CODEWITHSUNDEEP
phppnganimated-gif
hockeygoalie5
hockeygoalie5

Reputation: 11

Convert animated GIF to PNG

I'm trying to display only the first frame of an animated GIF to a PNG to use as a thumbnail. I currently have this code:

<?php
function myImageCreateFromGif($file_or_url) { 
$dummy_file = "/tmp/dummy.gif"; 
# if this is a url, use fopen to get the file data, then 
# save it to a dummy file 
if (preg_match("/(http|ftp):\/\//i", $file_or_url)) { 
        # open the file using fopen, which supports remote URLs 
        $input = fopen($file_or_url, "rb"); 
        # read the contents of the file 
        # will accept files up to 10Mb, but will probably get 
        # and EOF before that, we have to do it this way because 
        # filesize isn't designed to work with URLs.  sigh. 
        $image_data = fread($input, 10000000); 
        fclose($input); 
        # write the contents to a dummy file 
        $output = fopen("$dummy_file", "wb"); 
        fwrite($output, $image_data); 
        fclose($output); 
        # create the gif from the dummy file 
        $image = ImageCreateFromGif($dummy_file); 
        # get rid of the dummy file 
        unlink($dummy_file); 
    } 
    # if it's not a URL, we can simply open the image directly 
    else { 
        $image = ImageCreateFromGif($file_or_url); 
    } 
    if ($image) { return $image; } 
    else { return 0; } 
}
$image = "http://i.imgur.com/".$_GET["i"].".gif";
$img = myImageCreateFromGif($image);
if($img) {
    header("Content-Type: image/png");
    ImagePNG($img);
    ImageDestroy($img);
}
?>

Which works fine, but the GIF does not fully load before it becomes a PNG, so the page returns either a broken image if the GIF could not load at all, or a partially-loaded GIF that fills the unloaded part by repeating what it has managed to load. So, how can I get the GIF to load completely before making it a PNG?

Upvotes: 1

Views: 1394

Answers (2)

devsnd
devsnd

Reputation: 7722

You should use perl for retrieving files over http.

This is from the php manuals: http://www.php.net/manual/de/function.curl-exec.php

/**
 * Send a GET requst using cURL
 * @param string $url to request
 * @param array $get values to send
 * @param array $options for cURL
 * @return string
 */
function curl_get($url, array $get = NULL, array $options = array())
{   
    $defaults = array(
        CURLOPT_URL => $url. (strpos($url, '?') === FALSE ? '?' : ''). http_build_query($get),
        CURLOPT_HEADER => 0,
        CURLOPT_RETURNTRANSFER => TRUE,
        CURLOPT_TIMEOUT => 4
    );

    $ch = curl_init();
    curl_setopt_array($ch, ($options + $defaults));
    if( ! $result = curl_exec($ch))
    {
        trigger_error(curl_error($ch));
    }
    curl_close($ch);
    return $result;
}

It will return the file contents of the file you have set in th $url parameter.

Upvotes: 0

Kurt Pfeifle
Kurt Pfeifle

Reputation: 90335

I would use ImageMagick's convert to transform the first frame of the GIF into PNG. You address the first frame by adding [0] to the filename.

Oh, and recent versions of convert can directly handle URIs for source file locations just well:

 convert  "http://imgur.com/a.gif[0]"  a.png

or

 convert  "http://imgur.com/a.gif[0]"  -thumbnail  128x128  a.png

Upvotes: 1

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