Public Member Functions

getid3_la Class Reference

Public Member Functions

 getid3_la (&$fd, &$ThisFileInfo)

Detailed Description

Definition at line 18 of file module.audio.la.php.


Member Function Documentation

getid3_la::getid3_la ( &$  fd,
&$  ThisFileInfo 
)

Definition at line 21 of file module.audio.la.php.

References getid3_lib::LittleEndian2Int(), and getid3_lib::PrintHexBytes().

                                                 {
                $offset = 0;
                fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
                $rawdata = fread($fd, GETID3_FREAD_BUFFER_SIZE);

                switch (substr($rawdata, $offset, 4)) {
                        case 'LA02':
                        case 'LA03':
                        case 'LA04':
                                $ThisFileInfo['fileformat']          = 'la';
                                $ThisFileInfo['audio']['dataformat'] = 'la';
                                $ThisFileInfo['audio']['lossless']   = true;

                                $ThisFileInfo['la']['version_major'] = (int) substr($rawdata, $offset + 2, 1);
                                $ThisFileInfo['la']['version_minor'] = (int) substr($rawdata, $offset + 3, 1);
                                $ThisFileInfo['la']['version']       = (float) $ThisFileInfo['la']['version_major'] + ($ThisFileInfo['la']['version_minor'] / 10);
                                $offset += 4;

                                $ThisFileInfo['la']['uncompressed_size'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                $offset += 4;
                                if ($ThisFileInfo['la']['uncompressed_size'] == 0) {
                                        $ThisFileInfo['error'][] = 'Corrupt LA file: uncompressed_size == zero';
                                        return false;
                                }

                                $WAVEchunk = substr($rawdata, $offset, 4);
                                if ($WAVEchunk !== 'WAVE') {
                                        $ThisFileInfo['error'][] = 'Expected "WAVE" ('.getid3_lib::PrintHexBytes('WAVE').') at offset '.$offset.', found "'.$WAVEchunk.'" ('.getid3_lib::PrintHexBytes($WAVEchunk).') instead.';
                                        return false;
                                }
                                $offset += 4;

                                $ThisFileInfo['la']['fmt_size'] = 24;
                                if ($ThisFileInfo['la']['version'] >= 0.3) {

                                        $ThisFileInfo['la']['fmt_size']    = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                        $ThisFileInfo['la']['header_size'] = 49 + $ThisFileInfo['la']['fmt_size'] - 24;
                                        $offset += 4;

                                } else {

                                        // version 0.2 didn't support additional data blocks
                                        $ThisFileInfo['la']['header_size'] = 41;

                                }

                                $fmt_chunk = substr($rawdata, $offset, 4);
                                if ($fmt_chunk !== 'fmt ') {
                                        $ThisFileInfo['error'][] = 'Expected "fmt " ('.getid3_lib::PrintHexBytes('fmt ').') at offset '.$offset.', found "'.$fmt_chunk.'" ('.getid3_lib::PrintHexBytes($fmt_chunk).') instead.';
                                        return false;
                                }
                                $offset += 4;
                                $fmt_size = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                $offset += 4;

                                $ThisFileInfo['la']['raw']['format']  = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 2));
                                $offset += 2;

                                $ThisFileInfo['la']['channels']       = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 2));
                                $offset += 2;
                                if ($ThisFileInfo['la']['channels'] == 0) {
                                        $ThisFileInfo['error'][] = 'Corrupt LA file: channels == zero';
                                                return false;
                                }

                                $ThisFileInfo['la']['sample_rate'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                $offset += 4;
                                if ($ThisFileInfo['la']['sample_rate'] == 0) {
                                        $ThisFileInfo['error'][] = 'Corrupt LA file: sample_rate == zero';
                                                return false;
                                }

                                $ThisFileInfo['la']['bytes_per_second']     = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                $offset += 4;
                                $ThisFileInfo['la']['bytes_per_sample']     = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 2));
                                $offset += 2;
                                $ThisFileInfo['la']['bits_per_sample']      = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 2));
                                $offset += 2;

                                $ThisFileInfo['la']['samples']              = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                $offset += 4;

                                $ThisFileInfo['la']['raw']['flags']         = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 1));
                                $offset += 1;
                                $ThisFileInfo['la']['flags']['seekable']             = (bool) ($ThisFileInfo['la']['raw']['flags'] & 0x01);
                                if ($ThisFileInfo['la']['version'] >= 0.4) {
                                        $ThisFileInfo['la']['flags']['high_compression'] = (bool) ($ThisFileInfo['la']['raw']['flags'] & 0x02);
                                }

                                $ThisFileInfo['la']['original_crc']         = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                $offset += 4;

                                // mikeØbevin*de
                                // Basically, the blocksize/seekevery are 61440/19 in La0.4 and 73728/16
                                // in earlier versions. A seekpoint is added every blocksize * seekevery
                                // samples, so 4 * int(totalSamples / (blockSize * seekEvery)) should
                                // give the number of bytes used for the seekpoints. Of course, if seeking
                                // is disabled, there are no seekpoints stored.
                                if ($ThisFileInfo['la']['version'] >= 0.4) {
                                        $ThisFileInfo['la']['blocksize'] = 61440;
                                        $ThisFileInfo['la']['seekevery'] = 19;
                                } else {
                                        $ThisFileInfo['la']['blocksize'] = 73728;
                                        $ThisFileInfo['la']['seekevery'] = 16;
                                }

