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| author | Stefano Sabatini <stefasab@gmail.com> | 2013-01-23 12:06:41 +0100 |
|---|---|---|
| committer | Stefano Sabatini <stefasab@gmail.com> | 2013-01-24 12:26:21 +0100 |
| commit | c89a8ee23d7cc4c0f550cadd9a0b339b0aa977ef (patch) | |
| tree | 1122ff57c1b58b55a11ae070eb6a329fcc9ade8c /doc/eval.texi | |
| parent | ca1bc188f4e7ebd84f6446368946eec7a6014dc5 (diff) | |
| download | ffmpeg-c89a8ee23d7cc4c0f550cadd9a0b339b0aa977ef.tar.gz | |
doc/eval: fix/review the section about SI prefixes and usage
In particular, prefer "prefix" to "postfix" as in the tool manuals, and
specify powers of 2 and 10 explicitly.
This is based on the commit:
commit 2bf794b69820273e2284d69e9b9c98f5b7136add
Author: Marcus Stollsteimer <sto.mar@web.de>
Date: Mon Nov 19 21:39:20 2012 +0100
Diffstat (limited to 'doc/eval.texi')
| -rw-r--r-- | doc/eval.texi | 55 |
1 files changed, 28 insertions, 27 deletions
diff --git a/doc/eval.texi b/doc/eval.texi index 5769e0d1ba..f77b87deac 100644 --- a/doc/eval.texi +++ b/doc/eval.texi @@ -209,55 +209,56 @@ In your C code, you can extend the list of unary and binary functions, and define recognized constants, so that they are available for your expressions. -The evaluator also recognizes the International System number -postfixes. If 'i' is appended after the postfix, powers of 2 are used -instead of powers of 10. The 'B' postfix multiplies the value for 8, -and can be appended after another postfix or used alone. This allows -using for example 'KB', 'MiB', 'G' and 'B' as postfix. - -Follows the list of available International System postfixes, with +The evaluator also recognizes the International System unit prefixes. +If 'i' is appended after the prefix, binary prefixes are used, which +are based on powers of 1024 instead of powers of 1000. +The 'B' postfix multiplies the value by 8, and can be appended after a +unit prefix or used alone. This allows using for example 'KB', 'MiB', +'G' and 'B' as number postfix. + +The list of available International System prefixes follows, with indication of the corresponding powers of 10 and of 2. @table @option @item y --24 / -80 +10^-24 / 2^-80 @item z --21 / -70 +10^-21 / 2^-70 @item a --18 / -60 +10^-18 / 2^-60 @item f --15 / -50 +10^-15 / 2^-50 @item p --12 / -40 +10^-12 / 2^-40 @item n --9 / -30 +10^-9 / 2^-30 @item u --6 / -20 +10^-6 / 2^-20 @item m --3 / -10 +10^-3 / 2^-10 @item c --2 +10^-2 @item d --1 +10^-1 @item h -2 +10^2 @item k -3 / 10 +10^3 / 2^10 @item K -3 / 10 +10^3 / 2^10 @item M -6 / 20 +10^6 / 2^20 @item G -9 / 30 +10^9 / 2^30 @item T -12 / 40 +10^12 / 2^40 @item P -15 / 40 +10^15 / 2^40 @item E -18 / 50 +10^18 / 2^50 @item Z -21 / 60 +10^21 / 2^60 @item Y -24 / 70 +10^24 / 2^70 @end table @c man end |