AVIF

[TriVoxel]

Is your feature request related to a problem? Please describe.

I'm a Blender user. I'm disappointed by the lack of AVIF support. AVIF is significantly better than JPEG and PNG, and would empower me as an artist to create higher-quality, web-optimized images that use bandwidth more efficiently. The AVIF format has extremely efficient lossy and lossless compression, it supports 8-bit, 10-bit, and 12-bit color depths, 3 modes of chroma sampling, it supports high dynamic range, and it supports animation. Since all modern web browsers and operating systems support AVIF, now is the perfect time to add it.

Describe the solution you'd like

I would like full AVIF support, with granular control over the encoder speed (for compression efficiency), control over chroma sampling format, optional HDR encoding, bit depth options, and ability to select lossy or lossless compression.

Ideally, we would also have the ability to encode animation into the file. For that to happen, a program like Blender needs to be able to specify the frame time and control how many times the sequence loops (including never or infinite).

Describe alternatives you've considered

The only alternative is to export to something like 16-bit PNG and then use a tool like GIMP to convert images, or command line tools like ffmpeg and avifenc to convert videos into AVIF animations.

Additional context

AVIF is similar to HEIC. It utilizes the royalty-free AV1 video codec for 1 frame to encode/decode the image. Being royalty-free and open source, it should hopefully make this one a bit easier to implement in your library. I would really appreciate the inclusion of this image format, it would be life changing! Here's a link to my Right-Click Select proposal where I go into more detail and include some sample files!

[lgritz]

I'm pretty sure OpenImageIO already reads AVIF files with the same reader that we use for heic files, though you need to build OIIO with the libheif dependency available to be found at build time, and libheif in turn needs to be built with an AV1 encoder/decoder for AVIF support. I'm not sure if the Blender dependency building scripts have all those things set up the right way, but if they are, I think things are probably already fine on the OpenImageIO side.

I'm not sure if your comments about encoding AVIF are directed to OIIO or are just general venting, but OIIO isn't a video encoding library and doesn't write any video files of any format. Are these suggestions better directed toward Blender itself?

[TriVoxel]

@lgritz Hey! Sorry, I did link the request I made for Blender. I was sent here as OIIO is the library they rely on for here. The developer there mentioned that support would need to be added to OIIO before they could add the feature to Blender. I was trying to give a rationale for implementing AVIF into OIIO as I have personally discovered many benefits to using this format for web development and personal use, and to my dismay Blender does not currently support it.

I mentioned that AVIF uses the AV1 video codec because AV1 is royalty free which I'd assumed would have made it easier to implement. To be clear, I'm not suggesting OIIO implement video encoding, my intent was to suggest that OIIO utilize this efficient royalty-free compression algorithm for the express purpose of image encoding/decoding. To be clear, I'm asking for support of an image format.

Does your current AVIF implementation support animation? I don't know the specifics, but it seems like an animated AVIF bundles multiple still images into one file, assigning a time code to each frame to tell the decoder how fast to play it back. If this functionality does not exist, I would love to see it added at some point. It's basically like a modern version of GIF, where it's still an image, not video, but multiple frames can be combined into one file and the framerate is set per-frame. Such a feature would be really nice for Blender users so we can create efficient looping animations and display them on the internet!

I will pass your word along to that Blender forum. Thank you!

[lgritz]

OIIO is a still-image library, and it's not within its scope to handle video formats or CODECs per se. It does some very basic reading of video files, only in the sense that it can pretend it's an image file format that can hold more than one image (as can OpenEXR, TIFF, or GIF). But not in the sense of understanding playback, inter-frame coding, audio, or anything else that's essential to really being a video library. And though it can read individual frames from a variety of video files via ffmpeg, it can't write them.

So, yes, if Blender wants to read individual frames from avif file in the way it uses OpenImageIO for other image reading tasks, all it needs to do is ensure that it's built against libheif, and that libheif was built with avif support enabled.

But if you want Blender to directly output video files, we can't really help. Because Blender doesn't use OpenImageIO to output actual video files for ANY video format.

[TriVoxel]

@lgritz Thanks for taking the time to respond!

I did want to clarify that although it uses the compression component of AV1, it isn't actually a video at all.

An animated AVIF does not store inter-frame coding, audio, or anything else like that. It essentially just stores a bunch of still image frames within the file, and assigns some metadata to tell the decoder how long each frame should last, and how many times to loop (including none and infinite). It's basically like a simplified version of GIF.

So with AVIF, you aren't storing a video at all, it's packing a sequence of ordinary, still images into a file with some fancy metadata per-frame to tell the image decoder how fast to swap frames.

That being said, I do understand if that would be out of scope, it's just more of a thing I wish for because it's essentially still just a plain image file, but with multiple images crammed into one container with the ability to tell a decoder how fast to switch frames.

It's just something I'd appreciate getting some serious consideration. I digress! Thanks for taking the time to help!!