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php7-mysql-data/Kapitel_7/Lektion_4/wordpress/wp-includes/ID3/module.audio-video.flv.php
Jan Unger 88cf71d772 Initiale Version
2016-08-21 00:15:10 +02:00

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<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org> //
// available at http://getid3.sourceforge.net //
// or http://www.getid3.org //
// also https://github.com/JamesHeinrich/getID3 //
// //
// FLV module by Seth Kaufman <sethØwhirl-i-gig*com> //
// //
// * version 0.1 (26 June 2005) //
// //
// //
// * version 0.1.1 (15 July 2005) //
// minor modifications by James Heinrich <info@getid3.org> //
// //
// * version 0.2 (22 February 2006) //
// Support for On2 VP6 codec and meta information //
// by Steve Webster <steve.websterØfeaturecreep*com> //
// //
// * version 0.3 (15 June 2006) //
// Modified to not read entire file into memory //
// by James Heinrich <info@getid3.org> //
// //
// * version 0.4 (07 December 2007) //
// Bugfixes for incorrectly parsed FLV dimensions //
// and incorrect parsing of onMetaTag //
// by Evgeny Moysevich <moysevichØgmail*com> //
// //
// * version 0.5 (21 May 2009) //
// Fixed parsing of audio tags and added additional codec //
// details. The duration is now read from onMetaTag (if //
// exists), rather than parsing whole file //
// by Nigel Barnes <ngbarnesØhotmail*com> //
// //
// * version 0.6 (24 May 2009) //
// Better parsing of files with h264 video //
// by Evgeny Moysevich <moysevichØgmail*com> //
// //
// * version 0.6.1 (30 May 2011) //
// prevent infinite loops in expGolombUe() //
// //
// * version 0.7.0 (16 Jul 2013) //
// handle GETID3_FLV_VIDEO_VP6FLV_ALPHA //
// improved AVCSequenceParameterSetReader::readData() //
// by Xander Schouwerwou <schouwerwouØgmail*com> //
// //
/////////////////////////////////////////////////////////////////
// //
// module.audio-video.flv.php //
// module for analyzing Shockwave Flash Video files //
// dependencies: NONE //
// ///
/////////////////////////////////////////////////////////////////
define('GETID3_FLV_TAG_AUDIO', 8);
define('GETID3_FLV_TAG_VIDEO', 9);
define('GETID3_FLV_TAG_META', 18);
define('GETID3_FLV_VIDEO_H263', 2);
define('GETID3_FLV_VIDEO_SCREEN', 3);
define('GETID3_FLV_VIDEO_VP6FLV', 4);
define('GETID3_FLV_VIDEO_VP6FLV_ALPHA', 5);
define('GETID3_FLV_VIDEO_SCREENV2', 6);
define('GETID3_FLV_VIDEO_H264', 7);
define('H264_AVC_SEQUENCE_HEADER', 0);
define('H264_PROFILE_BASELINE', 66);
define('H264_PROFILE_MAIN', 77);
define('H264_PROFILE_EXTENDED', 88);
define('H264_PROFILE_HIGH', 100);
define('H264_PROFILE_HIGH10', 110);
define('H264_PROFILE_HIGH422', 122);
define('H264_PROFILE_HIGH444', 144);
define('H264_PROFILE_HIGH444_PREDICTIVE', 244);
class getid3_flv extends getid3_handler {
const magic = 'FLV';
public $max_frames = 100000; // break out of the loop if too many frames have been scanned; only scan this many if meta frame does not contain useful duration
public function Analyze() {
$info = &$this->getid3->info;
$this->fseek($info['avdataoffset']);
$FLVdataLength = $info['avdataend'] - $info['avdataoffset'];
$FLVheader = $this->fread(5);
$info['fileformat'] = 'flv';
$info['flv']['header']['signature'] = substr($FLVheader, 0, 3);
$info['flv']['header']['version'] = getid3_lib::BigEndian2Int(substr($FLVheader, 3, 1));
$TypeFlags = getid3_lib::BigEndian2Int(substr($FLVheader, 4, 1));
if ($info['flv']['header']['signature'] != self::magic) {
