// Copyright 2013 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.
package gif
import (
"bytes"
"image"
"image/color"
"image/color/palette"
_ "image/png"
"io/ioutil"
"math/rand"
"os"
"reflect"
"testing"
)
func readImg(filename string) (image.Image, error) {
f, err := os.Open(filename)
if err != nil {
return nil, err
}
defer f.Close()
m, _, err := image.Decode(f)
return m, err
}
func readGIF(filename string) (*GIF, error) {
f, err := os.Open(filename)
if err != nil {
return nil, err
}
defer f.Close()
return DecodeAll(f)
}
func delta(u0, u1 uint32) int64 {
d := int64(u0) - int64(u1)
if d < 0 {
return -d
}
return d
}
// averageDelta returns the average delta in RGB space. The two images must
// have the same bounds.
func averageDelta(m0, m1 image.Image) int64 {
b := m0.Bounds()
return averageDeltaBound(m0, m1, b, b)
}
// averageDeltaBounds returns the average delta in RGB space. The average delta is
// calulated in the specified bounds.
func averageDeltaBound(m0, m1 image.Image, b0, b1 image.Rectangle) int64 {
var sum, n int64
for y := b0.Min.Y; y < b0.Max.Y; y++ {
for x := b0.Min.X; x < b0.Max.X; x++ {
c0 := m0.At(x, y)
c1 := m1.At(x-b0.Min.X+b1.Min.X, y-b0.Min.Y+b1.Min.Y)
r0, g0, b0, _ := c0.RGBA()
r1, g1, b1, _ := c1.RGBA()
sum += delta(r0, r1)
sum += delta(g0, g1)
sum += delta(b0, b1)
n += 3
}
}
return sum / n
}
// lzw.NewWriter wants an interface which is basically the same thing as gif's
// writer interface. This ensures we're compatible.
var _ writer = blockWriter{}
var testCase = []struct {
filename string
tolerance int64
}{
{"../testdata/video-001.png", 1 << 12},
{"../testdata/video-001.gif", 0},
{"../testdata/video-001.interlaced.gif", 0},
}
func TestWriter(t *testing.T) {
for _, tc := range testCase {
m0, err := readImg(tc.filename)
if err != nil {
t.Error(tc.filename, err)
continue
}
var buf bytes.Buffer
err = Encode(&buf, m0, nil)
if err != nil {
t.Error(tc.filename, err)
continue
}
m1, err := Decode(&buf)
if err != nil {
t.Error(tc.filename, err)
continue
}
if m0.Bounds() != m1.Bounds() {
t.Errorf("%s, bounds differ: %v and %v", tc.filename, m0.Bounds(), m1.Bounds())
continue
}
// Compare the average delta to the tolerance level.
avgDelta := averageDelta(m0, m1)
if avgDelta > tc.tolerance {
t.Errorf("%s: average delta is too high. expected: %d, got %d", tc.filename, tc.tolerance, avgDelta)
continue
}
}
}
func TestSubImage(t *testing.T) {
m0, err := readImg("../testdata/video-001.gif")
if err != nil {
t.Fatalf("readImg: %v", err)
}
m0 = m0.(*image.Paletted).SubImage(image.Rect(0, 0, 50, 30))
var buf bytes.Buffer
err = Encode(&buf, m0, nil)
if err != nil {
t.Fatalf("Encode: %v", err)
}
m1, err := Decode(&buf)
if err != nil {
t.Fatalf("Decode: %v", err)
}
if m0.Bounds() != m1.Bounds() {
t.Fatalf("bounds differ: %v and %v", m0.Bounds(), m1.Bounds())
}
if averageDelta(m0, m1) != 0 {
t.Fatalf("images differ")
}
}
// palettesEqual reports whether two color.Palette values are equal, ignoring
// any trailing opaque-black palette entries.
