Goodbye to HD Radio (for the moment)

[johnb]

Nevalti,

The Windows 7 fix for HLS is relatively straightforward so the best thing is to get that working before thinking about the NAS.

I'll pm you with the details.

In essence the proceedure is:

- Make sure you have Triode's BBC iPlayer plugin installed in LMS
- Download ffmpeg and put it in the correct folder
- Install a new LMS plugin from bpa
- Download a revised BBC iPlayer menu and put it in the correct folder

[JFLL]

Thank you very much, John, for this very clear and useful summary (#54), and also to Nevalti and Dave for their additional comments. A lot of my listening during the day is done in the study where my desktop is, and the speakers there are only small Harman/Kardon HK19.5 units which came bundled with a Dell desktop in 2005 (yes, my desktop is that old, but still going strong, and I'm reasonably happy with the sound from the speakers). But it does seem that if I want to do off-air recording it might be better to avoid using the DAB radio.

Dave – in the evenings I usually listen to R3 (and sometimes record from) the Freeview signal on a DVD Recorder/Freeview receiver linked to decent but vintage B&O speakers. About a year ago we bought an LG TV through which you can listen to R3 on Freeview but, strangely, not record to an external hard drive as you can all the TV channels. Isn't that irritating? From what you say, though, the Freeview sound may not be as good as the 320 kbps AAC-LC stream?

[Dave2002]

Dave – in the evenings I usually listen to R3 (and sometimes record from) the Freeview signal on a DVD Recorder/Freeview receiver linked to decent but vintage B&O speakers. About a year ago we bought an LG TV through which you can listen to R3 on Freeview but, strangely, not record to an external hard drive as you can all the TV channels. Isn't that irritating? From what you say, though, the Freeview sound may not be as good as the 320 kbps AAC-LC stream?

I am losing touch with what the standards for audio and indeed for TV are now. When digital TV was introduced most of it was based on MPEG2. With the advent of HD TV, in some countries MPEG2 carried on, but in others MPEG4 seemed to take over - which gives a greater degree of compression on the video, and perhaps (subject to bit rates) better audio. Also it's by no means certain the DVB-S and DVB-T use the same standards, and parameters for the systems they use, though I think that broadly speaking they are similar.

There certainly was a time when I and others believed that at least there was a hypothetical possibility that TV sound could be better, using audio streams at 256 kbps, but without inside information and/or publicly available data, it's really quite hard to say. I have had devices in the past which would give some clues as to the various bit rates and codecs used, but I've not used them for some years.

Some TVs and/or set-top boxes are probably capable of multi-channel sound. Occasionally broadcasters do put out films in multi-channel, and with some ingenuity the audio can be fed to a surround sound system. Probably most users don't notice or know this.
I think I did it once with signals via an optical cable fed into a Sony Blu Ray player - which would have had to exploit a multimedia encoding, since SPDIF does not otherwise have enough capability for several PCM channels.

I'm sorry to hear that you can't record audio from your TV. Does your TV have an optical or coaxial audio out? That might provide a way - though our PVRs make it easy, and work with the programme guides, so repeat programming is very simple. It is possible to extract the audio by offloading the files to external hard drives through USB connections. I don't know what the options are for most modern TVs - some seem to have ethernet, or WiFi as well as SPDIF outputs. Our HDTV pre-dates such things.

Apart from the possible technical limitations of Freeview and Freesat sound - which nevertheless may have the capability for a reasonably high quality of audio - what broadcasters, including the BBC, actually do with the channels is not always a known quanitity. The feed-in chains for R3 to the TV networks may have an impact on the final sound quality.

[johnb]

The Freeview and Freesat R3 used to be 192 kbps Stereo, the same as DAB R3 used to be when R5LSX wasn't broadcasting. However, they weren't identical to the DAB mp2 so there must have been some difference in how they were processed, somewhere along the chain.

The 256 kbps mp2 that Dave mentioned was used for the audio in the BBC TV channels (standard definition), other TV channels used mp2 at lower bit rates.

