UK so up earlier than most British residents.

If I press the Radio 3 HD button I see the AAC stream at 320kb/s - so Flash reports.

That's as from UK (VPN on). From my Cyprus IP address (VPN off) it doesn't work.

The WMA stream is this one


http://www.bbc.co.uk/radio/listen/live/r3.asx

192kb/s but still very good.

There is a family of them



BBC WMA Streams mostly at 128

R1

http://bbc.co.uk/radio/listen/live/r1.asx

R2

http://bbc.co.uk/radio/listen/live/r2.asx

R3

http://bbc.co.uk/radio/listen/live/r3.asx

R4

http://bbc.co.uk/radio/listen/live/r4.asx

R4 Longwave

http://bbc.co.uk/radio/listen/live/r4lw.asx

R5 Live

http://bbc.co.uk/radio/listen/live/r5l.asx

R5 Live Sports Extra

http://bbc.co.uk/radio/listen/live/r5lsp.asx

R6 Music

http://bbc.co.uk/radio/listen/live/r6.asx

R7

http://bbc.co.uk/radio/listen/live/r7.asx

R Asian Network

http://bbc.co.uk/radio/listen/live/ran.asx



I have only checked Radio 4 before posting - I got 128kb/s as if in UK (VPN on) but only 49kb/s from my Cyprus IP address (VPN off)

This really is a black art!

---

And I too would be very pleased if Alan made a comparison of the 320kb/s AAC stream and the 192kb/s WMA stream.

A.S.
13-05-2011, 07:54 AM
The real thanks for the Radio 3 320kb AAC stream are to our member Pluto for discovering it, not me.

I'm really pressed for time these next days with our USA distributor about to arrive, then travelling to the Munich hifi show, and then on my return a visit from our Hong Kong distributor. I'll try and get around to the spectral analysis. If you have the means, try it yourself and publish but make the pictures understandable (see thread on Influencing Others).

Labarum
14-05-2011, 11:08 AM
Post #5 on this thread should be noted

http://forums.slimdevices.com/showthread.php?p=631165#post631165

It links to a BBC page showing most of the BBC Radio streams.

Mike Smith
17-05-2011, 07:22 PM
I'm two time zones ahead of UK so up earlier than most British residents.

If I press the Radio 3 HD button I see the AAC stream at 320kb/s - so Flash reports.

That's as from UK (VPN on). From my Cyprus IP address (VPN off) it doesn't work.


Yes it is I had not checked the flash, I had wrongly quessed it was a WMA file which is why I asked the question of Alan because I had found it sounded every bit as good as the AAC link, turns out it is the same thing so no requirement for the spectrum analysis, just as well as Alan is a busy man.



And I too would be very pleased if Alan made a comparison of the 320kb/s AAC stream and the 192kb/s WMA stream.


No real need now it is clear which is best.

Mike.

Labarum
17-05-2011, 07:41 PM
No real need now it is clear which is best.

Mike.

If you are suggesting that a 320kb/s AAC stream must necessarily be better than a 192 kb/s WMA stream I suggest that view is too simple.

If you are comparing the two BBC streams, that is probably truth, but if you were to compare the BBC Radio 3 HD 320kb/s AAC stream with (say) the WDR3 stream at 256kb/s MP3 it could go either way, and might easily depend on how the signal had been processed in the studio before transmission.

Once above a certain bit rate, dynamic compression (limiting the range of soft to loud) kills the music more than digital compression (bitrate and CODEC).

Labarum
27-05-2011, 03:52 PM
The BBC Radio 3 HD stream Alan referenced at the top of this thread seems to be off at the moment.

Some said it would be a short lived bonus.

The iPlayer R3 HD stream is still working - for UK IP addresses.

---

I referenced the D-Dur OGG-FLAC and OGG streams earlier

The technical stuff about D-Dur is here

http://www.cesnet.cz/doc/techzpravy/2008/using-flac-encoding/

Pluto
31-05-2011, 01:40 PM
The BBC Radio 3 HD stream Alan referenced at the top of this thread seems to be off at the moment.

http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

It's back as I type this message!

