public function Analyze()
{
$info =& $this->getid3->info;
// Overall tag structure:
// +-----------------------------+
// | Header (10 bytes) |
// +-----------------------------+
// | Extended Header |
// | (variable length, OPTIONAL) |
// +-----------------------------+
// | Frames (variable length) |
// +-----------------------------+
// | Padding |
// | (variable length, OPTIONAL) |
// +-----------------------------+
// | Footer (10 bytes, OPTIONAL) |
// +-----------------------------+
// Header
// ID3v2/file identifier "ID3"
// ID3v2 version $04 00
// ID3v2 flags (%ab000000 in v2.2, %abc00000 in v2.3, %abcd0000 in v2.4.x)
// ID3v2 size 4 * %0xxxxxxx
// shortcuts
$info['id3v2']['header'] = true;
$thisfile_id3v2 =& $info['id3v2'];
$thisfile_id3v2['flags'] = array();
$thisfile_id3v2_flags =& $thisfile_id3v2['flags'];
$this->fseek($this->StartingOffset);
$header = $this->fread(10);
if (substr($header, 0, 3) == 'ID3' && strlen($header) == 10) {
$thisfile_id3v2['majorversion'] = ord($header[3]);
$thisfile_id3v2['minorversion'] = ord($header[4]);
// shortcut
$id3v2_majorversion =& $thisfile_id3v2['majorversion'];
} else {
unset($info['id3v2']);
return false;
}
if ($id3v2_majorversion > 4) {
// this script probably won't correctly parse ID3v2.5.x and above (if it ever exists)
$info['error'][] = 'this script only parses up to ID3v2.4.x - this tag is ID3v2.' . $id3v2_majorversion . '.' . $thisfile_id3v2['minorversion'];
return false;
}
$id3_flags = ord($header[5]);
switch ($id3v2_majorversion) {
case 2:
// %ab000000 in v2.2
$thisfile_id3v2_flags['unsynch'] = (bool) ($id3_flags & 0x80);
// a - Unsynchronisation
$thisfile_id3v2_flags['compression'] = (bool) ($id3_flags & 0x40);
// b - Compression
break;
case 3:
// %abc00000 in v2.3
$thisfile_id3v2_flags['unsynch'] = (bool) ($id3_flags & 0x80);
// a - Unsynchronisation
$thisfile_id3v2_flags['exthead'] = (bool) ($id3_flags & 0x40);
// b - Extended header
$thisfile_id3v2_flags['experim'] = (bool) ($id3_flags & 0x20);
// c - Experimental indicator
break;
case 4:
// %abcd0000 in v2.4
$thisfile_id3v2_flags['unsynch'] = (bool) ($id3_flags & 0x80);
// a - Unsynchronisation
$thisfile_id3v2_flags['exthead'] = (bool) ($id3_flags & 0x40);
// b - Extended header
$thisfile_id3v2_flags['experim'] = (bool) ($id3_flags & 0x20);
// c - Experimental indicator
$thisfile_id3v2_flags['isfooter'] = (bool) ($id3_flags & 0x10);
// d - Footer present
break;
}
$thisfile_id3v2['headerlength'] = getid3_lib::BigEndian2Int(substr($header, 6, 4), 1) + 10;
// length of ID3v2 tag in 10-byte header doesn't include 10-byte header length
$thisfile_id3v2['tag_offset_start'] = $this->StartingOffset;
$thisfile_id3v2['tag_offset_end'] = $thisfile_id3v2['tag_offset_start'] + $thisfile_id3v2['headerlength'];
// create 'encoding' key - used by getid3::HandleAllTags()
// in ID3v2 every field can have it's own encoding type
// so force everything to UTF-8 so it can be handled consistantly
$thisfile_id3v2['encoding'] = 'UTF-8';
// Frames
// All ID3v2 frames consists of one frame header followed by one or more
// fields containing the actual information. The header is always 10
// bytes and laid out as follows:
//
// Frame ID $xx xx xx xx (four characters)
// Size 4 * %0xxxxxxx
// Flags $xx xx
$sizeofframes = $thisfile_id3v2['headerlength'] - 10;
// not including 10-byte initial header
