DB wrote:
"spiney" wrote in message
oups.com...
Mark Carver is wrong, both DTT and DAB use identical MP3 sound coding
(MP3 is the audio subset standard of MPEG2!).

No, you're wrong. DTT and DAB use MPEG1 layer 2 (aka MP2), which is a
broadcast standard. MP3 is correctly known as MPEG1 layer 3.

or MPEG2 layer3, or I suppose MPEG4 layer3...

Alex Bird wrote:
DB wrote:
"spiney" wrote in message
oups.com...
Mark Carver is wrong, both DTT and DAB use identical MP3 sound
coding (MP3 is the audio subset standard of MPEG2!).

No, you're wrong. DTT and DAB use MPEG1 layer 2 (aka MP2), which is a
broadcast standard. MP3 is correctly known as MPEG1 layer 3.

or MPEG2 layer3, or I suppose MPEG4 layer3...


MPEG-1 defined the most used sampling frequencies such as 44.1, 48, 32
kHz. MPEG-2 added lower sampling frequencies.

MPEG-4 Layer 3 doesn't exist. MPEG-4 audio consists of AAC and HE AAC
and a few ultra-low bit rate speech codecs and such like.

This site has a lot of good info on audio codecs:

http://www.audiocoding.com/modules/wiki/


--
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DAB sounds worse than FM wrote:

MPEG-4 Layer 3 doesn't exist. MPEG-4 audio consists of AAC and HE AAC
and a few ultra-low bit rate speech codecs and such like.

Maybe in a strict MPEG4 program stream, but almost all MPEG4 use -
perhaps being overtaken by mobile phones - is in avi files which have
layer 3 audio. I tend to call that MPEG4Layer3..

Alex

Alex Bird wrote:
DAB sounds worse than FM wrote:

MPEG-4 Layer 3 doesn't exist. MPEG-4 audio consists of AAC and HE AAC
and a few ultra-low bit rate speech codecs and such like.

Maybe in a strict MPEG4 program stream, but almost all MPEG4 use -
perhaps being overtaken by mobile phones - is in avi files which have
layer 3 audio.


They don't have to use MP3.


I tend to call that MPEG4Layer3..


Look at:

http://en.wikipedia.org/wiki/MP3

The name is derived from "MPEG-1 Audio Layer 3," more formally known as
"MPEG-1 Part 3 Layer 3" or "ISO/IEC 11172-3 Layer 3". Reportedly, the
".mp3" filename extension is also sometimes used on audio files encoded
using the newer "MPEG-2 Audio Layer 3" standard (a.k.a. "MPEG-2 Part 3
Layer 3" or "ISO/IEC 13818-3 Layer 3").

MPEG-4 Layer 3 is just mixing up different standards and it's incorect.

A lot of people refer to MP3 as MPEG-3, but here's what MPEG-3 is:

http://en.wikipedia.org/wiki/MPEG-3

You might think it's pedantic, but there is no such thing as MPEG-4
Layer 3. MPEG-4 uses 'Parts':

http://en.wikipedia.org/wiki/MPEG-4

e.g. MPEG-4 Part 10 is the new H.264 video codec.

Here's the audio part of MPEG-4:

http://en.wikipedia.org/wiki/MPEG-4_Part_3



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

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depends what u like. mpeg has variable bitrate coding, and other
"artifacts", whereas fm broadcasting uses heavy compression instead
(Optimod, last I heard). There's no such thing as "neutral sound
quality".

depends what u like. mpeg has variable bitrate coding, and other
"artifacts", whereas fm broadcasting uses heavy compression instead
(Optimod, last I heard). There's no such thing as "neutral sound
quality".

apology, a typo by me!

mpeg2 audio is used identically in DAB and DTT , at level 2.

MPEG 3 usually means "mpeg level 3 audio", ie the surround format.

mp3 is the consumer (ipod) sound format.

In article .com,
spiney writes
Mark Carver is wrong, both DTT and DAB use identical MP3 sound coding
(MP3 is the audio subset standard of MPEG2!).


Poor old Mark, after all what does he know after working more years than
I can remember in professional broadcast engineering;?.......
--
Tony Sayer

In article . com,
spiney writes
depends what u like. mpeg has variable bitrate coding, and other
"artifacts", whereas fm broadcasting uses heavy compression instead
(Optimod, last I heard). There's no such thing as "neutral sound
quality".


FM can and does use "Optimods" or more correctly multiband compression
but how that unit is set up and applied is another matter.

FM can sound as \\good\\ as CD if you want it too. I've been able to
demonstrate this with a Harris digital exciter and Audiolab tuner in a
direct off air comparison and only One person out of a group of Six
noticed any differences and these were on very long sustained low level
piano pieces.

Very few people get to hear what FM can be capable of....
--
Tony Sayer

spiney wrote:
apology, a typo by me!

mpeg2 audio is used identically in DAB and DTT , at level 2.


Layer 2, not level 2.


MPEG 3 usually means "mpeg level 3 audio", ie the surround format.


MPEG-3 doesn't exist. They did mean to move from MPEG-2 to MPEG-3 for
HDTV but then decided that MPEG-2 had all the necessary tools, so they
dropped the idea of MPEG-3. So they went straight from MPEG-2 to MPEG-4.

MPEG Level [sic] 3 audio does not exist either, in surround sound or
2-channel.

You're just getting everything wrong.


mp3 is the consumer (ipod) sound format.


I suggest that when you're in a hole, stop digging. You'll be in
Australia soon the way you're going.


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

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