Like the string.* filters, the convert.* filters perform actions similar to their names. The convert filters were added with PHP 5.0.0. For more information on a given filter, refer to the manual page for the corresponding function.
Use of these filters are equivalent to processing all stream data through
the base64_encode() and base64_decode()
convert.base64-encode supports parameters given as
an associative array. If
line-length is given, the
base64 output will be split into chunks of
characters each. If
line-break-chars is given, each
chunk will be delimited by the characters given. These parameters give the
same effect as using base64_encode() with
Example O-5. convert.base64-encode & convert.base64-decode
Use of the decode version of this filter is equivalent to processing all stream
data through the quoted_printable_decode() functions.
There is no function equivalent to convert.quoted-printable-encode.
convert.quoted-printable-encode supports parameters given as
an associative array. In addition to the parameters supported by
also supports boolean arguments
convert.base64-decode only supports the
line-break-chars parameter as a type-hint
for striping from the encoded payload.