diff --git a/.gitignore b/.gitignore
index 70102cd..334fc90 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 bin
 example.*
-test.*
\ No newline at end of file
+test.*
+*.exe
\ No newline at end of file
diff --git a/build.cmd b/build.cmd
deleted file mode 100644
index a981f78..0000000
--- a/build.cmd
+++ /dev/null
@@ -1,6 +0,0 @@
-@echo off
-
-echo Building...
-go build -o %USERPROFILE%/.bin/ffwebp.exe
-
-echo Done
diff --git a/cmd/ffwebp/banner.go b/cmd/ffwebp/banner.go
new file mode 100644
index 0000000..460a9ac
--- /dev/null
+++ b/cmd/ffwebp/banner.go
@@ -0,0 +1,36 @@
+package main
+
+import (
+	"runtime"
+	"sort"
+	"strings"
+
+	"github.com/coalaura/ffwebp/internal/codec"
+	"github.com/coalaura/ffwebp/internal/logx"
+)
+
+func banner() {
+	codecs := codec.All()
+
+	names := make([]string, len(codecs))
+
+	for i, c := range codecs {
+		names[i] = c.String()
+	}
+
+	sort.Strings(names)
+
+	build := strings.Join(names, ",")
+
+	logx.Printf("ffwebp version %s\n", Version)
+	logx.Printf(
+		"  built with %s %s %s\n",
+		runtime.Compiler,
+		runtime.Version(),
+		runtime.GOARCH,
+	)
+	logx.Printf(
+		"  configuration: -tags %s\n",
+		build,
+	)
+}
diff --git a/cmd/ffwebp/codecs.go b/cmd/ffwebp/codecs.go
deleted file mode 100644
index 351e254..0000000
--- a/cmd/ffwebp/codecs.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package main
-
-import (
-	_ "github.com/coalaura/ffwebp/internal/codec/gif"
-	_ "github.com/coalaura/ffwebp/internal/codec/jpeg"
-	_ "github.com/coalaura/ffwebp/internal/codec/png"
-)
diff --git a/cmd/ffwebp/main.go b/cmd/ffwebp/main.go
index 87d0c31..1f52294 100644
--- a/cmd/ffwebp/main.go
+++ b/cmd/ffwebp/main.go
@@ -3,10 +3,13 @@ package main
 import (
 	"context"
 	"io"
-	"log"
 	"os"
+	"path/filepath"
+	"time"
 
+	_ "github.com/coalaura/ffwebp/internal/builtins"
 	"github.com/coalaura/ffwebp/internal/codec"
+	"github.com/coalaura/ffwebp/internal/logx"
 	"github.com/coalaura/ffwebp/internal/opts"
 	"github.com/urfave/cli/v3"
 )
@@ -14,8 +17,6 @@ import (
 var Version = "dev"
 
 func main() {
-	log.SetOutput(os.Stderr)
-
 	flags := codec.Flags([]cli.Flag{
 		&cli.StringFlag{
 			Name:    "input",
@@ -45,10 +46,17 @@ func main() {
 			Aliases: []string{"l"},
 			Usage:   "force lossless mode (overrides --quality)",
 		},
-		&cli.StringFlag{
-			Name:    "resize",
-			Aliases: []string{"r"},
-			Usage:   "WxH, Wx or xH (keep aspect)",
+		&cli.BoolFlag{
+			Name:    "silent",
+			Aliases: []string{"s"},
+			Usage:   "hides all output",
+			Action: func(_ context.Context, _ *cli.Command, silent bool) error {
+				if silent {
+					logx.SetSilent()
+				}
+
+				return nil
+			},
 		},
 	})
 