func palettesEqual(p, q color.Palette) bool {
n := len(p)
if n > len(q) {
n = len(q)
}
for i := 0; i < n; i++ {
if p[i] != q[i] {
return false
}
}
for i := n; i < len(p); i++ {
r, g, b, a := p[i].RGBA()
if r != 0 || g != 0 || b != 0 || a != 0xffff {
return false
}
}
for i := n; i < len(q); i++ {
r, g, b, a := q[i].RGBA()
if r != 0 || g != 0 || b != 0 || a != 0xffff {
return false
}
}
return true
}
var frames = []string{
"../testdata/video-001.gif",
"../testdata/video-005.gray.gif",
}
func testEncodeAll(t *testing.T, go1Dot5Fields bool, useGlobalColorModel bool) {
const width, height = 150, 103
g0 := &GIF{
Image: make([]*image.Paletted, len(frames)),
Delay: make([]int, len(frames)),
LoopCount: 5,
}
for i, f := range frames {
g, err := readGIF(f)
if err != nil {
t.Fatal(f, err)
}
m := g.Image[0]
if m.Bounds().Dx() != width || m.Bounds().Dy() != height {
t.Fatalf("frame %d had unexpected bounds: got %v, want width/height = %d/%d",
i, m.Bounds(), width, height)
}
g0.Image[i] = m
}
// The GIF.Disposal, GIF.Config and GIF.BackgroundIndex fields were added
// in Go 1.5. Valid Go 1.4 or earlier code should still produce valid GIFs.
//
// On the following line, color.Model is an interface type, and
// color.Palette is a concrete (slice) type.
globalColorModel, backgroundIndex := color.Model(color.Palette(nil)), uint8(0)
if useGlobalColorModel {
globalColorModel, backgroundIndex = color.Palette(palette.WebSafe), uint8(1)
}
if go1Dot5Fields {
g0.Disposal = make([]byte, len(g0.Image))
for i := range g0.Disposal {
g0.Disposal[i] = DisposalNone
}
g0.Config = image.Config{
ColorModel: globalColorModel,
Width: width,
Height: height,
}
g0.BackgroundIndex = backgroundIndex
}
var buf bytes.Buffer
if err := EncodeAll(&buf, g0); err != nil {
t.Fatal("EncodeAll:", err)
}
encoded := buf.Bytes()
config, err := DecodeConfig(bytes.NewReader(encoded))
if err != nil {
t.Fatal("DecodeConfig:", err)
}
g1, err := DecodeAll(bytes.NewReader(encoded))
if err != nil {
t.Fatal("DecodeAll:", err)
}
if !reflect.DeepEqual(config, g1.Config) {
t.Errorf("DecodeConfig inconsistent with DecodeAll")
}
if !palettesEqual(g1.Config.ColorModel.(color.Palette), globalColorModel.(color.Palette)) {
t.Errorf("unexpected global color model")
}
if w, h := g1.Config.Width, g1.Config.Height; w != width || h != height {
t.Errorf("got config width * height = %d * %d, want %d * %d", w, h, width, height)
}
if g0.LoopCount != g1.LoopCount {
t.Errorf("loop counts differ: %d and %d", g0.LoopCount, g1.LoopCount)
}
if backgroundIndex != g1.BackgroundIndex {
t.Errorf("background indexes differ: %d and %d", backgroundIndex, g1.BackgroundIndex)
}
if len(g0.Image) != len(g1.Image) {
t.Fatalf("image lengths differ: %d and %d", len(g0.Image), len(g1.Image))
}
if len(g1.Image) != len(g1.Delay) {
t.Fatalf("image and delay lengths differ: %d and %d", len(g1.Image), len(g1.Delay))
}
if len(g1.Image) != len(g1.Disposal) {
