diff options
Diffstat (limited to 'config/mpv/scripts/subs2srs/utils/base64.lua')
| -rw-r--r-- | config/mpv/scripts/subs2srs/utils/base64.lua | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/config/mpv/scripts/subs2srs/utils/base64.lua b/config/mpv/scripts/subs2srs/utils/base64.lua new file mode 100644 index 0000000..0fe2d06 --- /dev/null +++ b/config/mpv/scripts/subs2srs/utils/base64.lua @@ -0,0 +1,46 @@ +--[[ +Copyright: Ren Tatsumoto and contributors +License: GNU GPL, version 3 or later; http://www.gnu.org/licenses/gpl.html + +Encoding and decoding in base64 +]] + +-- http://lua-users.org/wiki/BaseSixtyFour + +-- character table string +local b = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/' + +-- encoding +local function enc(data) + return ((data:gsub('.', function(x) + local r,b='',x:byte() + for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end + return r; + end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x) + if (#x < 6) then return '' end + local c=0 + for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end + return b:sub(c+1,c+1) + end)..({ '', '==', '=' })[#data%3+1]) +end + +-- decoding +local function dec(data) + data = string.gsub(data, '[^'..b..'=]', '') + return (data:gsub('.', function(x) + if (x == '=') then return '' end + local r,f='',(b:find(x)-1) + for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end + return r; + end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x) + if (#x ~= 8) then return '' end + local c=0 + for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(8-i) or 0) end + return string.char(c) + end)) +end + +return { + enc = enc, + dec = dec, +} |
