[MPlayer-users] Re: units: KB, KiB, KBit/s, MB, MiB, MBit/s, ... (was:)chopping off credits

[zimon@iki.fi]

On Wed, Aug 27, 2003 at 09:58:04AM +0200, Bill Eldridge wrote:
> D Richard Felker III wrote:
> >On Tue, Aug 26, 2003 at 01:24:07AM -0400, Matthew W. Miller wrote:
> >>On Tue, Aug 26, 2003 at 12:27:39AM -0400, D Richard Felker III wrote:
> >>>On Mon, Aug 25, 2003 at 10:26:51PM -0500, Jonathan Rogers wrote:
> >>>>... 700-800MiB CD-R ... mebibyte ...
> >>>Are you just using these ridiculous-sounding units to annoy people, or
> >>>to try to "convert" people, or what?
> >>They are perfectly standard and not ridiculous.
> >>http://physics.nist.gov/cuu/Units/binary.html
> >I'm quite aware. Many standards are ridiculous.
> So is being off by 7% because someone thought Gigabit included those 
> miniscule little bits

Interesting note is, that one of the reasons why KiB, MiB, GiB, TiB were
"invented" is that the error will increase when we use bigger and bigger
amounts of memory, bits, bytes.

Maybe couple of years ago it was not a problem, but now as soon we will
have TB harddisks, GiB physical memories and MiBit/s cables it is becoming 
more important or there WILL BE confusing errors when different people
mean different things with their units.

In < http://www.iec.ch/online_news/etech/arch_2003/etech_0503/focus.htm >
"
The problem is that, even at the SI tera-scale (1012), the discrepancy 
with the binary equivalent is not the 2,4 percent at kilo-scale but rather
approaching 10 percent. At exa-scale, it is nearer 20 percent.
The niceties of mathematics dictate that the bigger the number of bytes,
the bigger the differential, so the inaccuracies - for engineers,
marketing staff and public alike - are set to grow more and more
significant. This is one good reason for the IEC to have standardized 
prefixes for binary multiples.
"

After 10 years from now, when someone is reading these historical notes about
us talking about MPlayer, they may get confused what exactly we meant by
bitrates and storage sizes of media files. 

I have known these units before, but until now haven't really paid attention
although for example when partitioning 120GB harddisk the problem came front
just couple of months ago. 

MPlayer man page talks quite much about bitrates. 
vbitrate=800 means 800 kBit/s = 800 000 Bit/s. But because potential
confusion, it has "(warning: 1kBit = 1000 Bits)" in there.

Pop quiz: One minute of raw video at 800 Kbit/s will take X amount of memory
when stored in raw format? X is...
a) 6.00 MB
b) 6.00 MiB
c) 5.72 MB
d) 5.72 MiB
Or how long it will take to send one hour through DSL cable when ISP only 
tells the capacity is "1M".