@@ -66,22 +74,27 @@ func main() {
 	}
 
 	if err := app.Run(context.Background(), os.Args); err != nil {
-		log.Fatal(err)
+		logx.Errorf("fatal: %v", err)
+		os.Exit(1)
 	}
 }
 
 func run(_ context.Context, cmd *cli.Command) error {
+	banner()
+
 	var (
 		input  string
 		output string
 
 		common opts.Common
 
-		reader io.Reader = os.Stdin
-		writer io.Writer = os.Stdout
+		reader io.Reader    = os.Stdin
+		writer *countWriter = &countWriter{w: os.Stdout}
 	)
 
 	if input = cmd.String("input"); input != "-" {
+		logx.Printf("opening input file %q\n", filepath.ToSlash(input))
+
 		file, err := os.OpenFile(input, os.O_RDONLY, 0)
 		if err != nil {
 			return err
@@ -90,9 +103,13 @@ func run(_ context.Context, cmd *cli.Command) error {
 		defer file.Close()
 
 		reader = file
+	} else {
+		logx.Printf("reading input from <stdin>\n")
 	}
 
 	if output = cmd.String("output"); output != "-" {
+		logx.Printf("opening output file %q\n", filepath.ToSlash(output))
+
 		file, err := os.OpenFile(output, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
 		if err != nil {
 			return err
@@ -100,31 +117,47 @@ func run(_ context.Context, cmd *cli.Command) error {
 
 		defer file.Close()
 
-		writer = file
+		writer = &countWriter{w: file}
+	} else {
+		logx.Printf("writing output to <stdout>\n")
 	}
 
 	common.Quality = cmd.Int("quality")
 	common.Lossless = cmd.Bool("lossless")
 
+	common.FillDefaults()
+
+	sniffed, reader, err := codec.Sniff(reader)
+	if err != nil {
+		return err
+	}
+
+	logx.Printf("sniffed codec: %s (%q)\n", sniffed.Codec, sniffed)
+
 	oCodec, err := codec.Detect(output, cmd.String("codec"))
 	if err != nil {
 		return err
 	}
 
-	iCodec, reader, err := codec.Sniff(reader)
+	logx.Printf("output codec: %s (forced=%v)\n", oCodec, cmd.IsSet("codec"))
+
+	t0 := time.Now()
+
+	img, err := sniffed.Codec.Decode(reader)
 	if err != nil {
 		return err
 	}
 
-	img, err := iCodec.Decode(reader)
+	logx.Printf("decoded image: %dx%d %s in %s\n", img.Bounds().Dx(), img.Bounds().Dy(), colorModel(img), time.Since(t0).Truncate(time.Millisecond))
+
+	t1 := time.Now()
+
+	err = oCodec.Encode(writer, img, common)
 	if err != nil {
 		return err
 	}
 
-	resized, err := resize(img, cmd)
-	if err != nil {
-		return err
-	}
+	logx.Printf("encoded %d KiB in %s\n", (writer.n+1023)/1024, time.Since(t1).Truncate(time.Millisecond))
 
