strip metadata for webp and avif

webp and avif is mainly for browser, it's safe to strip metadata.

vips/foreign.c

@@ -159,7 +159,11 @@ int set_gifsave_options(VipsOperation *operation, SaveParams *params) {
 int set_avifsave_options(VipsOperation *operation, SaveParams *params) {
   int ret = vips_object_set(
       VIPS_OBJECT(operation), "compression", VIPS_FOREIGN_HEIF_COMPRESSION_AV1,
-      "lossless", params->heifLossless, "speed", params->avifSpeed, NULL);
+      "lossless", params->heifLossless,
+      "effort", 9 - params->avifSpeed, // speed is deprecated
+      "strip", params->stripMetadata,
+      "subsample_mode", VIPS_FOREIGN_SUBSAMPLE_AUTO, // set to auto as we always set lossless
+      NULL);
 
   if (!ret && params->quality) {
     ret = vips_object_set(VIPS_OBJECT(operation), "Q", params->quality, NULL);

vips/foreign.go

@@ -230,6 +230,7 @@ func vipsSaveAVIFToBuffer(in *C.VipsImage, params AvifExportParams) ([]byte, err
 	p := C.create_save_params(C.AVIF)
 	p.inputImage = in
 	p.outputFormat = C.AVIF
+	p.stripMetadata = C.int(boolToInt(params.StripMetadata))
 	p.quality = C.int(params.Quality)
 	p.heifLossless = C.int(boolToInt(params.Lossless))
 	p.avifSpeed = C.int(params.Speed)

vips/process.go

@@ -595,6 +595,7 @@ func (v *Processor) export(
 		return image.ExportPng(opts)
 	case ImageTypeWEBP:
 		opts := NewWebpExportParams()
+		opts.StripMetadata = true
 		if quality > 0 {
 			opts.Quality = quality
 		}
@@ -613,6 +614,7 @@ func (v *Processor) export(
 		return image.ExportGIF(opts)
 	case ImageTypeAVIF:
 		opts := NewAvifExportParams()
+		opts.StripMetadata = true
 		if quality > 0 {
 			opts.Quality = quality
 		}