在imagecreatefromgif()函数的PHP手册页中有一个简短的代码片段，应该是你所需要的：

由ZeBadger提供的图片评论＃59787

在search同样问题的解决scheme时，我注意到php.net网站对Davide和Kris所指代码的后续操作，但根据作者的说法，内存密集程度更低，可能更less的磁盘密集。

我会在这里复制它，因为它可能是有趣的。

来源： http ： //www.php.net/manual/en/function.imagecreatefromgif.php#88005

function is_ani($filename) { if(!($fh = @fopen($filename, 'rb'))) return false; $count = 0; //an animated gif contains multiple "frames", with each frame having a //header made up of: // * a static 4-byte sequence (\x00\x21\xF9\x04) // * 4 variable bytes // * a static 2-byte sequence (\x00\x2C) // We read through the file til we reach the end of the file, or we've found // at least 2 frame headers while(!feof($fh) && $count < 2) { $chunk = fread($fh, 1024 * 100); //read 100kb at a time $count += preg_match_all('#\x00\x21\xF9\x04.{4}\x00[\x2C\x21]#s', $chunk, $matches); } fclose($fh); return $count > 1; }

这是工作function：

/** * Thanks to ZeBadger for original example, and Davide Gualano for pointing me to it * Original at http://it.php.net/manual/en/function.imagecreatefromgif.php#59787 **/ function is_animated_gif( $filename ) { $raw = file_get_contents( $filename ); $offset = 0; $frames = 0; while ($frames < 2) { $where1 = strpos($raw, "\x00\x21\xF9\x04", $offset); if ( $where1 === false ) { break; } else { $offset = $where1 + 1; $where2 = strpos( $raw, "\x00\x2C", $offset ); if ( $where2 === false ) { break; } else { if ( $where1 + 8 == $where2 ) { $frames ++; } $offset = $where2 + 1; } } } return $frames > 1; }

如果给定的文件太大，用file_get_contents读取整个文件可能会花费太多的内存。 我已经重新考虑了以前给出的函数，它只读取了足够的字节来检查帧，并且一find至less2帧就返回。

<?php /** * Detects animated GIF from given file pointer resource or filename. * * @param resource|string $file File pointer resource or filename * @return bool */ function is_animated_gif($file) { $fp = null; if (is_string($file)) { $fp = fopen($file, "rb"); } else { $fp = $file; /* Make sure that we are at the beginning of the file */ fseek($fp, 0); } if (fread($fp, 3) !== "GIF") { fclose($fp); return false; } $frames = 0; while (!feof($fp) && $frames < 2) { if (fread($fp, 1) === "\x00") { /* Some of the animated GIFs do not contain graphic control extension (starts with 21 f9) */ if (fread($fp, 1) === "\x2c" || fread($fp, 2) === "\x21\xf9") { $frames++; } } } fclose($fp); return $frames > 1; }

animationGIF必须具有以下string

"\x21\xFF\x0B\x4E\x45\x54\x53\x43\x41\x50\x45\x32\x2E\x30"