Labarum
31-05-2011, 02:03 PM
I confirm that. Great news. And it is still available internationally. I have just turned my VPN off to check.

Labarum
01-06-2011, 08:17 PM
Listening to the Wigmore Gala Concert on the BBC HD stream

http://www.bbc.co.uk/programmes/b011j85x

Quite excellent.

Supersnake
02-06-2011, 04:12 AM
Listening to the Wigmore Gala Concert on the BBC HD stream

http://www.bbc.co.uk/programmes/b011j85x

Quite excellent.

Am in United States and like before, we are still unable to call up the HD stream. The BBC HD server responds with "Not available in your area".

QUESTION: Is the BBC Radio 3 HD stream of higher audio quality than the http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls AAC 320 kbps 44100HZ stereo stream that Alan posted?

Labarum
02-06-2011, 06:49 AM
I have just tested "that" stream - Alan's stream - which I was listening to last night.


http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

It worked in Foobar from my laptop in Cyprus with my VPN off.

If you click the buttons in the BBC iPlayer webpage for "HD" you probably wont get it as it's locked up in Flash and limited to UK.

You have to cut and paste the url for the stream into a music software player that will handle AAC like Foobar, Songbird, iTunes; or into a hardware internet radio like Squeezebox - that's why I have sent the urls in "code", to make it easy to cut and paste.

Supersnake
02-06-2011, 09:21 AM
I have just tested "that" stream - Alan's stream - which I was listening to last night.


http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls .

Have edited and clarified my post to indicate the same. Alan's stream plugs into Foobar and plays without any problem.
However, it is the BBC HD stream that we in the United States are unable to play, as Labarum has noted.

Labarum
02-06-2011, 12:21 PM
To clarify further "Alan's Stream" IS the BBC Radio 3 HD stream accessed directly - you have to copy it manually into the media player.

Exactly the same stream is accessed by clicking the R3 HD button on the webpage, but if you do it that way, the 320kb/s AAC stream is locked up in the Flash routines of the BBC iPlayer, and it is iPlayer that sets the territorial restrictions.

If you are in UK you will receive the HD data by either means.

If you are outside the UK you must copy the URL into your media player of choice that will handle the AAC format.

If you are outside the UK but use a VPN to give yourself a UK IP address you will receive the HD data by either means.

---

If you use a Squeezebox install the iPlayer Plugin by Triode (not the App) and you will access the HD stream at 320kb/s from a UK IP address.

Once the plugin is installed go to "BBC iPlayer" in the Squeezebox web interface. Look at the bottom of the page for "Special Events" and click.

Choose "Listen Live - AAC Test Streams" - There you will see the whole family of BBC AAC streams.

Choose Radio 3 and (probably) save it as a favourite.

Only Radio 3 streams at 320kb/s - the rest seem to be 128kb/s.

You can also copy "Alan's url" into the manual tune feature of the Squeezebox and save as a favourite.

Supersnake
02-06-2011, 08:57 PM
Is the BBC Radio 3 HD stream of higher audio quality than the http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls AAC 320 kbps 44100HZ stereo stream that Alan posted?


To clarify further "Alan's Stream" IS the BBC Radio 3 HD stream accessed directly ....

Aha! I was hoping that they would be the same stream, thank you.
Am now a more happy Yank knowing that I too am able to listen to the BBC Radio 3 HD stream, via Alan's url of course (smile).

HUG-1
10-06-2011, 11:08 AM
Not to be missed! The BBC Philharmonic Play Music from Your Favouite Films etc. including Star Wars.