t.Fatalf("image and disposal lengths differ: %d and %d", len(g1.Image), len(g1.Disposal))
}
for i := range g0.Image {
m0, m1 := g0.Image[i], g1.Image[i]
if m0.Bounds() != m1.Bounds() {
t.Errorf("frame %d: bounds differ: %v and %v", i, m0.Bounds(), m1.Bounds())
}
d0, d1 := g0.Delay[i], g1.Delay[i]
if d0 != d1 {
t.Errorf("frame %d: delay values differ: %d and %d", i, d0, d1)
}
p0, p1 := uint8(0), g1.Disposal[i]
if go1Dot5Fields {
p0 = DisposalNone
}
if p0 != p1 {
t.Errorf("frame %d: disposal values differ: %d and %d", i, p0, p1)
}
}
}
func TestEncodeAllGo1Dot4(t *testing.T) { testEncodeAll(t, false, false) }
func TestEncodeAllGo1Dot5(t *testing.T) { testEncodeAll(t, true, false) }
func TestEncodeAllGo1Dot5GlobalColorModel(t *testing.T) { testEncodeAll(t, true, true) }
func TestEncodeMismatchDelay(t *testing.T) {
images := make([]*image.Paletted, 2)
for i := range images {
images[i] = image.NewPaletted(image.Rect(0, 0, 5, 5), palette.Plan9)
}
g0 := &GIF{
Image: images,
Delay: make([]int, 1),
}
if err := EncodeAll(ioutil.Discard, g0); err == nil {
t.Error("expected error from mismatched delay and image slice lengths")
}
g1 := &GIF{
Image: images,
Delay: make([]int, len(images)),
Disposal: make([]byte, 1),
}
for i := range g1.Disposal {
g1.Disposal[i] = DisposalNone
}
if err := EncodeAll(ioutil.Discard, g1); err == nil {
t.Error("expected error from mismatched disposal and image slice lengths")
}
}
func TestEncodeZeroGIF(t *testing.T) {
if err := EncodeAll(ioutil.Discard, &GIF{}); err == nil {
t.Error("expected error from providing empty gif")
}
}
func TestEncodeAllFramesOutOfBounds(t *testing.T) {
images := []*image.Paletted{
image.NewPaletted(image.Rect(0, 0, 5, 5), palette.Plan9),
image.NewPaletted(image.Rect(2, 2, 8, 8), palette.Plan9),
image.NewPaletted(image.Rect(3, 3, 4, 4), palette.Plan9),
}
for _, upperBound := range []int{6, 10} {
g := &GIF{
Image: images,
Delay: make([]int, len(images)),
Disposal: make([]byte, len(images)),
Config: image.Config{
Width: upperBound,
Height: upperBound,
},
}
err := EncodeAll(ioutil.Discard, g)
if upperBound >= 8 {
if err != nil {
t.Errorf("upperBound=%d: %v", upperBound, err)
}
} else {
if err == nil {
t.Errorf("upperBound=%d: got nil error, want non-nil", upperBound)
}
}
}
}
func TestEncodeNonZeroMinPoint(t *testing.T) {
points := []image.Point{
{-8, -9},
{-4, -4},
{-3, +3},
{+0, +0},
{+2, +2},
}
for _, p := range points {
src := image.NewPaletted(image.Rectangle{
Min: p,
Max: p.Add(image.Point{6, 6}),
}, palette.Plan9)
var buf bytes.Buffer
if err := Encode(&buf, src, nil); err != nil {
t.Errorf("p=%v: Encode: %v", p, err)
continue
}
m, err := Decode(&buf)
if err != nil {
t.Errorf("p=%v: Decode: %v", p, err)
continue
}
if got, want := m.Bounds(), image.Rect(0, 0, 6, 6); got != want {
t.Errorf("p=%v: got %v, want %v", p, got, want)
}
}
// Also test having a source image (gray on the diagonal) that has a
// non-zero Bounds().Min, but isn't an image.Paletted.
