Goodbye to HD Radio (for the moment)

[Bryn]

Bryn, what is the effect or implications of this change? Improved quality?

Difficult to say. I doubt even aac saves anything much above 16kHz, so upping the sampling rate from 44.1kHz to 48kHz is probably more to do with some change in the coding equipment, I would guess. Which humans can hear up to 22.05kHz, let alone 24kHz* anyway. I will however, have a look at some spectral analyses in a week or so (i.e. when I have time).

For those, if any, who wonder why I mention 22.05kHz and 24kHz, try an Internet search for "Nyquist frequency".

[johnb]

Information care of the slimdevices (Squeezebox) forum.

These are the URLs for the new live HLS streams from the Akamai server. All of them are 320 kbps AAC-LC:

http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_one.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_1xtra.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_two.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_three.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_fourfm.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_fourlw.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_four_extra.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_five_live.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_radio_five_live_sports_extra.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_6music.m3u8
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/uk/sbr_high/ak/bbc_asian_network.m3u8

If someone has a player that supports HLS (and JRiver apparently does) they can try these URLs to see if they work.

The streams are also available from the Limelight server - to receive those I understand that the /ak/ is replaced by /llnw/ (not tested by me).

The /sbr_high/ denotes 320 kbps AAC, but there are other (lower) bit rate streams available:

/sbr_high/ = 320kbps
/sbr_med/ = 128kbps
/sbr_low/ = 96kbps
/sbr_vlow/ = 48kbps

[Edit]
For non-Uk residents the URLs are similar but with "/uk/" replaced by "/nonuk/" and only the 96kbps and 46kbps apply, e.g.

http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/nonuk/sbr_low/ak/bbc_radio_three.m3u8
or
http://a.files.bbci.co.uk/media/live/manifesto/audio/simulcast/hls/nonuk/sbr_low/llnw/bbc_radio_three.m3u8

[Dave2002]

I'm still trying to figure out what this is all about. From the preceding posts it seems that HLS (HTTP Live Streaming) is relevant:

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

http://www.streamingmedia.com/Articles/Editorial/What-Is-.../What-is-HLS-%28HTTP-Live-Streaming%29-78221.aspx

From what I've read, HLS seems a reasonably sensible approach to distributing streaming services over a network, so that in itself need not present any problems.

It looks as though insufficient attention has been paid to the client software at the end user's sites to maintain continuity of service, or at least service at the quality levels which some would prefer. Where client software can be updated, this may eventually be resolved by the manufacturers and software developers, though some software or equipment may not be updated. It is somewhat annoying when this happens due to changes by broadcasters, as happened to at least one Freeview box we owned (Nokia), which eventually became useless as the transmission standards changed, and there were no software updates to bring the device back into functionality. This is currently in store, pending delivery to a recycling centre, though it has long been superseded by other units as we moved to PVRs.

The comments by some owners of expensive streamers may demonstrate rather more expensive parallels of our experiences - I hope there will be solutions.

The current changes don't seem to have been well explained, certainly not in advance, and as an end user I'm not quite sure what I need to do, if I can, to keep the quality levels up. This hasn't bothered me too much during the last few weeks as mostly I've been listening to CDs and other streaming services.

Where changes or upgrades are apparently seamless, few people care. This does not seem to be the case with the recent changes.

As a Mac user, what will have changed? What can I, or should I, do?

[Phileas]

As a Mac user, what will have changed? What can I, or should I, do?

The urls now made public (see above) are for the HLS streams which as I understand it is an Apple protocol so OS X should handle them ok.

They seem to play directly in Safari.

[Dave2002]

The urls now made public (see above) are for the HLS streams which as I understand it is an Apple protocol so OS X should handle them ok.

They seem to play directly in Safari.

I tried the R3 stream from msg 17. Indeed this does work in Safari - which presumably has a viable plug-in. In Firefox it opens a file, and then asks for an application. The suggested one is iTunes, but nothing happens once selected. In Chrome the "file" downloads, but then nothing. The file is presumably some sort of steering file for an application or plug-in.

Opera behaves in the same way as Firefox, so the only one which actually produces audible output is Safari.

Maybe the same would apply in Windows - there is a Windows version of Safari.

[OldTechie]

... so the only one which actually produces audible output is Safari.

Maybe the same would apply in Windows - there is a Windows version of Safari.

Unfortunately, Apple abandoned updates to Windows Safari some time ago. The last one was version 5.1.7 - and that just tries to download the file. On my PC it gets opened in iTunes by default where it does nothing.

Opening the URL in Quicktime or iTunes does not work. JRiver and Foobar2000 also fail. Windows Media Player plays five or six segments of about 6 seconds each, but with a gap between them. VLC plays it semi-successfully. It takes a full processor's processing time and occasionally produces an audible glitch between the stream segments. Pressing pause and then play results in it continuing but playing the segments out of order.

