我想解码base64编码的数据，哪一个是image.gif?我如何在php中做到这一点

Question

我正在使用库中的以下代码https://github.com/antimatter15/jsgif.我试图将下面给出的代码转换为gif图像文件，但无法实现。

    var encoder = new GIFEncoder();
            encoder.setRepeat(0);
            encoder.start();
            var st = '|100:167.1,D,Pencil,3,#000|100:167.1,U|100:167.1,D|102:163.1,M|135:125.1|206:97.1|289:99.1|323:134.1|3
16:252.1|205:331.1|234:260.1|504:102.1|581:92.1|631:95.1|635:132.1|512:209.1,U|385:29.1,D,,,#66c|384:29.1,M|384:40.1|378:84.
1|365:168.1|360:215.1|354:269.1|354:300.1|357:313.1|405:319.1|450:314.1|507:291.1|546:260.1|534:223.1|487:171.1|418:119.1|29
0:131.1|220:201.1|168:284.1|157:339.1|170:353.1|256:308.1|348:212.1|390:118.1|399:77.1|397:68.1|298:82.1|176:168.1|90:265.1|
70:290.1|70:292.1|250:150.1|465:14.1|594:-42.9|606:-39.9|550:29.1|442:170.1|335:322.1|258:430.1|258:430.1,U';
            var frames_array = st.split('|');
            $.each(frames_array,function(index,value) {
               encoder.addFrame(value);
                });
            encoder.finish();
            var binary_gif = encoder.stream().getData();
            var data_url = 'data:image/gif;base64,'+encode64(binary_gif);

我得到的data_url如下所示

data:image/gif;base64,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‏

我需要将此编码代码转换为gif图像文件。如何进一步实现

Answer 1

试试这个，也许这会帮助你

<?php
function base64url_decode($data) {
return base64_decode(str_pad(strtr($data, '-_', '+/'), strlen($data) % 4,     '=', STR_PAD_RIGHT));
}
?>

Answer 2

使用这个（PHP伪代码）：http://php.net/manual/en/function.imagecreatefromstring.php

function imagegif_from_base64($base64)
{
    return imagecreatefromstring(base64_decode(substr($base64, 22) /* remove the "data:image/gif;base64," string */));
}

相关的从base64字符串获取图像

Answer 3

当你使用jsgif库时，你可以这样做来解码图像

    $imgstr = 'data:image/gif;base64,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‏';
    $new_data=explode(";",$imgstr);
    $type=$new_data[0];
    $imgdata=explode(",",$new_data[1]);
    $imgstr = base64_decode($imgdata[1]);
    // or choose any name instead sample.gif
    file_put_contents("sample.gif", base64_decode($imgstr));

Answer 4

如果你只想使用PHP，试试这个：

$str = 'data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAA...';
$data = str_replace('data:image/gif;base64,', '', $str);
$data = str_replace(' ', '+', $data);
$data = base64_decode($data); // base64 decoded image data
$source_img = imagecreatefromstring($data);
$file = uniqid() .'.gif';
$success = file_put_contents($file, $data);

这将把.gif图像保存在php文件所在的同一文件夹中。