$info['error'][] = 'Expecting "'.getid3_lib::PrintHexBytes(self::magic).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($info['flv']['header']['signature']).'"';
unset($info['flv'], $info['fileformat']);
return false;
}
$info['flv']['header']['hasAudio'] = (bool) ($TypeFlags & 0x04);
$info['flv']['header']['hasVideo'] = (bool) ($TypeFlags & 0x01);
$FrameSizeDataLength = getid3_lib::BigEndian2Int($this->fread(4));
$FLVheaderFrameLength = 9;
if ($FrameSizeDataLength > $FLVheaderFrameLength) {
$this->fseek($FrameSizeDataLength - $FLVheaderFrameLength, SEEK_CUR);
}
$Duration = 0;
$found_video = false;
$found_audio = false;
$found_meta = false;
$found_valid_meta_playtime = false;
$tagParseCount = 0;
$info['flv']['framecount'] = array('total'=>0, 'audio'=>0, 'video'=>0);
$flv_framecount = &$info['flv']['framecount'];
while ((($this->ftell() + 16) < $info['avdataend']) && (($tagParseCount++ <= $this->max_frames) || !$found_valid_meta_playtime)) {
$ThisTagHeader = $this->fread(16);
$PreviousTagLength = getid3_lib::BigEndian2Int(substr($ThisTagHeader, 0, 4));
$TagType = getid3_lib::BigEndian2Int(substr($ThisTagHeader, 4, 1));
$DataLength = getid3_lib::BigEndian2Int(substr($ThisTagHeader, 5, 3));
$Timestamp = getid3_lib::BigEndian2Int(substr($ThisTagHeader, 8, 3));
$LastHeaderByte = getid3_lib::BigEndian2Int(substr($ThisTagHeader, 15, 1));
$NextOffset = $this->ftell() - 1 + $DataLength;
if ($Timestamp > $Duration) {
$Duration = $Timestamp;
}
$flv_framecount['total']++;
switch ($TagType) {
case GETID3_FLV_TAG_AUDIO:
$flv_framecount['audio']++;
if (!$found_audio) {
$found_audio = true;
$info['flv']['audio']['audioFormat'] = ($LastHeaderByte >> 4) & 0x0F;
$info['flv']['audio']['audioRate'] = ($LastHeaderByte >> 2) & 0x03;
$info['flv']['audio']['audioSampleSize'] = ($LastHeaderByte >> 1) & 0x01;
$info['flv']['audio']['audioType'] = $LastHeaderByte & 0x01;
}
break;
case GETID3_FLV_TAG_VIDEO:
$flv_framecount['video']++;
if (!$found_video) {
$found_video = true;
$info['flv']['video']['videoCodec'] = $LastHeaderByte & 0x07;
$FLVvideoHeader = $this->fread(11);
if ($info['flv']['video']['videoCodec'] == GETID3_FLV_VIDEO_H264) {
// this code block contributed by: moysevichØgmail*com
$AVCPacketType = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 0, 1));
if ($AVCPacketType == H264_AVC_SEQUENCE_HEADER) {
// read AVCDecoderConfigurationRecord
$configurationVersion = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 4, 1));
$AVCProfileIndication = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 5, 1));
$profile_compatibility = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 6, 1));
$lengthSizeMinusOne = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 7, 1));
$numOfSequenceParameterSets = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 8, 1));
if (($numOfSequenceParameterSets & 0x1F) != 0) {
// there is at least one SequenceParameterSet
// read size of the first SequenceParameterSet
//$spsSize = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 9, 2));
$spsSize = getid3_lib::LittleEndian2Int(substr($FLVvideoHeader, 9, 2));
// read the first SequenceParameterSet
$sps = $this->fread($spsSize);
if (strlen($sps) == $spsSize) { // make sure that whole SequenceParameterSet was red
$spsReader = new AVCSequenceParameterSetReader($sps);
$spsReader->readData();
$info['video']['resolution_x'] = $spsReader->getWidth();
$info['video']['resolution_y'] = $spsReader->getHeight();
}
}
}
// end: moysevichØgmail*com
} elseif ($info['flv']['video']['videoCodec'] == GETID3_FLV_VIDEO_H263) {
