DAB vs MP3 : has anyone tested Ligiti's ATMOSPHERES (it ha..

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"DAB sounds worse than FM" <me@privacy.net> schreef in bericht
news:zlufd.1448$fq6.376@newsfe1-gui.ntli.net...
> They use "companding" (COMpression - exPANDING), see section 3.2 on
> here:
>
> http://tallyho.bc.nu/~steve/nicam.html
>
> so it gets the performance of almost 14-bit linear PCM with 10-bits per
> sample.

Okay, that's even better. Pity its replacement is not as good. (Digital TV
with Mp2 sound)

gr, hwh

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Brian Gregory [UK] wrote:
> "DAB sounds worse than FM" <me@privacy.net> wrote in message
> news:zlufd.1448$fq6.376@newsfe1-gui.ntli.net...
>> They use "companding" (COMpression - exPANDING), see section 3.2 on
>> here: http://tallyho.bc.nu/~steve/nicam.html
>>
>
> I don't see anything one would normally call compression or expanding
> in that description.
>
> While Companding may be what the C in NICAM stands for it doesn't
> give much of a clue as to what is actually happening.
>
> It's more along the lines of using a 10 bit floating point number
> instead of a 14 bit integer


Encoding something that takes 14-bits with 10-bits results in
compression, and the reverse of this is called expansion. Combine
COMpression with exPANDING and you get companding.

The plain old telephone system (POTS) uses companding as well. Who'd
have thought it, the old dog and bone using compression? But it does:
A-law companding:

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


>> so it gets the performance of almost 14-bit linear PCM with 10-bits
>> per sample.
>
> That's true though.


Think about the definition of "compression".


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

DAB sounds worse than FM, Freeview, digital satellite, cable and
broadband internet radio

Archived from groups: alt.radio.digital,alt.video.digital-tv (More info?)

Brian Gregory [UK] wrote:
> "DAB sounds worse than FM" <me@privacy.net> wrote in message
> news:hxzfd.1527$fq6.553@newsfe1-gui.ntli.net...
>> Encoding something that takes 14-bits with 10-bits results in
>> compression, and the reverse of this is called expansion. Combine
>> COMpression with exPANDING and you get companding.
>
> But the Expansion takes place as part of the decoding. It's not part
> of the encoding process.


I didn't say it was. But what's the difference between this and MPEG
audio? It's compressed at the broadcaster's end, and expanded (from,
say, 192kbps up to 16-bit linear PCM) at the decoder.

NICAM does use compression.


> If you include what happens when decoding any distribution system for
> compressed audio such as DAB, DVB-T, or MP3 files could be described
> as using companding because the are all expanded again during the
> decoding or playing process.


Indeed, and I don't know why, say, MPEG audio is called "compressed
audio" while NICAM and telephone signals are described as being
"companded", but, ultimately, no matter what you call it, they both use
compression.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

DAB sounds worse than FM, Freeview, digital satellite, cable and
broadband internet radio

Archived from groups: alt.radio.digital,alt.video.digital-tv (More info?)

Doug McDonald wrote:
> A question: has anybody responded to the ORIGINAL
> question? The one in the subject line?


No.

BTW Doug, did you read October's EBU Technical Review Editorial? I
suggest you sot down with a glass of moonshine prior to reading the
following paragraph:

http://www.ebu.ch/trev_300-editorial.html

"Much attention at IBC 2004 in Amsterdam was focussed on handheld
devices displaying TV-like services but, for me, one of the best
exhibits at IBC 2004 involved DVB-T reception on a lap-top computer:
reception of the Dutch DVB-T services was "rock solid" even when I waved
the lap-top above my head during one of the sessions. I must admit that
this prompted me to say "Eat your hearts out, ATSC!" because we know
that our friends in ATSC simply cannot match that level of performance."

BTW, if Bush wins, all Americans are banned from this newsgroup with
immediate effect.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

DAB sounds worse than FM, Freeview, digital satellite, cable and
broadband internet radio

Archived from groups: alt.radio.digital,alt.video.digital-tv (More info?)

Doug McDonald wrote:
> DAB sounds worse than FM wrote:
>
>>
>> "Much attention at IBC 2004 in Amsterdam was focussed on handheld
>> devices displaying TV-like services but, for me, one of the best
>> exhibits at IBC 2004 involved DVB-T reception on a lap-top computer:
>> reception of the Dutch DVB-T services was "rock solid" even when I
>> waved the lap-top above my head during one of the sessions. I must
>> admit that this prompted me to say "Eat your hearts out, ATSC!"
>> because we know that our friends in ATSC simply cannot match that
>> level of performance."
>
>
> Performance? I didn't know that Holland was transmitting HDTV!!!
>
> Performance .... what performance?????
>
> How big was the laptop screen? HDTV on a laptop? You'd
> need really good eyes to see it!!


Oh hello, Doug's having one of his episodes again.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

DAB sounds worse than FM, Freeview, digital satellite, cable and
broadband internet radio