It is possible that this is still the situation, though changes might have occurred.

[gurnemanz]

Dave – in the evenings I usually listen to R3 (and sometimes record from) the Freeview signal on a linked to decent but vintage B&O speakers. About a year ago we bought an LG TV through which you can listen to R3 on Freeview but, strangely, not record to an external hard drive as you can all the TV channels. Isn't that irritating? From what you say, though, the Freeview sound may not be as good as the 320 kbps AAC-LC stream?

Like you, I record TV (Panasonic) to an external hard drive which also works well in HD and also find it irritating that it won't record radio. Also like you, I listen to a DVD Recorder/Freeview receiver, which has now become my main radio source, and since you can easily record radio to it using its EPG, the above problem is avoided. I have taken a digital lead from it to my amp via a DAC which has a remote control for easy switching from one source to another. This set-up works very well for me with good sound.

[Dave2002]

The 256 kbps mp2 that Dave mentioned was used for the audio in the BBC TV channels (standard definition), other TV channels used mp2 at lower bit rates.

It is possible that this is still the situation, though changes might have occurred.

Some TV Proms programmes were definitely noted as in 256kbps formats, but that was years ago. Who knows what the situation is now!

[JFLL]

Like you, I record TV (Panasonic) to an external hard drive which also works well in HD and also find it irritating that it won't record radio. Also like you, I listen to a DVD Recorder/Freeview receiver, which has now become my main radio source, and since you can easily record radio to it using its EPG, the above problem is avoided. I have taken a digital lead from it to my amp via a DAC which has a remote control for easy switching from one source to another. This set-up works very well for me with good sound.

This is exactly what I do (Freeview to DAC to amp). The old Freeview/DVD recorder, as well as allowing recording of radio channels to the inbuilt hard drive, also comes in useful when one wants to watch one programme and record another showing at the same time, or indeed to record two programmes running at the same time – one being recorded from the TV to the external hard drive, the other to the Freeview/DVD player hard drive. The operations are entirely independent. I'm still unclear why, if a 7-year old Freeview player could record radio channels, why new TVs can't, or at least mine (an LG 'Smart' TV – ha!) can't.

(Thanks, Dave, for further clarification on the sound issues.)

[Phileas]

As i understood it, the TV feed uses the FM feed converted to MPEG, so it's not the same as the DAB feed because it's been through the optimod thingy.

[Bryn]

This is from 2009, and deals specifically with Proms broadcasts, but much of it may well still be relevant, especially the bit about the BBC FOUR feed apparently not passing thorough an Optimod stage.

[Phileas]

This is from 2009, and deals specifically with Proms broadcasts, but much of it may well still be relevant, especially the bit about the BBC FOUR feed apparently not passing thorough an Optimod stage.

I stand corrected. I'm not sure where I got my information from.

[Dave2002]

This is from 2009, and deals specifically with Proms broadcasts, but much of it may well still be relevant, especially the bit about the BBC FOUR feed apparently not passing thorough an Optimod stage.

Thanks. It was good to be reminded of the possibility of surround sound via the HD TV channels.

Surround sound is transmitted on BBC HD at 384kbps using Dolby Digital encoding. Dolby Digital has a frequency range from about 3 Hz to 18 kHz.

Surround sound is likely to be processed|digitally compressed|compressed in some ways, particularly for films because of "effects", but also because the links used will not have a capacity to support a modestly large number (4-8) at high bit rates. This applies in the broadcasting chain, and perhaps also in the replay chain unless HDMI is used.

Whether surround sound is helpful for broadcast material, such as concerts, is an open question.

What I also don't know, on reflection, is whether PVRs such as mine, can record aurround sound audio if that is available in the live broadcast. Mostly we use a Foxsat Humax machine, which I've just reconnected with an optical link to a DAC. The sound quality on recordings of programmes such as CD review sounded adequate, rather than good, when I sampled recently. I haven't checked the SQ on the BT (Humax) Youview box. However, it is very convenient to just leave the PVR boxes recording because of the programmed guides etc., and that may be an acceptable compromise for some programmes - convenience over quality.