$PictureSizeType = (getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 3, 2))) >> 7;
$PictureSizeType = $PictureSizeType & 0x0007;
$info['flv']['header']['videoSizeType'] = $PictureSizeType;
switch ($PictureSizeType) {
case 0:
//$PictureSizeEnc = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 5, 2));
//$PictureSizeEnc <<= 1;
//$info['video']['resolution_x'] = ($PictureSizeEnc & 0xFF00) >> 8;
//$PictureSizeEnc = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 6, 2));
//$PictureSizeEnc <<= 1;
//$info['video']['resolution_y'] = ($PictureSizeEnc & 0xFF00) >> 8;
$PictureSizeEnc['x'] = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 4, 2)) >> 7;
$PictureSizeEnc['y'] = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 5, 2)) >> 7;
$info['video']['resolution_x'] = $PictureSizeEnc['x'] & 0xFF;
$info['video']['resolution_y'] = $PictureSizeEnc['y'] & 0xFF;
break;
case 1:
$PictureSizeEnc['x'] = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 4, 3)) >> 7;
$PictureSizeEnc['y'] = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 6, 3)) >> 7;
$info['video']['resolution_x'] = $PictureSizeEnc['x'] & 0xFFFF;
$info['video']['resolution_y'] = $PictureSizeEnc['y'] & 0xFFFF;
break;
case 2:
$info['video']['resolution_x'] = 352;
$info['video']['resolution_y'] = 288;
break;
case 3:
$info['video']['resolution_x'] = 176;
$info['video']['resolution_y'] = 144;
break;
case 4:
$info['video']['resolution_x'] = 128;
$info['video']['resolution_y'] = 96;
break;
case 5:
$info['video']['resolution_x'] = 320;
$info['video']['resolution_y'] = 240;
break;
case 6:
$info['video']['resolution_x'] = 160;
$info['video']['resolution_y'] = 120;
break;
default:
$info['video']['resolution_x'] = 0;
$info['video']['resolution_y'] = 0;
break;
}
} elseif ($info['flv']['video']['videoCodec'] == GETID3_FLV_VIDEO_VP6FLV_ALPHA) {
/* contributed by schouwerwouØgmail*com */
if (!isset($info['video']['resolution_x'])) { // only when meta data isn't set
$PictureSizeEnc['x'] = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 6, 2));
$PictureSizeEnc['y'] = getid3_lib::BigEndian2Int(substr($FLVvideoHeader, 7, 2));
$info['video']['resolution_x'] = ($PictureSizeEnc['x'] & 0xFF) << 3;
$info['video']['resolution_y'] = ($PictureSizeEnc['y'] & 0xFF) << 3;
}
/* end schouwerwouØgmail*com */
}
if (!empty($info['video']['resolution_x']) && !empty($info['video']['resolution_y'])) {
$info['video']['pixel_aspect_ratio'] = $info['video']['resolution_x'] / $info['video']['resolution_y'];
}
}
break;
// Meta tag
case GETID3_FLV_TAG_META:
if (!$found_meta) {
$found_meta = true;
$this->fseek(-1, SEEK_CUR);
$datachunk = $this->fread($DataLength);
$AMFstream = new AMFStream($datachunk);
$reader = new AMFReader($AMFstream);
$eventName = $reader->readData();
$info['flv']['meta'][$eventName] = $reader->readData();
unset($reader);
$copykeys = array('framerate'=>'frame_rate', 'width'=>'resolution_x', 'height'=>'resolution_y', 'audiodatarate'=>'bitrate', 'videodatarate'=>'bitrate');
foreach ($copykeys as $sourcekey => $destkey) {
if (isset($info['flv']['meta']['onMetaData'][$sourcekey])) {
switch ($sourcekey) {
case 'width':
case 'height':
$info['video'][$destkey] = intval(round($info['flv']['meta']['onMetaData'][$sourcekey]));
break;
case 'audiodatarate':
$info['audio'][$destkey] = getid3_lib::CastAsInt(round($info['flv']['meta']['onMetaData'][$sourcekey] * 1000));
break;
case 'videodatarate':
case 'frame_rate':
default:
$info['video'][$destkey] = $info['flv']['meta']['onMetaData'][$sourcekey];