if (!empty($thisfile_id3v2['exthead']['length'])) {
$sizeofframes -= $thisfile_id3v2['exthead']['length'] + 4;
}
if (!empty($thisfile_id3v2_flags['isfooter'])) {
$sizeofframes -= 10;
// footer takes last 10 bytes of ID3v2 header, after frame data, before audio
}
if ($sizeofframes > 0) {
$framedata = $this->fread($sizeofframes);
// read all frames from file into $framedata variable
// if entire frame data is unsynched, de-unsynch it now (ID3v2.3.x)
if (!empty($thisfile_id3v2_flags['unsynch']) && $id3v2_majorversion <= 3) {
$framedata = $this->DeUnsynchronise($framedata);
}
// [in ID3v2.4.0] Unsynchronisation [S:6.1] is done on frame level, instead
// of on tag level, making it easier to skip frames, increasing the streamability
// of the tag. The unsynchronisation flag in the header [S:3.1] indicates that
// there exists an unsynchronised frame, while the new unsynchronisation flag in
// the frame header [S:4.1.2] indicates unsynchronisation.
//$framedataoffset = 10 + ($thisfile_id3v2['exthead']['length'] ? $thisfile_id3v2['exthead']['length'] + 4 : 0); // how many bytes into the stream - start from after the 10-byte header (and extended header length+4, if present)
$framedataoffset = 10;
// how many bytes into the stream - start from after the 10-byte header
// Extended Header
if (!empty($thisfile_id3v2_flags['exthead'])) {
$extended_header_offset = 0;
if ($id3v2_majorversion == 3) {
// v2.3 definition:
//Extended header size $xx xx xx xx // 32-bit integer
//Extended Flags $xx xx
// %x0000000 %00000000 // v2.3
// x - CRC data present
//Size of padding $xx xx xx xx
$thisfile_id3v2['exthead']['length'] = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 4), 0);
$extended_header_offset += 4;
$thisfile_id3v2['exthead']['flag_bytes'] = 2;
$thisfile_id3v2['exthead']['flag_raw'] = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, $thisfile_id3v2['exthead']['flag_bytes']));
$extended_header_offset += $thisfile_id3v2['exthead']['flag_bytes'];
$thisfile_id3v2['exthead']['flags']['crc'] = (bool) ($thisfile_id3v2['exthead']['flag_raw'] & 0x8000);
$thisfile_id3v2['exthead']['padding_size'] = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 4));
$extended_header_offset += 4;
if ($thisfile_id3v2['exthead']['flags']['crc']) {
$thisfile_id3v2['exthead']['flag_data']['crc'] = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 4));
$extended_header_offset += 4;
}
$extended_header_offset += $thisfile_id3v2['exthead']['padding_size'];
} elseif ($id3v2_majorversion == 4) {
// v2.4 definition:
//Extended header size 4 * %0xxxxxxx // 28-bit synchsafe integer
//Number of flag bytes $01
//Extended Flags $xx
// %0bcd0000 // v2.4
// b - Tag is an update
// Flag data length $00
// c - CRC data present
// Flag data length $05
// Total frame CRC 5 * %0xxxxxxx
// d - Tag restrictions
// Flag data length $01
$thisfile_id3v2['exthead']['length'] = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 4), true);
$extended_header_offset += 4;
$thisfile_id3v2['exthead']['flag_bytes'] = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 1));
// should always be 1
$extended_header_offset += 1;
$thisfile_id3v2['exthead']['flag_raw'] = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, $thisfile_id3v2['exthead']['flag_bytes']));
$extended_header_offset += $thisfile_id3v2['exthead']['flag_bytes'];