-	return oCodec.Encode(writer, resized, common)
+	return nil
 }
diff --git a/cmd/ffwebp/resize.go b/cmd/ffwebp/resize.go
deleted file mode 100644
index 9de1d6b..0000000
--- a/cmd/ffwebp/resize.go
+++ /dev/null
@@ -1,53 +0,0 @@
-package main
-
-import (
-	"errors"
-	"image"
-	"strconv"
-	"strings"
-
-	"github.com/disintegration/imaging"
-	"github.com/urfave/cli/v3"
-)
-
-func resize(img image.Image, cmd *cli.Command) (image.Image, error) {
-	options := strings.ToLower(cmd.String("resize"))
-
-	index := strings.Index(options, "x")
-	if index == -1 {
-		return img, nil
-	}
-
-	var (
-		width  int
-		height int
-	)
-
-	wRaw := options[:index]
-	if wRaw != "" {
-		w64, err := strconv.ParseInt(wRaw, 10, 64)
-		if err != nil {
-			return nil, err
-		}
-
-		width = int(max(0, w64))
-	}
-
-	hRaw := options[index:]
-	if hRaw != "" {
-		h64, err := strconv.ParseInt(hRaw, 10, 64)
-		if err != nil {
-			return nil, err
-		}
-
-		height = int(max(0, h64))
-	}
-
-	if width == 0 && height == 0 {
-		return nil, errors.New("at least one size needs to be specified for resizing")
-	}
-
-	resized := imaging.Resize(img, width, height, imaging.Lanczos)
-
-	return resized, nil
-}
diff --git a/cmd/ffwebp/utils.go b/cmd/ffwebp/utils.go
new file mode 100644
index 0000000..d442c33
--- /dev/null
+++ b/cmd/ffwebp/utils.go
@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"image"
+	"image/color"
+)
+
+func colorModel(img image.Image) string {
+	model := img.ColorModel()
+
+	switch model {
+	case color.RGBAModel:
+		return "RGBA"
+	case color.RGBA64Model:
+		return "RGBA64"
+	case color.NRGBAModel:
+		return "NRGBA"
+	case color.NRGBA64Model:
+		return "NRGBA64"
+	case color.AlphaModel:
+		return "Alpha"
+	case color.Alpha16Model:
+		return "Alpha16"
+	case color.GrayModel:
+		return "Gray"
+	case color.Gray16Model:
+		return "Gray16"
+	}
+
+	return fmt.Sprintf("%T", model)
+}
diff --git a/cmd/ffwebp/writer.go b/cmd/ffwebp/writer.go
new file mode 100644
index 0000000..cbaad51
--- /dev/null
+++ b/cmd/ffwebp/writer.go
@@ -0,0 +1,16 @@
+package main
+
+import "io"
+
+type countWriter struct {
+	w io.Writer
+	n int64
+}
+
+func (cw *countWriter) Write(p []byte) (int, error) {
+	m, err := cw.w.Write(p)
+
+	cw.n += int64(m)
+
+	return m, err
+}
diff --git a/go.mod b/go.mod
index 271f398..818f443 100644
--- a/go.mod
+++ b/go.mod
@@ -2,9 +2,6 @@ module github.com/coalaura/ffwebp
 
 go 1.24.2
 
-require (
-	github.com/disintegration/imaging v1.6.2
-	github.com/urfave/cli/v3 v3.3.8
-)
+require github.com/urfave/cli/v3 v3.3.8
 
 require golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8
diff --git a/go.sum b/go.sum
index e4f7dac..eaef168 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,5 @@
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/disintegration/imaging v1.6.2 h1:w1LecBlG2Lnp8B3jk5zSuNqd7b4DXhcjwek1ei82L+c=
-github.com/disintegration/imaging v1.6.2/go.mod h1:44/5580QXChDfwIclfc/PCwrr44amcmDAg8hxG0Ewe4=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
diff --git a/cmd/ffwebp/codecs_bmp.go b/internal/builtins/bmp.go
similarity index 52%
rename from cmd/ffwebp/codecs_bmp.go
rename to internal/builtins/bmp.go
index e353b24..0ac17db 100644
--- a/cmd/ffwebp/codecs_bmp.go
+++ b/internal/builtins/bmp.go
@@ -1,7 +1,7 @@
-//go:build bmp
-// +build bmp
+//go:build bmp || full
+// +build bmp full
 
