Use JSONObject. I wrote the following tests using your example data and they passed.
public void testJsonParsing() throws JSONException {
JSONObject manual = new JSONObject();
manual.put("media:info", "value3");
String rawData = "{ \"title\": \"value1\", \"link\": \"value2\", \"media:info\": \"value3\" }";
JSONObject parsed = new JSONObject(rawData);
String expected = "value3";
String actual = manual.getString("media:info");
assertEquals("Actual equals expected", expected, actual);
actual = parsed.getString("media:info");
assertEquals("Actual equals expected", expected, actual);
}