$thisfile_id3v2['exthead']['flags']['update'] = (bool) ($thisfile_id3v2['exthead']['flag_raw'] & 0x40);
$thisfile_id3v2['exthead']['flags']['crc'] = (bool) ($thisfile_id3v2['exthead']['flag_raw'] & 0x20);
$thisfile_id3v2['exthead']['flags']['restrictions'] = (bool) ($thisfile_id3v2['exthead']['flag_raw'] & 0x10);
if ($thisfile_id3v2['exthead']['flags']['update']) {
$ext_header_chunk_length = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 1));
// should be 0
$extended_header_offset += 1;
}
if ($thisfile_id3v2['exthead']['flags']['crc']) {
$ext_header_chunk_length = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 1));
// should be 5
$extended_header_offset += 1;
$thisfile_id3v2['exthead']['flag_data']['crc'] = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, $ext_header_chunk_length), true, false);
$extended_header_offset += $ext_header_chunk_length;
}
if ($thisfile_id3v2['exthead']['flags']['restrictions']) {
$ext_header_chunk_length = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 1));
// should be 1
$extended_header_offset += 1;
// %ppqrrstt
$restrictions_raw = getid3_lib::BigEndian2Int(substr($framedata, $extended_header_offset, 1));
$extended_header_offset += 1;
$thisfile_id3v2['exthead']['flags']['restrictions']['tagsize'] = ($restrictions_raw & 0xc0) >> 6;
// p - Tag size restrictions
$thisfile_id3v2['exthead']['flags']['restrictions']['textenc'] = ($restrictions_raw & 0x20) >> 5;
// q - Text encoding restrictions
$thisfile_id3v2['exthead']['flags']['restrictions']['textsize'] = ($restrictions_raw & 0x18) >> 3;
// r - Text fields size restrictions
$thisfile_id3v2['exthead']['flags']['restrictions']['imgenc'] = ($restrictions_raw & 0x4) >> 2;
// s - Image encoding restrictions
$thisfile_id3v2['exthead']['flags']['restrictions']['imgsize'] = ($restrictions_raw & 0x3) >> 0;
// t - Image size restrictions
$thisfile_id3v2['exthead']['flags']['restrictions_text']['tagsize'] = $this->LookupExtendedHeaderRestrictionsTagSizeLimits($thisfile_id3v2['exthead']['flags']['restrictions']['tagsize']);
$thisfile_id3v2['exthead']['flags']['restrictions_text']['textenc'] = $this->LookupExtendedHeaderRestrictionsTextEncodings($thisfile_id3v2['exthead']['flags']['restrictions']['textenc']);
$thisfile_id3v2['exthead']['flags']['restrictions_text']['textsize'] = $this->LookupExtendedHeaderRestrictionsTextFieldSize($thisfile_id3v2['exthead']['flags']['restrictions']['textsize']);
$thisfile_id3v2['exthead']['flags']['restrictions_text']['imgenc'] = $this->LookupExtendedHeaderRestrictionsImageEncoding($thisfile_id3v2['exthead']['flags']['restrictions']['imgenc']);
$thisfile_id3v2['exthead']['flags']['restrictions_text']['imgsize'] = $this->LookupExtendedHeaderRestrictionsImageSizeSize($thisfile_id3v2['exthead']['flags']['restrictions']['imgsize']);
}
if ($thisfile_id3v2['exthead']['length'] != $extended_header_offset) {
$info['warning'][] = 'ID3v2.4 extended header length mismatch (expecting ' . intval($thisfile_id3v2['exthead']['length']) . ', found ' . intval($extended_header_offset) . ')';
}
}
$framedataoffset += $extended_header_offset;
$framedata = substr($framedata, $extended_header_offset);
}
// end extended header
while (isset($framedata) && strlen($framedata) > 0) {
// cycle through until no more frame data is left to parse
if (strlen($framedata) <= $this->ID3v2HeaderLength($id3v2_majorversion)) {
