AVIF support is disabled

Status changed to 'Confirmed' because the bug affects multiple users.

Thanks for taking the time to report this bug and trying to make Ubuntu better.

To triage this bug I created a Ubuntu Lunar (23.04) container and installed php, after that I ran the command you mentioned:

root@php-test:~# php -r 'imageavif(imagecreatefromjpeg(__DIR__ . "/foo.jpeg"));'
PHP Fatal error: Uncaught Error: Call to undefined function imageavif() in Command line code:1
Stack trace:
#0 {main}
  thrown in Command line code on line 1
root@php-test:~# php -i | grep AVIF

The error is different from what you presented. After some investigation, I noticed you need to install php8.1-gd package, and then you will get:

root@php-test:~# php -r 'imageavif(imagecreatefromjpeg(__DIR__ . "/foo.jpeg"));'
PHP Warning: imagecreatefromjpeg(/root/foo.jpeg): Failed to open stream: No such file or directory in Command line code on line 1
PHP Fatal error: Uncaught TypeError: imageavif(): Argument #1 ($image) must be of type GdImage, bool given in Command line code:1
Stack trace:
#0 Command line code(1): imageavif()
#1 {main}
  thrown in Command line code on line 1
root@php-test:~# php -i | grep AVIF
AVIF Support => enabled

The error above is expected because I had no image to be processed. And as you can see from the second command, the AVIF support is enabled. So please, if you want to use this function, install the php8.1-gd package and it should work for you.

Since this does not seem to me a bug in the package, I am marking it as Invalid. If you believe this is not the case, please mark it as New again and provide more information.

I have php8.1-gd installed and "php -i | grep AVIF" does indeed declare that AVIF support is enabled but then I get an error saying it is not.

Hello and thanks for this bug report. I can reproduce the issue as described.

The culprit is that avif support is disabled in src:libgd2, see:

libgd2 (2.3.3-9ubuntu1) mantic; urgency=low

  * Merge from Debian unstable. Remaining changes:
    - Drop the dependencies on libavif and libheif; libheif is blocked on a
      Main Inclusion Request, and libavif has an extensive rust dependency
      tree that makes it unsuitable for main.

There's a similar entry for lunar. I think this is valid wishlist bug for libgd2, so I'm changing the affected package.

@Pierre: to set the correct expectations: should this be fixed at some point, the fix will not be backported to Ubuntu stable releases. If you really need avif, I suggest rebuilding libgd2 straight from Debian in a PPA (the "drop libavif" change is specific to Ubuntu).