PHP使用GIFEncoder生成动态gif滚动字幕

PHP使用GIFEncoder生成动态gif滚动字幕

2009/03/11 (7:42 下午)

作者：胡子

分类：PHP

标签：GIFEncoder, PHP, 使用, 动态gif, 滚动字幕, 生成

一个滚动字幕。要求用php生成gif图片。所以上网找了GIFEncoder这个类库。确实很好用，但是，应用过程中也出现了一些小问题，现在放在这里，以供参考，少走弯路。

1. Class GIFEncoder {
2. var $GIF = “GIF89a”;                /* GIF header 6 bytes        */
3. var $VER = “GIFEncoder V2.06″;        /* Encoder version                */
5. var $BUF = Array ( );
6. var $LOP =  0;
7. var $DIS =  2;
8. var $COL = -1;
9. var $IMG = -1;
11. var $ERR = Array (
12. ‘ERR00′ =>”Does not supported function for only one image!”,
13. ‘ERR01′ =>”Source is not a GIF image!”,
14. ‘ERR02′ =>”Unintelligible flag “,
15. ‘ERR03′ =>”Could not make animation from animated GIF source”,
16.     );
18. /*
19.     :::::::::::::::::::::::::::::::::::::::::::::::::::
20.     ::
21.     ::        GIFEncoder…作者：邢海龙 tdweb0718
22.     ::
23.     */
24. function GIFEncoder        (
25. $GIF_src, $GIF_dly, $GIF_lop, $GIF_dis,
26. $GIF_red, $GIF_grn, $GIF_blu, $GIF_mod
27.     ) {
28. if ( ! is_array ( $GIF_src ) && ! is_array ( $GIF_tim ) ) {
29.             printf        ( “%s: %s”, $this->VER, $this->ERR [ 'ERR00' ] );
30. exit        ( 0 );
31.         }
32. $this->LOP = ( $GIF_lop > -1 ) ? $GIF_lop : 0;
33. $this->DIS = ( $GIF_dis > -1 ) ? ( ( $GIF_dis < 3 ) ? $GIF_dis : 3 ) : 2;
34. $this->COL = ( $GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1 ) ?
35.         ( $GIF_red | ( $GIF_grn << 8 ) | ( $GIF_blu << 16 ) ) : -1;
37. for ( $i = 0; $i < count ( $GIF_src ); $i++ ) {
38. if ( strToLower ( $GIF_mod ) == “url” ) {
39. $this->BUF [ ] = fread ( fopen ( $GIF_src [ $i ], “rb” ), filesize ( $GIF_src [ $i ] ) );
40.             }
41. else if ( strToLower ( $GIF_mod ) == “bin” ) {
42. $this->BUF [ ] = $GIF_src [ $i ];
43.             }
44. else {
45.                 printf        ( “%s: %s ( %s )!”, $this->VER, $this->ERR [ 'ERR02' ], $GIF_mod );
46. exit        ( 0 );
47.             }
48. if ( substr ( $this->BUF [ $i ], 0, 6 ) != “GIF87a” && substr ( $this->BUF [ $i ], 0, 6 ) != “GIF89a” ) {
49.                 printf        ( “%s: %d %s”, $this->VER, $i, $this->ERR [ 'ERR01' ] );
50. exit        ( 0 );
51.             }
52. for ( $j = ( 13 + 3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0×07 ) ) ), $k = TRUE; $k; $j++ ) {
53. switch ( $this->BUF [ $i ] { $j } ) {
54. case “!”:
55. if ( ( substr ( $this->BUF [ $i ], ( $j + 3 ), 8 ) ) == “NETSCAPE” ) {
56.                             printf        ( “%s: %s ( %s source )!”, $this->VER, $this->ERR [ 'ERR03' ], ( $i + 1 ) );
57. exit        ( 0 );
58.                         }
59. break;
60. case “;”:
61. $k = FALSE;
62. break;
63.                 }
64.             }
65.         }
66.         GIFEncoder::GIFAddHeader ( );
67. for ( $i = 0; $i < count ( $this->BUF ); $i++ ) {
68.             GIFEncoder::GIFAddFrames ( $i, $GIF_dly [ $i ] );
69.         }
70.         GIFEncoder::GIFAddFooter ( );
71.     }
72. /*
73.     :::::::::::::::::::::::::::::::::::::::::::::::::::
74.     ::
75.     ::        GIFAddHeader…
76.     ::
77.     */
78. function GIFAddHeader ( ) {
79. $cmap = 0;
81. if ( ord ( $this->BUF [ 0 ] { 10 } ) & 0×80 ) {
82. $cmap = 3 * ( 2 << ( ord ( $this->BUF [ 0 ] { 10 } ) & 0×07 ) );
84. $this->GIF .= substr ( $this->BUF [ 0 ], 6, 7                );
85. $this->GIF .= substr ( $this->BUF [ 0 ], 13, $cmap        );
86. $this->GIF .= “!37713NETSCAPE2.031″ . GIFEncoder::GIFWord ( $this->LOP ) . “”;
87.         }
88.     }
89. /*
90.     :::::::::::::::::::::::::::::::::::::::::::::::::::
91.     ::
92.     ::        GIFAddFrames…
93.     ::
94.     */
95. function GIFAddFrames ( $i, $d ) {
97. $Locals_str = 13 + 3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0×07 ) );
99. $Locals_end = strlen ( $this->BUF [ $i ] ) – $Locals_str – 1;
100. $Locals_tmp = substr ( $this->BUF [ $i ], $Locals_str, $Locals_end );
