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// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build ignore
//
// This build tag means that "go install golang.org/x/image/..." doesn't
// install this manual test. Use "go run main.go" to explicitly run it.
// Program webp-manual-test checks that the Go WEBP library's decodings match
// the C WEBP library's.
package main // import "golang.org/x/image/cmd/webp-manual-test"
import (
"bytes"
"encoding/hex"
"flag"
"fmt"
"image"
"io"
"log"
"os"
"os/exec"
"path/filepath"
"sort"
"strings"
"golang.org/x/image/webp"
)
var (
dwebp = flag.String("dwebp", "/usr/bin/dwebp", "path to the dwebp program "+
"installed from https://developers.google.com/speed/webp/download")
testdata = flag.String("testdata", "", "path to the libwebp-test-data directory "+
"checked out from https://chromium.googlesource.com/webm/libwebp-test-data")
)
func main() {
flag.Parse()
if err := checkDwebp(); err != nil {
flag.Usage()
log.Fatal(err)
}
if *testdata == "" {
flag.Usage()
log.Fatal("testdata flag was not specified")
}
f, err := os.Open(*testdata)
if err != nil {
log.Fatalf("Open: %v", err)
}
defer f.Close()
names, err := f.Readdirnames(-1)
if err != nil {
log.Fatalf("Readdirnames: %v", err)
}
sort.Strings(names)
nFail, nPass := 0, 0
for _, name := range names {
if !strings.HasSuffix(name, "webp") {
continue
}
if err := test(name); err != nil {
fmt.Printf("FAIL\t%s\t%v\n", name, err)
nFail++
} else {
fmt.Printf("PASS\t%s\n", name)
nPass++
}
}
fmt.Printf("%d PASS, %d FAIL, %d TOTAL\n", nPass, nFail, nPass+nFail)
if nFail != 0 {
os.Exit(1)
}
}
func checkDwebp() error {
if *dwebp == "" {
return fmt.Errorf("dwebp flag was not specified")
}
if _, err := os.Stat(*dwebp); err != nil {
return fmt.Errorf("could not find dwebp program at %q", *dwebp)
}
b, err := exec.Command(*dwebp, "-version").Output()
if err != nil {
return fmt.Errorf("could not determine the dwebp program version for %q: %v", *dwebp, err)
}
switch s := string(bytes.TrimSpace(b)); s {
case "0.4.0", "0.4.1", "0.4.2":
return fmt.Errorf("the dwebp program version %q for %q has a known bug "+
"(https://bugs.chromium.org/p/webp/issues/detail?id=239). Please use a newer version.", s, *dwebp)
}
return nil
}
// test tests a single WEBP image.
func test(name string) error {
filename := filepath.Join(*testdata, name)
f, err := os.Open(filename)
if err != nil {
return fmt.Errorf("Open: %v", err)
}
defer f.Close()
gotImage, err := webp.Decode(f)
if err != nil {
return fmt.Errorf("Decode: %v", err)
}
format, encode := "-pgm", encodePGM
if _, lossless := gotImage.(*image.NRGBA); lossless {
format, encode = "-pam", encodePAM
}
got, err := encode(gotImage)
if err != nil {
return fmt.Errorf("encode: %v", err)
}
stdout := new(bytes.Buffer)
stderr := new(bytes.Buffer)
c := exec.Command(*dwebp, filename, format, "-o", "/dev/stdout")
c.Stdout = stdout
c.Stderr = stderr
if err := c.Run(); err != nil {
os.Stderr.Write(stderr.Bytes())
return fmt.Errorf("executing dwebp: %v", err)
}
want := stdout.Bytes()
if len(got) != len(want) {
return fmt.Errorf("encodings have different length: got %d, want %d", len(got), len(want))
}
for i, g := range got {
if w := want[i]; g != w {
return fmt.Errorf("encodings differ at position 0x%x: got 0x%02x, want 0x%02x", i, g, w)
}
}
return nil
}
// encodePAM encodes gotImage in the PAM format.
func encodePAM(gotImage image.Image) ([]byte, error) {
m, ok := gotImage.(*image.NRGBA)
if !ok {
return nil, fmt.Errorf("lossless image did not decode to an *image.NRGBA")
}
b := m.Bounds()
w, h := b.Dx(), b.Dy()
buf := new(bytes.Buffer)
fmt.Fprintf(buf, "P7\nWIDTH %d\nHEIGHT %d\nDEPTH 4\nMAXVAL 255\nTUPLTYPE RGB_ALPHA\nENDHDR\n", w, h)
for y := b.Min.Y; y < b.Max.Y; y++ {
o := m.PixOffset(b.Min.X, y)
buf.Write(m.Pix[o : o+4*w])
}
return buf.Bytes(), nil
}
// encodePGM encodes gotImage in the PGM format in the IMC4 layout.
func encodePGM(gotImage image.Image) ([]byte, error) {
var (
m *image.YCbCr
ma *image.NYCbCrA
)
switch g := gotImage.(type) {
case *image.YCbCr:
m = g
case *image.NYCbCrA:
m = &g.YCbCr
ma = g
default:
return nil, fmt.Errorf("lossy image did not decode to an *image.YCbCr")
}
if m.SubsampleRatio != image.YCbCrSubsampleRatio420 {
return nil, fmt.Errorf("lossy image did not decode to a 4:2:0 YCbCr")
}
b := m.Bounds()
w, h := b.Dx(), b.Dy()
w2, h2 := (w+1)/2, (h+1)/2
outW, outH := 2*w2, h+h2
if ma != nil {
outH += h
}
buf := new(bytes.Buffer)
fmt.Fprintf(buf, "P5\n%d %d\n255\n", outW, outH)
for y := b.Min.Y; y < b.Max.Y; y++ {
o := m.YOffset(b.Min.X, y)
buf.Write(m.Y[o : o+w])
if w&1 != 0 {
buf.WriteByte(0x00)
}
}
for y := b.Min.Y; y < b.Max.Y; y += 2 {
o := m.COffset(b.Min.X, y)
buf.Write(m.Cb[o : o+w2])
buf.Write(m.Cr[o : o+w2])
}
if ma != nil {
for y := b.Min.Y; y < b.Max.Y; y++ {
o := ma.AOffset(b.Min.X, y)
buf.Write(ma.A[o : o+w])
if w&1 != 0 {
buf.WriteByte(0x00)
}
}
}
return buf.Bytes(), nil
}
// dump can be useful for debugging.
func dump(w io.Writer, b []byte) {
h := hex.Dumper(w)
h.Write(b)
h.Close()
}
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