GetId3() by James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g //. More...

Collaboration diagram for GetId3\Module\AudioVideo\AVCSequenceParameterSetReader:

Public Member Functions
	__construct ($sps)

	readData ()

	skipBits ($bits)

	getBit ()

	getBits ($bits)

	expGolombUe ()

	expGolombSe ()

	getWidth ()

	getHeight ()

Data Fields
	$sps

	$start = 0

	$currentBytes = 0

	$currentBits = 0

	$width

	$height

const	H264_AVC_SEQUENCE_HEADER = 0

const	H264_PROFILE_BASELINE = 66

const	H264_PROFILE_MAIN = 77

const	H264_PROFILE_EXTENDED = 88

const	H264_PROFILE_HIGH = 100

const	H264_PROFILE_HIGH10 = 110

const	H264_PROFILE_HIGH422 = 122

const	H264_PROFILE_HIGH444 = 144

const	H264_PROFILE_HIGH444_PREDICTIVE = 244

Detailed Description

GetId3() by James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g //.

AVCSequenceParameterSetReader

Author: James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g; Seth Kaufman seth@.nosp@m.whir.nosp@m.l-i-g.nosp@m.ig.c.nosp@m.om Flv http://www.getid3.org

Definition at line 30 of file AVCSequenceParameterSetReader.php.

Constructor & Destructor Documentation

◆ __construct()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::__construct ( $sps )

Parameters

type $sps

Definition at line 53 of file AVCSequenceParameterSetReader.php.

References GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\$sps.

     {
         $this->sps = $sps;
     }

Member Function Documentation

◆ expGolombSe()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::expGolombSe ( )

Returns: type

Definition at line 180 of file AVCSequenceParameterSetReader.php.

References $result, and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\expGolombUe().

Referenced by GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\readData().

     {
         $result = $this->expGolombUe();
         if (($result & 0x01) == 0) {
             return -($result >> 1);
         } else {
             return ($result + 1) >> 1;
         }
     }

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◆ expGolombUe()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::expGolombUe ( )

Returns: int

Definition at line 159 of file AVCSequenceParameterSetReader.php.

References GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\getBit(), and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\getBits().

Referenced by GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\expGolombSe(), and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\readData().

     {
         $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;
     }

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◆ getBit()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::getBit ( )

Returns: type

Definition at line 130 of file AVCSequenceParameterSetReader.php.

References GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\$currentBits, $result, GetId3\Lib\Helper\BigEndian2Int(), and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\skipBits().

Referenced by GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\expGolombUe(), GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\getBits(), and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\readData().

     {
         $result = (Helper::BigEndian2Int(substr($this->sps,
                                                            $this->currentBytes,
                                                            1)) >> (7 - $this->currentBits)) & 0x01;
         $this->skipBits(1);
 
         return $result;
     }

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◆ getBits()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::getBits ( $bits )

Parameters

type $bits

Returns: type

Definition at line 145 of file AVCSequenceParameterSetReader.php.

References $result, and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\getBit().

Referenced by GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\expGolombUe(), and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\readData().

     {
         $result = 0;
         for ($i = 0; $i < $bits; $i++) {
             $result = ($result << 1) + $this->getBit();
         }
 
         return $result;
     }

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◆ getHeight()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::getHeight ( )

Returns: type

Definition at line 203 of file AVCSequenceParameterSetReader.php.

References GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\$height.

     {
         return $this->height;
     }

◆ getWidth()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::getWidth ( )

Returns: type

Definition at line 194 of file AVCSequenceParameterSetReader.php.

References GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\$width.

     {
         return $this->width;
     }

◆ readData()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::readData ( )

Definition at line 61 of file AVCSequenceParameterSetReader.php.

References $size, array, GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\expGolombSe(), GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\expGolombUe(), GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\getBit(), GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\getBits(), and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\skipBits().

     {
         $this->skipBits(8);
         $this->skipBits(8);
         $profile = $this->getBits(8); //        read profile
         $this->skipBits(16);
         $this->expGolombUe(); //        read sps id
         if (in_array($profile,
                      array(self::H264_PROFILE_HIGH, self::H264_PROFILE_HIGH10, self::H264_PROFILE_HIGH422, self::H264_PROFILE_HIGH444, self::H264_PROFILE_HIGH444_PREDICTIVE))) {
             if ($this->expGolombUe() == 3) {
                 $this->skipBits(1);
             }
             $this->expGolombUe();
             $this->expGolombUe();
             $this->skipBits(1);
             if ($this->getBit()) {
                 for ($i = 0; $i < 8; $i++) {
                     if ($this->getBit()) {
                         $size = $i < 6 ? 16 : 64;
                         $lastScale = 8;
                         $nextScale = 8;
                         for ($j = 0; $j < $size; $j++) {
                             if ($nextScale != 0) {
                                 $deltaScale = $this->expGolombUe();
                                 $nextScale = ($lastScale + $deltaScale + 256) % 256;
                             }
                             if ($nextScale != 0) {
                                 $lastScale = $nextScale;
                             }
                         }
                     }
                 }
             }
         }
         $this->expGolombUe();
         $pocType = $this->expGolombUe();
         if ($pocType == 0) {
             $this->expGolombUe();
         } elseif ($pocType == 1) {
             $this->skipBits(1);
             $this->expGolombSe();
             $this->expGolombSe();
             $pocCycleLength = $this->expGolombUe();
             for ($i = 0; $i < $pocCycleLength; $i++) {
                 $this->expGolombSe();
             }
         }
         $this->expGolombUe();
         $this->skipBits(1);
         $this->width = ($this->expGolombUe() + 1) * 16;
         $heightMap = $this->expGolombUe() + 1;
         $this->height = (2 - $this->getBit()) * $heightMap * 16;
     }

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◆ skipBits()

GetId3\Module\AudioVideo\AVCSequenceParameterSetReader::skipBits ( $bits )

Parameters

type $bits

Definition at line 119 of file AVCSequenceParameterSetReader.php.

Referenced by GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\getBit(), and GetId3\Module\AudioVideo\AVCSequenceParameterSetReader\readData().

     {
         $newBits = $this->currentBits + $bits;
         $this->currentBytes += (int) floor($newBits / 8);
         $this->currentBits = $newBits % 8;
     }

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