module.audio.vqf.php

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<?php
//  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 getid3_vqf
{
        function getid3_vqf(&$fd, &$ThisFileInfo) {
                // based loosely on code from TTwinVQ by Jurgen Faul <jfaulØgmx*de>
                // http://jfaul.de/atl  or  http://j-faul.virtualave.net/atl/atl.html

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

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

                fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
                $VQFheaderData = fread($fd, 16);

                $offset = 0;
                $thisfile_vqf_raw['header_tag']     =               substr($VQFheaderData, $offset, 4);
                if ($thisfile_vqf_raw['header_tag'] != 'TWIN') {
                        $ThisFileInfo['error'][] = 'Expecting "TWIN" at offset '.$ThisFileInfo['avdataoffset'].', found "'.$thisfile_vqf_raw['header_tag'].'"';
                        unset($ThisFileInfo['vqf']);
                        unset($ThisFileInfo['fileformat']);
                        return false;
                }
                $offset += 4;
                $thisfile_vqf_raw['version']        =               substr($VQFheaderData, $offset, 8);
                $offset += 8;
                $thisfile_vqf_raw['size']           = getid3_lib::BigEndian2Int(substr($VQFheaderData, $offset, 4));
                $offset += 4;

                while (ftell($fd) < $ThisFileInfo['avdataend']) {

                        $ChunkBaseOffset = ftell($fd);
                        $chunkoffset = 0;
                        $ChunkData = fread($fd, 8);
                        $ChunkName = substr($ChunkData, $chunkoffset, 4);
                        if ($ChunkName == 'DATA') {
                                $ThisFileInfo['avdataoffset'] = $ChunkBaseOffset;
                                break;
                        }
                        $chunkoffset += 4;
                        $ChunkSize = getid3_lib::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                        $chunkoffset += 4;
                        if ($ChunkSize > ($ThisFileInfo['avdataend'] - ftell($fd))) {
                                $ThisFileInfo['error'][] = 'Invalid chunk size ('.$ChunkSize.') for chunk "'.$ChunkName.'" at offset '.$ChunkBaseOffset;
                                break;
                        }
                        if ($ChunkSize > 0) {
                                $ChunkData .= fread($fd, $ChunkSize);
                        }

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

                                        $thisfile_vqf_COMM['channel_mode']   = getid3_lib::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                                        $chunkoffset += 4;
                                        $thisfile_vqf_COMM['bitrate']        = getid3_lib::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                                        $chunkoffset += 4;
                                        $thisfile_vqf_COMM['sample_rate']    = getid3_lib::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                                        $chunkoffset += 4;
                                        $thisfile_vqf_COMM['security_level'] = getid3_lib::BigEndian2Int(substr($ChunkData, $chunkoffset, 4));
                                        $chunkoffset += 4;

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

                                        if ($ThisFileInfo['audio']['bitrate'] == 0) {
                                                $ThisFileInfo['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':
                                        $thisfile_vqf['DSIZ'] = getid3_lib::BigEndian2Int(substr($ChunkData, 8, 4));
                                        break;

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

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

                if (isset($thisfile_vqf['DSIZ']) && (($thisfile_vqf['DSIZ'] != ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset'] - strlen('DATA'))))) {
                        switch ($thisfile_vqf['DSIZ']) {
                                case 0:
                                case 1:
                                        $ThisFileInfo['warning'][] = 'Invalid DSIZ value "'.$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';
                                        $ThisFileInfo['audio']['encoder'] = 'Ahead Nero';
                                        break;

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

                return true;
        }

        function VQFchannelFrequencyLookup($frequencyid) {
                static $VQFchannelFrequencyLookup = array(
                        11 => 11025,
                        22 => 22050,
                        44 => 44100
                );
                return (isset($VQFchannelFrequencyLookup[$frequencyid]) ? $VQFchannelFrequencyLookup[$frequencyid] : $frequencyid * 1000);
        }

        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);
        }

}


?>