// insufficient room left in ID3v2 header for actual data - must be padding
$thisfile_id3v2['padding']['start'] = $framedataoffset;
$thisfile_id3v2['padding']['length'] = strlen($framedata);
$thisfile_id3v2['padding']['valid'] = true;
for ($i = 0; $i < $thisfile_id3v2['padding']['length']; $i++) {
if ($framedata[$i] != "") {
$thisfile_id3v2['padding']['valid'] = false;
$thisfile_id3v2['padding']['errorpos'] = $thisfile_id3v2['padding']['start'] + $i;
$info['warning'][] = 'Invalid ID3v2 padding found at offset ' . $thisfile_id3v2['padding']['errorpos'] . ' (the remaining ' . ($thisfile_id3v2['padding']['length'] - $i) . ' bytes are considered invalid)';
break;
}
}
break;
// skip rest of ID3v2 header
}
if ($id3v2_majorversion == 2) {
// Frame ID $xx xx xx (three characters)
// Size $xx xx xx (24-bit integer)
// Flags $xx xx
$frame_header = substr($framedata, 0, 6);
// take next 6 bytes for header
$framedata = substr($framedata, 6);
// and leave the rest in $framedata
$frame_name = substr($frame_header, 0, 3);
$frame_size = getid3_lib::BigEndian2Int(substr($frame_header, 3, 3), 0);
$frame_flags = 0;
// not used for anything in ID3v2.2, just set to avoid E_NOTICEs
} elseif ($id3v2_majorversion > 2) {
// Frame ID $xx xx xx xx (four characters)
// Size $xx xx xx xx (32-bit integer in v2.3, 28-bit synchsafe in v2.4+)
// Flags $xx xx
$frame_header = substr($framedata, 0, 10);
// take next 10 bytes for header
$framedata = substr($framedata, 10);
// and leave the rest in $framedata
$frame_name = substr($frame_header, 0, 4);
if ($id3v2_majorversion == 3) {
$frame_size = getid3_lib::BigEndian2Int(substr($frame_header, 4, 4), 0);
// 32-bit integer
} else {
// ID3v2.4+
$frame_size = getid3_lib::BigEndian2Int(substr($frame_header, 4, 4), 1);
// 32-bit synchsafe integer (28-bit value)
}
if ($frame_size < strlen($framedata) + 4) {
$nextFrameID = substr($framedata, $frame_size, 4);
if ($this->IsValidID3v2FrameName($nextFrameID, $id3v2_majorversion)) {
// next frame is OK
} elseif ($frame_name == "" . 'MP3' || $frame_name == "" . 'MP' || $frame_name == ' MP3' || $frame_name == 'MP3e') {
// MP3ext known broken frames - "ok" for the purposes of this test
} elseif ($id3v2_majorversion == 4 && $this->IsValidID3v2FrameName(substr($framedata, getid3_lib::BigEndian2Int(substr($frame_header, 4, 4), 0), 4), 3)) {
$info['warning'][] = 'ID3v2 tag written as ID3v2.4, but with non-synchsafe integers (ID3v2.3 style). Older versions of (Helium2; iTunes) are known culprits of this. Tag has been parsed as ID3v2.3';
$id3v2_majorversion = 3;
$frame_size = getid3_lib::BigEndian2Int(substr($frame_header, 4, 4), 0);
// 32-bit integer
}
}
$frame_flags = getid3_lib::BigEndian2Int(substr($frame_header, 8, 2));
}
if ($id3v2_majorversion == 2 && $frame_name == "" || $frame_name == "") {
// padding encountered
$thisfile_id3v2['padding']['start'] = $framedataoffset;
$thisfile_id3v2['padding']['length'] = strlen($frame_header) + strlen($framedata);
$thisfile_id3v2['padding']['valid'] = true;
$len = strlen($framedata);
for ($i = 0; $i < $len; $i++) {
if ($framedata[$i] != "") {
$thisfile_id3v2['padding']['valid'] = false;
$thisfile_id3v2['padding']['errorpos'] = $thisfile_id3v2['padding']['start'] + $i;
$info['warning'][] = 'Invalid ID3v2 padding found at offset ' . $thisfile_id3v2['padding']['errorpos'] . ' (the remaining ' . ($thisfile_id3v2['padding']['length'] - $i) . ' bytes are considered invalid)';
