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Topic: UK DAB digital radio sinks to a new low (Read 23696 times) previous topic - next topic
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UK DAB digital radio sinks to a new low

Reply #25 –
It doesn't sound like 64kbps. 64kbps actually sounds decent. What I heard was absolutely terrible. It really, and truly sounded like a 24/32k stream, much like di.fm's 24k stream.

UK DAB digital radio sinks to a new low

Reply #26 –
64kbps HE-AAC should sound better than 128kbps mp2, though neither is really transparent so it could depend what artefacts annoy you most.

If 64kbps HE-AAC sounds really bad, then the feed into the encoder is probably really bad!

Cheers,
David.

UK DAB digital radio sinks to a new low

Reply #27 –
Well, I'm very sympathetic.  In years of working on coding, I've found that that which is good at 256 kb/s (for stereo) gets used at 128. That which is good at 160kb/s gets used at 96. That which is (barely) good at 128 gets used at 48...

And so on.

And to think the number of times that people told me "in 5 years nobody will need to do any coding".
-----
J. D. (jj) Johnston

UK DAB digital radio sinks to a new low

Reply #28 –
I recorded some radio on my Humax PVR9200T  last night. The Humax lets me transfer the TS (transport stream) file, via USB, to my laptop, which I then load into ProjectX to demux the stream(s).

Here's the results, extrapolated from the ProjectX log:

Code: [Select]
BBC Radio 1              MPEG-1, Layer2, 48000Hz, stereo, 192kbps
BBC 1Xtra                MPEG-1, Layer2, 48000Hz, jstereo, 160kbps
BBC Radio 2              MPEG-1, Layer2, 48000Hz, stereo, 192kbps
BBC Radio 3              MPEG-1, Layer2, 48000Hz, stereo, 192kbps
BBC Radio 4              MPEG-1, Layer2, 48000Hz, stereo, 192kbps
BBC Radio 5 Live         MPEG-1, Layer2, 48000Hz, mono, 96kbps
BBC Radio 5 Live Sport   MPEG-1, Layer2, 48000Hz, mono, 96kbps
BBC 6 Music              MPEG-1, Layer2, 48000Hz, jstereo, 160kbps
BBC 7                    MPEG-1, Layer2, 48000Hz, jstereo, 160kbps
BBC World Service        MPEG-1, Layer2, 48000Hz, mono, 64kbps

Files were recorded between 19:07 and 19:45 last night.
I'm on a horse.

UK DAB digital radio sinks to a new low

Reply #29 –
A bit off topic, but in the Beeb's defence and for Radio 3 in particular, their website is broadcasting the complete works of Tchaikovsky and Stravinsky this week. With content like that, even the shortcomings of 32kbps RealAudio can be overlooked! (at least, sound quality becomes less of an issue until regular programming resumes) I've been busy time-shifting it all for listening later at leisure.

UK DAB digital radio sinks to a new low

Reply #30 –
Quote from: Synthetic Soul on
I recorded some radio on my Humax PVR9200T  last night.


Having searched for the PVR9200T, listed as a Freeview set-top-box with 160GB hard disc, am I right in assuming that those bitrates refer to the radio channels as broadcast on Freeview (the UK's terrestrial digital TV service) in the South West, rather than another digital TV service such as cable or satellite.

If it is, that's hopeful for reasonable quality (about as good as FM) for the most popular channels all at 192 kbps full stereo.

Incidentally, does anyone have any idea what audio bitrate is used for the major terrestrial TV (video)channels - presumably also MPEG-1 layer II stereo audio alongside MPEG-2 video?
Dynamic – the artist formerly known as DickD

UK DAB digital radio sinks to a new low

Reply #31 –
Quote from: Dynamic on
Having searched for the PVR9200T, listed as a Freeview set-top-box with 160GB hard disc, am I right in assuming that those bitrates refer to the radio channels as broadcast on Freeview (the UK's terrestrial digital TV service) in the South West, rather than another digital TV service such as cable or satellite.
Correct on all accounts.

Quote from: Dynamic on
Incidentally, does anyone have any idea what audio bitrate is used for the major terrestrial TV (video)channels - presumably also MPEG-1 layer II stereo audio alongside MPEG-2 video?
I tend to mainly take films from Film4 off onto the laptop.  I have just checked a few and they are all MPEG-1, Layer2, 48000Hz, stereo, 160kbps.  I did have one stream a while back that had two audio streams, but can't remember the bitrates.
I'm on a horse.

UK DAB digital radio sinks to a new low

Reply #32 –
BBC1/2/3/CBBC/4/CBeebies (TV) audio on Freeview and satellite is 256kbps mp2 stereo.

Freeview audio and video bitrates are listed here:
http://www.aums30.dsl.pipex.com/home.htm

The various digital radio bitrates on DAB and the digital TV platforms are listed here:
http://www.digitalradiotech.co.uk/dab/digi...o_bit_rates.htm

There are some strange (stupid!) encoder settings in use on some services, and some transcoding going on too - you need to listen to find out which sounds best, rather than just trust the bitrate as an indicator of quality (though I think HA regulars will know that  ).

BBC Radio 3 @ 192kbps mp2 on DAB is still the highest quality broadcast of any BBC Radio station. The IP multicasts may be 128kbps AAC, but they're transcoded at present.

The 256kbps TV audio is generally higher quality than all the radio stations (though I suspect there's still transcoding), and of course the 320kbps you can receive in the UK from German radio stations via satellite is much better still (and nothing to do with the BBC!).

Cheers,
David.

UK DAB digital radio sinks to a new low

Reply #33 –
Ah, looks like I should have looked around a little first.

Thanks for the tables 2Bdecided, very useful.  As someone who burns to DVD the resolution is of particular interest also.
I'm on a horse.

UK DAB digital radio sinks to a new low

Reply #34 –
Quote from: 2Bdecided on
BBC Radio 3 @ 192kbps mp2 on DAB is still the highest quality broadcast of any BBC Radio station. The IP multicasts may be 128kbps AAC, but they're transcoded at present.

Are you sure? BBC 3 at nighttime is streamed through the Norwegian 'NRK Alltid Klassisk' as Ogg Vorbis @ vbr 172 kbps, which should be noticable better. Are you saying this is transcoded from mp2@192? Btw, all national channels in Norway are streamed as ogg 172.
 

UK DAB digital radio sinks to a new low

Reply #35 –
Quote from: tycho on
BBC 3 at nighttime is streamed through the Norwegian 'NRK Alltid Klassisk' as Ogg Vorbis @ vbr 172 kbps, which should be noticable better. Are you saying this is transcoded from mp2@192?


No, I wasn't aware of that broadcast.

If it is sourced from Radio 3, I have no idea how it's sent over to Norway for broadcast.

Quote
Btw, all national channels in Norway are streamed as ogg 172


Nice!

Cheers,
David.