                                $ThisFileInfo['la']['seekpoint_count'] = 0;
                                if ($ThisFileInfo['la']['flags']['seekable']) {
                                        $ThisFileInfo['la']['seekpoint_count'] = floor($ThisFileInfo['la']['samples'] / ($ThisFileInfo['la']['blocksize'] * $ThisFileInfo['la']['seekevery']));

                                        for ($i = 0; $i < $ThisFileInfo['la']['seekpoint_count']; $i++) {
                                                $ThisFileInfo['la']['seekpoints'][] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                                $offset += 4;
                                        }
                                }

                                if ($ThisFileInfo['la']['version'] >= 0.3) {

                                        // Following the main header information, the program outputs all of the
                                        // seekpoints. Following these is what I called the 'footer start',
                                        // i.e. the position immediately after the La audio data is finished.
                                        $ThisFileInfo['la']['footerstart'] = getid3_lib::LittleEndian2Int(substr($rawdata, $offset, 4));
                                        $offset += 4;

                                        if ($ThisFileInfo['la']['footerstart'] > $ThisFileInfo['filesize']) {
                                                $ThisFileInfo['warning'][] = 'FooterStart value points to offset '.$ThisFileInfo['la']['footerstart'].' which is beyond end-of-file ('.$ThisFileInfo['filesize'].')';
                                                $ThisFileInfo['la']['footerstart'] = $ThisFileInfo['filesize'];
                                        }

                                } else {

                                        // La v0.2 didn't have FooterStart value
                                        $ThisFileInfo['la']['footerstart'] = $ThisFileInfo['avdataend'];

                                }

                                if ($ThisFileInfo['la']['footerstart'] < $ThisFileInfo['avdataend']) {
                                        if ($RIFFtempfilename = tempnam('*', 'id3')) {
                                                if ($RIFF_fp = fopen($RIFFtempfilename, 'w+b')) {
                                                        $RIFFdata = 'WAVE';
                                                        if ($ThisFileInfo['la']['version'] == 0.2) {
                                                                $RIFFdata .= substr($rawdata, 12, 24);
                                                        } else {
                                                                $RIFFdata .= substr($rawdata, 16, 24);
                                                        }
                                                        if ($ThisFileInfo['la']['footerstart'] < $ThisFileInfo['avdataend']) {
                                                                fseek($fd, $ThisFileInfo['la']['footerstart'], SEEK_SET);
                                                                $RIFFdata .= fread($fd, $ThisFileInfo['avdataend'] - $ThisFileInfo['la']['footerstart']);
                                                        }
                                                        $RIFFdata = 'RIFF'.getid3_lib::LittleEndian2String(strlen($RIFFdata), 4, false).$RIFFdata;
                                                        fwrite($RIFF_fp, $RIFFdata, strlen($RIFFdata));
                                                        $dummy = $ThisFileInfo;
                                                        $dummy['filesize']     = strlen($RIFFdata);
                                                        $dummy['avdataoffset'] = 0;
                                                        $dummy['avdataend']    = $dummy['filesize'];

                                                        $riff = new getid3_riff($RIFF_fp, $dummy);
                                                        if (empty($dummy['error'])) {
                                                                $ThisFileInfo['riff'] = $dummy['riff'];
                                                        } else {
                                                                $ThisFileInfo['warning'][] = 'Error parsing RIFF portion of La file: '.implode($dummy['error']);
                                                        }
                                                        unset($dummy);
                                                        fclose($RIFF_fp);
                                                }
                                                unlink($RIFFtempfilename);
                                        }
                                }

                                // $ThisFileInfo['avdataoffset'] should be zero to begin with, but just in case it's not, include the addition anyway
                                $ThisFileInfo['avdataend']    = $ThisFileInfo['avdataoffset'] + $ThisFileInfo['la']['footerstart'];
                                $ThisFileInfo['avdataoffset'] = $ThisFileInfo['avdataoffset'] + $offset;

                                //$ThisFileInfo['la']['codec']                = RIFFwFormatTagLookup($ThisFileInfo['la']['raw']['format']);
                                $ThisFileInfo['la']['compression_ratio']    = (float) (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) / $ThisFileInfo['la']['uncompressed_size']);
                                $ThisFileInfo['playtime_seconds']           = (float) ($ThisFileInfo['la']['samples'] / $ThisFileInfo['la']['sample_rate']) / $ThisFileInfo['la']['channels'];
                                if ($ThisFileInfo['playtime_seconds'] == 0) {
                                        $ThisFileInfo['error'][] = 'Corrupt LA file: playtime_seconds == zero';
                                        return false;
                                }

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

                        default:
                                if (substr($rawdata, $offset, 2) == 'LA') {
                                        $ThisFileInfo['error'][] = 'This version of getID3() (v'.GETID3_VERSION.') doesn\'t support LA version '.substr($rawdata, $offset + 2, 1).'.'.substr($rawdata, $offset + 3, 1).' which this appears to be - check http://getid3.sourceforge.net for updates.';
                                } else {
                                        $ThisFileInfo['error'][] = 'Not a LA (Lossless-Audio) file';
                                }
                                return false;
                                break;
                }

                $ThisFileInfo['audio']['channels']    = $ThisFileInfo['la']['channels'];
                $ThisFileInfo['audio']['sample_rate'] = (int) $ThisFileInfo['la']['sample_rate'];
                $ThisFileInfo['audio']['encoder']     = 'LA v'.$ThisFileInfo['la']['version'];

                return true;
        }

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The documentation for this class was generated from the following file: