Public Member Functions

getid3_mpc Class Reference

getID3() by James Heinrich <info@getid3.org> // More...

Public Member Functions

 getid3_mpc (&$fd, &$ThisFileInfo)
 MPCprofileNameLookup ($profileid)
 MPCfrequencyLookup ($frequencyid)
 MPCpeakDBLookup ($intvalue)
 MPCencoderVersionLookup ($encoderversion)

Detailed Description

getID3() by James Heinrich <info@getid3.org> //

Definition at line 17 of file module.audio.mpc.php.


Member Function Documentation

getid3_mpc::getid3_mpc ( &$  fd,
&$  ThisFileInfo 
)

Definition at line 20 of file module.audio.mpc.php.

References getid3_lib::CastAsInt(), getid3_lib::LittleEndian2Int(), MPCencoderVersionLookup(), MPCfrequencyLookup(), MPCpeakDBLookup(), and MPCprofileNameLookup().

                                                  {
                // http://www.uni-jena.de/~pfk/mpp/sv8/header.html

                $ThisFileInfo['mpc']['header'] = array();
                $thisfile_mpc_header           = &$ThisFileInfo['mpc']['header'];

                $ThisFileInfo['fileformat']               = 'mpc';
                $ThisFileInfo['audio']['dataformat']      = 'mpc';
                $ThisFileInfo['audio']['bitrate_mode']    = 'vbr';
                $ThisFileInfo['audio']['channels']        = 2;  // the format appears to be hardcoded for stereo only
                $ThisFileInfo['audio']['lossless']        = false;

                fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);

                $thisfile_mpc_header['size'] = 28;
                $MPCheaderData = fread($fd, $thisfile_mpc_header['size']);
                $offset = 0;

                if (substr($MPCheaderData, $offset, 3) == 'MP+') {

                        // great, this is SV7+
                        $thisfile_mpc_header['raw']['preamble'] = substr($MPCheaderData, $offset, 3); // should be 'MP+'
                        $offset += 3;

                } elseif (preg_match('/^[\x00\x01\x10\x11\x40\x41\x50\x51\x80\x81\x90\x91\xC0\xC1\xD0\xD1][\x20-37][\x00\x20\x40\x60\x80\xA0\xC0\xE0]/s', substr($MPCheaderData, 0, 4))) {

                        // this is SV4 - SV6, handle seperately
            $thisfile_mpc_header['size'] = 8;

            // add size of file header to avdataoffset - calc bitrate correctly + MD5 data
                    $ThisFileInfo['avdataoffset'] += $thisfile_mpc_header['size'];

                        // Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :)
                        $HeaderDWORD[0] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 0, 4));
                        $HeaderDWORD[1] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 4, 4));


                        // DDDD DDDD  CCCC CCCC  BBBB BBBB  AAAA AAAA
                        // aaaa aaaa  abcd dddd  dddd deee  eeff ffff
                        //
                        // a = bitrate       = anything
                        // b = IS            = anything
                        // c = MS            = anything
                        // d = streamversion = 0000000004 or 0000000005 or 0000000006
                        // e = maxband       = anything
                        // f = blocksize     = 000001 for SV5+, anything(?) for SV4

                        $thisfile_mpc_header['target_bitrate']       =        (($HeaderDWORD[0] & 0xFF800000) >> 23);
                        $thisfile_mpc_header['intensity_stereo']     = (bool) (($HeaderDWORD[0] & 0x00400000) >> 22);
                        $thisfile_mpc_header['mid-side_stereo']      = (bool) (($HeaderDWORD[0] & 0x00200000) >> 21);
                        $thisfile_mpc_header['stream_major_version'] =         ($HeaderDWORD[0] & 0x001FF800) >> 11;
                        $thisfile_mpc_header['stream_minor_version'] = 0; // no sub-version numbers before SV7
                        $thisfile_mpc_header['max_band']             =         ($HeaderDWORD[0] & 0x000007C0) >>  6;  // related to lowpass frequency, not sure how it translates exactly
                        $thisfile_mpc_header['block_size']           =         ($HeaderDWORD[0] & 0x0000003F);

                        switch ($thisfile_mpc_header['stream_major_version']) {
                                case 4:
                                        $thisfile_mpc_header['frame_count'] = ($HeaderDWORD[1] >> 16);
                                        break;

                                case 5:
                                case 6:
                                        $thisfile_mpc_header['frame_count'] =  $HeaderDWORD[1];
                                        break;

                                default:
                                        $ThisFileInfo['error'] = 'Expecting 4, 5 or 6 in version field, found '.$thisfile_mpc_header['stream_major_version'].' instead';
                                        unset($ThisFileInfo['mpc']);
                                        return false;
                                        break;
                        }

                        if (($thisfile_mpc_header['stream_major_version'] > 4) && ($thisfile_mpc_header['block_size'] != 1)) {
                                $ThisFileInfo['warning'][] = 'Block size expected to be 1, actual value found: '.$thisfile_mpc_header['block_size'];
                        }

                        $thisfile_mpc_header['sample_rate']   = 44100; // AB: used by all files up to SV7
                        $ThisFileInfo['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
                        $thisfile_mpc_header['samples']       = $thisfile_mpc_header['frame_count'] * 1152 * $ThisFileInfo['audio']['channels'];

                        if ($thisfile_mpc_header['target_bitrate'] == 0) {
                                $ThisFileInfo['audio']['bitrate_mode'] = 'vbr';
                        } else {
                                $ThisFileInfo['audio']['bitrate_mode'] = 'cbr';
                        }

                        $ThisFileInfo['mpc']['bitrate']   = ($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8 * 44100 / $thisfile_mpc_header['frame_count'] / 1152;
                        $ThisFileInfo['audio']['bitrate'] = $ThisFileInfo['mpc']['bitrate'];
                        $ThisFileInfo['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_major_version'];

                        return true;

                } else {

                        $ThisFileInfo['error'][] = 'Expecting "MP+" at offset '.$ThisFileInfo['avdataoffset'].', found "'.substr($MPCheaderData, $offset, 3).'"';
                        unset($ThisFileInfo['fileformat']);
                        unset($ThisFileInfo['mpc']);
                        return false;

                }

                // Continue with SV7+ handling
                $StreamVersionByte                           = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
                $offset += 1;
                $thisfile_mpc_header['stream_major_version'] = ($StreamVersionByte & 0x0F);
                $thisfile_mpc_header['stream_minor_version'] = ($StreamVersionByte & 0xF0) >> 4;
                $thisfile_mpc_header['frame_count']          = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
                $offset += 4;

                switch ($thisfile_mpc_header['stream_major_version']) {
                        case 7:
                                //$ThisFileInfo['fileformat'] = 'SV7';
                                break;

                        default:
                                $ThisFileInfo['error'][] = 'Only Musepack SV7 supported';
                                return false;
                }

                $FlagsDWORD1                                   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
                $offset += 4;
                $thisfile_mpc_header['intensity_stereo']       = (bool) (($FlagsDWORD1 & 0x80000000) >> 31);
                $thisfile_mpc_header['mid_side_stereo']        = (bool) (($FlagsDWORD1 & 0x40000000) >> 30);
                $thisfile_mpc_header['max_subband']            =         ($FlagsDWORD1 & 0x3F000000) >> 24;
                $thisfile_mpc_header['raw']['profile']         =         ($FlagsDWORD1 & 0x00F00000) >> 20;
                $thisfile_mpc_header['begin_loud']             = (bool) (($FlagsDWORD1 & 0x00080000) >> 19);
                $thisfile_mpc_header['end_loud']               = (bool) (($FlagsDWORD1 & 0x00040000) >> 18);
                $thisfile_mpc_header['raw']['sample_rate']     =         ($FlagsDWORD1 & 0x00030000) >> 16;
                $thisfile_mpc_header['max_level']              =         ($FlagsDWORD1 & 0x0000FFFF);

