@param out buffer for decoded data
@param in null-terminated input string
@param out_size size in bytes of the out buffer, must be at
least 3/4 of the length of in, that is AV_BASE64_DECODE_SIZE(strlen(in))
@return number of bytes written, or a negative value in case of
invalid input
Decode a base64-encoded string.
@param out buffer for decoded data @param in null-terminated input string @param out_size size in bytes of the out buffer, must be at least 3/4 of the length of in, that is AV_BASE64_DECODE_SIZE(strlen(in)) @return number of bytes written, or a negative value in case of invalid input