[BC] Does a Glut of New Signals Mean More Revenue?

[Dana Puopolo]

I meant MPEG-2 as in MP4 or AAC.

OR as in here:

http://en.wikipedia.org/wiki/MPEG-2

-D

------ Original Message ------
Received: Sun, 27 Aug 2006 01:40:30 AM EDT
From: Peter Smerdon <psmerdon at fastmail.com.au>
To: "Broadcasters' Mailing List" <broadcast at radiolists.net>
Subject: Re: [BC] Does a Glut of New Signals Mean More Revenue?

Dana,

They are two different algorithms (codecs) for different applications.

MPEG2 (I'm assuming you mean MPEG-1 Layer 2) was developed a l-o-n-g 
time ago for use with relatively high bitrates.
It is regarded as "imperceptible" at 256kbps (tho' some say 192kbps is 
fine).
Conventional wisdom is that "MP1-LII" is not suited to low bitrate use - 
and a lot of testing by European broadcast authorities confirms this.
MP1-L11 is used in Eureka 147 - "EuroDAB" and the UK has a lot of DAB 
stations at 128kbps (and lower!) and there are a lot of complaints about 
artifacts from the enthusiasts.

HD Radio uses a totally different algorithm (codec) - ISTR it's now a 
close cousin of AAC (remember I'm in Australia - so I'm not dealing with 
this stuff day-to-day).
AAC is much newer, and was designed for the much lower bitrates. I 
recall its "sweet spot" is between 96 and 64 kbps (but I'm open to 
correction on this).

AAC will always sound MUCH MUCH better at 48kbps than MP1-LII.
Though there are variables to take into account, like the quality of the 
encoder code. I've heard MP1-LII mono audio at 64kbps go from "not good 
enough for cueing purposes" to "good enough to put to air" (for 3 mins 
on AM)with a firmware upgrade to a particular ISDN codec.

Cheers,

Peter Smerdon.

Dana Puopolo wrote:
> I'm using a 57 kbit mono MPEG2 stream for an STL. What I can't understand
is
> that some here who have heard it say it's barely usable for AM, yet these
same
> people claim that 48 kbit stereo IBOC sounds great.
> 
> The numbers simply don't make sense.
> 
> -D
> 


-- 
=============================
Peter Smerdon.

Radio 3mp - Easy Listening
sen-1116  - Let's Talk Sport

Melbourne, Australia.
=============================
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