Created
September 23, 2012 11:30
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Resizes Animated GIF Files (resize each frame)
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| <? | |
| /** | |
| * Resizes Animated GIF Files | |
| * | |
| * ///IMPORTANT NOTE: The script needs a temporary directory where all the frames should be extracted. | |
| * Create a directory with a 777 permission level and write the path into $temp_dir variable below. | |
| * | |
| * Default directory is "frames". | |
| */ | |
| class gifresizer { | |
| public $temp_dir = "frames"; | |
| private $pointer = 0; | |
| private $index = 0; | |
| private $globaldata = array(); | |
| private $imagedata = array(); | |
| private $imageinfo = array(); | |
| private $handle = 0; | |
| private $orgvars = array(); | |
| private $encdata = array(); | |
| private $parsedfiles = array(); | |
| private $originalwidth = 0; | |
| private $originalheight = 0; | |
| private $wr,$hr; | |
| private $props = array(); | |
| private $decoding = false; | |
| /** | |
| * Public part of the class | |
| * | |
| * @orgfile - Original file path | |
| * @newfile - New filename with path | |
| * @width - Desired image width | |
| * @height - Desired image height | |
| */ | |
| function resize($orgfile,$newfile,$width,$height){ | |
| $this->decode($orgfile); | |
| $this->wr=$width/$this->originalwidth; | |
| $this->hr=$height/$this->originalheight; | |
| $this->resizeframes(); | |
| $this->encode($newfile,$width,$height); | |
| $this->clearframes(); | |
| } | |
| /** | |
| * GIF Decoder function. | |
| * Parses the GIF animation into single frames. | |
| */ | |
| private function decode($filename){ | |
| $this->decoding = true; | |
| $this->clearvariables(); | |
| $this->loadfile($filename); | |
| $this->get_gif_header(); | |
| $this->get_graphics_extension(0); | |
| $this->get_application_data(); | |
| $this->get_application_data(); | |
| $this->get_image_block(0); | |
| $this->get_graphics_extension(1); | |
| $this->get_comment_data(); | |
| $this->get_application_data(); | |
| $this->get_image_block(1); | |
| while(!$this->checkbyte(0x3b) && !$this->checkEOF()){ | |
| $this->get_comment_data(1); | |
| $this->get_graphics_extension(2); | |
| $this->get_image_block(2); | |
| } | |
| $this->writeframes(time()); | |
| $this->closefile(); | |
| $this->decoding = false; | |
| } | |
| /** | |
| * GIF Encoder function. | |
| * Combines the parsed GIF frames into one single animation. | |
| */ | |
| private function encode($new_filename,$newwidth,$newheight){ | |
| $mystring = ""; | |
| $this->pointer = 0; | |
| $this->imagedata = array(); | |
| $this->imageinfo = array(); | |
| $this->handle = 0; | |
| $this->index=0; | |
| $k=0; | |
| foreach($this->parsedfiles as $imagepart){ | |
| $this->loadfile($imagepart); | |
| $this->get_gif_header(); | |
| $this->get_application_data(); | |
| $this->get_comment_data(); | |
| $this->get_graphics_extension(0); | |
| $this->get_image_block(0); | |
| //get transparent color index and color | |
| if(isset($this->encdata[$this->index-1])) | |
| $gxdata = $this->encdata[$this->index-1]["graphicsextension"]; | |
| else | |
| $gxdata = null; | |
| $ghdata = $this->imageinfo["gifheader"]; | |
| $trcolor = ""; | |
| $hastransparency=($gxdata[3]&&1==1); | |
| if($hastransparency){ | |
| $trcx = ord($gxdata[6]); | |
| $trcolor = substr($ghdata,13+$trcx*3,3); | |
| } | |
| //global color table to image data; | |
| $this->transfercolortable($this->imageinfo["gifheader"],$this->imagedata[$this->index-1]["imagedata"]); | |