                $thisfile_mpc_header['raw']['title_peak']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
                $offset += 2;
                $thisfile_mpc_header['raw']['title_gain']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
                $offset += 2;

                $thisfile_mpc_header['raw']['album_peak']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
                $offset += 2;
                $thisfile_mpc_header['raw']['album_gain']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
                $offset += 2;

                $FlagsDWORD2                                   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
                $offset += 4;
                $thisfile_mpc_header['true_gapless']           = (bool) (($FlagsDWORD2 & 0x80000000) >> 31);
                $thisfile_mpc_header['last_frame_length']      =         ($FlagsDWORD2 & 0x7FF00000) >> 20;


                $thisfile_mpc_header['raw']['not_sure_what']   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 3));
                $offset += 3;
                $thisfile_mpc_header['raw']['encoder_version'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
                $offset += 1;

                $thisfile_mpc_header['profile']     = $this->MPCprofileNameLookup($thisfile_mpc_header['raw']['profile']);
                $thisfile_mpc_header['sample_rate'] = $this->MPCfrequencyLookup($thisfile_mpc_header['raw']['sample_rate']);
                if ($thisfile_mpc_header['sample_rate'] == 0) {
                        $ThisFileInfo['error'][] = 'Corrupt MPC file: frequency == zero';
                        return false;
                }
                $ThisFileInfo['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
                $thisfile_mpc_header['samples']       = ((($thisfile_mpc_header['frame_count'] - 1) * 1152) + $thisfile_mpc_header['last_frame_length']) * $ThisFileInfo['audio']['channels'];

                $ThisFileInfo['playtime_seconds']     = ($thisfile_mpc_header['samples'] / $ThisFileInfo['audio']['channels']) / $ThisFileInfo['audio']['sample_rate'];
                if ($ThisFileInfo['playtime_seconds'] == 0) {
                        $ThisFileInfo['error'][] = 'Corrupt MPC file: playtime_seconds == zero';
                        return false;
                }

                // add size of file header to avdataoffset - calc bitrate correctly + MD5 data
                $ThisFileInfo['avdataoffset'] += $thisfile_mpc_header['size'];

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

                $thisfile_mpc_header['title_peak']        = $thisfile_mpc_header['raw']['title_peak'];
                $thisfile_mpc_header['title_peak_db']     = $this->MPCpeakDBLookup($thisfile_mpc_header['title_peak']);
                if ($thisfile_mpc_header['raw']['title_gain'] < 0) {
                        $thisfile_mpc_header['title_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['title_gain']) / -100;
                } else {
                        $thisfile_mpc_header['title_gain_db'] = (float) $thisfile_mpc_header['raw']['title_gain'] / 100;
                }

                $thisfile_mpc_header['album_peak']        = $thisfile_mpc_header['raw']['album_peak'];
                $thisfile_mpc_header['album_peak_db']     = $this->MPCpeakDBLookup($thisfile_mpc_header['album_peak']);
                if ($thisfile_mpc_header['raw']['album_gain'] < 0) {
                        $thisfile_mpc_header['album_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['album_gain']) / -100;
                } else {
                        $thisfile_mpc_header['album_gain_db'] = (float) $thisfile_mpc_header['raw']['album_gain'] / 100;;
                }
                $thisfile_mpc_header['encoder_version']   = $this->MPCencoderVersionLookup($thisfile_mpc_header['raw']['encoder_version']);

