Is it possible using Microsoft HEVC extension to encode/decode HEIF?

[TimYao18]

I want to say that I have already bought Microsoft's HEIF/HEVC Extension. Is it possible to use the Windows HEIF/HEVC codec for encoding?

Also, if possible, can I use the built-in Windows JPEG codec as well? Currently, I'm facing an issue with the JPEG library, as I don't know how to add openjpeg to the libheif codec.

[farindk]

OpenJPEG is for JPEG2000. You probably want to add libjpeg or libjpeg-turbo for regular JPEG support.

I don't think that it would be possible to write a plugin to uses the Microsoft HEVC Extension. I am not sure through which API this would be accessible. If you have any information about that, let me know.

[silverbacknet]

The extension hooks into the WIC (Windows Imaging Component) infrastructure as a plugin, so it wouldn't be hugely difficult to implement, I think. There's even a code sample for a basic AVIF encode at https://learn.microsoft.com/en-us/windows/win32/wic/heif-codec . The main options are basically quality, colorspace, and color profile, not a whole lot of fanciness, lol. I'm not sure if 10-bit encoding is supported at all via the extension, I'll have to test that out, but WIC itself has all the colorspaces you could want. (Mapping them might be a pain, not sure.)

The exception is I don't know and can't find whether HDR parameters can be directly set via WIC. You might have to drop down to Media Foundation for that, which is dramatically more complex and messier.

[farindk]

Thanks for the link to WIC. Very helpful.

Still, I'm not sure WIC would work as a libheif plugin. The API seems to be very high-level (raw image in, HEIC file out). What we would need instead is a raw h265 codec interface like libx265. Libheif would still generate the file structure, and handle cutting the image in tiles, adding metadata, and so on. With WIC, we would bypass libheif completely.

The only possibility would probably be to use WIC to encode to an intermediary file, and then decompose that again by libheif, copying over the compressed data. But that seems very fragile since it will depend on assumptions about how WIC generates the files and will break if there is any change by Microsoft.