| $imageblock = &$this->imagedata[$this->index-1]["imagedata"]; | |
| //if transparency exists transfer transparency index | |
| if($hastransparency){ | |
| $haslocalcolortable = ((ord($imageblock[9])&128)==128); | |
| if($haslocalcolortable){ | |
| //local table exists. determine boundaries and look for it. | |
| $tablesize=(pow(2,(ord($imageblock[9])&7)+1)*3)+10; | |
| $this->orgvars[$this->index-1]["transparent_color_index"] = | |
| ((strrpos(substr($this->imagedata[$this->index-1]["imagedata"],0,$tablesize),$trcolor)-10)/3); | |
| }else{ | |
| //local table doesnt exist, look at the global one. | |
| $tablesize=(pow(2,(ord($gxdata[10])&7)+1)*3)+10; | |
| $this->orgvars[$this->index-1]["transparent_color_index"] = | |
| ((strrpos(substr($ghdata,0,$tablesize),$trcolor)-10)/3); | |
| } | |
| } | |
| //apply original delay time,transparent index and disposal values to graphics extension | |
| if(!$this->imagedata[$this->index-1]["graphicsextension"]) $this->imagedata[$this->index-1]["graphicsextension"] = chr(0x21).chr(0xf9).chr(0x04).chr(0x00).chr(0x00).chr(0x00).chr(0x00).chr(0x00); | |
| $imagedata = &$this->imagedata[$this->index-1]["graphicsextension"]; | |
| $imagedata[3] = chr((ord($imagedata[3]) & 0xE3) | ($this->orgvars[$this->index-1]["disposal_method"] << 2)); | |
| $imagedata[4] = chr(($this->orgvars[$this->index-1]["delay_time"] % 256)); | |
| $imagedata[5] = chr(floor($this->orgvars[$this->index-1]["delay_time"] / 256)); | |
| if($hastransparency){ | |
| $imagedata[6] = chr($this->orgvars[$this->index-1]["transparent_color_index"]); | |
| } | |
| $imagedata[3] = chr(ord($imagedata[3])|$hastransparency); | |
| //apply calculated left and top offset | |
| $imageblock[1] = chr(round(($this->orgvars[$this->index-1]["offset_left"]*$this->wr) % 256)); | |
| $imageblock[2] = chr(floor(($this->orgvars[$this->index-1]["offset_left"]*$this->wr) / 256)); | |
| $imageblock[3] = chr(round(($this->orgvars[$this->index-1]["offset_top"]*$this->hr) % 256)); | |
| $imageblock[4] = chr(floor(($this->orgvars[$this->index-1]["offset_top"]*$this->hr) / 256)); | |
| if($this->index==1){ | |
| if(!isset($this->imageinfo["applicationdata"]) || !$this->imageinfo["applicationdata"]) | |
| $this->imageinfo["applicationdata"]=chr(0x21).chr(0xff).chr(0x0b)."NETSCAPE2.0".chr(0x03).chr(0x01).chr(0x00).chr(0x00).chr(0x00); | |
| if(!isset($this->imageinfo["commentdata"]) || !$this->imageinfo["commentdata"]) | |
| $this->imageinfo["commentdata"] = chr(0x21).chr(0xfe).chr(0x10)."PHPGIFRESIZER1.0".chr(0); | |
| $mystring .= $this->orgvars["gifheader"]. $this->imageinfo["applicationdata"].$this->imageinfo["commentdata"]; | |
| if(isset($this->orgvars["hasgx_type_0"]) && $this->orgvars["hasgx_type_0"]) $mystring .= $this->globaldata["graphicsextension_0"]; | |
| if(isset($this->orgvars["hasgx_type_1"]) && $this->orgvars["hasgx_type_1"]) $mystring .= $this->globaldata["graphicsextension"]; | |
| } | |
| $mystring .= $imagedata . $imageblock; | |
| $k++; | |
| $this->closefile(); | |
| } | |
| $mystring .= chr(0x3b); | |
| //applying new width & height to gif header | |
| $mystring[6] = chr($newwidth % 256); | |
| $mystring[7] = chr(floor($newwidth / 256)); | |
| $mystring[8] = chr($newheight % 256); | |
| $mystring[9] = chr(floor($newheight / 256)); | |
| $mystring[11]= $this->orgvars["background_color"]; | |
| //if(file_exists($new_filename)){unlink($new_filename);} | |
| file_put_contents($new_filename,$mystring); | |
| } | |
| /** | |
| * Variable Reset function | |
