[peel] Re: FLAC it is then!

[Alasdair Macdonald]

FM radio has a carrier signal at 19kHz and certainly has it's own
limitations. But those limitations don't exactly correspond to the
limitations and artifacts of mp3 encoding.

And even if you have a lower quality source, this is not an argument
for transferring such material to low-quality media or format. Do
record companies sell 1930's blues records on the cheapest quality
cassettes, because the source material is on noisey, degraded vinyl,
and it doesn't really matter, or do they sell such material on CD and
ensure that the product is as close to the original sound as possible?
You could say that low-quality source material demands a *higher*
quality copying process.

DAB, Freeview and Satellite broadcast bitrates can vary, even for the
same broadcaster / channel. But to take one example, that of BBC 6
Music, which is not available via any non-digital source, this is
broadcast at a bitrate of 160kbps via Freeview, 160kbps via Sky
Satellite, and I don't know the online bitrate.

Freeview and Satellite broadcasts are usually mp2 by the way, not sure
about DAB. The exception is some Dolby Digital broadcasts (5.1), which
I am only aware of on Sky film channels and some BBC HD programming.
5.1 is 385kbps and this is of course the same quality as you'd
typically get on a commercial DVD with 5.1 sound.

Let's take another example - XFM radio. This *is* available via FM,
although I am told that it is a low quality / compressed (in dynamic
range) signal. The bitrate for their Sky Satellite broadcasts is
128kbps, and I rather suspect that they have a poor quality encoder,
because it sounds really rather poor.

TV audio bitrates vary too. BBC channels at 256k (although the red
button stuff is 128k via Satellite, 192 via Freeview IIRC). ITV
channels have lower audio bitrates, 192 IIRC, and lower video bitrates
too. And anyone that has ever tuned in to Euronews will know how awful
their audio can be.

The fact of the matter is that many people can distinguish mp3 sources
from uncompressed digital sources even up to quite high bitrates.
Personally, I am aware that my hearing has degraded in particular over
the past couple of years as a consequence of an ear infection and
tinnitus. But I can still hear artifacts in all commercial broadcasts
below 256kbps. From the comments that have been posted to this list,
it's evident that a number of people here have hearing that is just as
degraded, and worse. But it's really rather important, when
circulating audio material to others, to consider *their* hearing
abilities, and not your own.

ogg is (technically) better than mp3, the reason that mp3 is popular
is because it got in there first, and hardware players were created to
use this new standard. Subsequent models and generations of players
have kept the name and technical specs, although many mp3 players will
play ogg. Certainly both of mine do.

Alasdair

On 29/11/2007, thebarguest <thebarguest@...> wrote:
> Yes, the point about the source is crucial. I think I read
> somewhere that radio FM was/is broadcast at a frequency range
> equivalent to about 128kbps (or was it 192); obviously therefore,
> encoding at rates higher than this is simply a waste of space ....
> Also, I heard recently that the soon-to-be-compulsory digital
> broadcasts are of a lower audio quality than existing FM - anyone
> for anti-progress / devolution ?
>
>
> --- In peel@yahoogroups.com, Roger Carruthers <roger.carruthers@...>
> wrote:
> >
> > Fwiw, there is also Apple¹s Lossless encoder that ships with
> > QuickTime/iTunes, and which definitely can be played Œon the fly¹,
> ie. you
> > don¹t have to decompress it first, but can play it as it is...
> >  But I repeat my earlier point, if your source is not a good one
> eg. a good
> > FM source onto R2R, DAT or possibly MD*, then you¹ve not much to
> lose by
> > using a decent quality lossy encoder (.mp3, .ogg etc.) with which
> you will
> > get a much better file size reduction.
> > Cheers
> > Roger
> >
> > *if we¹re really into splitting hairs, MD uses ATRAC compression,
> which is
> > lossy, so although it sounds pretty good, it¹s already lost
> something, even
> > if you make a digital copy...