<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.audio.la.php                                         //
// module for analyzing BONK audio files                       //
// dependencies: module.tag.id3v2.php (optional)               //
//                                                            ///
/////////////////////////////////////////////////////////////////


class getid3_bonk
{
    function getid3_bonk(&$fd, &$ThisFileInfo) {

        // shortcut
        $ThisFileInfo['bonk'] = array();
        $thisfile_bonk        = &$ThisFileInfo['bonk'];

        $thisfile_bonk['dataoffset']      = $ThisFileInfo['avdataoffset'];
        $thisfile_bonk['dataend']         = $ThisFileInfo['avdataend'];

        // scan-from-end method, for v0.6 and higher
        fseek($fd, $thisfile_bonk['dataend'] - 8, SEEK_SET);
        $PossibleBonkTag = fread($fd, 8);
        while ($this->BonkIsValidTagName(substr($PossibleBonkTag, 4, 4), true)) {
            $BonkTagSize = getid3_lib::LittleEndian2Int(substr($PossibleBonkTag, 0, 4));
            fseek($fd, 0 - $BonkTagSize, SEEK_CUR);
            $BonkTagOffset = ftell($fd);
            $TagHeaderTest = fread($fd, 5);
            if (($TagHeaderTest{0} != "\x00") || (substr($PossibleBonkTag, 4, 4) != strtolower(substr($PossibleBonkTag, 4, 4)))) {
                $ThisFileInfo['error'][] = 'Expecting "Ø'.strtoupper(substr($PossibleBonkTag, 4, 4)).'" at offset '.$BonkTagOffset.', found "'.$TagHeaderTest.'"';
                return false;
            }
            $BonkTagName = substr($TagHeaderTest, 1, 4);

            $thisfile_bonk[$BonkTagName]['size']   = $BonkTagSize;
            $thisfile_bonk[$BonkTagName]['offset'] = $BonkTagOffset;
            $this->HandleBonkTags($fd, $BonkTagName, $ThisFileInfo);
            $NextTagEndOffset = $BonkTagOffset - 8;
            if ($NextTagEndOffset < $thisfile_bonk['dataoffset']) {
                if (empty($ThisFileInfo['audio']['encoder'])) {
                    $ThisFileInfo['audio']['encoder'] = 'Extended BONK v0.9+';
                }
                return true;
            }
            fseek($fd, $NextTagEndOffset, SEEK_SET);
            $PossibleBonkTag = fread($fd, 8);
        }

        // seek-from-beginning method for v0.4 and v0.5
        if (empty($thisfile_bonk['BONK'])) {
            fseek($fd, $thisfile_bonk['dataoffset'], SEEK_SET);
            do {
                $TagHeaderTest = fread($fd, 5);
                switch ($TagHeaderTest) {
                    case "\x00".'BONK':
                        if (empty($ThisFileInfo['audio']['encoder'])) {
                            $ThisFileInfo['audio']['encoder'] = 'BONK v0.4';
                        }
                        break;

                    case "\x00".'INFO':
                        $ThisFileInfo['audio']['encoder'] = 'Extended BONK v0.5';
                        break;

                    default:
                        break 2;
                }
                $BonkTagName = substr($TagHeaderTest, 1, 4);
                $thisfile_bonk[$BonkTagName]['size']   = $thisfile_bonk['dataend'] - $thisfile_bonk['dataoffset'];
                $thisfile_bonk[$BonkTagName]['offset'] = $thisfile_bonk['dataoffset'];
                $this->HandleBonkTags($fd, $BonkTagName, $ThisFileInfo);

            } while (true);
        }

        // parse META block for v0.6 - v0.8
        if (empty($thisfile_bonk['INFO']) && isset($thisfile_bonk['META']['tags']['info'])) {
            fseek($fd, $thisfile_bonk['META']['tags']['info'], SEEK_SET);
            $TagHeaderTest = fread($fd, 5);
            if ($TagHeaderTest == "\x00".'INFO') {
                $ThisFileInfo['audio']['encoder'] = 'Extended BONK v0.6 - v0.8';

                $BonkTagName = substr($TagHeaderTest, 1, 4);
                $thisfile_bonk[$BonkTagName]['size']   = $thisfile_bonk['dataend'] - $thisfile_bonk['dataoffset'];
                $thisfile_bonk[$BonkTagName]['offset'] = $thisfile_bonk['dataoffset'];
                $this->HandleBonkTags($fd, $BonkTagName, $ThisFileInfo);
            }
        }

        if (empty($ThisFileInfo['audio']['encoder'])) {
            $ThisFileInfo['audio']['encoder'] = 'Extended BONK v0.9+';
        }
        if (empty($thisfile_bonk['BONK'])) {
            unset($ThisFileInfo['bonk']);
        }
        return true;

    }

    function HandleBonkTags(&$fd, &$BonkTagName, &$ThisFileInfo) {

        switch ($BonkTagName) {
            case 'BONK':
                // shortcut
                $thisfile_bonk_BONK = &$ThisFileInfo['bonk']['BONK'];

                $BonkData = "\x00".'BONK'.fread($fd, 17);
                $thisfile_bonk_BONK['version']            =        getid3_lib::LittleEndian2Int(substr($BonkData,  5, 1));
                $thisfile_bonk_BONK['number_samples']     =        getid3_lib::LittleEndian2Int(substr($BonkData,  6, 4));
                $thisfile_bonk_BONK['sample_rate']        =        getid3_lib::LittleEndian2Int(substr($BonkData, 10, 4));