                $ThisFileInfo['replay_gain']['track']['adjustment'] = $thisfile_mpc_header['title_gain_db'];
                $ThisFileInfo['replay_gain']['album']['adjustment'] = $thisfile_mpc_header['album_gain_db'];

                if ($thisfile_mpc_header['title_peak'] > 0) {
                        $ThisFileInfo['replay_gain']['track']['peak'] = $thisfile_mpc_header['title_peak'];
                } elseif (round($thisfile_mpc_header['max_level'] * 1.18) > 0) {
                        $ThisFileInfo['replay_gain']['track']['peak'] = getid3_lib::CastAsInt(round($thisfile_mpc_header['max_level'] * 1.18)); // why? I don't know - see mppdec.c
                }
                if ($thisfile_mpc_header['album_peak'] > 0) {
                        $ThisFileInfo['replay_gain']['album']['peak'] = $thisfile_mpc_header['album_peak'];
                }

                //$ThisFileInfo['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_major_version'].'.'.$thisfile_mpc_header['stream_minor_version'].', '.$thisfile_mpc_header['encoder_version'];
                $ThisFileInfo['audio']['encoder'] = $thisfile_mpc_header['encoder_version'];
                $ThisFileInfo['audio']['encoder_options'] = $thisfile_mpc_header['profile'];

                return true;
        }

Here is the call graph for this function:

getid3_mpc::MPCencoderVersionLookup ( encoderversion  ) 

Definition at line 266 of file module.audio.mpc.php.

Referenced by getid3_mpc().

                                                          {
                //Encoder version * 100  (106 = 1.06)
                //EncoderVersion % 10 == 0        Release (1.0)
                //EncoderVersion %  2 == 0        Beta (1.06)
                //EncoderVersion %  2 == 1        Alpha (1.05a...z)

                if ($encoderversion == 0) {
                        // very old version, not known exactly which
                        return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05';
                }

                if (($encoderversion % 10) == 0) {

                        // release version
                        return number_format($encoderversion / 100, 2);

                } elseif (($encoderversion % 2) == 0) {

                        // beta version
                        return number_format($encoderversion / 100, 2).' beta';

                }

                // alpha version
                return number_format($encoderversion / 100, 2).' alpha';
        }

Here is the caller graph for this function:

getid3_mpc::MPCfrequencyLookup ( frequencyid  ) 

Definition at line 249 of file module.audio.mpc.php.

Referenced by getid3_mpc().

                                                  {
                static $MPCfrequencyLookup = array(
                        0 => 44100,
                        1 => 48000,
                        2 => 37800,
                        3 => 32000
                );
                return (isset($MPCfrequencyLookup[$frequencyid]) ? $MPCfrequencyLookup[$frequencyid] : 'invalid');
        }

Here is the caller graph for this function:

getid3_mpc::MPCpeakDBLookup ( intvalue  ) 

Definition at line 259 of file module.audio.mpc.php.

Referenced by getid3_mpc().

                                            {
                if ($intvalue > 0) {
                        return ((log10($intvalue) / log10(2)) - 15) * 6;
                }
                return false;
        }

Here is the caller graph for this function:

getid3_mpc::MPCprofileNameLookup ( profileid  ) 

Definition at line 227 of file module.audio.mpc.php.

Referenced by getid3_mpc().

                                                  {
                static $MPCprofileNameLookup = array(
                        0  => 'no profile',
                        1  => 'Experimental',
                        2  => 'unused',
                        3  => 'unused',
                        4  => 'unused',
                        5  => 'below Telephone (q = 0.0)',
                        6  => 'below Telephone (q = 1.0)',
                        7  => 'Telephone (q = 2.0)',
                        8  => 'Thumb (q = 3.0)',
                        9  => 'Radio (q = 4.0)',
                        10 => 'Standard (q = 5.0)',
                        11 => 'Extreme (q = 6.0)',
                        12 => 'Insane (q = 7.0)',
                        13 => 'BrainDead (q = 8.0)',
                        14 => 'above BrainDead (q = 9.0)',
                        15 => 'above BrainDead (q = 10.0)'
                );
                return (isset($MPCprofileNameLookup[$profileid]) ? $MPCprofileNameLookup[$profileid] : 'invalid');
        }

Here is the caller graph for this function:


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