fix: default EnableWebPEncoding to false and reduce artwork parallelism

Changed EnableWebPEncoding default to false so that upgrading users get
the same JPEG/PNG encoding behavior as v0.60.3 out of the box, avoiding
the WebP WASM overhead until native libwebp is available. Users can
opt in to WebP by setting EnableWebPEncoding=true. Also reduced the
default DevArtworkMaxRequests to half the CPU count (min 2) to lower
resource pressure during artwork processing.

conf/configuration.go

@@ -724,7 +724,7 @@ func setViperDefaults() {
 	viper.SetDefault("mpvcmdtemplate", "mpv --audio-device=%d --no-audio-display %f --input-ipc-server=%s")
 	viper.SetDefault("coverartpriority", "cover.*, folder.*, front.*, embedded, external")
 	viper.SetDefault("coverartquality", 75)
-	viper.SetDefault("enablewebpencoding", true)
+	viper.SetDefault("enablewebpencoding", false)
 	viper.SetDefault("artistartpriority", "artist.*, album/artist.*, external")
 	viper.SetDefault("artistimagefolder", "")
 	viper.SetDefault("discartpriority", "disc*.*, cd*.*, cover.*, folder.*, front.*, discsubtitle, embedded")
@@ -820,7 +820,7 @@ func setViperDefaults() {
 	viper.SetDefault("devuishowconfig", true)
 	viper.SetDefault("devneweventstream", true)
 	viper.SetDefault("devoffsetoptimize", 50000)
-	viper.SetDefault("devartworkmaxrequests", max(4, runtime.NumCPU()))
+	viper.SetDefault("devartworkmaxrequests", max(2, runtime.NumCPU()/2))
 	viper.SetDefault("devartworkthrottlebackloglimit", consts.RequestThrottleBacklogLimit)
 	viper.SetDefault("devartworkthrottlebacklogtimeout", consts.RequestThrottleBacklogTimeout)
 	viper.SetDefault("devartistinfotimetolive", consts.ArtistInfoTimeToLive)

core/artwork/artwork_internal_test.go

@@ -380,24 +380,24 @@ var _ = Describe("Artwork", func() {
 			})
 		})
 		When("Square is false", func() {
-			It("returns WebP even if original image is a PNG", func() {
+			It("returns PNG if original image is a PNG", func() {
 				conf.Server.CoverArtPriority = "front.png"
 				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 15, false)
 				Expect(err).ToNot(HaveOccurred())
 
 				img, format, err := image.Decode(r)
 				Expect(err).ToNot(HaveOccurred())
-				Expect(format).To(Equal("webp"))
+				Expect(format).To(Equal("png"))
 				Expect(img.Bounds().Size().X).To(Equal(15))
 				Expect(img.Bounds().Size().Y).To(Equal(15))
 			})
-			It("returns WebP if original image is not a PNG", func() {
+			It("returns JPEG if original image is not a PNG", func() {
 				conf.Server.CoverArtPriority = "cover.jpg"
 				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 200, false)
 				Expect(err).ToNot(HaveOccurred())
 
 				img, format, err := image.Decode(r)
-				Expect(format).To(Equal("webp"))
+				Expect(format).To(Equal("jpeg"))
 				Expect(err).ToNot(HaveOccurred())
 				Expect(img.Bounds().Size().X).To(Equal(200))
 				Expect(img.Bounds().Size().Y).To(Equal(200))
@@ -430,12 +430,39 @@ var _ = Describe("Artwork", func() {
 					Expect(img.Bounds().Size().X).To(Equal(size))
 					Expect(img.Bounds().Size().Y).To(Equal(size))
 				},
-				Entry("portrait png image", "png", "webp", false, 200),
+				Entry("portrait png image", "png", "png", false, 200),
-				Entry("landscape png image", "png", "webp", true, 200),
+				Entry("landscape png image", "png", "png", true, 200),
-				Entry("portrait jpg image", "jpg", "webp", false, 200),
+				Entry("portrait jpg image", "jpg", "png", false, 200),
-				Entry("landscape jpg image", "jpg", "webp", true, 200),
+				Entry("landscape jpg image", "jpg", "png", true, 200),
 			)
 		})
+		When("EnableWebPEncoding is true and square is false", func() {
+			BeforeEach(func() {
+				conf.Server.EnableWebPEncoding = true
+			})
+			It("returns WebP even if original image is a PNG", func() {
+				conf.Server.CoverArtPriority = "front.png"
+				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 15, false)
+				Expect(err).ToNot(HaveOccurred())
+
+				img, format, err := image.Decode(r)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(format).To(Equal("webp"))
+				Expect(img.Bounds().Size().X).To(Equal(15))
+				Expect(img.Bounds().Size().Y).To(Equal(15))
+			})
+			It("returns WebP if original image is not a PNG", func() {
+				conf.Server.CoverArtPriority = "cover.jpg"
+				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 200, false)
+				Expect(err).ToNot(HaveOccurred())
+
+				img, format, err := image.Decode(r)
+				Expect(format).To(Equal("webp"))
+				Expect(err).ToNot(HaveOccurred())
+				Expect(img.Bounds().Size().X).To(Equal(200))
+				Expect(img.Bounds().Size().Y).To(Equal(200))
+			})
+		})
 		When("EnableWebPEncoding is false and square is false", func() {
 			BeforeEach(func() {
 				conf.Server.EnableWebPEncoding = false