102. $Global_len = 2 << ( ord ( $this->BUF [ 0  ] { 10 } ) & 0×07 );
103. $Locals_len = 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0×07 );
105. $Global_rgb = substr ( $this->BUF [ 0  ], 13,
106.         3 * ( 2 << ( ord ( $this->BUF [ 0  ] { 10 } ) & 0×07 ) ) );
107. $Locals_rgb = substr ( $this->BUF [ $i ], 13,
108.         3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0×07 ) ) );
110. $Locals_ext = “!xF9×04″ . chr ( ( $this->DIS << 2 ) + 0 ) .
111. chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . “x0×0″;
113. if ( $this->COL > -1 && ord ( $this->BUF [ $i ] { 10 } ) & 0×80 ) {
114. for ( $j = 0; $j < ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0×07 ) ); $j++ ) {
115. if        (
116.                 ord ( $Locals_rgb { 3 * $j + 0 } ) == ( $this->COL >>  0 ) & 0xFF &
117.                 ord ( $Locals_rgb { 3 * $j + 1 } ) == ( $this->COL >>  8 ) & 0xFF &
118.                 ord ( $Locals_rgb { 3 * $j + 2 } ) == ( $this->COL >> 16 ) & 0xFF
119.                 ) {
120. $Locals_ext = “!xF9×04″ . chr ( ( $this->DIS << 2 ) + 1 ) .
121. chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . chr ( $j ) . “x0″;
122. break;
123.                 }
124.             }
125.         }
126. switch ( $Locals_tmp { 0 } ) {
127. case “!”:
128. $Locals_img = substr ( $Locals_tmp, 8, 10 );
129. $Locals_tmp = substr ( $Locals_tmp, 18, strlen ( $Locals_tmp ) – 18 );
130. break;
131. case “,”:
132. $Locals_img = substr ( $Locals_tmp, 0, 10 );
133. $Locals_tmp = substr ( $Locals_tmp, 10, strlen ( $Locals_tmp ) – 10 );
134. break;
135.         }
136. if ( ord ( $this->BUF [ $i ] { 10 } ) & 0×80 && $this->IMG > -1 ) {
137. if ( $Global_len == $Locals_len ) {
138. if ( GIFEncoder::GIFBlockCompare ( $Global_rgb, $Locals_rgb, $Global_len ) ) {
139. $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );
140.                 }
141. else {
142. $byte  = ord ( $Locals_img { 9 } );
143. $byte |= 0×80;
144. $byte &= 0xF8;
145. $byte |= ( ord ( $this->BUF [ 0 ] { 10 } ) & 0×07 );
146. $Locals_img { 9 } = chr ( $byte );
147. $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
148.                 }
149.             }
150. else {
151. $byte  = ord ( $Locals_img { 9 } );
152. $byte |= 0×80;
153. $byte &= 0xF8;
154. $byte |= ( ord ( $this->BUF [ $i ] { 10 } ) & 0×07 );
155. $Locals_img { 9 } = chr ( $byte );
156. $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
157.             }
158.         }
159. else {
160. $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );
161.         }
162. $this->IMG  = 1;
163.     }
164. /*
165.     :::::::::::::::::::::::::::::::::::::::::::::::::::
166.     ::
167.     ::        GIFAddFooter…
168.     ::
169.     */
170. function GIFAddFooter ( ) {
171. $this->GIF .= “;”;
172.     }
173. /*
174.     :::::::::::::::::::::::::::::::::::::::::::::::::::
175.     ::
176.     ::        GIFBlockCompare…
177.     ::
178.     */
179. function GIFBlockCompare ( $GlobalBlock, $LocalBlock, $Len ) {
181. for ( $i = 0; $i < $Len; $i++ ) {
182. if        (
183. $GlobalBlock { 3 * $i + 0 } != $LocalBlock { 3 * $i + 0 } ||
184. $GlobalBlock { 3 * $i + 1 } != $LocalBlock { 3 * $i + 1 } ||
185. $GlobalBlock { 3 * $i + 2 } != $LocalBlock { 3 * $i + 2 }
186.             ) {
187. return ( 0 );
188.             }
189.         }
191. return ( 1 );
192.     }
193. /*
194.     :::::::::::::::::::::::::::::::::::::::::::::::::::
195.     ::
196.     ::        GIFWord…
197.     ::
198.     */
199. function GIFWord ( $int ) {
201. return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) );
202.     }
203. /*
204.     :::::::::::::::::::::::::::::::::::::::::::::::::::
205.     ::
206.     ::        GetAnimation…
207.     ::
208.     */
209. function GetAnimation ( ) {
210. return ( $this->GIF );
211.     }
212. }
213. ?>