| * If a instance is used multiple times, it's needed. Trust me. | |
| */ | |
| private function clearvariables(){ | |
| $this->pointer = 0; | |
| $this->index = 0; | |
| $this->imagedata = array(); | |
| $this->imageinfo = array(); | |
| $this->handle = 0; | |
| $this->parsedfiles = array(); | |
| } | |
| /** | |
| * Clear Frames function | |
| * For deleting the frames after encoding. | |
| */ | |
| private function clearframes(){ | |
| foreach($this->parsedfiles as $temp_frame){ | |
| unlink($temp_frame); | |
| } | |
| } | |
| /** | |
| * Frame Writer | |
| * Writes the GIF frames into files. | |
| */ | |
| private function writeframes($prepend){ | |
| for($i=0;$i<sizeof($this->imagedata);$i++){ | |
| file_put_contents($this->temp_dir."/frame_".$prepend."_".str_pad($i,2,"0",STR_PAD_LEFT).".gif",$this->imageinfo["gifheader"].$this->imagedata[$i]["graphicsextension"].$this->imagedata[$i]["imagedata"].chr(0x3b)); | |
| $this->parsedfiles[]=$this->temp_dir."/frame_".$prepend."_".str_pad($i,2,"0",STR_PAD_LEFT).".gif"; | |
| } | |
| } | |
| /** | |
| * Color Palette Transfer Device | |
| * Transferring Global Color Table (GCT) from frames into Local Color Tables in animation. | |
| */ | |
| private function transfercolortable($src,&$dst){ | |
| //src is gif header,dst is image data block | |
| //if global color table exists,transfer it | |
| if((ord($src[10])&128)==128){ | |
| //Gif Header Global Color Table Length | |
| $ghctl = pow(2,$this->readbits(ord($src[10]),5,3)+1)*3; | |
| //cut global color table from gif header | |
| $ghgct = substr($src,13,$ghctl); | |
| //check image block color table length | |
| if((ord($dst[9])&128)==128){ | |
| //Image data contains color table. skip. | |
| }else{ | |
| //Image data needs a color table. | |
| //get last color table length so we can truncate the dummy color table | |
| $idctl = pow(2,$this->readbits(ord($dst[9]),5,3)+1)*3; | |
| //set color table flag and length | |
| $dst[9] = chr(ord($dst[9]) | (0x80 | (log($ghctl/3,2)-1))); | |
| //inject color table | |
| $dst = substr($dst,0,10).$ghgct.substr($dst,-1*strlen($dst)+10); | |
| } | |
| }else{ | |
| //global color table doesn't exist. skip. | |
| } | |
| } | |
| /** | |
| * GIF Parser Functions. | |
| * Below functions are the main structure parser components. | |
| */ | |
| private function get_gif_header(){ | |
| $this->p_forward(10); | |
| if($this->readbits(($mybyte=$this->readbyte_int()),0,1)==1){ | |
| $this->p_forward(2); | |
| $this->p_forward(pow(2,$this->readbits($mybyte,5,3)+1)*3); | |
| }else{ | |
| $this->p_forward(2); | |
| } | |
| $this->imageinfo["gifheader"]=$this->datapart(0,$this->pointer); | |
| if($this->decoding){ | |
| $this->orgvars["gifheader"]=$this->imageinfo["gifheader"]; | |
| $this->originalwidth = ord($this->orgvars["gifheader"][7])*256+ord($this->orgvars["gifheader"][6]); | |
| $this->originalheight = ord($this->orgvars["gifheader"][9])*256+ord($this->orgvars["gifheader"][8]); | |
| $this->orgvars["background_color"]=$this->orgvars["gifheader"][11]; | |
| } | |
| } | |
| //------------------------------------------------------- | |
| private function get_application_data(){ | |
| $startdata = $this->readbyte(2); | |
| if($startdata==chr(0x21).chr(0xff)){ | |
| $start = $this->pointer - 2; | |
| $this->p_forward($this->readbyte_int()); | |
| $this->read_data_stream($this->readbyte_int()); | |
| $this->imageinfo["applicationdata"] = $this->datapart($start,$this->pointer-$start); | |
| }else{ | |
| $this->p_rewind(2); | |
| } | |
| } | |