                $thisfile_bonk_BONK['channels']           =        getid3_lib::LittleEndian2Int(substr($BonkData, 14, 1));
                $thisfile_bonk_BONK['lossless']           = (bool) getid3_lib::LittleEndian2Int(substr($BonkData, 15, 1));
                $thisfile_bonk_BONK['joint_stereo']       = (bool) getid3_lib::LittleEndian2Int(substr($BonkData, 16, 1));
                $thisfile_bonk_BONK['number_taps']        =        getid3_lib::LittleEndian2Int(substr($BonkData, 17, 2));
                $thisfile_bonk_BONK['downsampling_ratio'] =        getid3_lib::LittleEndian2Int(substr($BonkData, 19, 1));
                $thisfile_bonk_BONK['samples_per_packet'] =        getid3_lib::LittleEndian2Int(substr($BonkData, 20, 2));

                $ThisFileInfo['avdataoffset'] = $thisfile_bonk_BONK['offset'] + 5 + 17;
                $ThisFileInfo['avdataend']    = $thisfile_bonk_BONK['offset'] + $thisfile_bonk_BONK['size'];

                $ThisFileInfo['fileformat']               = 'bonk';
                $ThisFileInfo['audio']['dataformat']      = 'bonk';
                $ThisFileInfo['audio']['bitrate_mode']    = 'vbr'; // assumed
                $ThisFileInfo['audio']['channels']        = $thisfile_bonk_BONK['channels'];
                $ThisFileInfo['audio']['sample_rate']     = $thisfile_bonk_BONK['sample_rate'];
                $ThisFileInfo['audio']['channelmode']     = ($thisfile_bonk_BONK['joint_stereo'] ? 'joint stereo' : 'stereo');
                $ThisFileInfo['audio']['lossless']        = $thisfile_bonk_BONK['lossless'];
                $ThisFileInfo['audio']['codec']           = 'bonk';

                $ThisFileInfo['playtime_seconds'] = $thisfile_bonk_BONK['number_samples'] / ($thisfile_bonk_BONK['sample_rate'] * $thisfile_bonk_BONK['channels']);
                if ($ThisFileInfo['playtime_seconds'] > 0) {
                    $ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['bonk']['dataend'] - $ThisFileInfo['bonk']['dataoffset']) * 8) / $ThisFileInfo['playtime_seconds'];
                }
                break;

            case 'INFO':
                // shortcut
                $thisfile_bonk_INFO = &$ThisFileInfo['bonk']['INFO'];

                $thisfile_bonk_INFO['version'] = getid3_lib::LittleEndian2Int(fread($fd, 1));
                $thisfile_bonk_INFO['entries_count'] = 0;
                $NextInfoDataPair = fread($fd, 5);
                if (!$this->BonkIsValidTagName(substr($NextInfoDataPair, 1, 4))) {
                    while (!feof($fd)) {
                        //$CurrentSeekInfo['offset']  = getid3_lib::LittleEndian2Int(substr($NextInfoDataPair, 0, 4));
                        //$CurrentSeekInfo['nextbit'] = getid3_lib::LittleEndian2Int(substr($NextInfoDataPair, 4, 1));
                        //$thisfile_bonk_INFO[] = $CurrentSeekInfo;

                        $NextInfoDataPair = fread($fd, 5);
                        if ($this->BonkIsValidTagName(substr($NextInfoDataPair, 1, 4))) {
                            fseek($fd, -5, SEEK_CUR);
                            break;
                        }
                        $thisfile_bonk_INFO['entries_count']++;
                    }
                }
                break;

            case 'META':
                $BonkData = "\x00".'META'.fread($fd, $ThisFileInfo['bonk']['META']['size'] - 5);
                $ThisFileInfo['bonk']['META']['version'] = getid3_lib::LittleEndian2Int(substr($BonkData,  5, 1));

                $MetaTagEntries = floor(((strlen($BonkData) - 8) - 6) / 8); // BonkData - xxxxmeta - ØMETA
                $offset = 6;
                for ($i = 0; $i < $MetaTagEntries; $i++) {
                    $MetaEntryTagName   =                  substr($BonkData, $offset, 4);
                    $offset += 4;
                    $MetaEntryTagOffset = getid3_lib::LittleEndian2Int(substr($BonkData, $offset, 4));
                    $offset += 4;
                    $ThisFileInfo['bonk']['META']['tags'][$MetaEntryTagName] = $MetaEntryTagOffset;
                }
                break;

            case ' ID3':
                $ThisFileInfo['audio']['encoder'] = 'Extended BONK v0.9+';

                // ID3v2 checking is optional
                if (class_exists('getid3_id3v2')) {
                    $ThisFileInfo['bonk'][' ID3']['valid'] = new getid3_id3v2($fd, $ThisFileInfo, $ThisFileInfo['bonk'][' ID3']['offset'] + 2);
                }
                break;

            default:
                $ThisFileInfo['warning'][] = 'Unexpected Bonk tag "'.$BonkTagName.'" at offset '.$ThisFileInfo['bonk'][$BonkTagName]['offset'];
                break;

        }
    }

    function BonkIsValidTagName($PossibleBonkTag, $ignorecase=false) {
        static $BonkIsValidTagName = array('BONK', 'INFO', ' ID3', 'META');
        foreach ($BonkIsValidTagName as $validtagname) {
            if ($validtagname == $PossibleBonkTag) {
                return true;
            } elseif ($ignorecase && (strtolower($validtagname) == strtolower($PossibleBonkTag))) {
                return true;
            }
        }
        return false;
    }

}


?>