{
p := image.Point{+2, +2}
src := image.NewRGBA(image.Rectangle{
Min: p,
Max: p.Add(image.Point{6, 6}),
})
src.SetRGBA(2, 2, color.RGBA{0x22, 0x22, 0x22, 0xFF})
src.SetRGBA(3, 3, color.RGBA{0x33, 0x33, 0x33, 0xFF})
src.SetRGBA(4, 4, color.RGBA{0x44, 0x44, 0x44, 0xFF})
src.SetRGBA(5, 5, color.RGBA{0x55, 0x55, 0x55, 0xFF})
src.SetRGBA(6, 6, color.RGBA{0x66, 0x66, 0x66, 0xFF})
src.SetRGBA(7, 7, color.RGBA{0x77, 0x77, 0x77, 0xFF})
var buf bytes.Buffer
if err := Encode(&buf, src, nil); err != nil {
t.Errorf("gray-diagonal: Encode: %v", err)
return
}
m, err := Decode(&buf)
if err != nil {
t.Errorf("gray-diagonal: Decode: %v", err)
return
}
if got, want := m.Bounds(), image.Rect(0, 0, 6, 6); got != want {
t.Errorf("gray-diagonal: got %v, want %v", got, want)
return
}
rednessAt := func(x int, y int) uint32 {
r, _, _, _ := m.At(x, y).RGBA()
// Shift by 8 to convert from 16 bit color to 8 bit color.
return r >> 8
}
// Round-tripping a still (non-animated) image.Image through
// Encode+Decode should shift the origin to (0, 0).
if got, want := rednessAt(0, 0), uint32(0x22); got != want {
t.Errorf("gray-diagonal: rednessAt(0, 0): got 0x%02x, want 0x%02x", got, want)
}
if got, want := rednessAt(5, 5), uint32(0x77); got != want {
t.Errorf("gray-diagonal: rednessAt(5, 5): got 0x%02x, want 0x%02x", got, want)
}
}
}
func TestEncodeImplicitConfigSize(t *testing.T) {
// For backwards compatibility for Go 1.4 and earlier code, the Config
// field is optional, and if zero, the width and height is implied by the
// first (and in this case only) frame's width and height.
//
// A Config only specifies a width and height (two integers) while an
// image.Image's Bounds method returns an image.Rectangle (four integers).
// For a gif.GIF, the overall bounds' top-left point is always implicitly
// (0, 0), and any frame whose bounds have a negative X or Y will be
// outside those overall bounds, so encoding should fail.
for _, lowerBound := range []int{-1, 0, 1} {
images := []*image.Paletted{
image.NewPaletted(image.Rect(lowerBound, lowerBound, 4, 4), palette.Plan9),
}
g := &GIF{
Image: images,
Delay: make([]int, len(images)),
}
err := EncodeAll(ioutil.Discard, g)
if lowerBound >= 0 {
if err != nil {
t.Errorf("lowerBound=%d: %v", lowerBound, err)
}
} else {
if err == nil {
t.Errorf("lowerBound=%d: got nil error, want non-nil", lowerBound)
}
}
}
}
func TestEncodePalettes(t *testing.T) {
const w, h = 5, 5
pals := []color.Palette{{
color.RGBA{0x00, 0x00, 0x00, 0xff},
color.RGBA{0x01, 0x00, 0x00, 0xff},
color.RGBA{0x02, 0x00, 0x00, 0xff},
}, {
color.RGBA{0x00, 0x00, 0x00, 0xff},
color.RGBA{0x00, 0x01, 0x00, 0xff},
}, {
color.RGBA{0x00, 0x00, 0x03, 0xff},
color.RGBA{0x00, 0x00, 0x02, 0xff},
color.RGBA{0x00, 0x00, 0x01, 0xff},
color.RGBA{0x00, 0x00, 0x00, 0xff},
}, {
color.RGBA{0x10, 0x07, 0xf0, 0xff},