| //------------------------------------------------------- | |
| private function get_comment_data(){ | |
| $startdata = $this->readbyte(2); | |
| if($startdata==chr(0x21).chr(0xfe)){ | |
| $start = $this->pointer - 2; | |
| $this->read_data_stream($this->readbyte_int()); | |
| $this->imageinfo["commentdata"] = $this->datapart($start,$this->pointer-$start); | |
| }else{ | |
| $this->p_rewind(2); | |
| } | |
| } | |
| //------------------------------------------------------- | |
| private function get_graphics_extension($type){ | |
| $startdata = $this->readbyte(2); | |
| if($startdata==chr(0x21).chr(0xf9)){ | |
| $start = $this->pointer - 2; | |
| $this->p_forward($this->readbyte_int()); | |
| $this->p_forward(1); | |
| if($type==2){ | |
| $this->imagedata[$this->index]["graphicsextension"] = $this->datapart($start,$this->pointer-$start); | |
| }else if($type==1){ | |
| $this->orgvars["hasgx_type_1"] = 1; | |
| $this->globaldata["graphicsextension"] = $this->datapart($start,$this->pointer-$start); | |
| }else if($type==0 && $this->decoding==false){ | |
| $this->encdata[$this->index]["graphicsextension"] = $this->datapart($start,$this->pointer-$start); | |
| }else if($type==0 && $this->decoding==true){ | |
| $this->orgvars["hasgx_type_0"] = 1; | |
| $this->globaldata["graphicsextension_0"] = $this->datapart($start,$this->pointer-$start); | |
| } | |
| }else{ | |
| $this->p_rewind(2); | |
| } | |
| } | |
| //------------------------------------------------------- | |
| private function get_image_block($type){ | |
| if($this->checkbyte(0x2c)){ | |
| $start = $this->pointer; | |
| $this->p_forward(9); | |
| if($this->readbits(($mybyte=$this->readbyte_int()),0,1)==1){ | |
| $this->p_forward(pow(2,$this->readbits($mybyte,5,3)+1)*3); | |
| } | |
| $this->p_forward(1); | |
| $this->read_data_stream($this->readbyte_int()); | |
| $this->imagedata[$this->index]["imagedata"] = $this->datapart($start,$this->pointer-$start); | |
| if($type==0){ | |
| $this->orgvars["hasgx_type_0"] = 0; | |
| if(isset($this->globaldata["graphicsextension_0"])) | |
| $this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension_0"]; | |
| else | |
| $this->imagedata[$this->index]["graphicsextension"]=null; | |
| unset($this->globaldata["graphicsextension_0"]); | |
| }elseif($type==1){ | |
| if(isset($this->orgvars["hasgx_type_1"]) && $this->orgvars["hasgx_type_1"]==1){ | |
| $this->orgvars["hasgx_type_1"] = 0; | |
| $this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension"]; | |
| unset($this->globaldata["graphicsextension"]); | |
| }else{ | |
| $this->orgvars["hasgx_type_0"] = 0; | |
| $this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension_0"]; | |
| unset($this->globaldata["graphicsextension_0"]); | |
| } | |
| } | |
| $this->parse_image_data(); | |
| $this->index++; | |
| } | |
| } | |
| //------------------------------------------------------- | |
| private function parse_image_data(){ | |
| $this->imagedata[$this->index]["disposal_method"] = $this->get_imagedata_bit("ext",3,3,3); | |
| $this->imagedata[$this->index]["user_input_flag"] = $this->get_imagedata_bit("ext",3,6,1); | |
| $this->imagedata[$this->index]["transparent_color_flag"] = $this->get_imagedata_bit("ext",3,7,1); | |
| $this->imagedata[$this->index]["delay_time"] = $this->dualbyteval($this->get_imagedata_byte("ext",4,2)); | |
| $this->imagedata[$this->index]["transparent_color_index"] = ord($this->get_imagedata_byte("ext",6,1)); | |
| $this->imagedata[$this->index]["offset_left"] = $this->dualbyteval($this->get_imagedata_byte("dat",1,2)); | |
