Way to select encoder when saving AVIF

[saschanaz]

Feature request

What are you trying to achieve?

Wanted to try rav1e as the default AVIF encoder was too slow, but it seems there's no way for that.

When you searched for similar feature requests, what did you find that might be related?

Couldn't find one when querying with "select encoder". The caller isn't setting encoder, so I guess it's an issue anyway.

sharp/src/pipeline.cc

Lines 915 to 923 in 844deaf

	VipsArea *area = reinterpret_cast<VipsArea*>(image.heifsave_buffer(VImage::option()
	->set("strip", !baton->withMetadata)
	->set("Q", baton->heifQuality)
	->set("compression", baton->heifCompression)
	->set("effort", baton->heifEffort)
	->set("bitdepth", 8)
	->set("subsample_mode", baton->heifChromaSubsampling == "4:4:4"
	? VIPS_FOREIGN_SUBSAMPLE_OFF : VIPS_FOREIGN_SUBSAMPLE_ON)
	->set("lossless", baton->heifLossless)));

What would you expect the API to look like?

Perhaps .avif({ encoder: "rav1e" })?

What alternatives have you considered?

Wanted to try wasm-vips instead but it seemingly doesn't support heifsave at all. kleisauke/wasm-vips#44

Please provide sample image(s) that help explain this feature

(Not applicable)

[lovell]

To use rav1e, you'll need to compile your own libvips, libheif and rav1e and install them globally before re-installing sharp.

There's an issue tracking the future possible use of rav1e in the prebuilt binaries at lovell/sharp-libvips#97 but there's a lack of recent evidence that it's still faster than aom, which is still under heavy development.