-package main
+package builtins
 
 import (
 	_ "github.com/coalaura/ffwebp/internal/codec/bmp"
diff --git a/internal/builtins/builtins.go b/internal/builtins/builtins.go
new file mode 100644
index 0000000..7b4beb8
--- /dev/null
+++ b/internal/builtins/builtins.go
@@ -0,0 +1,3 @@
+package builtins
+
+// does nothing :)
diff --git a/internal/builtins/gif.go b/internal/builtins/gif.go
new file mode 100644
index 0000000..31a798b
--- /dev/null
+++ b/internal/builtins/gif.go
@@ -0,0 +1,8 @@
+//go:build gif || core || full
+// +build gif core full
+
+package builtins
+
+import (
+	_ "github.com/coalaura/ffwebp/internal/codec/gif"
+)
diff --git a/internal/builtins/jpeg.go b/internal/builtins/jpeg.go
new file mode 100644
index 0000000..90c9d74
--- /dev/null
+++ b/internal/builtins/jpeg.go
@@ -0,0 +1,8 @@
+//go:build jpeg || core || full
+// +build jpeg core full
+
+package builtins
+
+import (
+	_ "github.com/coalaura/ffwebp/internal/codec/jpeg"
+)
diff --git a/internal/builtins/png.go b/internal/builtins/png.go
new file mode 100644
index 0000000..8f2ee61
--- /dev/null
+++ b/internal/builtins/png.go
@@ -0,0 +1,8 @@
+//go:build png || core || full
+// +build png core full
+
+package builtins
+
+import (
+	_ "github.com/coalaura/ffwebp/internal/codec/png"
+)
diff --git a/cmd/ffwebp/codecs_tiff.go b/internal/builtins/tiff.go
similarity index 51%
rename from cmd/ffwebp/codecs_tiff.go
rename to internal/builtins/tiff.go
index 12809aa..18b277c 100644
--- a/cmd/ffwebp/codecs_tiff.go
+++ b/internal/builtins/tiff.go
@@ -1,7 +1,7 @@
-//go:build tiff
-// +build tiff
+//go:build tiff || full
+// +build tiff full
 
-package main
+package builtins
 
 import (
 	_ "github.com/coalaura/ffwebp/internal/codec/tiff"
diff --git a/internal/codec/bmp/bmp.go b/internal/codec/bmp/bmp.go
index 5289ae8..8a731c7 100644
--- a/internal/codec/bmp/bmp.go
+++ b/internal/codec/bmp/bmp.go
@@ -18,7 +18,7 @@ func init() {
 
 type impl struct{}
 
-func (impl) Name() string {
+func (impl) String() string {
 	return "bmp"
 }
 
@@ -30,20 +30,20 @@ func (impl) Flags(flags []cli.Flag) []cli.Flag {
 	return flags
 }
 
-func (impl) Sniff(reader io.ReaderAt) (int, error) {
+func (impl) Sniff(reader io.ReaderAt) (int, []byte, error) {
 	magic := []byte{0x42, 0x4D}
 
 	buf := make([]byte, 2)
 
 	if _, err := reader.ReadAt(buf, 0); err != nil {
-		return 0, err
+		return 0, nil, err
 	}
 
 	if bytes.Equal(buf, magic) {
-		return 100, nil
+		return 100, magic, nil
 	}
 
-	return 0, nil
+	return 0, nil, nil
 }
 
 func (impl) Decode(reader io.Reader) (image.Image, error) {
diff --git a/internal/codec/codec.go b/internal/codec/codec.go
index d3e3ffd..1583c40 100644
--- a/internal/codec/codec.go
+++ b/internal/codec/codec.go
@@ -9,12 +9,12 @@ import (
 )
 
 type Codec interface {
-	Name() string
+	String() string
 
 	Flags([]cli.Flag) []cli.Flag
 	Extensions() []string
 
-	Sniff(io.ReaderAt) (int, error)
+	Sniff(io.ReaderAt) (int, []byte, error)
 	Decode(io.Reader) (image.Image, error)
 	Encode(io.Writer, image.Image, opts.Common) error
 }
@@ -22,7 +22,7 @@ type Codec interface {
 var codecs = map[string]Codec{}
 
 func Register(c Codec) {
-	codecs[c.Name()] = c
+	codecs[c.String()] = c
 }
 
 func Flags(flags []cli.Flag) []cli.Flag {
diff --git a/internal/codec/detect.go b/internal/codec/detect.go
index 11598d1..577323f 100644
--- a/internal/codec/detect.go
+++ b/internal/codec/detect.go
@@ -9,7 +9,27 @@ import (
 	"strings"
 )
 
