ico

internal/builtins/ico.go

@@ -0,0 +1,8 @@
+//go:build ico || core || full
+// +build ico core full
+
+package builtins
+
+import (
+	_ "github.com/coalaura/ffwebp/internal/codec/ico"
+)

internal/codec/ico/ico.go

@@ -0,0 +1,80 @@
+package ico
+
+import (
+	"bytes"
+	"image"
+	"io"
+
+	"github.com/sergeymakinen/go-ico"
+
+	"github.com/coalaura/ffwebp/internal/codec"
+	"github.com/coalaura/ffwebp/internal/opts"
+	"github.com/urfave/cli/v3"
+)
+
+func init() {
+	codec.Register(impl{})
+}
+
+type impl struct{}
+
+func (impl) String() string {
+	return "ico"
+}
+
+func (impl) Extensions() []string {
+	return []string{"ico", "cur"}
+}
+
+func (impl) Flags(flags []cli.Flag) []cli.Flag {
+	return flags
+}
+
+func (impl) Sniff(reader io.ReaderAt) (int, []byte, error) {
+	magicICO := []byte{0x00, 0x00, 0x01, 0x00}
+	magicCUR := []byte{0x00, 0x00, 0x02, 0x00}
+
+	buf := make([]byte, 4)
+
+	if _, err := reader.ReadAt(buf, 0); err != nil {
+		return 0, nil, err
+	}
+
+	if bytes.Equal(buf, magicICO) || bytes.Equal(buf, magicCUR) {
+		return 100, buf, nil
+	}
+
+	return 0, nil, nil
+}
+
+func (impl) Decode(r io.Reader) (image.Image, error) {
+	images, err := ico.DecodeAll(r)
+	if err != nil {
+		return nil, err
+	}
+
+	var (
+		best     image.Image
+		bestArea int
+	)
+
+	for _, img := range images {
+		bounds := img.Bounds()
+		area := bounds.Dx() * bounds.Dy()
+
+		if area > bestArea {
+			best = img
+			bestArea = area
+		}
+	}
+
+	if best == nil {
+		return nil, io.EOF
+	}
+
+	return best, nil
+}
+
+func (impl) Encode(w io.Writer, img image.Image, _ opts.Common) error {
+	return ico.Encode(w, img)
+}