sintonia/airtime_mvc/application/common/FileDataHelper.php

<?php

class FileDataHelper {

    public static function getAudioMimeTypeArray() {
        return array(
            "audio/ogg" => "ogg",
            "application/ogg" => "ogg",
            "audio/vorbis" => "ogg",
            "audio/mp3" => "mp3",
            "audio/mpeg" => "mp3",
            "audio/mpeg3" => "mp3",
            "audio/aac" => "aac",
            "audio/aacp" => "aac",
            "audio/mp4" => "mp4",
            "audio/x-flac" => "flac",
            "audio/wav" => "wav",
            "audio/x-wav" => "wav",
            "audio/mp2" => "mp2",
            "audio/mp1" => "mp1",
            "audio/x-ms-wma" => "wma",
            "audio/basic" => "au",
        );
    }

    /**
     * We want to throw out invalid data and process the upload successfully
     * at all costs, so check the data and sanitize it if necessary
     * @param array $data array containing new file metadata
     */
    public static function sanitizeData(&$data)
    {
        if (array_key_exists("track_number", $data)) {
            // If the track number isn't numeric, this will return 0
            $data["track_number"] = intval($data["track_number"]);
        }
        if (array_key_exists("year", $data)) {
            // If the track number isn't numeric, this will return 0
            $data["year"] = intval($data["year"]);
        }
        if (array_key_exists("bpm", $data)) {
            //Some BPM tags are silly and include the word "BPM". Let's strip that...
            $data["bpm"] = str_ireplace("BPM", "", $data["bpm"]);
            // This will convert floats to ints too.
            $data["bpm"] = intval($data["bpm"]);
        }
    }

    /**
     * Return a suitable extension for the given file
     *
     * @param string $mime
     *
     * @return string file extension with(!) a dot (for convenience)
     *
     * @throws Exception
     */
    public static function getFileExtensionFromMime($mime)
    {
        $mime = trim(strtolower($mime));
        try {
            return ('.' . static::getAudioMimeTypeArray()[$mime]);
        } catch (Exception $e) {
            throw new Exception("Unknown file type: $mime");
        }
    }

}