1// Copyright 2012 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package jpeg
6
7import (
8	"bytes"
9	"fmt"
10	"image"
11	"image/color"
12	"io"
13	"io/ioutil"
14	"math/rand"
15	"os"
16	"strings"
17	"testing"
18	"time"
19)
20
21// TestDecodeProgressive tests that decoding the baseline and progressive
22// versions of the same image result in exactly the same pixel data, in YCbCr
23// space for color images, and Y space for grayscale images.
24func TestDecodeProgressive(t *testing.T) {
25	testCases := []string{
26		"../testdata/video-001",
27		"../testdata/video-001.q50.410",
28		"../testdata/video-001.q50.411",
29		"../testdata/video-001.q50.420",
30		"../testdata/video-001.q50.422",
31		"../testdata/video-001.q50.440",
32		"../testdata/video-001.q50.444",
33		"../testdata/video-005.gray.q50",
34		"../testdata/video-005.gray.q50.2x2",
35		"../testdata/video-001.separate.dc.progression",
36	}
37	for _, tc := range testCases {
38		m0, err := decodeFile(tc + ".jpeg")
39		if err != nil {
40			t.Errorf("%s: %v", tc+".jpeg", err)
41			continue
42		}
43		m1, err := decodeFile(tc + ".progressive.jpeg")
44		if err != nil {
45			t.Errorf("%s: %v", tc+".progressive.jpeg", err)
46			continue
47		}
48		if m0.Bounds() != m1.Bounds() {
49			t.Errorf("%s: bounds differ: %v and %v", tc, m0.Bounds(), m1.Bounds())
50			continue
51		}
52		// All of the video-*.jpeg files are 150x103.
53		if m0.Bounds() != image.Rect(0, 0, 150, 103) {
54			t.Errorf("%s: bad bounds: %v", tc, m0.Bounds())
55			continue
56		}
57
58		switch m0 := m0.(type) {
59		case *image.YCbCr:
60			m1 := m1.(*image.YCbCr)
61			if err := check(m0.Bounds(), m0.Y, m1.Y, m0.YStride, m1.YStride); err != nil {
62				t.Errorf("%s (Y): %v", tc, err)
63				continue
64			}
65			if err := check(m0.Bounds(), m0.Cb, m1.Cb, m0.CStride, m1.CStride); err != nil {
66				t.Errorf("%s (Cb): %v", tc, err)
67				continue
68			}
69			if err := check(m0.Bounds(), m0.Cr, m1.Cr, m0.CStride, m1.CStride); err != nil {
70				t.Errorf("%s (Cr): %v", tc, err)
71				continue
72			}
73		case *image.Gray:
74			m1 := m1.(*image.Gray)
75			if err := check(m0.Bounds(), m0.Pix, m1.Pix, m0.Stride, m1.Stride); err != nil {
76				t.Errorf("%s: %v", tc, err)
77				continue
78			}
79		default:
80			t.Errorf("%s: unexpected image type %T", tc, m0)
81			continue
82		}
83	}
84}
85
86func decodeFile(filename string) (image.Image, error) {
87	f, err := os.Open(filename)
88	if err != nil {
89		return nil, err
90	}
91	defer f.Close()
92	return Decode(f)
93}
94
95type eofReader struct {
96	data     []byte // deliver from Read without EOF
97	dataEOF  []byte // then deliver from Read with EOF on last chunk
98	lenAtEOF int
99}
100
101func (r *eofReader) Read(b []byte) (n int, err error) {
102	if len(r.data) > 0 {
103		n = copy(b, r.data)
104		r.data = r.data[n:]
105	} else {
106		n = copy(b, r.dataEOF)
107		r.dataEOF = r.dataEOF[n:]
108		if len(r.dataEOF) == 0 {
109			err = io.EOF
110			if r.lenAtEOF == -1 {
111				r.lenAtEOF = n
112			}
113		}
114	}
115	return
116}
117
118func TestDecodeEOF(t *testing.T) {
119	// Check that if reader returns final data and EOF at same time, jpeg handles it.
