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
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