updated with json builder for xml stuff.

incontext.php

<?php

// required: apt-get install apt-get install php5-tidy
if (!file_exists('incontxt-download.tidy.xml')) {
    $config = array(
        'indent' => true,
        'clean' => true,
        'input-xml' => true,
        'output-xml' => true,
        'wrap' => false
    );
    if (file_exists('incontxt-download.xml')) {
        $xmlstr = tidy_repair_file('incontxt-download.xml', $config);
        file_put_contents('incontxt-download.tidy.xml', $xmlstr);
    } else
        die('-1');
}

$xml = simplexml_load_file('incontxt-download.tidy.xml', null, LIBXML_PARSEHUGE);

// lets get the prids of all incontext id's, then you can get the links
//<str name="id">KRO_30_93730</str> --> KRO_1605885 (PRID)
if (!file_exists('incontxtid2prid.json')) {
    $data = array();
    foreach ($xml->result->doc as $doc) {
        foreach ($doc->str as $str) {
            if ($str['name'] != 'id') {
                continue;
            }
            $exp = explode('_', $str); //print_r( $exp);

            print("Episode lookup " . $str . " exp2:" . ($exp[2]));
            $prid = file_get_contents('http://getprid.kro.nl/getprid.ashx?episodeid=' . ($exp[2]));
            print(" PRID:" . $prid . " Result:");

            if ($prid == 'Episode not found') {
                print($prid . " on:" . $str . "\n");
            } else {
                print('Episode found on ' . $str . " with: " . $prid . "\n");
                $data[(string) $str] = $prid;
            }
        }
    }
    $json = json_encode($data);
    file_put_contents('incontxtid2prid.json', $json);
}

if (!file_exists('incontxt.json')) {
    $data = array();
    foreach ($xml->result->doc as $doc) {

        //   get id         <str name="id">KRO_370_4286</str>
        $fields = array();
        foreach ($doc->str as $str) {
            //print("Name found: ". (string)$str['name'] ." value: " . (string)$str );
            $fields[(string) $str['name']] = (string) $str;
            //print("\n");
        }
        //print_r($fields);

        foreach ($doc->arr as $arr) {
            // print("Name found: " . (string) $arr['name'] ." value: ");
            foreach ($arr as $item) {
                $fields[((string) $arr['name'])][] = (string) $item; //print((string) $item);
            }
            //print("\n");
        }
        //print_r($fields);
        $data[($fields['id'])] = $fields;
    }
    file_put_contents('incontxt.json', json_encode($data));
}
?>