Dim As String test_str = String(16777216,"a")

Dim As Single enc_tbeg, enc_tend
Dim As Single dec_tbeg, dec_tend
Dim As String to64 = ""
Dim As String from64 = ""

enc_tbeg = timer
to64 = Encode64(test_str)
enc_tend = timer
Print "Encode_TIME: " & enc_tend - enc_tbeg
Print "Encoded_STR: " &  Right(to64,45)
Print "Encoded_LEN: " &  Len(to64)
Print "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
dec_tbeg = timer
from64 = Decode64(to64)
dec_tend = timer
Print "Decode_TIME: " & dec_tend - dec_tbeg
Print "Decoded_STR: " & Right(from64,45)
Print "Decoded_LEN: " &  Len(from64)

Sleep

' encoder by Joshy (D.J.Peters)
Function enc_base64(ByRef bs64 As String) As String export
      Dim as Integer j,k=0
      Dim as Integer l=len(bs64)
      if l=0 then return ""
      dim as string arr64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" & _
                            "abcdefghijklmnopqrstuvwxyz" & _
                            "0123456789+/"
      Dim as string  t64

      t64 = String(((l+2)\3)*4,"=")
      For j = 0 To l - ((l Mod 3)+1) Step 3
        t64[k+0] = arr64[(bs64[j+0] shr 2)]
        t64[k+1] = arr64[(((bs64[j+0] and 3) shl 4) + (bs64[j+1] shr 4))]
        t64[k+2] = arr64[(((bs64[j+1] and &H0F) shl 2) + (bs64[j+2] shr 6))]
        t64[k+3] = arr64[(bs64[j+2] and &H3F)]
        k += 4
      Next
      If (l mod 3) = 2 Then
        t64[k+0] = arr64[(bs64[j+0] shr 2)]
        t64[k+1] = arr64[(((bs64[j+0] and 3) shl 4) + (bs64[j+1] shr 4))]
        t64[k+2] = arr64[(((bs64[j+1] and &H0F) shl 2) + (bs64[j+2] shr 6))]
        t64[k+3]=61
      ElseIf (l mod 3) = 1 Then
        t64[k+0] = arr64[(bs64[j+0] shr 2)]
        t64[k+1] = arr64[((((bs64[j+0] and 3) shl 4) + (bs64[j+1] shr 4)))]
        t64[k+2]=61
        t64[k+3]=61
      End If
      return t64
End Function

' decoder from EXT lib
function dec_base64(byval str_b64 as const String) As String export
       Dim As Integer sb64_len = Len(str_b64)
       If sb64_len < 4 Then Return ""
       Dim out_Str As String = String(((sb64_len \ 4) * 3), !"\0")
       static _decode_tbl(255) as ubyte => { _
       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, _              ' 0..31
       0,0,0,0,0,0,0,0,0,0,0, _                    ' 32..42
       62,0,0,0,63, _                    ' 43 (+), 44..46, 47 (/)
       52,53,54,55,56,57,58,59,60,61, _                    ' 48..57 (0..9)
       0,0,0,0,0,0,0, _                    ' 58..64
       0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25, _          ' 65..90 (A..Z)
       0,0,0,0,0,0, _                    ' 91..96
       26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,_ ' 97..122 (a..z)
       0,0,0,0,0 }                    ' 123..127

       Dim out_blen As Integer = 0
       for ctr64 as Integer = 0 to sb64_len - 1 Step 4
          dim as uinteger buf = (_decode_tbl(str_b64[ctr64+0]) shl 18) or _
                (_decode_tbl(str_b64[ctr64+1]) shl 12) or _
                (_decode_tbl(str_b64[ctr64+2]) shl  6) or _
                (_decode_tbl(str_b64[ctr64+3]))
          If str_b64[ctr64+2] = 61 And str_b64[ctr64+3] = 61 Then
             out_Str[out_blen+0] = buf shr 16
             out_blen += 1
             Exit for
          ElseIf str_b64[ctr64+2] <> 61 And str_b64[ctr64+3] = 61 Then
             out_Str[out_blen+0] = buf shr 16
             out_Str[out_blen+1] = (buf shr 8) and &hFF
             out_blen += 2
             Exit for
          EndIf
          out_Str[out_blen+0] = buf shr 16
          out_Str[out_blen+1] += (buf shr 8) and &hFF
          out_Str[out_blen+2] += buf and &hFF
          out_blen += 3
       Next
       Return Left(out_Str,out_blen)
end Function

'================= TEST BASE64 ==================================

Dim As String test_str = String(16777216,"a")

Dim As Single enc_tbeg, enc_tend
Dim As Single dec_tbeg, dec_tend
Dim As String to64 = ""
Dim As String from64 = ""

enc_tbeg = timer
to64 = enc_base64(test_str)
enc_tend = timer
Print "Encode_TIME: " & enc_tend - enc_tbeg
Print "Encoded_STR: " &  Right(to64,45)
Print "Encoded_LEN: " &  Len(to64)
Print "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
dec_tbeg = timer
from64 = dec_base64(to64)
dec_tend = timer
Print "Decode_TIME: " & dec_tend - dec_tbeg
Print "Decoded_STR: " & Right(from64,45)
Print "Decoded_LEN: " &  Len(from64)

Sleep

function dec_base64(str_b64 as String) As String export

function dec_base64(byval str_b64 as const String) As String export

Dim As String test_str = String(83886080,"a")

enc_base64(bs64 As Const String)
dec_base64(str_b64 as Const String)

Encode_TIME: 0.5029297
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Decode_TIME: 0.6176758

enc_base64(byref bs64 As String)
dec_base64(byref str_b64 as String)

Encode_TIME: 0.4951172
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Decode_TIME: 0.6201172

enc_base64(byval bs64 As String)
dec_base64(byval str_b64 as String)

Encode_TIME: 0.5214844
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Decode_TIME: 0.6850586