-func Sniff(reader io.Reader) (Codec, io.Reader, error) {
+type Sniffed struct {
+	Header     []byte
+	Confidence int
+	Codec      Codec
+}
+
+func (s *Sniffed) String() string {
+	var builder strings.Builder
+
+	for _, b := range s.Header {
+		if b >= 32 && b <= 126 {
+			builder.WriteByte(b)
+		} else {
+			builder.WriteRune('.')
+		}
+	}
+
+	return builder.String()
+}
+
+func Sniff(reader io.Reader) (*Sniffed, io.Reader, error) {
 	buf, err := io.ReadAll(reader)
 	if err != nil {
 		return nil, nil, err
@@ -18,18 +38,20 @@ func Sniff(reader io.Reader) (Codec, io.Reader, error) {
 	ra := bytes.NewReader(buf)
 
 	var (
-		guess Codec
 		best  int
+		magic []byte
+		guess Codec
 	)
 
 	for _, codec := range codecs {
-		confidence, err := codec.Sniff(ra)
+		confidence, header, err := codec.Sniff(ra)
 		if err != nil {
 			return nil, nil, err
 		}
 
 		if confidence > best {
 			best = confidence
+			magic = header
 			guess = codec
 		}
 	}
@@ -38,7 +60,11 @@ func Sniff(reader io.Reader) (Codec, io.Reader, error) {
 		return nil, nil, errors.New("unknown format")
 	}
 
-	return guess, bytes.NewReader(buf), nil
+	return &Sniffed{
+		Header:     magic,
+		Confidence: best,
+		Codec:      guess,
+	}, bytes.NewReader(buf), nil
 }
 
 func Detect(output, override string) (Codec, error) {
diff --git a/internal/codec/gif/gif.go b/internal/codec/gif/gif.go
index be9d52b..ba81d79 100644
--- a/internal/codec/gif/gif.go
+++ b/internal/codec/gif/gif.go
@@ -8,6 +8,7 @@ import (
 	"io"
 
 	"github.com/coalaura/ffwebp/internal/codec"
+	"github.com/coalaura/ffwebp/internal/logx"
 	"github.com/coalaura/ffwebp/internal/opts"
 	"github.com/urfave/cli/v3"
 )
@@ -20,7 +21,7 @@ func init() {
 
 type impl struct{}
 
-func (impl) Name() string {
+func (impl) String() string {
 	return "gif"
 }
 
@@ -44,21 +45,25 @@ func (impl) Flags(flags []cli.Flag) []cli.Flag {
 	})
 }
 
-func (impl) Sniff(reader io.ReaderAt) (int, error) {
+func (impl) Sniff(reader io.ReaderAt) (int, []byte, error) {
 	magic7a := []byte("GIF87a")
 	magic9a := []byte("GIF89a")
 
 	buf := make([]byte, 6)
 
 	if _, err := reader.ReadAt(buf, 0); err != nil {
-		return 0, err
+		return 0, nil, err
 	}
 
-	if bytes.Equal(buf, magic7a) || bytes.Equal(buf, magic9a) {
-		return 100, nil
+	if bytes.Equal(buf, magic7a) {
+		return 100, magic7a, nil
 	}
 
-	return 0, nil
+	if bytes.Equal(buf, magic9a) {
+		return 100, magic9a, nil
+	}
+
+	return 0, nil, nil
 }
 
 func (impl) Decode(reader io.Reader) (image.Image, error) {
@@ -66,6 +71,8 @@ func (impl) Decode(reader io.Reader) (image.Image, error) {
 }
 
 func (impl) Encode(writer io.Writer, img image.Image, options opts.Common) error {
+	logx.Printf("gif: colors=%d\n", numColors)
+
 	return gif.Encode(writer, img, &gif.Options{
 		NumColors: numColors,
 	})
diff --git a/internal/codec/jpeg/jpeg.go b/internal/codec/jpeg/jpeg.go
index c34c944..6c325af 100644
--- a/internal/codec/jpeg/jpeg.go
+++ b/internal/codec/jpeg/jpeg.go
@@ -7,6 +7,7 @@ import (
 	"io"
 