The quality on the audio HD streams is probably better, on the whole. I notice some recent references here to DAB, and I would say that at its best DAB has been rather good, but there have been occasions (some very well documented) when quality has dropped. Also, some people do manage to get very good stereo quality from FM, though it requires a good signal and good equipment. I have heard such, and been very surprised at the high SQ possible. This is not possible in every area though.

We still use a mix of modes to listen, though perhaps most frequently use the computer streams for higher quality, and for listen again.

[Andrew Slater]

Here is the definitive answer for the Freeview streams for BBC Multiplex A on a relay of the Winter Hill transmitter in the north-west of England, from a file generated today (R3 is at 192 kbps mp2, as are R1, R2 and R4):

avprobe version 0.8.16-4:0.8.16-0ubuntu0.12.04.1, Copyright (c) 2007-2014 the Libav developers
built on Sep 16 2014 18:33:49 with gcc 4.6.3

Input #0, mpegts, from 'BBC_MUXA_2015-02-22.ts':
Duration: 06:37:51.78, start: 33145.393611, bitrate: 22 kb/s
Program 4168
Metadata:
service_name : BBC ONE N West
service_provider:
Stream #0.15[0x65]: Video: mpeg2video (Main), yuv420p, 704x576 [PAR 16:11 DAR 16:9], 15000 kb/s, 36.72 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0.16[0x66](eng): Audio: mp2, 48000 Hz, stereo, s16, 256 kb/s
Stream #0.17[0x6a](eng): Audio: mp2, 48000 Hz, mono, s16, 64 kb/s (visual impaired)
Stream #0.18[0x69](eng): Subtitle: dvbsub
Stream #0.19[0x98]: Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s
Program 4287
Metadata:
service_name : BBC TWO
service_provider:
Stream #0.54[0xc9]: Video: mpeg2video (Main), yuv420p, 704x576 [PAR 16:11 DAR 16:9], 15000 kb/s, 43.27 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0.31[0xca](eng): Audio: mp2, 48000 Hz, stereo, s16, 256 kb/s
Stream #0.70[0xce](eng): Audio: mp2, 48000 Hz, mono, s16, 64 kb/s (visual impaired)
Stream #0.71[0xcd](eng): Subtitle: dvbsub
Program 4288
Metadata:
service_name : BBC THREE
service_provider:
Program 4352
Metadata:
service_name : BBC NEWS
service_provider:
Stream #0.40[0x1f5]: Video: mpeg2video (Main), yuv420p, 704x576 [PAR 16:11 DAR 16:9], 15000 kb/s, 67.19 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0.63[0x1f6](eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s
Stream #0.64[0x1f9](eng): Subtitle: dvbsub
Program 4416
Metadata:
service_name : BBC Red Button
service_provider:
Program 4544
Metadata:
service_name : BBC FOUR
service_provider:
Program 4608
Metadata:
service_name : CBBC
service_provider:
Stream #0.14[0x12d]: Video: mpeg2video (Main), yuv420p, 704x576 [PAR 16:11 DAR 16:9], 15000 kb/s, 37.90 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0.48[0x12e](eng): Audio: mp2, 48000 Hz, stereo, s16, 256 kb/s
Stream #0.49[0x132](eng): Audio: mp2, 48000 Hz, mono, s16, 64 kb/s (visual impaired)
Stream #0.50[0x131](eng): Subtitle: dvbsub
Program 4672
Metadata:
service_name : CBeebies
service_provider:
Stream #0.8[0x191]: Video: mpeg2video (Main), yuv420p, 704x576 [PAR 16:11 DAR 16:9], 15000 kb/s, 41.30 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0.25[0x192](eng): Audio: mp2, 48000 Hz, stereo, s16, 256 kb/s
Stream #0.26[0x196](eng): Audio: mp3, 0 channels (visual impaired)
Stream #0.27[0x195](eng): Subtitle: dvbsub
Program 4736
Metadata:
service_name : BBC Parliament
service_provider:
Stream #0.0[0x259]: Video: mpeg2video (Main), yuv420p, 544x576 [PAR 32:17 DAR 16:9], 15000 kb/s, 68.42 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0.1[0x25a](eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s
Stream #0.2[0x25d](eng): Subtitle: dvbsub
Program 5632
Metadata:
service_name : BBC R5L
service_provider:
Stream #0.66[0x57a](eng): Audio: mp2, 48000 Hz, mono, s16, 96 kb/s
Program 5696
Metadata:
service_name : BBC R5SX
service_provider:
Stream #0.58[0x5de](eng): Audio: mp2, 48000 Hz, mono, s16, 96 kb/s
Program 5760
Metadata:
service_name : BBC 6 Music
service_provider:
Stream #0.43[0x642](eng): Audio: mp2, 48000 Hz, stereo, s16, 160 kb/s
Program 5824
Metadata:
service_name : BBC Radio 4 Ex
service_provider:
Stream #0.68[0x6a6](eng): Audio: mp2, 48000 Hz, stereo, s16, 160 kb/s
Program 5888
Metadata:
service_name : BBC R1X
service_provider:
Stream #0.55[0x70a](eng): Audio: mp2, 48000 Hz, stereo, s16, 160 kb/s
Program 5952
Metadata:
service_name : BBC Asian Net.
service_provider:
Stream #0.9[0x76e](eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s
Program 6016
Metadata:
service_name : BBC World Sv.
service_provider:
Stream #0.24[0x7d2](eng): Audio: mp2, 48000 Hz, mono, s16, 96 kb/s
Program 6720
Metadata:
service_name : BBC Radio 1
service_provider:
Stream #0.38[0x3ea](eng): Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
Program 6784
Metadata:
service_name : BBC Radio 2
service_provider:
Stream #0.46[0x44e](eng): Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
Program 6848
Metadata:
service_name : BBC Radio 3
service_provider:
Stream #0.12[0x4b2](eng): Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
Program 6912
Metadata:
service_name : BBC Radio 4
service_provider:
Stream #0.23[0x516](eng): Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
Program 7168
Metadata:
service_name : BBC RB 1
service_provider:
Stream #0.35[0x385]: Video: mpeg2video (Main), yuv420p, 544x576 [PAR 32:17 DAR 16:9], 15000 kb/s, 37.86 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0.34[0x3b7](eng): Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
Stream #0.41[0x3b8](und): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s

[Dave2002]

That looks interesting. The avprobe tool seems versatile, but does it need a direct connection to the digital data stream? Probably!

Not quite sure how to do that - not with my current kit anyway. Some of those USB TV tuner dongles might do the job, or an external TV tuner, but I'm not sure how one could do satellite streams. I used to have TV tuner devices which could link to PCs.

http://libav.org/avprobe.html

[Andrew Slater]

It's quite involved - I have a USB receiver linked in to some software which allows it to be tuned to a particular multiplex. What I did was record a few seconds of the whole multiplex and then used avprobe to give some stats on it.

There are satellite USB tuners on the market, I believe, which can be read using similar software.

Avconv allows the streams to be split out and saved as individual mp2 files (for audio) and mpg files (for video/audio). I do most of my recording this way - I can record many hours of one or more channels simultaneously!

[AuntDaisy]

Gr-r-r--there go, my heart's abhorrence! Sometimes, I hate the BBC and their arrogance - they've b#ggered up the radio streams again.

We live in an area with terrible FM & DAB reception and, since Sounds is utter drivel, Internet radio is the only real option for R3 listening (e.g. TTN, EMS, Lunchtime concert, COTW).
Anyway, HLS streams that used to work on a variety of devices now don't - Auntie changed them around midday.

If you have the same problem, try this webpage for the updated stream URLs - and pray they work for a while

P.S. HD Radio 3 is now http://as-hls-ww-live.akamaized.net/....norewind.m3u8
P.P.S. Not sure if this is the correct thread to moan on - please move if needed.