color.RGBA{0x20, 0x07, 0xf0, 0xff},
color.RGBA{0x30, 0x07, 0xf0, 0xff},
color.RGBA{0x40, 0x07, 0xf0, 0xff},
color.RGBA{0x50, 0x07, 0xf0, 0xff},
}}
g0 := &GIF{
Image: []*image.Paletted{
image.NewPaletted(image.Rect(0, 0, w, h), pals[0]),
image.NewPaletted(image.Rect(0, 0, w, h), pals[1]),
image.NewPaletted(image.Rect(0, 0, w, h), pals[2]),
image.NewPaletted(image.Rect(0, 0, w, h), pals[3]),
},
Delay: make([]int, len(pals)),
Disposal: make([]byte, len(pals)),
Config: image.Config{
ColorModel: pals[2],
Width: w,
Height: h,
},
}
var buf bytes.Buffer
if err := EncodeAll(&buf, g0); err != nil {
t.Fatalf("EncodeAll: %v", err)
}
g1, err := DecodeAll(&buf)
if err != nil {
t.Fatalf("DecodeAll: %v", err)
}
if len(g0.Image) != len(g1.Image) {
t.Fatalf("image lengths differ: %d and %d", len(g0.Image), len(g1.Image))
}
for i, m := range g1.Image {
if got, want := m.Palette, pals[i]; !palettesEqual(got, want) {
t.Errorf("frame %d:\ngot %v\nwant %v", i, got, want)
}
}
}
func TestEncodeBadPalettes(t *testing.T) {
const w, h = 5, 5
for _, n := range []int{256, 257} {
for _, nilColors := range []bool{false, true} {
pal := make(color.Palette, n)
if !nilColors {
for i := range pal {
pal[i] = color.Black
}
}
err := EncodeAll(ioutil.Discard, &GIF{
Image: []*image.Paletted{
image.NewPaletted(image.Rect(0, 0, w, h), pal),
},
Delay: make([]int, 1),
Disposal: make([]byte, 1),
Config: image.Config{
ColorModel: pal,
Width: w,
Height: h,
},
})
got := err != nil
want := n > 256 || nilColors
if got != want {
t.Errorf("n=%d, nilColors=%t: err != nil: got %t, want %t", n, nilColors, got, want)
}
}
}
}
func TestColorTablesMatch(t *testing.T) {
const trIdx = 100
global := color.Palette(palette.Plan9)
if rgb := global[trIdx].(color.RGBA); rgb.R == 0 && rgb.G == 0 && rgb.B == 0 {
t.Fatalf("trIdx (%d) is already black", trIdx)
}
// Make a copy of the palette, substituting trIdx's slot with transparent,
// just like decoder.decode.
local := append(color.Palette(nil), global...)
local[trIdx] = color.RGBA{}
const testLen = 3 * 256
const padded = 7
e := new(encoder)
if l, err := encodeColorTable(e.globalColorTable[:], global, padded); err != nil || l != testLen {
t.Fatalf("Failed to encode global color table: got %d, %v; want nil, %d", l, err, testLen)
}
if l, err := encodeColorTable(e.localColorTable[:], local, padded); err != nil || l != testLen {
t.Fatalf("Failed to encode local color table: got %d, %v; want nil, %d", l, err, testLen)
}
if bytes.Equal(e.globalColorTable[:testLen], e.localColorTable[:testLen]) {
t.Fatal("Encoded color tables are equal, expected mismatch")
}
if !e.colorTablesMatch(len(local), trIdx) {
t.Fatal("colorTablesMatch() == false, expected true")
}
}
func TestEncodeCroppedSubImages(t *testing.T) {
// This test means to ensure that Encode honors the Bounds and Strides of
// images correctly when encoding.