 	"github.com/coalaura/ffwebp/internal/codec"
+	"github.com/coalaura/ffwebp/internal/logx"
 	"github.com/coalaura/ffwebp/internal/opts"
 	"github.com/urfave/cli/v3"
 )
@@ -17,7 +18,7 @@ func init() {
 	codec.Register(impl{})
 }
 
-func (impl) Name() string {
+func (impl) String() string {
 	return "jpeg"
 }
 
@@ -29,20 +30,20 @@ func (impl) Flags(flags []cli.Flag) []cli.Flag {
 	return flags
 }
 
-func (impl) Sniff(reader io.ReaderAt) (int, error) {
-	marker := []byte{0xFF, 0xD8, 0xFF}
+func (impl) Sniff(reader io.ReaderAt) (int, []byte, error) {
+	magic := []byte{0xFF, 0xD8, 0xFF}
 
 	buf := make([]byte, 3)
 
 	if _, err := reader.ReadAt(buf, 0); err != nil {
-		return 0, err
+		return 0, nil, err
 	}
 
-	if bytes.Equal(buf, marker) {
-		return 100, nil
+	if bytes.Equal(buf, magic) {
+		return 100, magic, nil
 	}
 
-	return 0, nil
+	return 0, nil, nil
 }
 
 func (impl) Decode(reader io.Reader) (image.Image, error) {
@@ -50,6 +51,8 @@ func (impl) Decode(reader io.Reader) (image.Image, error) {
 }
 
 func (impl) Encode(writer io.Writer, img image.Image, options opts.Common) error {
+	logx.Printf("jpeg: quality=%d\n", options.Quality)
+
 	return jpeg.Encode(writer, img, &jpeg.Options{
 		Quality: options.Quality,
 	})
diff --git a/internal/codec/png/png.go b/internal/codec/png/png.go
index bbdc0ba..cfc8ff8 100644
--- a/internal/codec/png/png.go
+++ b/internal/codec/png/png.go
@@ -8,6 +8,7 @@ import (
 	"io"
 
 	"github.com/coalaura/ffwebp/internal/codec"
+	"github.com/coalaura/ffwebp/internal/logx"
 	"github.com/coalaura/ffwebp/internal/opts"
 	"github.com/urfave/cli/v3"
 )
@@ -22,7 +23,7 @@ func init() {
 	codec.Register(impl{})
 }
 
-func (impl) Name() string {
+func (impl) String() string {
 	return "png"
 }
 
@@ -46,20 +47,20 @@ func (impl) Flags(flags []cli.Flag) []cli.Flag {
 	})
 }
 
-func (impl) Sniff(reader io.ReaderAt) (int, error) {
+func (impl) Sniff(reader io.ReaderAt) (int, []byte, error) {
 	magic := []byte{0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A}
 
 	buf := make([]byte, len(magic))
 
 	if _, err := reader.ReadAt(buf, 0); err != nil {
-		return 0, err
+		return 0, nil, err
 	}
 
 	if bytes.Equal(buf, magic) {
-		return 100, nil
+		return 100, magic, nil
 	}
 
-	return 0, nil
+	return 0, nil, nil
 }
 
 func (impl) Decode(reader io.Reader) (image.Image, error) {
@@ -67,6 +68,8 @@ func (impl) Decode(reader io.Reader) (image.Image, error) {
 }
 
 func (impl) Encode(writer io.Writer, img image.Image, _ opts.Common) error {
+	logx.Printf("png: compression=%d\n", compression)
+
 	encoder := png.Encoder{
 		CompressionLevel: compressionLevel(compression),
 	}
diff --git a/internal/codec/tiff/tiff.go b/internal/codec/tiff/tiff.go
index a78a544..2e36dd6 100644
--- a/internal/codec/tiff/tiff.go
+++ b/internal/codec/tiff/tiff.go
@@ -9,6 +9,7 @@ import (
 	"golang.org/x/image/tiff"
 
