PHP做视频网站，让程序自动实现视频格式转换、设置视频大小、生成视频缩略图

一、PHP实现转换

　　　在做视频网站的时候，最头痛的问题可能是格式转换、视频缩略图等。下面我将用PHP实现这一些功能。PHP是没有自带视频的函数，所以会用到第三方的软件工具来实现。

 

二、什么是FFmpeg

　　　FFmpeg是一个开源免费跨平台的视频和音频流方案，属于自由软件，采用LGPL或GPL许可证（依据你选择的组件）。它提供了录制、转换以及流化音视频的完整解决方案。它包含了非常先进的音频/视频编解码库libavcodec，为了保证高可移植性和编解码质量，libavcodec里很多codec都是从头开发的。

FFmpeg在Linux平台下开发，但它同样也可以在其它操作系统环境中编译运行，包括Windows、Mac OS X等。

这个项目最早由Fabrice Bellard发起，现在由Michael Niedermayer维护。许多FFmpeg的开发人员都来自MPlayer项目，而且当前FFmpeg也是放在MPlayer项目组的服务器上。项目的名称来自MPEG视频编码标准，前面的"FF“代表"Fast Forward“。 更多详情》

 

/* 转视频   */
$cmd="ffmpeg.exe -i tiwer_update_move.avi -ab 56 -ar 22050 -b 500 -r 15 -s 500x600 201112120089123.flv";  

exec($cmd);  

/*  视频截图*/
$cmd="ffmpeg.exe -itiwer_update_move.avi -f image2 -ss 10 -s 600*500 -vframes 1 201112120089123.jpg";

exec($cmd);

 三、生成缩略图

 

include("ImageHelper.class.php");

 /* 生成缩略图 */
 $thumbnail = new ImageHelper();  
 $thumbnail->resizeimage("2012121208123.jpg", 30,30, 0, "2012121208123_small.jpg");

 

　　

