Can I request that a method be added which tells you the number of times a gif loops? I'm extracting frames then resizing them and then using your other library (GifCreator) to recompile the frames back into an animated gif.

For the moment I'm setting it to loop indefinitely, but ideally I should specify the number of loops as specified in the source file.

If there's a simple vanilla PHP way of getting the loops then I'm all ears!

It seems that the frame durations are missing a place. When I get the frame duration of a 10000ms frame, it returns only 1000. When I get the frame duration of a 200ms frame, it returns only 20. Unless I'm mistaken.

hello, I use your code,but it show this problem.

Uncaught Error: Class 'GifFrameExtractor' not found in C:\xampp\htdocs\gites\a.php:5 Stack trace: #0 {main} thrown in C:\xampp\htdocs\gites\a.php on line 5

my GifFrameExtractor.php and gif image and my demo.php is in same folder.
I dont know why it can not found?
this is my code
` <?php include("GifFrameExtractor.php");

 $gifFilePath = 'a_g.gif';
 if (GifFrameExtractor::isAnimatedGif($gifFilePath)) { // check this is an animated GIF

$gfe = new GifFrameExtractor();
$gfe->extract($gifFilePath);
$totalDuration = $gfe->getTotalDuration();
 echo $totalDuration;
// Do something with extracted frames ...
}

?>`

please help me ,thanks

There appears to be an issue with memory usage in this script:

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 906 bytes) in gifframeextractor.php on line 149

The gif being processed: http://yum.gifsicle.com/0ed0dc3.gif

The gif is only about 2.5Mb so not sure why it is trying to allocate over 64MB.

Thanks!

GifCreator has an option to specify the loop count of the created GIF; is it possible to obtain this value for a GIF that has been read by GifFrameExtractor?

I downloaded this code because I wanted to be able to extract frames from GIFs, but I found a few problems applying it to some GIFs that used the "Leave" method for image disposal, where it would combine a frame with the previous frame using transparency.

There were two problems --

The first is that it copied the image to the composite sprite using the maximum height and width, like so, imagecopyresampled($sprite, $img, $this->frameSources[$i]["offset_left"], $this->frameSources[$i]["offset_top"], 0, 0, $this->gifMaxWidth, $this->gifMaxHeight, $this->gifMaxWidth, $this->gifMaxHeight);

However, if the second image was smaller in dimensions than the first, this would effectively black out anything past the dimensions of the first. The compositing would need to be done like this instead, imagecopyresampled($sprite, $img, $this->frameSources[$i]["offset_left"], $this->frameSources[$i]["offset_top"], 0, 0, $this->frameSources[$i]["width"], $this->frameSources[$i]["height"], $this->frameSources[$i]["width"], $this->frameSources[$i]["height"]);

Of course, that would only be for frames with the "Leave" method; otherwise it makes sense to black it out if the dimensions are kept to the maximum height and width. Though I'm not sure that's how animated GIFs work.

Second, it used the current index to determine the disposal method, $this->frameSources[$i]['disposal_method']

While the disposal method applies to the previous frame, so needs to be taken from the previous image data. So it needs to be addressed like this, $this->frameSources[$i-1]['disposal_method']

The project obviously looks like it has a lot left unimplemented and it looks like @Sybio has been gone for a while, but I'm leaving this documented here for anyone that might find interest in it.

For about 70% of the transparent GIFs I test, getFramePositions() is returning all zeros. These are transparent GIFs with lots of alpha padding. My understanding is when there is alpha pixel padding getFramePositions() should NOT return zero. Is this correct? Thanks.

In GifFrameExtractor at line 220. Something inside here is causing the entire php instance to crap out, the only way out is to restart PHP. I tried to set a time out but even that doesn't work something is screwy in this file!

        while (!$this->checkByte(0x3b) && !$this->checkEOF()) {

            $this->getCommentData(1);
            $this->parseGraphicsExtension(2);
            $this->getFrameString(2);
            $this->getApplicationData();
        }

@Sybio I was unable to delete the source file after extraction. I was getting permission error and that only occur when i use $gifExtract->extract($rawSource);

So i found out it was a permission issue. So i tried

@chmod($rawSource, 465);
@unlink($rawSource);

But what if the code is running on a shared host with chmod restriction. So I look into the GifFrameExtractor.php file and I found out the file wasn't closed after processing.

So I made a slit tweak by adding $this->closeFile(); and it fix the problem.

private function parseFramesInfo($filename)
    {
        $this->openFile($filename);
        $this->parseGifHeader();
        $this->parseGraphicsExtension(0);
        $this->getApplicationData();
        $this->getApplicationData();
        $this->getFrameString(0);
        $this->parseGraphicsExtension(1);
        $this->getCommentData();
        $this->getApplicationData();
        $this->getFrameString(1);
        
        while (!$this->checkByte(0x3b) && !$this->checkEOF()) {
            
            $this->getCommentData(1);
            $this->parseGraphicsExtension(2);
            $this->getFrameString(2);
            $this->getApplicationData();
        }
        $this->closeFile();
    }