More info here. (http://www.bbc.co.uk/programmes/b011pptk)

Be sure to listen in 320kb AAC "HD SOUND" direct from the BBC website

www.bbc.co.uk/radio3

Suggestion. If you are recording for your own listening later, considering wide dynamic range on AAC feed using TotalRecorder set record boost to no more than +8dB to avoid clipping. (May not apply on every computer).

Labarum
10-06-2011, 11:18 AM
Users outside the UK will not be able to access the BBC HD stream by clicking the button on the webpage quoted above.

They need to cut and paste the URL below into a music player that will process AAC.


http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

HUG-1
10-06-2011, 12:55 PM
Do you have a suggestion (other than TotalRecorder which we are familiar with) for how to capture that stream, to save it for future private replay? We are not exactly sure how TR works, whether it captures and interprets the raw binary stream before/after the user's browser, the stream as it enters the sound card, in the sound card or at the sound card's output. Or maybe at none of those stages.

Labarum
10-06-2011, 01:15 PM
I have never attempted to record such a stream.

1. I have used the iPlayer Listen Again feature as it is made available using the Squeezebox iPlayer plugin by Triode. That is not a recording to keep forever. I have never looked at what bitrate is available for a R3 "Listen Again". I suspect is is not the very best. I will ask in another place.

2. What will "Audacity" do? http://audacity.sourceforge.net/

Edit:

Just had a play with Audacity. I am sure it will do it provided you can access

"Stereo Mix", "Wave", or "What U hear" in your soundcard control pane.

I was looking for this feature for another purpose the other day and it is disabled in my laptop, and I cannot find the drivers to enable the feature.

Labarum
11-06-2011, 10:44 AM
After discussing a number of options with an expert in another place, here is a relatively simple digital recording method that uses free software.

VLC Media Player

If you do not have a copy download from here

http://www.vlcmediaplayer.org/download.html

The process is entirely automatic.

1. Start VLC.

It will probably start after installation.

2. From "Media" menu select "Convert/Save"

3. Click on "Network" Tab and copy the BBC R3 URL


http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

into the "Network URL" field. Then click on "Convert/Save" button at bottom.

You have now chosen the source of the recording, you must now specify the place to store it.

4. You now have a "Convert" dialog box with BBC3 URL in "source" field. Enter a file name with directory (e.g. "C:\BBC\SatConcert.flac") into the "Destination file" field.

More expert computer users will need no more instruction than above; but to expand. You now need to give the VLC Player a place to store the recorded music, and to give this recording a name.

In the "Convert" Pane that is now open, to the right of the "Destination" box, click "Browse". On the left scroll down till you see "Computer". Supposing you have only one Hard Disc click "Local Disc C". Click the RIGHT mouse button in the right side of the open window. You will now be offered options. Click "New" and then "Folder". Give the folder a name by typing in the highlighted box, and LEFT click on the box. Keep it simple. Maybe "BBC"? You now have a new folder on your hard drive (C:\BBC\) for storing your recorded radio programmes. This will serve for all future recordings.

Now your must give your first recording a name. Just below where you have made your new folder you will see a box called "File Name". Type in a unique name for the file you are about to record. eg Concert1.flac, BachPno.flac SatPM.flac Notice they MUST all end dot flac (.flac)

In future you may chose not to use the "Browse" button, but just type in the FULL name for a new recording
e.g. C:\BBC\WaterMus.flac , C:\BBC\SunJazz.flac C:\BBC\RecordReview11_06_11.flac


5. In "Settings" and "Profile" select "Audio - Flac" and also check the "Deinterlace" box. Then click "Start"

You have chosen a recording source, the BBC R3 HD stream off the Network; you have chosen a place to put the recording, and you have chosen a format in which to store it. The source started as a stream in high quality AAC format, which is a "lossy" format for efficient transmission over the internet. Now you want to store it without further lossy compression. You could store it as an uncompressed WAW file and the advanced features of the VLC player allow that, but FLAC is fine. It will store the recording without further loss and do it in half the space.