break;
}
}
}
if (!empty($info['flv']['meta']['onMetaData']['duration'])) {
$found_valid_meta_playtime = true;
}
}
break;
default:
// noop
break;
}
$this->fseek($NextOffset);
}
$info['playtime_seconds'] = $Duration / 1000;
if ($info['playtime_seconds'] > 0) {
$info['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
}
if ($info['flv']['header']['hasAudio']) {
$info['audio']['codec'] = self::audioFormatLookup($info['flv']['audio']['audioFormat']);
$info['audio']['sample_rate'] = self::audioRateLookup($info['flv']['audio']['audioRate']);
$info['audio']['bits_per_sample'] = self::audioBitDepthLookup($info['flv']['audio']['audioSampleSize']);
$info['audio']['channels'] = $info['flv']['audio']['audioType'] + 1; // 0=mono,1=stereo
$info['audio']['lossless'] = ($info['flv']['audio']['audioFormat'] ? false : true); // 0=uncompressed
$info['audio']['dataformat'] = 'flv';
}
if (!empty($info['flv']['header']['hasVideo'])) {
$info['video']['codec'] = self::videoCodecLookup($info['flv']['video']['videoCodec']);
$info['video']['dataformat'] = 'flv';
$info['video']['lossless'] = false;
}
// Set information from meta
if (!empty($info['flv']['meta']['onMetaData']['duration'])) {
$info['playtime_seconds'] = $info['flv']['meta']['onMetaData']['duration'];
$info['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
}
if (isset($info['flv']['meta']['onMetaData']['audiocodecid'])) {
$info['audio']['codec'] = self::audioFormatLookup($info['flv']['meta']['onMetaData']['audiocodecid']);
}
if (isset($info['flv']['meta']['onMetaData']['videocodecid'])) {
$info['video']['codec'] = self::videoCodecLookup($info['flv']['meta']['onMetaData']['videocodecid']);
}
return true;
}
public static function audioFormatLookup($id) {
static $lookup = array(
0 => 'Linear PCM, platform endian',
1 => 'ADPCM',
2 => 'mp3',
3 => 'Linear PCM, little endian',
4 => 'Nellymoser 16kHz mono',
5 => 'Nellymoser 8kHz mono',
6 => 'Nellymoser',
7 => 'G.711A-law logarithmic PCM',
8 => 'G.711 mu-law logarithmic PCM',
9 => 'reserved',
10 => 'AAC',
11 => 'Speex',
12 => false, // unknown?
13 => false, // unknown?
14 => 'mp3 8kHz',
15 => 'Device-specific sound',
);
return (isset($lookup[$id]) ? $lookup[$id] : false);
}
public static function audioRateLookup($id) {
static $lookup = array(
0 => 5500,
1 => 11025,
2 => 22050,
3 => 44100,
);
return (isset($lookup[$id]) ? $lookup[$id] : false);
}
public static function audioBitDepthLookup($id) {
static $lookup = array(
0 => 8,
1 => 16,
);
return (isset($lookup[$id]) ? $lookup[$id] : false);
}
public static function videoCodecLookup($id) {
static $lookup = array(
GETID3_FLV_VIDEO_H263 => 'Sorenson H.263',
GETID3_FLV_VIDEO_SCREEN => 'Screen video',
GETID3_FLV_VIDEO_VP6FLV => 'On2 VP6',
GETID3_FLV_VIDEO_VP6FLV_ALPHA => 'On2 VP6 with alpha channel',
GETID3_FLV_VIDEO_SCREENV2 => 'Screen video v2',
GETID3_FLV_VIDEO_H264 => 'Sorenson H.264',
);
return (isset($lookup[$id]) ? $lookup[$id] : false);
}
}
class AMFStream {
public $bytes;
public $pos;
public function __construct(&$bytes) {
$this->bytes =& $bytes;
$this->pos = 0;
}
public function readByte() {
return getid3_lib::BigEndian2Int(substr($this->bytes, $this->pos++, 1));
}
public function readInt() {
return ($this->readByte() << 8) + $this->readByte();
}
public function readLong() {
return ($this->readByte() << 24) + ($this->readByte() << 16) + ($this->readByte() << 8) + $this->readByte();
}
public function readDouble() {
return getid3_lib::BigEndian2Float($this->read(8));
}
public function readUTF() {