break;
}
}
break;
// skip rest of ID3v2 header
}
if ($frame_name == 'COM ') {
$info['warning'][] = 'error parsing "' . $frame_name . '" (' . $framedataoffset . ' bytes into the ID3v2.' . $id3v2_majorversion . ' tag). (ERROR: IsValidID3v2FrameName("' . str_replace("", ' ', $frame_name) . '", ' . $id3v2_majorversion . '))). [Note: this particular error has been known to happen with tags edited by iTunes (versions "X v2.0.3", "v3.0.1" are known-guilty, probably others too)]';
$frame_name = 'COMM';
}
if ($frame_size <= strlen($framedata) && $this->IsValidID3v2FrameName($frame_name, $id3v2_majorversion)) {
unset($parsedFrame);
$parsedFrame['frame_name'] = $frame_name;
$parsedFrame['frame_flags_raw'] = $frame_flags;
$parsedFrame['data'] = substr($framedata, 0, $frame_size);
$parsedFrame['datalength'] = getid3_lib::CastAsInt($frame_size);
$parsedFrame['dataoffset'] = $framedataoffset;
$this->ParseID3v2Frame($parsedFrame);
$thisfile_id3v2[$frame_name][] = $parsedFrame;
$framedata = substr($framedata, $frame_size);
} else {
// invalid frame length or FrameID
if ($frame_size <= strlen($framedata)) {
if ($this->IsValidID3v2FrameName(substr($framedata, $frame_size, 4), $id3v2_majorversion)) {
// next frame is valid, just skip the current frame
$framedata = substr($framedata, $frame_size);
$info['warning'][] = 'Next ID3v2 frame is valid, skipping current frame.';
} else {
// next frame is invalid too, abort processing
//unset($framedata);
$framedata = null;
$info['error'][] = 'Next ID3v2 frame is also invalid, aborting processing.';
}
} elseif ($frame_size == strlen($framedata)) {
// this is the last frame, just skip
$info['warning'][] = 'This was the last ID3v2 frame.';
} else {
// next frame is invalid too, abort processing
//unset($framedata);
$framedata = null;
$info['warning'][] = 'Invalid ID3v2 frame size, aborting.';
}
if (!$this->IsValidID3v2FrameName($frame_name, $id3v2_majorversion)) {
switch ($frame_name) {
case "" . 'MP':
case "" . 'MP3':
case ' MP3':
case 'MP3e':
case "" . 'MP':
case ' MP':
case 'MP3':
$info['warning'][] = 'error parsing "' . $frame_name . '" (' . $framedataoffset . ' bytes into the ID3v2.' . $id3v2_majorversion . ' tag). (ERROR: !IsValidID3v2FrameName("' . str_replace("", ' ', $frame_name) . '", ' . $id3v2_majorversion . '))). [Note: this particular error has been known to happen with tags edited by "MP3ext (www.mutschler.de/mp3ext/)"]';
break;
default:
$info['warning'][] = 'error parsing "' . $frame_name . '" (' . $framedataoffset . ' bytes into the ID3v2.' . $id3v2_majorversion . ' tag). (ERROR: !IsValidID3v2FrameName("' . str_replace("", ' ', $frame_name) . '", ' . $id3v2_majorversion . '))).';
break;
}
} elseif (!isset($framedata) || $frame_size > strlen($framedata)) {
$info['error'][] = 'error parsing "' . $frame_name . '" (' . $framedataoffset . ' bytes into the ID3v2.' . $id3v2_majorversion . ' tag). (ERROR: $frame_size (' . $frame_size . ') > strlen($framedata) (' . (isset($framedata) ? strlen($framedata) : 'null') . ')).';
} else {
$info['error'][] = 'error parsing "' . $frame_name . '" (' . $framedataoffset . ' bytes into the ID3v2.' . $id3v2_majorversion . ' tag).';
}
}
$framedataoffset += $frame_size + $this->ID3v2HeaderLength($id3v2_majorversion);
}
}
// Footer
// The footer is a copy of the header, but with a different identifier.