| $this->imagedata[$this->index]["offset_top"] = $this->dualbyteval($this->get_imagedata_byte("dat",3,2)); | |
| $this->imagedata[$this->index]["width"] = $this->dualbyteval($this->get_imagedata_byte("dat",5,2)); | |
| $this->imagedata[$this->index]["height"] = $this->dualbyteval($this->get_imagedata_byte("dat",7,2)); | |
| $this->imagedata[$this->index]["local_color_table_flag"] = $this->get_imagedata_bit("dat",9,0,1); | |
| $this->imagedata[$this->index]["interlace_flag"] = $this->get_imagedata_bit("dat",9,1,1); | |
| $this->imagedata[$this->index]["sort_flag"] = $this->get_imagedata_bit("dat",9,2,1); | |
| $this->imagedata[$this->index]["color_table_size"] = pow(2,$this->get_imagedata_bit("dat",9,5,3)+1)*3; | |
| $this->imagedata[$this->index]["color_table"] = substr($this->imagedata[$this->index]["imagedata"],10,$this->imagedata[$this->index]["color_table_size"]); | |
| $this->imagedata[$this->index]["lzw_code_size"] = ord($this->get_imagedata_byte("dat",10,1)); | |
| if($this->decoding){ | |
| $this->orgvars[$this->index]["transparent_color_flag"] = $this->imagedata[$this->index]["transparent_color_flag"]; | |
| $this->orgvars[$this->index]["transparent_color_index"] = $this->imagedata[$this->index]["transparent_color_index"]; | |
| $this->orgvars[$this->index]["delay_time"] = $this->imagedata[$this->index]["delay_time"]; | |
| $this->orgvars[$this->index]["disposal_method"] = $this->imagedata[$this->index]["disposal_method"]; | |
| $this->orgvars[$this->index]["offset_left"] = $this->imagedata[$this->index]["offset_left"]; | |
| $this->orgvars[$this->index]["offset_top"] = $this->imagedata[$this->index]["offset_top"]; | |
| } | |
| } | |
| //------------------------------------------------------- | |
| private function get_imagedata_byte($type,$start,$length){ | |
| if($type=="ext") | |
| return substr($this->imagedata[$this->index]["graphicsextension"],$start,$length); | |
| elseif($type=="dat") | |
| return substr($this->imagedata[$this->index]["imagedata"],$start,$length); | |
| } | |
| //------------------------------------------------------- | |
| private function get_imagedata_bit($type,$byteindex,$bitstart,$bitlength){ | |
| if($type=="ext") | |
| return $this->readbits(ord(substr($this->imagedata[$this->index]["graphicsextension"],$byteindex,1)),$bitstart,$bitlength); | |
| elseif($type=="dat") | |
| return $this->readbits(ord(substr($this->imagedata[$this->index]["imagedata"],$byteindex,1)),$bitstart,$bitlength); | |
| } | |
| //------------------------------------------------------- | |
| private function dualbyteval($s){ | |
| $i = ord($s[1])*256 + ord($s[0]); | |
| return $i; | |
| } | |
| //------------ Helper Functions --------------------- | |
| private function read_data_stream($first_length){ | |
| $this->p_forward($first_length); | |
| $length=$this->readbyte_int(); | |
| if($length!=0) { | |
| while($length!=0){ | |
| $this->p_forward($length); | |
| $length=$this->readbyte_int(); | |
| } | |
| } | |
| return true; | |
| } | |
| //------------------------------------------------------- | |
| private function loadfile($filename){ | |
| $this->handle = fopen($filename,"rb"); | |
| $this->pointer = 0; | |
| } | |
| //------------------------------------------------------- | |
| private function closefile(){ | |
| fclose($this->handle); | |
| $this->handle=0; | |
| } | |
| //------------------------------------------------------- | |
| private function readbyte($byte_count){ | |
| $data = fread($this->handle,$byte_count); | |