四、工具类与软件下载

　　４.１ 图片处理工具类如下

ImageHelper.class.php

  1 /**
  2  * 图片处理工具
  3  *
  4  * Project: BoBo Manage System
  5  * This is NOT a freeware, use is subject to license terms!
  6  * 
  7  * Site: http://www.bobo123.cn
  8  *
  9  * $Id: ImageHelper.class.php 269 2011-03-08 00:44:01Z wgw8299 $
 10  *
 11  * Copyright © 2007-2012 Bobo123.CN Developer Team. All Rights Reserved.
 12  */
 13 class ImageHelper {  
 14 
 15 
 16     var $type;  
 17      
 18      
 19     /* 实际宽度 */ 
 20     var $width;  
 21      
 22     /* 实际高度  */ 
 23     var $height;  
 24      
 25     /* 改变后的宽度   */
 26     var $resize_width;  
 27      
 28     /* 改变后的高度 */  
 29     var $resize_height;  
 30      
 31     /* 是否裁图   */
 32     var $cut;  
 33      
 34     /* 源图象  */ 
 35     var $srcimg;  
 36      
 37     /* 目标图象地址  */ 
 38     var $dstimg;  
 39      
 40     /* 临时创建的图象  */ 
 41     var $im;  
 42   
 43     function resizeimage($img, $wid, $hei,$c,$dstpath) {  
 44        
 45         $this->srcimg = $img;  
 46         $this->resize_width = $wid;  
 47         $this->resize_height = $hei;  
 48         $this->cut = $c;  
 49          
 50         /* 图片的类型  */ 
 51         $this->type = strtolower(substr(strrchr($this->srcimg,"."),1));  
 52          
 53         /* 初始化图象  */ 
 54         $this->initi_img();  
 55          
 56         /* 目标图象地址   */
 57         $this -> dst_img($dstpath);  
 58          
 59          
 60         $this->width = imagesx($this->im);  
 61         $this->height = imagesy($this->im);  
 62          
 63         /* 生成图象  */
 64         $this->newimg();  
 65          
 66         ImageDestroy ($this->im);  
 67     }  
 68   
 69     function newimg() {  
 70   
 71         /* 改变后的图象的比例  */ 
 72         $resize_ratio = ($this->resize_width)/($this->resize_height);  
 73   
 74         /* 实际图象的比例 */  
 75         $ratio = ($this->width)/($this->height);  
 76   
 77   
 78         if(($this->cut)=="1") {  
 79             /* 裁图高度优先 */  
 80             if($ratio>=$resize_ratio){  
 81                 $newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);  
 82                 imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width,$this->resize_height, (($this->height)*$resize_ratio), $this->height);  
 83                 ImageJpeg ($newimg,$this->dstimg);  
 84             }  
 85              
 86              
 87             /* 裁图 宽度优先  */ 
 88             if($ratio<$resize_ratio) {  
 89                 $newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);  
 90                 imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, $this->resize_height, $this->width, (($this->width)/$resize_ratio));  
 91                 ImageJpeg ($newimg,$this->dstimg);  
 92             }  
 93         } else {  
 94         
 95             /* 不裁图  */ 
 96             if($ratio>=$resize_ratio) {  
 97                 $newimg = imagecreatetruecolor($this->resize_width,($this->resize_width)/$ratio);  
 98                 imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, ($this->resize_width)/$ratio, $this->width, $this->height);  
 99                 ImageJpeg ($newimg,$this->dstimg);  
100             }  
101             if($ratio<$resize_ratio) {  
102                 $newimg = imagecreatetruecolor(($this->resize_height)*$ratio,$this->resize_height);  
103                 imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, ($this->resize_height)*$ratio, $this->resize_height, $this->width, $this->height);  
104                 ImageJpeg ($newimg,$this->dstimg);  
105             }  
106         }  
107     }  
108   
109     /* 初始化图象 */  
110     function initi_img() {  
111         if($this->type=="jpg") {  
112             $this->im = imagecreatefromjpeg($this->srcimg);  
113         }  
114          
115         if($this->type=="gif") {  
116             $this->im = imagecreatefromgif($this->srcimg);  
117         }  
118          
119         if($this->type=="png") {  
120             $this->im = imagecreatefrompng($this->srcimg);  
121         }  
122          
123         if($this->type=="bmp") {  
124             $this->im = $this->imagecreatefrombmp($this->srcimg);  
125         }  
126     }  
127   
128   
129     /* 图象目标地址   */
130     function dst_img($dstpath) {  
131         $full_length  = strlen($this->srcimg);  
132         $type_length  = strlen($this->type);  
133         $name_length  = $full_length-$type_length;  
134         $name = substr($this->srcimg,0,$name_length-1);  
135         $this->dstimg = $dstpath;  
136     }  
137     
138     
139      
140     function ConvertBMP2GD($src, $dest = false) {  
141         if(!($src_f = fopen($src, "rb"))) {  
142             return false;  