6. VLC screen will appear and no music will be played just the elapsed time incrementing if stream is converted.

7. Click stop button to stop conversion (recording).

To play your recording go to the "Media" tab on the VLC player and chose "Open File". If you do not see the file you have just recorded on the right use the left of the pane to go to "Computer/Local Drive C:/BBC" or whatever path (address) you chose earlier.

Click the file and it will play.

I have just tried all this, connected my laptop to my DAC by USB and the recording sounded very fine.

I am assured this recoding method does not modify the bitream in any way - what goes into the recording comes out.

If further help is needed post on this thread.

Please remember the Radio 3 HD stream accessed using the URL in this post is "experimental" and may come and go.

Acknowledgement: With many thanks to BPA on the Squeezebox Forum. His instructions to me are in bold.

Pluto
12-06-2011, 11:41 AM
...The source started as a stream in high quality AAC format, which is a "lossy" format for efficient transmission over the internet. Now you want to store it without further lossy compression. You could store it as an uncompressed WAW file and the advanced features of the VLC player allow that, but FLAC is fine
It would make more sense to record the raw AAC bitstream rather than convert it to anything, as AAC is more compact than the derived WAV (or FLAC) would ever be. Any thoughts on this?

Labarum
12-06-2011, 11:50 AM
I guess it would. I am relaying advice from another place and from someone who knows much more than I.

He has said to me by PM


VLC just takes the AAC from BBC, strips the ICY metadata such as program name (which is why you can't dump the stream straight from BBC, then uses *faad (same a SBS) to decode pure AAC stream into PCM and then encodes into Flac. No bits are harmed in the process.

This may be the best solution with this free software and domestic hardware.

Can you tell us otherwise?

---
* faad http://www.audiocoding.com/faad2.html

Pluto
12-06-2011, 01:02 PM
Can you tell us otherwise?
No - but the idea of transcoding to FLAC seems rather inefficient given that AAC is more-or-less the same as M4A which is a standard file format. I'm sure there must be a way of storing the raw data to disk rather than artificially bloating it as we are discussing here.

320kb/s is roughly a quarter of the rate of PCM 16/44. FLAC achieves 50% compression, give or take - so storing FLAC rather than raw 320kb/s AAC means you are using twice as much storage as is strictly necessary (but possibly more relevant, twice as much network bandwidth when subsequently transporting it).

Labarum
12-06-2011, 04:15 PM
Yea. But this is a dirty engineering solution for occasional domestic use - it works, and it's free!

Labarum
13-06-2011, 03:16 PM
The BBC Radio 3 HD stream at


http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

is working again, but remember it is "experimental".

Labarum
19-06-2011, 03:36 PM
Listening to this "live" concert in HD

http://www.bbc.co.uk/programmes/b011y7rt

Fabulous.

A.S.
26-06-2011, 03:41 PM
Thanks to Pluto, he made a recording of the marvellous BBC Philharmonic's Film Music concert on 10th June. This was off the 'high quality wide bandwidth HD' sound feed to the internet, in AAC - at at least 44k sampling, hence 22kHz bandwidth.

Out of curiosity, here is a spectrum analysis of the first seconds of the concert from that HD feed, see attached.

The interesting point is that whilst the studio announcer's speech extends (admittedly in a dark colour hence low audio level) to beyond 20kHz* the concert itself has a sharp brickwall filter cutting of the top above about 17kHz ( a strange number).

*The odd thing is that this is without doubt a wider bandwidth feed than the normal BBC circuit. Within normal (incl. FM) transmission, there is a sharp cut-off at 15kHz and this is seemingly applied in the continuity (i.e. routing source) studio in Broadcasting House. So the fact that the continuity announcer's voice extends far beyond that frequency confirms that the AAC feed is taken from before the 15kHz cut, as we would expect. But why the filter at about 17kHz on what is already a wide bandwidth potential? Is this a one-off or what we can expect in live concerts from Manchester?

