avifenc: Integrate LibRaw to support RAW image files as input

[EwoutH]

LibRaw (https://www.libraw.org/ | https://github.com/LibRaw/LibRaw) is a library for reading RAW files from digital cameras. It supports decoding RAW images in various formats, including CRW/CR2, NEF, RAF, DNG. I would allow to encode RAW images directly to AVIF images in avifenc.

DPReview has loads of RAW images from various brands available for download for testing.

[novomesk]

Such utility would require many adjustable options (or to support some config files where the settings are listed). When photographers develop RAW files, they adjust white balance, exposure, lights+shadows, noise reduction, colors, ... Automatic-mass conversion would be good for quickly obtaining image previews. Photographer usually needs to set desired values individually to obtain professional results.

[1480c1]

This would probably be best left up to a different project or program rather than integrating it into the basic application

[novomesk]

Well, I would like to have good RAW->AVIF converter too, I would use it to mass convert volume of less important photos.

I attempted to create such tool by myself using libraw. The tool worked but I was not happy with its visual quality. Other tools which merely display embedded JPG preview had nicer photos than my tool. There is a need of some post-processing. I am able to modify the result manually to achieve desired results but so far I was unsuccessful to do it automatically.

Meanwhile I use Bach Processing function in program called nomacs to perform mass conversion from RAW->AVIF.