143         }  
144         if(!($dest_f = fopen($dest, "wb"))) {  
145             return false;  
146         }  
147         $header = unpack("vtype/Vsize/v2reserved/Voffset", fread($src_f,14));  
148         $info = unpack("Vsize/Vwidth/Vheight/vplanes/vbits/Vcompression/Vimagesize/Vxres/Vyres/Vncolor/Vimportant", fread($src_f, 40));  
149          
150         extract($info);  
151         extract($header);  
152          
153         if($type != 0x4D42) { // signature "BM"  
154             return false;  
155         }  
156          
157         $palette_size = $offset - 54;  
158         $ncolor = $palette_size / 4;  
159         $gd_header = "";  
160         // true-color vs. palette  
161         $gd_header .= ($palette_size == 0) ? "\xFF\xFE" : "\xFF\xFF";  
162         $gd_header .= pack("n2", $width, $height);  
163         $gd_header .= ($palette_size == 0) ? "\x01" : "\x00";  
164         if($palette_size) {  
165             $gd_header .= pack("n", $ncolor);  
166         }  
167         
168         $gd_header .= "\xFF\xFF\xFF\xFF";  
169   
170         fwrite($dest_f, $gd_header);  
171   
172         if($palette_size) {  
173             $palette = fread($src_f, $palette_size);  
174             $gd_palette = "";  
175             $j = 0;  
176             while($j < $palette_size) {  
177                 $b = $palette{$j++};  
178                 $g = $palette{$j++};  
179                 $r = $palette{$j++};  
180                 $a = $palette{$j++};  
181                 $gd_palette .= "$r$g$b$a";  
182             }  
183             $gd_palette .= str_repeat("\x00\x00\x00\x00", 256 - $ncolor);  
184             fwrite($dest_f, $gd_palette);  
185         }  
186   
187         $scan_line_size = (($bits * $width) + 7) >> 3;  
188         $scan_line_align = ($scan_line_size & 0x03) ? 4 - ($scan_line_size &  
189         0x03) : 0;  
190   
191         for($i = 0, $l = $height - 1; $i < $height; $i++, $l--) {  
192             // BMP stores scan lines starting from bottom  
193             fseek($src_f, $offset + (($scan_line_size + $scan_line_align) * $l));  
194             $scan_line = fread($src_f, $scan_line_size);  
195             if($bits == 24) {  
196                 $gd_scan_line = "";  
197                 $j = 0;  
198                 while($j < $scan_line_size) {  
199                     $b = $scan_line{$j++};  
200                     $g = $scan_line{$j++};  
201                     $r = $scan_line{$j++};  
202                     $gd_scan_line .= "\x00$r$g$b";  
203                 }  
204             }  
205             else if($bits == 8) {  
206                 $gd_scan_line = $scan_line;  
207             }  
208             else if($bits == 4) {  
209                 $gd_scan_line = "";  
210                 $j = 0;  
211                 while($j < $scan_line_size) {  
212                     $byte = ord($scan_line{$j++});  
213                     $p1 = chr($byte >> 4);  
214                     $p2 = chr($byte & 0x0F);  
215                     $gd_scan_line .= "$p1$p2";  
216                 }  
217                 $gd_scan_line = substr($gd_scan_line, 0, $width);  
218             }  
219             else if($bits == 1) {  
220                 $gd_scan_line = "";  
221                 $j = 0;  
222                 while($j < $scan_line_size) {  
223                     $byte = ord($scan_line{$j++});  
224                     $p1 = chr((int) (($byte & 0x80) != 0));  
225                     $p2 = chr((int) (($byte & 0x40) != 0));  
226                     $p3 = chr((int) (($byte & 0x20) != 0));  
227                     $p4 = chr((int) (($byte & 0x10) != 0));  
228                     $p5 = chr((int) (($byte & 0x08) != 0));  
229                     $p6 = chr((int) (($byte & 0x04) != 0));  
230                     $p7 = chr((int) (($byte & 0x02) != 0));  
231                     $p8 = chr((int) (($byte & 0x01) != 0));  
232                     $gd_scan_line .= "$p1$p2$p3$p4$p5$p6$p7$p8";  
233                 }  
234                 $gd_scan_line = substr($gd_scan_line, 0, $width);  
235             }  
236             fwrite($dest_f, $gd_scan_line);  
237         }  
238         fclose($src_f);  
239         fclose($dest_f);  
240         return true;  
241     }  
242   
243     function imagecreatefrombmp($filename) {  
244         $tmp_name = tempnam("/tmp", "GD");  
245         if($this->ConvertBMP2GD($filename, $tmp_name)) {  
246             $img = imagecreatefromgd($tmp_name);  
247             unlink($tmp_name);  
248             return $img;  
249         }  
250         return false;  
251     }  
252      
253      
254 }

 　　4.2 软件下载

　　FFmpeg官方下载：http://ffmpeg.org/download.html