Detect encoding and make everything UTF-8

I'm reading out lots of texts from various RSS feeds and inserting them into my database. Of course, there are several different character encodings used in the feeds, e.g. UTF-8 and ISO 8859-1. Unfortunately, there are sometimes problems with the encodings of the texts. Example: 1. The "ß" in "Fußball" should look like this in my database: "Ÿ". If it is a "Ÿ", it is displayed correctly. 2. Sometimes, the "ß" in "Fußball" looks like this in my database: "ß". Then it is displayed wrongly, of course. 3. In other cases, the "ß" is saved as a "ß" - so without any change. Then it is also displayed wrongly. What can I do to avoid the cases 2 and 3? How can I make everything the same encoding, preferably UTF-8? When must I use `utf8_encode()`, when must I use `utf8_decode()` (it's clear what the effect is but when must I use the functions?) and when must I do nothing with the input? How do I make everything the same encoding? Perhaps with the function `mb_detect_encoding()`? Can I write a function for this? So my problems are: 1. How do I find out what encoding the text uses? 2. How do I convert it to UTF-8 - whatever the old encoding is? Would a function like this work? function correct_encoding($text) { $current_encoding = mb_detect_encoding($text, 'auto'); $text = iconv($current_encoding, 'UTF-8', $text); return $text; } I've tested it, but it doesn't work. What's wrong with it?