$length = $this->readInt();
return $this->read($length);
}
public function readLongUTF() {
$length = $this->readLong();
return $this->read($length);
}
public function read($length) {
$val = substr($this->bytes, $this->pos, $length);
$this->pos += $length;
return $val;
}
public function peekByte() {
$pos = $this->pos;
$val = $this->readByte();
$this->pos = $pos;
return $val;
}
public function peekInt() {
$pos = $this->pos;
$val = $this->readInt();
$this->pos = $pos;
return $val;
}
public function peekLong() {
$pos = $this->pos;
$val = $this->readLong();
$this->pos = $pos;
return $val;
}
public function peekDouble() {
$pos = $this->pos;
$val = $this->readDouble();
$this->pos = $pos;
return $val;
}
public function peekUTF() {
$pos = $this->pos;
$val = $this->readUTF();
$this->pos = $pos;
return $val;
}
public function peekLongUTF() {
$pos = $this->pos;
$val = $this->readLongUTF();
$this->pos = $pos;
return $val;
}
}
class AMFReader {
public $stream;
public function __construct(&$stream) {
$this->stream =& $stream;
}
public function readData() {
$value = null;
$type = $this->stream->readByte();
switch ($type) {
// Double
case 0:
$value = $this->readDouble();
break;
// Boolean
case 1:
$value = $this->readBoolean();
break;
// String
case 2:
$value = $this->readString();
break;
// Object
case 3:
$value = $this->readObject();
break;
// null
case 6:
return null;
break;
// Mixed array
case 8:
$value = $this->readMixedArray();
break;
// Array
case 10:
$value = $this->readArray();
break;
// Date
case 11:
$value = $this->readDate();
break;
// Long string
case 13:
$value = $this->readLongString();
break;
// XML (handled as string)
case 15:
$value = $this->readXML();
break;
// Typed object (handled as object)
case 16:
$value = $this->readTypedObject();
break;
// Long string
default:
$value = '(unknown or unsupported data type)';
break;
}
return $value;
}
public function readDouble() {
return $this->stream->readDouble();
}
public function readBoolean() {
return $this->stream->readByte() == 1;
}
public function readString() {
return $this->stream->readUTF();
}
public function readObject() {
// Get highest numerical index - ignored
// $highestIndex = $this->stream->readLong();
$data = array();
while ($key = $this->stream->readUTF()) {
$data[$key] = $this->readData();
}
// Mixed array record ends with empty string (0x00 0x00) and 0x09
if (($key == '') && ($this->stream->peekByte() == 0x09)) {
// Consume byte
$this->stream->readByte();
}
return $data;
}
public function readMixedArray() {
// Get highest numerical index - ignored
$highestIndex = $this->stream->readLong();
$data = array();
while ($key = $this->stream->readUTF()) {
if (is_numeric($key)) {
$key = (float) $key;
}
$data[$key] = $this->readData();
}
// Mixed array record ends with empty string (0x00 0x00) and 0x09
if (($key == '') && ($this->stream->peekByte() == 0x09)) {
// Consume byte
$this->stream->readByte();
}
return $data;
}
public function readArray() {
$length = $this->stream->readLong();
$data = array();
for ($i = 0; $i < $length; $i++) {
$data[] = $this->readData();
}
return $data;
}
public function readDate() {
$timestamp = $this->stream->readDouble();
$timezone = $this->stream->readInt();
return $timestamp;
}
public function readLongString() {
return $this->stream->readLongUTF();
}
public function readXML() {
return $this->stream->readLongUTF();
}
public function readTypedObject() {
$className = $this->stream->readUTF();
return $this->readObject();
}
}
class AVCSequenceParameterSetReader {
