[vorbis] Ogg Vorbis and Bitrate

[Marshall Eubanks]

Jay Sprenkle wrote:

> Ugh! What I wanted to know was why
> byte measurements are in powers of 2, when every other usage
> of the same word refers to powers of 10? To use your own argument,
> The greeks standardized the usage of kilo more than a thousand years
> ago.
> "If it works, why fix it?" So why did someone in 1900's feel the need
> to redefine "kilo" but only as applies to bytes? What they did was,
> again using your own words, "really cause confusion" by changing the
> definition arbitrarily and inconsistantly.
>
> Jonathon Fowler wrote:
> >
> > Bit-measurements have always been expressed as powers of 10 (ie. kilobit
> >   == 1000 bit, megabit == 1000000 bit, etc). Byte-measurements have
> > always been expressed as powers of 2 (ie. kilobyte == 1024 bytes,
> > megabyte == 1048576 bytes). It would be best to pick a convention and
> > stick to it regardless of whether it's right or wrong otherwise there
> > really will be confusion. Just look at the US and British
> > interpretations of a "billion" dollars. A billion dollars US is a
> > thousand-million dollars (usually) British. Frankly, if it works, why
> > fix it.
> >
> > Jonathon
> >
> > Jay Sprenkle wrote:
> >
> > >>On Sun, Sep 09, 2001 at 04:56:21PM -0400, Sterling Windmill wrote:
> > >>
> > >>>In Ogg Vorbis, does one kilobit equal 1000 bits, or 1024 bits?
> > >>>
> > >>Kilobit is 1000 bits
> > >>Kilobyte is 1024 bits
> > >>
> > >>Always (at least I really hope so!)
> > >>
> > >>
> > >
> > > I assume you had a typo above, and you meant:
> > >
> > > Kilobit is 1000 bits
> > > Kilobyte is 1024 BYTEs
> > >
> > > I've heard lots of discussion about it,
> > > but what I was taught in school was kilo
> > > was greek for 1000. In most usages "kilo XXX"
> > > means "1000 of XXX". In electronics terms
> > > I understand we use it collectively wrong
> > > from a linguistic accuracy point of view
> > > and define it as a power of 2, or 1024.
> > >
> > > I was not aware that anyone was defining
> > > it differently for bits vs bytes:
> > > kilo means 1000 for bits, 1024 for bytes.
> > >
> > > Who came up with that, and can we start
> > > stomping it out as quickly as possible?
> > > We really need more absurd inconsistant
> > > rules in the world.
> > >
> > > _________________________________________________________
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> > >
> > >
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> > >
> >
> > --
> > __________________________________________
> > After a number of decimal places, nobody gives a damn.
> >
> > Jonathon Fowler
> > jonof at edgenetwk.com - ICQ 17263235
> > http://jonof.edgenetwk.com/
> > __________________________________________
> > Edge Network: Gaming with an Edge!
> > http://www.edgenetwk.com/
> > http://www.edgegaming.com/
> >

<broken record mode>
Kilo is an SI (Systeme International == metric) prefix. It means 1000, properly, and nothing else.

HOWEVER

Early on in the days of computer memory, it was realized that memory is best
organized in powers of 2. I think that this dates back to the days when "core"
memory was little ferromagnetic cores (like a 0.1 mm donut) storing one bit
and 1024 of such guys was a lot. IBM standardized the "byte" notation
early on (much Internet stuff uses octet (1 octet == 1 byte)).

As memory has grown, it frequently uses the same structure as before, just shrunken and
replicated, literally doubling or more commonly quadrupling the previous memory.

So, a memory chip always has a power of 2 amount of storage.
A 1 megabyte chip therefore has 1024 x 1024 == 1048576 bytes on it. So, it was easy to
say, this is a 1 meg chip, not a 1.048 meg chip, especially since there are NO 1.000 x 10^6 byte chips.

This usage was well established when I got in the game in about 1972. I do not think that
you are going to change it.

Telecommunications NEVER uses this and rarely uses bytes - in telecom, 1 kilobit per second == 1000 bits per second.
So, you get into the shorthand where 8 kbps == 8 kilo bits per second == 8000 bits per second
but one kB = 1024 Bytes == 8192 bits (note the capitalization convention).

Yes, I have seen this cause problems, but there it is.
</broken record mode>

--
                                 Regards
                                 Marshall Eubanks

T.M. Eubanks
Multicast Technologies, Inc
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