文字滚动分为两种情况。第一种为水平滚动

1. require_once(”GIFEncoder.class.php”);
2. $count=0;   \设置默认计数器
3. while(true){
4. $str = $_REQUEST['str'] ? $_REQUEST['str']:”暂无输入”;
5. $length=strlen($str)*9;     \计算行长度，这个计算的比较简单，就是每个字数*9个像素
6. $im=imagecreatefromgif(”hudongbg.gif”);     \根据图片创建图像
7. $white = ImageColorAllocate($im,255,255,255);       \设置一个白色
8. $str = iconv(”GB2312″,”UTF-8″,$str);        \特别注意的是转换编码，因为之后用到的imagettftext只能用utf-8编码
9. $now=220-$count*5;      \当前运行的水平位置
10.     imagettftext($im,13,0,$now,20,$white,”ziti.ttf”,$str);      \根据字体在图片上写文字，参数意思（图像源，文字大小，倾斜角度，水平位置，垂直位置，颜色，使用的字体文件，要写的内容
11.     imagegif($im);      
12.     imagedestroy($im);
13. $imagedata[] = ob_get_contents();       \创建这一帧的图像数据
14.     ob_clean();
15. $count++;
16. if ($now+$length<0){    \如果最后一个文字移动到头，那么结束
17. break;
18.     }
19. }
20. $diy[]=0;\开始延迟时间
21. $gif = new GIFEncoder($imagedata,$diy,0,2,0,0,0,”bin”);
23. ob_start();
24. Header (’Content-type:image/gif’);
26. echo $gif->GetAnimation();
27. ?>

然后是垂直的

1. /*
3. 从url获得”str=第一行;第二行;第三行”的数据
5. */
6. require_once(”GIFEncoder.class.php”);
7. $array_str=array();
8. $str=$_GET['str'];
9. /*
11. 将$str转化成数组
13. */
14. if ($str!=”){
15. $array_str=explode(”;”,$str);
16. }else{
17. $array_str=array(”欢迎您光临本店！”);
18. }
19. /*
21. 如果数组元素没有值，清除最后一个“;”
23. */
24. foreach( $array_str as $k=>$v){
25. if( !$v )
26.     unset( $array_str[$k] );
27. }
30. for ($i=0,$length=count($array_str);$i<$length;$i++){
31. for ($k=0;$k<20;$k++){
32. $im=imagecreatefromgif(”hudongbg.gif”);     \根据图片创建图像
33. $white = ImageColorAllocate($im,255,255,255);       \设置一个白色
34. $test = iconv(”GB2312″,”UTF-8″,$array_str[$i]);     \特别注意的是转换编码，因为之后用到的imagettftext只能用utf-8编码，注意，一定要用字符串接收，不能用数组，否则会乱码
35. $heigth=40-$k;        \当前文字高度
36.         imagettftext($im,13,0,0,$heigth,$white,”ziti.ttf”,$test);        \将文字写入图片
37.         imagegif($im);
38. $imagedata[] = ob_get_contents();
39.         ob_clean();
40.     }
41. }
42. /*
43. 这里是设置每一张图片的延迟时间，到第20帧的时候，延迟2秒。这样才能出现文字走到顶，停顿一会的效果
44. */
46. $delay=array();
47. for ($i=1,$length=count($array_str)*20;$i<=$length;$i++){
48. if ($i%20==0){
49. $delay[$i-1]=”200″;
50.     }else{
51. $delay[$i-1]=”1″;
52.     }
53. }
54. $transparent=array(0);
55. $gif = new GIFEncoder($imagedata,$delay,0,2,0,0,$transparent,”bin”);
56. ob_start();
57. Header (’Content-type:image/gif’);
58. echo $gif->GetAnimation();
59. ?>