public $sps;
public $start = 0;
public $currentBytes = 0;
public $currentBits = 0;
public $width;
public $height;
public function __construct($sps) {
$this->sps = $sps;
}
public function readData() {
$this->skipBits(8);
$this->skipBits(8);
$profile = $this->getBits(8); // read profile
if ($profile > 0) {
$this->skipBits(8);
$level_idc = $this->getBits(8); // level_idc
$this->expGolombUe(); // seq_parameter_set_id // sps
$this->expGolombUe(); // log2_max_frame_num_minus4
$picOrderType = $this->expGolombUe(); // pic_order_cnt_type
if ($picOrderType == 0) {
$this->expGolombUe(); // log2_max_pic_order_cnt_lsb_minus4
} elseif ($picOrderType == 1) {
$this->skipBits(1); // delta_pic_order_always_zero_flag
$this->expGolombSe(); // offset_for_non_ref_pic
$this->expGolombSe(); // offset_for_top_to_bottom_field
$num_ref_frames_in_pic_order_cnt_cycle = $this->expGolombUe(); // num_ref_frames_in_pic_order_cnt_cycle
for ($i = 0; $i < $num_ref_frames_in_pic_order_cnt_cycle; $i++) {
$this->expGolombSe(); // offset_for_ref_frame[ i ]
}
}
$this->expGolombUe(); // num_ref_frames
$this->skipBits(1); // gaps_in_frame_num_value_allowed_flag
$pic_width_in_mbs_minus1 = $this->expGolombUe(); // pic_width_in_mbs_minus1
$pic_height_in_map_units_minus1 = $this->expGolombUe(); // pic_height_in_map_units_minus1
$frame_mbs_only_flag = $this->getBits(1); // frame_mbs_only_flag
if ($frame_mbs_only_flag == 0) {
$this->skipBits(1); // mb_adaptive_frame_field_flag
}
$this->skipBits(1); // direct_8x8_inference_flag
$frame_cropping_flag = $this->getBits(1); // frame_cropping_flag
$frame_crop_left_offset = 0;
$frame_crop_right_offset = 0;
$frame_crop_top_offset = 0;
$frame_crop_bottom_offset = 0;
if ($frame_cropping_flag) {
$frame_crop_left_offset = $this->expGolombUe(); // frame_crop_left_offset
$frame_crop_right_offset = $this->expGolombUe(); // frame_crop_right_offset
$frame_crop_top_offset = $this->expGolombUe(); // frame_crop_top_offset
$frame_crop_bottom_offset = $this->expGolombUe(); // frame_crop_bottom_offset
}
$this->skipBits(1); // vui_parameters_present_flag
// etc
$this->width = (($pic_width_in_mbs_minus1 + 1) * 16) - ($frame_crop_left_offset * 2) - ($frame_crop_right_offset * 2);
$this->height = ((2 - $frame_mbs_only_flag) * ($pic_height_in_map_units_minus1 + 1) * 16) - ($frame_crop_top_offset * 2) - ($frame_crop_bottom_offset * 2);
}
}
public function skipBits($bits) {
$newBits = $this->currentBits + $bits;
$this->currentBytes += (int)floor($newBits / 8);
$this->currentBits = $newBits % 8;
}
public function getBit() {
$result = (getid3_lib::BigEndian2Int(substr($this->sps, $this->currentBytes, 1)) >> (7 - $this->currentBits)) & 0x01;
$this->skipBits(1);
return $result;
}
public function getBits($bits) {
$result = 0;
for ($i = 0; $i < $bits; $i++) {
$result = ($result << 1) + $this->getBit();
}
return $result;
}
public function expGolombUe() {
$significantBits = 0;
$bit = $this->getBit();
while ($bit == 0) {
$significantBits++;
$bit = $this->getBit();
if ($significantBits > 31) {
// something is broken, this is an emergency escape to prevent infinite loops
return 0;
}
}
return (1 << $significantBits) + $this->getBits($significantBits) - 1;
}
public function expGolombSe() {
$result = $this->expGolombUe();
if (($result & 0x01) == 0) {
return -($result >> 1);
} else {
return ($result + 1) >> 1;
}
}
public function getWidth() {
return $this->width;
}
public function getHeight() {
return $this->height;
}
}
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