whole := image.NewPaletted(image.Rect(0, 0, 100, 100), palette.Plan9)
subImages := []image.Rectangle{
image.Rect(0, 0, 50, 50),
image.Rect(50, 0, 100, 50),
image.Rect(0, 50, 50, 50),
image.Rect(50, 50, 100, 100),
image.Rect(25, 25, 75, 75),
image.Rect(0, 0, 100, 50),
image.Rect(0, 50, 100, 100),
image.Rect(0, 0, 50, 100),
image.Rect(50, 0, 100, 100),
}
for _, sr := range subImages {
si := whole.SubImage(sr)
buf := bytes.NewBuffer(nil)
if err := Encode(buf, si, nil); err != nil {
t.Errorf("Encode: sr=%v: %v", sr, err)
continue
}
if _, err := Decode(buf); err != nil {
t.Errorf("Decode: sr=%v: %v", sr, err)
}
}
}
type offsetImage struct {
image.Image
Rect image.Rectangle
}
func (i offsetImage) Bounds() image.Rectangle {
return i.Rect
}
func TestEncodeWrappedImage(t *testing.T) {
m0, err := readImg("../testdata/video-001.gif")
if err != nil {
t.Fatalf("readImg: %v", err)
}
// Case 1: Enocde a wrapped image.Image
buf := new(bytes.Buffer)
w0 := offsetImage{m0, m0.Bounds()}
err = Encode(buf, w0, nil)
if err != nil {
t.Fatalf("Encode: %v", err)
}
w1, err := Decode(buf)
if err != nil {
t.Fatalf("Dencode: %v", err)
}
avgDelta := averageDelta(m0, w1)
if avgDelta > 0 {
t.Fatalf("Wrapped: average delta is too high. expected: 0, got %d", avgDelta)
}
// Case 2: Enocde a wrapped image.Image with offset
b0 := image.Rectangle{
Min: image.Point{
X: 128,
Y: 64,
},
Max: image.Point{
X: 256,
Y: 128,
},
}
w0 = offsetImage{m0, b0}
buf = new(bytes.Buffer)
err = Encode(buf, w0, nil)
if err != nil {
t.Fatalf("Encode: %v", err)
}
w1, err = Decode(buf)
if err != nil {
t.Fatalf("Dencode: %v", err)
}
b1 := image.Rectangle{
Min: image.Point{
X: 0,
Y: 0,
},
Max: image.Point{
X: 128,
Y: 64,
},
}
avgDelta = averageDeltaBound(m0, w1, b0, b1)
if avgDelta > 0 {
t.Fatalf("Wrapped and offset: average delta is too high. expected: 0, got %d", avgDelta)
}
}
func BenchmarkEncode(b *testing.B) {
bo := image.Rect(0, 0, 640, 480)
rnd := rand.New(rand.NewSource(123))
// Restrict to a 256-color paletted image to avoid quantization path.
palette := make(color.Palette, 256)
for i := range palette {
palette[i] = color.RGBA{
uint8(rnd.Intn(256)),
uint8(rnd.Intn(256)),
uint8(rnd.Intn(256)),
255,
}
}
img := image.NewPaletted(image.Rect(0, 0, 640, 480), palette)
for y := bo.Min.Y; y < bo.Max.Y; y++ {
for x := bo.Min.X; x < bo.Max.X; x++ {
img.Set(x, y, palette[rnd.Intn(256)])
}
}
b.SetBytes(640 * 480 * 4)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
Encode(ioutil.Discard, img, nil)
}
}
func BenchmarkQuantizedEncode(b *testing.B) {
img := image.NewRGBA(image.Rect(0, 0, 640, 480))
bo := img.Bounds()
rnd := rand.New(rand.NewSource(123))
for y := bo.Min.Y; y < bo.Max.Y; y++ {
for x := bo.Min.X; x < bo.Max.X; x++ {
img.SetRGBA(x, y, color.RGBA{
uint8(rnd.Intn(256)),
uint8(rnd.Intn(256)),
uint8(rnd.Intn(256)),
255,
})
}
}
b.SetBytes(640 * 480 * 4)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
Encode(ioutil.Discard, img, nil)
}
}
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