| $this->pointer += $byte_count; | |
| return $data; | |
| } | |
| //------------------------------------------------------- | |
| private function readbyte_int(){ | |
| $data = fread($this->handle,1); | |
| $this->pointer++; | |
| return ord($data); | |
| } | |
| //------------------------------------------------------- | |
| private function readbits($byte,$start,$length){ | |
| $bin = str_pad(decbin($byte),8,"0",STR_PAD_LEFT); | |
| $data = substr($bin,$start,$length); | |
| return bindec($data); | |
| } | |
| //------------------------------------------------------- | |
| private function p_rewind($length){ | |
| $this->pointer-=$length; | |
| fseek($this->handle,$this->pointer); | |
| } | |
| //------------------------------------------------------- | |
| private function p_forward($length){ | |
| $this->pointer+=$length; | |
| fseek($this->handle,$this->pointer); | |
| } | |
| //------------------------------------------------------- | |
| private function datapart($start,$length){ | |
| fseek($this->handle,$start); | |
| $data = fread($this->handle,$length); | |
| fseek($this->handle,$this->pointer); | |
| return $data; | |
| } | |
| //------------------------------------------------------- | |
| private function checkbyte($byte){ | |
| if(fgetc($this->handle)==chr($byte)){ | |
| fseek($this->handle,$this->pointer); | |
| return true; | |
| }else{ | |
| fseek($this->handle,$this->pointer); | |
| return false; | |
| } | |
| } | |
| //------------------------------------------------------- | |
| private function checkEOF(){ | |
| if(fgetc($this->handle)===false){ | |
| return true; | |
| }else{ | |
| fseek($this->handle,$this->pointer); | |
| return false; | |
| } | |
| } | |
| //------------------------------------------------------- | |
| /** | |
| * Debug Functions. | |
| * Parses the GIF animation into single frames. | |
| */ | |
| private function debug($string){ | |
| echo "<pre>"; | |
| for($i=0;$i<strlen($string);$i++){ | |
| echo str_pad(dechex(ord($string[$i])),2,"0",STR_PAD_LEFT). " "; | |
| } | |
| echo "</pre>"; | |
| } | |
| //------------------------------------------------------- | |
| private function debuglen($var,$len){ | |
| echo "<pre>"; | |
| for($i=0;$i<$len;$i++){ | |
| echo str_pad(dechex(ord($var[$i])),2,"0",STR_PAD_LEFT). " "; | |
| } | |
| echo "</pre>"; | |
| } | |
| //------------------------------------------------------- | |
| private function debugstream($length){ | |
| $this->debug($this->datapart($this->pointer,$length)); | |
| } | |
| //------------------------------------------------------- | |
| /** | |
| * GD Resizer Device | |
| * Resizes the animation frames | |
| */ | |
| private function resizeframes(){ | |
| $k=0; | |
| foreach($this->parsedfiles as $img){ | |
| $src = imagecreatefromgif($img); | |
| $sw = $this->imagedata[$k]["width"]; | |
| $sh = $this->imagedata[$k]["height"]; | |
| $nw = round($sw * $this->wr); | |
| $nh = round($sh * $this->hr); | |
| $sprite = imagecreatetruecolor($nw,$nh); | |
| $trans = imagecolortransparent($sprite); | |
| imagealphablending($sprite, false); | |
| imagesavealpha($sprite, true); | |
| imagepalettecopy($sprite,$src); | |
| imagefill($sprite,0,0,imagecolortransparent($src)); | |
| imagecolortransparent($sprite,imagecolortransparent($src)); | |
| imagecopyresized($sprite,$src,0,0,0,0,$nw,$nh,$sw,$sh); | |
| imagegif($sprite,$img); | |
| imagedestroy($sprite); | |
| imagedestroy($src); | |
| $k++; | |
| } | |
| } | |
| } | |
| ?> |
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