Vqf.php

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<?php

namespace GetId3\Module\Audio;

use GetId3\Handler\BaseHandler;
use GetId3\Lib\Helper;

//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
// See readme.txt for more details                             //
//                                                             //
// module.audio.vqf.php                                        //
// module for analyzing VQF audio files                        //
// dependencies: NONE                                          //
//                                                            ///

class Vqf extends BaseHandler
{
    public function analyze()
    {
        $info = &$this->getid3->info;

        // based loosely on code from TTwinVQ by Jurgen Faul <jfaulØgmx*de>
        // http://jfaul.de/atl  or  http://j-faul.virtualave.net/atl/atl.html

        $info['fileformat']            = 'vqf';
        $info['audio']['dataformat']   = 'vqf';
        $info['audio']['bitrate_mode'] = 'cbr';
        $info['audio']['lossless']     = false;

        // shortcut
        $info['vqf']['raw'] = array();
        $thisfile_vqf               = &$info['vqf'];
        $thisfile_vqf_raw           = &$thisfile_vqf['raw'];

        fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
        $VQFheaderData = fread($this->getid3->fp, 16);

        $offset = 0;
        $thisfile_vqf_raw['header_tag'] = substr($VQFheaderData, $offset, 4);
        $magic = 'TWIN';
        if ($thisfile_vqf_raw['header_tag'] != $magic) {
            $info['error'][] = 'Expecting "'.Helper::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.Helper::PrintHexBytes($thisfile_vqf_raw['header_tag']).'"';
            unset($info['vqf']);
            unset($info['fileformat']);

            return false;
        }
        $offset += 4;
        $thisfile_vqf_raw['version'] =                           substr($VQFheaderData, $offset, 8);
        $offset += 8;
        $thisfile_vqf_raw['size']    = Helper::BigEndian2Int(substr($VQFheaderData, $offset, 4));
        $offset += 4;

        while (ftell($this->getid3->fp) < $info['avdataend']) {

            $ChunkBaseOffset = ftell($this->getid3->fp);
            $chunkoffset = 0;
            $ChunkData = fread($this->getid3->fp, 8);
            $ChunkName = substr($ChunkData, $chunkoffset, 4);
            if ($ChunkName == 'DATA') {
                $info['avdataoffset'] = $ChunkBaseOffset;
                break;
            }
            $chunkoffset += 4;
            $ChunkSize = Helper::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
            $chunkoffset += 4;
            if ($ChunkSize > ($info['avdataend'] - ftell($this->getid3->fp))) {
                $info['error'][] = 'Invalid chunk size ('.$ChunkSize.') for chunk "'.$ChunkName.'" at offset '.$ChunkBaseOffset;
                break;
            }
            if ($ChunkSize > 0) {
                $ChunkData .= fread($this->getid3->fp, $ChunkSize);
            }

            switch ($ChunkName) {
                case 'COMM':
                    // shortcut
                    $thisfile_vqf['COMM'] = array();
                    $thisfile_vqf_COMM    = &$thisfile_vqf['COMM'];

                    $thisfile_vqf_COMM['channel_mode']   = Helper::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                    $chunkoffset += 4;
                    $thisfile_vqf_COMM['bitrate']        = Helper::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                    $chunkoffset += 4;
                    $thisfile_vqf_COMM['sample_rate']    = Helper::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                    $chunkoffset += 4;
                    $thisfile_vqf_COMM['security_level'] = Helper::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                    $chunkoffset += 4;

                    $info['audio']['channels']        = $thisfile_vqf_COMM['channel_mode'] + 1;
                    $info['audio']['sample_rate']     = $this->VQFchannelFrequencyLookup($thisfile_vqf_COMM['sample_rate']);
                    $info['audio']['bitrate']         = $thisfile_vqf_COMM['bitrate'] * 1000;
                    $info['audio']['encoder_options'] = 'CBR' . ceil($info['audio']['bitrate']/1000);

                    if ($info['audio']['bitrate'] == 0) {
                        $info['error'][] = 'Corrupt VQF file: bitrate_audio == zero';

                        return false;
                    }
                    break;

                case 'NAME':
                case 'AUTH':
                case '(c) ':
                case 'FILE':
                case 'COMT':
                case 'ALBM':
                    $thisfile_vqf['comments'][$this->VQFcommentNiceNameLookup($ChunkName)][] = trim(substr($ChunkData, 8));
                    break;

                case 'DSIZ':
                    $thisfile_vqf['DSIZ'] = Helper::BigEndian2Int(substr($ChunkData, 8, 4));
                    break;

                default:
                    $info['warning'][] = 'Unhandled chunk type "'.$ChunkName.'" at offset '.$ChunkBaseOffset;
                    break;
            }
        }

        $info['playtime_seconds'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['audio']['bitrate'];

        if (isset($thisfile_vqf['DSIZ']) && (($thisfile_vqf['DSIZ'] != ($info['avdataend'] - $info['avdataoffset'] - strlen('DATA'))))) {
            switch ($thisfile_vqf['DSIZ']) {
                case 0:
                case 1:
                    $info['warning'][] = 'Invalid DSIZ value "'.$thisfile_vqf['DSIZ'].'". This is known to happen with VQF files encoded by Ahead Nero, and seems to be its way of saying this is TwinVQF v'.($thisfile_vqf['DSIZ'] + 1).'.0';
                    $info['audio']['encoder'] = 'Ahead Nero';
                    break;

                default:
                    $info['warning'][] = 'Probable corrupted file - should be '.$thisfile_vqf['DSIZ'].' bytes, actually '.($info['avdataend'] - $info['avdataoffset'] - strlen('DATA'));
                    break;
            }
        }

        return true;
    }

    public function VQFchannelFrequencyLookup($frequencyid)
    {
        static $VQFchannelFrequencyLookup = array(
            11 => 11025,
            22 => 22050,
            44 => 44100
        );

        return (isset($VQFchannelFrequencyLookup[$frequencyid]) ? $VQFchannelFrequencyLookup[$frequencyid] : $frequencyid * 1000);
    }

    public function VQFcommentNiceNameLookup($shortname)
    {
        static $VQFcommentNiceNameLookup = array(
            'NAME' => 'title',
            'AUTH' => 'artist',
            '(c) ' => 'copyright',
            'FILE' => 'filename',
            'COMT' => 'comment',
            'ALBM' => 'album'
        );

        return (isset($VQFcommentNiceNameLookup[$shortname]) ? $VQFcommentNiceNameLookup[$shortname] : $shortname);
    }

}