I see Linn is having trouble with their DS and is promising to do something: see post 52 from a staff member on their forum at http://forums.linn.co.uk/bb/showthre...d=29419&page=6

[french frank]

The latest BBC blog on 't subject:

http://www.bbc.co.uk/blogs/internet/entries/2ff95543-7547-4b2d-9305-563428fb74f5

"Radio 3 HD – unfortunately Radio 3 HD is no longer available as a ShoutCast stream, but is available in our chunked HTTP formats. This means that some internet radios will get a reduced quality experience as they will switch to our MP3 ShoutCast offering which is not available in HD sound. Many though will be able to switch across to the new formats either immediately or in the coming months as the manufacturers and aggregators roll-out updates."

[Phileas]

P

I tried the R3 stream from msg 17. Indeed this does work in Safari - which presumably has a viable plug-in. In Firefox it opens a file, and then asks for an application. The suggested one is iTunes, but nothing happens once selected. In Chrome the "file" downloads, but then nothing. The file is presumably some sort of steering file for an application or plug-in.

Opera behaves in the same way as Firefox, so the only one which actually produces audible output is Safari.

Maybe the same would apply in Windows - there is a Windows version of Safari.

You can just go to the R3 website and play from there.

[amcluesent]

I have Squeezebox with Logitech Media Server using the BBC 320kbps streams embedded in the HLS protocol, using the techniques posted in the last 48 hours.

From what I've seen/read -

- Squeezebox owners not running a local LMS are currently limited to the 128kpbs MP3 streams from Shoutcast. Folks running low-powered NAS for LMS may still be out of luck due to CPU load of transcoding with the "ffmpeg" application, but there's work to optimise this ongoing.
- Manufacturer supported devices like Sonos, Linn, Naim etc. limited to the 128kpbs MP3 streams from vTuner and the other aggregators until manufacturers update firmware to decode HLS
- Generic UPnP based streamers, I've read that minimserver can use the ffmpeg transcoder as LMS does, no details of how to as yet, and present the BBC streams in a way the players can understand.

[Dave2002]

P

You can just go to the R3 website and play from there.

I don't understand that comment. Do you mean from Safari in Mac OS X?

I'm not sure that it would work from Firefox or Chrome in Mac OS X, or on Windows.

[Phileas]

I don't understand that comment. Do you mean from Safari in Mac OS X?

I'm not sure that it would work from Firefox or Chrome in Mac OS X, or on Windows.

I mean the Listen Live link on the R3 website. It works with Chrome on Windows 7. It works with Safari on iOS 8. I assumed it would work in OS X.

[Dave2002]

I mean the Listen Live link on the R3 website. It works with Chrome on Windows 7. It works with Safari on iOS 8. I assumed it would work in OS X.

I checked in Safari, Firefox, Chrome and Opera in Mac OS X, and the Listen Live link does seem to work. Looking at the popup window the live stream may be HD - as there is an HD logo, and the sound does seem to be clear enough. Listen Again does also seem to work in the browsers, though there's no HD logo, and the sound may be more subdued. I can't say definitely that it is a lower bit rate stream or different codec, though that might be my suspicion.

There is evidence of some lack of care in the sites, as there is still mention of RadioPlayer in some of the pop ups on some of the browsers, but the RadioPlayer site seems to be defunct.

[Phileas]

The urls made public in this thread are for the HLS streams. I don't know what kind of streams are being played by the BBC Radio website pop-ups - they might be HDS which I believe is an Adobe thing.

I just assumed they would be AAC, not MP3

I noticed a comment from this blog:

http://www.bbc.co.uk/blogs/internet/entries/28dfd220-7ca1-3683-ac16-3938cfb4b882

16. Posted by Jim Simmons
on
29 Sept 2014 16:51
Here are a few replies to the comments. Sorry for the delay. I will try to be a bit clearer this time.

Audio Factory will deliver live streams and streams of on-demand programmes using the AAC codec. Specifically AAC-LC at 320kb/s and 128kb/s bit rate and HE-AAC(v1) at 96kb/s and 48kb/s. The AAC-LC bit rate pair will be for high quality connections (e.g. wifi) the HE-AAC (v1) will be for international streams and mobile. We have chosen v1 over v2 as this has a slightly greater range of compatible devices. This will be the same for all UK BBC radio stations. i.e. Not World Service yet.

These streams will be delivered to devices using the HLS (for iOS and Android) and HDS (for desktop) delivery methods. This will replace windows media for some devices and rtmp for desktop machines

[Dave2002]

Specifically AAC-LC at 320kb/s and 128kb/s bit rate and HE-AAC(v1) at 96kb/s and 48kb/s.

This doesn't seem specific enough to identify which programmes are at 320 kbps and which at 128 kbps. 128 kbps AAC will be OKish,but not up to the same level as the 320 kbps distribution. I think the live broadcasts are 320 kbps, but my suspicion is that the on-demand streams may not be. 128 kbps aac could still be perceived as as good as, or better than, DAB.

[johnb]

Dave, after checking the bandwidth of R3 on-demand (Windows 7) it certainly isn't 128kbps. It does seem to average around 320kbps (the stream comes in spikes every few seconds so it is only possible to get an approximate kbps).