// ID3v2 identifier "3DI"
// ID3v2 version $04 00
// ID3v2 flags %abcd0000
// ID3v2 size 4 * %0xxxxxxx
if (isset($thisfile_id3v2_flags['isfooter']) && $thisfile_id3v2_flags['isfooter']) {
$footer = $this->fread(10);
if (substr($footer, 0, 3) == '3DI') {
$thisfile_id3v2['footer'] = true;
$thisfile_id3v2['majorversion_footer'] = ord($footer[3]);
$thisfile_id3v2['minorversion_footer'] = ord($footer[4]);
}
if ($thisfile_id3v2['majorversion_footer'] <= 4) {
$id3_flags = ord(substr($footer[5]));
$thisfile_id3v2_flags['unsynch_footer'] = (bool) ($id3_flags & 0x80);
$thisfile_id3v2_flags['extfoot_footer'] = (bool) ($id3_flags & 0x40);
$thisfile_id3v2_flags['experim_footer'] = (bool) ($id3_flags & 0x20);
$thisfile_id3v2_flags['isfooter_footer'] = (bool) ($id3_flags & 0x10);
$thisfile_id3v2['footerlength'] = getid3_lib::BigEndian2Int(substr($footer, 6, 4), 1);
}
}
// end footer
if (isset($thisfile_id3v2['comments']['genre'])) {
$genre = array();
foreach ($thisfile_id3v2['comments']['genre'] as $key => $value) {
unset($thisfile_id3v2['comments']['genre'][$key]);
$genre = getid3_lib::flipped_array_merge_noclobber($genre, $this->ParseID3v2GenreString($value));
}
$thisfile_id3v2['comments']['genre'] = getid3_lib::flipped_array_merge_noclobber($thisfile_id3v2['comments']['genre'], $genre);
}
if (isset($thisfile_id3v2['comments']['track'])) {
foreach ($thisfile_id3v2['comments']['track'] as $key => $value) {
if (strstr($value, '/')) {
list($thisfile_id3v2['comments']['tracknum'][$key], $thisfile_id3v2['comments']['totaltracks'][$key]) = explode('/', $thisfile_id3v2['comments']['track'][$key]);
}
}
}
if (!isset($thisfile_id3v2['comments']['year']) && !empty($thisfile_id3v2['comments']['recording_time'][0]) && preg_match('#^([0-9]{4})#', trim($thisfile_id3v2['comments']['recording_time'][0]), $matches)) {
$thisfile_id3v2['comments']['year'] = array($matches[1]);
}
if (!empty($thisfile_id3v2['TXXX'])) {
// MediaMonkey does this, maybe others: write a blank RGAD frame, but put replay-gain adjustment values in TXXX frames
foreach ($thisfile_id3v2['TXXX'] as $txxx_array) {
switch ($txxx_array['description']) {
case 'replaygain_track_gain':
if (empty($info['replay_gain']['track']['adjustment']) && !empty($txxx_array['data'])) {
$info['replay_gain']['track']['adjustment'] = floatval(trim(str_replace('dB', '', $txxx_array['data'])));
}
break;
case 'replaygain_track_peak':
if (empty($info['replay_gain']['track']['peak']) && !empty($txxx_array['data'])) {
$info['replay_gain']['track']['peak'] = floatval($txxx_array['data']);
}
break;
case 'replaygain_album_gain':
if (empty($info['replay_gain']['album']['adjustment']) && !empty($txxx_array['data'])) {
$info['replay_gain']['album']['adjustment'] = floatval(trim(str_replace('dB', '', $txxx_array['data'])));
}
break;
}
}
}
// Set avdataoffset
$info['avdataoffset'] = $thisfile_id3v2['headerlength'];
if (isset($thisfile_id3v2['footer'])) {
$info['avdataoffset'] += 10;
}
return true;
}