 	"github.com/coalaura/ffwebp/internal/codec"
+	"github.com/coalaura/ffwebp/internal/logx"
 	"github.com/coalaura/ffwebp/internal/opts"
 	"github.com/urfave/cli/v3"
 )
@@ -24,7 +25,7 @@ func init() {
 
 type impl struct{}
 
-func (impl) Name() string {
+func (impl) String() string {
 	return "tiff"
 }
 
@@ -56,21 +57,25 @@ func (impl) Flags(flags []cli.Flag) []cli.Flag {
 	)
 }
 
-func (impl) Sniff(reader io.ReaderAt) (int, error) {
+func (impl) Sniff(reader io.ReaderAt) (int, []byte, error) {
 	magicLE := []byte{0x49, 0x49, 0x2A, 0x00}
 	magicBE := []byte{0x4D, 0x4D, 0x00, 0x2A}
 
 	buf := make([]byte, 4)
 
 	if _, err := reader.ReadAt(buf, 0); err != nil {
-		return 0, err
+		return 0, nil, err
 	}
 
-	if bytes.Equal(buf, magicLE) || bytes.Equal(buf, magicBE) {
-		return 100, nil
+	if bytes.Equal(buf, magicLE) {
+		return 100, magicLE, nil
 	}
 
-	return 0, nil
+	if bytes.Equal(buf, magicBE) {
+		return 100, magicBE, nil
+	}
+
+	return 0, nil, nil
 }
 
 func (impl) Decode(reader io.Reader) (image.Image, error) {
@@ -78,6 +83,8 @@ func (impl) Decode(reader io.Reader) (image.Image, error) {
 }
 
 func (impl) Encode(writer io.Writer, img image.Image, options opts.Common) error {
+	logx.Printf("tiff: compression=%d predictor=%t\n", compression, predictor)
+
 	return tiff.Encode(writer, img, &tiff.Options{
 		Compression: compressionType(compression),
 		Predictor:   predictor,
diff --git a/internal/logx/logx.go b/internal/logx/logx.go
new file mode 100644
index 0000000..35ee5ff
--- /dev/null
+++ b/internal/logx/logx.go
@@ -0,0 +1,54 @@
+package logx
+
+import (
+	"fmt"
+	"image"
+	"os"
+	"sync/atomic"
+	"time"
+)
+
+var enabled atomic.Bool
+
+func init() {
+	enabled.Store(true)
+}
+
+func SetSilent() {
+	enabled.Store(false)
+}
+
+func Printf(format string, a ...any) {
+	if !enabled.Load() {
+		return
+	}
+
+	for i, v := range a {
+		switch r := v.(type) {
+		case time.Time:
+			a[i] = time.Since(r)
+		case image.Image:
+			b := r.Bounds()
+
+			a[i] = fmt.Sprintf("%dx%dx", b.Dx(), b.Dy())
+		default:
+			a[i] = v
+		}
+	}
+
+	fmt.Fprintf(os.Stderr, format, a...)
+}
+
+func PrintKV(codec, key string, val any) {
+	if !enabled.Load() {
+		return
+	}
+
+	Printf("%s: %s=%v\n", codec, key, val)
+}
+
+func Errorf(f string, a ...any) {
+	fmt.Fprintf(os.Stderr, f, a...)
+
+	os.Exit(1)
+}
diff --git a/run.cmd b/run.cmd
new file mode 100644
index 0000000..361b1da
--- /dev/null
+++ b/run.cmd
@@ -0,0 +1,6 @@
+@echo off
+
+echo Rebuilding...
+go build -tags full -o ffwebp.exe .\cmd\ffwebp
+
+.\ffwebp.exe %*
\ No newline at end of file