Having said this, be the upper cut-off frequency 17kHz or 22kHz, I can't hear that high any more, and it certainly doesn't impact on my enjoyment. Listened to on these humble Logitech PC speakers, the overall sound is fantastic - and in fact there are several interesting musical examples that could help explain the point I've made before about the difficulty conventional loudspeakers have in reproducing brass instruments - which are very well presented in this recording.

I just need some free time to make the excepts for you. (Free time - what's that??)

>

Pluto
01-07-2011, 03:40 PM
The interesting point is that whilst the studio announcer's speech extends to beyond 20kHz, the concert itself has a sharp brickwall filter cutting of the top above about 17kHz ( a strange number).
Alan, for clarification - by "studio announcer" do you mean the voice preceding the concert or the announcer (? Mark Kermode) who takes part in it?

I know nothing of the nature of the feeds from Manchester, but I wouldn't mind betting that the strange 17kHz LPF you describe is related to the trip from Manchester to London continuity.

Not strictly related, but bear in mind that most perceptual coding schemes incorporate significant low pass filtering: if your mission is to discard those parts of the audio that your scheme deems to be of little or no use to the auditory system, the first thing probably worth doing is to get rid of those parts of the sound that are of least value - above 15kHz for starters!

Owentdc
03-07-2011, 12:45 PM
Below is a screenshot of the station listing in the Classical category under Radio.

A.S.
07-07-2011, 10:28 PM
Alan, for clarification - by "studio announcer" do you mean the voice preceding the concert or the announcer (? Mark Kermode) who takes part in it?The announcer I'm referring to is the Continuity Announcer, most likely in BH London. Mark and all the film music is truncated at about 17kHz or thereabouts. I guess that the the performance (live or recorded) appears as a source on the Continuity Announcer's desk, and he fades up whatever technical parameters that source is (alongside his microphone) into the data stream that's encoded for us as AAC, 320kb.

I wouldn't think that he is audibly aware of, or needs to be concerned by, or is interested in any technical data such as bit rate or bandwidth of sources presented to him, providing that they are not clipped or too quiet.

weaver
08-07-2011, 12:20 PM
The announcer I'm referring to is the Continuity Announcer, most likely in BH London. Mark and all the film music is truncated at about 17kHz or thereabouts. I guess that the the performance (live or recorded) appears as a source on the Continuity Announcer's desk, and he fades up whatever technical parameters that source is (alongside his microphone) into the data stream that's encoded for us as AAC, 320kb.

I wouldn't think that he is audibly aware of, or needs to be concerned by, or is interested in any technical data such as bit rate or bandwidth of sources presented to him, providing that they are not clipped or too quiet.

I've linked to this article before (when the Proms 2010 were first put out in HD) but it seems relevant again here as it gives a breakdown of the signal path of a live broadcast at the BBC: BBC R&D blog (http://www.bbc.co.uk/blogs/researchanddevelopment/2010/09/bbc-proms-in-extra-high-quality-n-the-internet--the-tech.shtml)

HUG-1
08-07-2011, 08:19 PM
Can't see anything in the linked BBC blog that explains why the audio from the concert abruptly truncated at about 17kHz. 17kHz to 22kHz can be delivered by 44k sampling.

As noted previously in the example shown the Continuity Announcer's voice had frequency content extending right out to 22kHz. The concert he fed to us didn't.

mhennessy
19-12-2012, 01:57 AM
An old thread, but an interesting one...

The 15kHz bandwidth limit is applied to FM only; either by the Optimod processor, or, more probably, by the anti-alias filters of the NICAM distribution units (if these are now fed via AES, then there will be a sample-rate converter that obviously filters at 15kHz). The NICAM distribution is 32kHz, of course. And for those who aren't aware, NICAM is used to digitally distribute the signals to the major FM transmitting sites, and has done so for more than 30 years. Some of us my remember the introduction of NICAM stereo sound to analogue TV sound in the late 1980s/early 1990s. This - "NICAM 768" - was a gentle modification of the established "NICAM 3" scheme. NICAM is a 14 bit system, though only 10 bits are ever broadcast at once. But I digress...

The 17kHz BW does indeed suggest that perceptual coding is somewhere in the way. So, an obvious question: does anyone know where the orchestra was? Was it an OB? Almost probably. In which case, there's every chance that AAC or APTX was used to get the signal from the OB truck back over an ISDN circuit (typically at 128kb/s for most simple OBs) - obviously something like the Proms gets a better circuit.

The switching between 48 and 44.1kHz that Rupert discusses is probably one of the more benign things we do to the audio. The first time you go down to 44.1kHz, you lose anything above 22kHz - subsequently converting back to 48kHz doesn't add anything, and going back to 44.1kHz a second time shouldn't alter anything.

Let me know if there are any more questions and I'll do some digging (no promises though - it was a long time ago!)

Mark

sparklite
05-09-2014, 02:28 PM
This is an old thread, I know, but I live in Canada and when I try to play the 320kpbs stream all I get is a 56k AAC stream. Even if I manually add the 320 version of BBC Radio 3 it shows up as 56k. Any thoughts? Anyone else with this problem?

Labarum
05-09-2014, 04:07 PM
This is an old thread, I know, but I live in Canada and when I try to play the 320kpbs stream all I get is a 56k AAC stream. Even if I manually add the 320 version of BBC Radio 3 it shows up as 56k. Any thoughts? Anyone else with this problem?

What happens of you tune to


http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

I have just run this in VLC and on my Squeezebox, but I am in UK this week. Next week I will be the other side of Europe so will be able to try it there.

If you use any of the BBCs easy ways to connect you will get the lowest bitrate outside UK. The above URL may work for you.

The full list is here, but I have not checked them all.



Radio 1 (128kbps AAC)http://www.bbc.co.uk/radio/listen/live/r1_aaclca.pls

Radio 2 (128kbps AAC) http://www.bbc.co.uk/radio/listen/live/r2_aaclca.pls

Radio 3 (320kbps AAC) http://www.bbc.co.uk/radio/listen/live/r3_aaclca.pls

Radio 4 (128kbps AAC) http://www.bbc.co.uk/radio/listen/live/r4_aaclca.pls

Radio 5 Live (128kbps AAC) http://www.bbc.co.uk/radio/listen/live/r5l_aaclca.pls

6 Music (128kbps AAC) http://www.bbc.co.uk/radio/listen/live/r6_aaclca.pls

Radio 1xtra (128knps AAC) http://www.bbc.co.uk/radio/listen/live/r1x_aaclca.pls

Radio 4 Extra (128kbps AAC) http://www.bbc.co.uk/radio/listen/live/r4x_aaclca.pls

Radio 5 Live Sports Extra (128kbps AAC) http://www.bbc.co.uk/radio/listen/live/r5lsp_aaclca.pls

Asian Network (128kbps AAC) http://www.bbc.co.uk/radio/listen/live/ran_aaclca.pls

willem
05-09-2014, 10:15 PM
I just tried from Holland: the bit rate of the content is fluctuating around 55kbs. 32000Hz. The input bitrate is a bit higher. To be honest, I am no expert.

Labarum
05-09-2014, 10:31 PM
I'll try next week when I get back to Cyprus. I haven't looked at the issue for years as my server in Cyprus runs a VPN back to my UK flat, so I am always "in" the UK!

pkwba
06-09-2014, 08:21 AM
I just tried from Holland: the bit rate of the content is fluctuating around 55kbs. 32000Hz. The input bitrate is a bit higher. To be honest, I am no expert.

Confirm. Input rate 64kb/s , factual up to 55kb/s 32kHz played with VLC. Computer wired to 1Gb/s net with present (just checked) 242 Mb/s transmission (via UPC) can receive hd tv by cable. Probably commercial limitations.


ATB