120	data, err := ioutil.ReadFile("../testdata/video-001.jpeg")
121	if err != nil {
122		t.Fatal(err)
123	}
124
125	n := len(data)
126	for i := 0; i < n; {
127		r := &eofReader{data[:n-i], data[n-i:], -1}
128		_, err := Decode(r)
129		if err != nil {
130			t.Errorf("Decode with Read() = %d, EOF: %v", r.lenAtEOF, err)
131		}
132		if i == 0 {
133			i = 1
134		} else {
135			i *= 2
136		}
137	}
138}
139
140// check checks that the two pix data are equal, within the given bounds.
141func check(bounds image.Rectangle, pix0, pix1 []byte, stride0, stride1 int) error {
142	if stride0 <= 0 || stride0%8 != 0 {
143		return fmt.Errorf("bad stride %d", stride0)
144	}
145	if stride1 <= 0 || stride1%8 != 0 {
146		return fmt.Errorf("bad stride %d", stride1)
147	}
148	// Compare the two pix data, one 8x8 block at a time.
149	for y := 0; y < len(pix0)/stride0 && y < len(pix1)/stride1; y += 8 {
150		for x := 0; x < stride0 && x < stride1; x += 8 {
151			if x >= bounds.Max.X || y >= bounds.Max.Y {
152				// We don't care if the two pix data differ if the 8x8 block is
153				// entirely outside of the image's bounds. For example, this can
154				// occur with a 4:2:0 chroma subsampling and a 1x1 image. Baseline
155				// decoding works on the one 16x16 MCU as a whole; progressive
156				// decoding's first pass works on that 16x16 MCU as a whole but
157				// refinement passes only process one 8x8 block within the MCU.
158				continue
159			}
160
161			for j := 0; j < 8; j++ {
162				for i := 0; i < 8; i++ {
163					index0 := (y+j)*stride0 + (x + i)
164					index1 := (y+j)*stride1 + (x + i)
165					if pix0[index0] != pix1[index1] {
166						return fmt.Errorf("blocks at (%d, %d) differ:\n%sand\n%s", x, y,
167							pixString(pix0, stride0, x, y),
168							pixString(pix1, stride1, x, y),
169						)
170					}
171				}
172			}
173		}
174	}
175	return nil
176}
177
178func pixString(pix []byte, stride, x, y int) string {
179	s := bytes.NewBuffer(nil)
180	for j := 0; j < 8; j++ {
181		fmt.Fprintf(s, "\t")
182		for i := 0; i < 8; i++ {
183			fmt.Fprintf(s, "%02x ", pix[(y+j)*stride+(x+i)])
184		}
185		fmt.Fprintf(s, "\n")
186	}
187	return s.String()
188}
189
190func TestTruncatedSOSDataDoesntPanic(t *testing.T) {
191	b, err := ioutil.ReadFile("../testdata/video-005.gray.q50.jpeg")
192	if err != nil {
193		t.Fatal(err)
194	}
195	sosMarker := []byte{0xff, 0xda}
196	i := bytes.Index(b, sosMarker)
197	if i < 0 {
198		t.Fatal("SOS marker not found")
199	}
200	i += len(sosMarker)
201	j := i + 10
202	if j > len(b) {
203		j = len(b)
204	}
205	for ; i < j; i++ {
206		Decode(bytes.NewReader(b[:i]))
207	}
208}
209
210func TestLargeImageWithShortData(t *testing.T) {
211	// This input is an invalid JPEG image, based on the fuzzer-generated image
212	// in issue 10413. It is only 504 bytes, and shouldn't take long for Decode
213	// to return an error. The Start Of Frame marker gives the image dimensions
214	// as 8192 wide and 8192 high, so even if an unreadByteStuffedByte bug
215	// doesn't technically lead to an infinite loop, such a bug can still cause
216	// an unreasonably long loop for such a short input.
217	const input = "" +
218		"\xff\xd8\xff\xe0\x00\x10\x4a\x46\x49\x46\x00\x01\x01\x00\x00\x01" +
219		"\x00\x01\x00\x00\xff\xdb\x00\x43\x00\x10\x0b\x0c\x0e\x0c\x0a\x10" +
220		"\x0e\x89\x0e\x12\x11\x10\x13\x18\xff\xd8\xff\xe0\x00\x10\x4a\x46" +
221		"\x49\x46\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00\xff\xdb\x00\x43" +
222		"\x00\x10\x0b\x0c\x0e\x0c\x0a\x10\x0e\x0d\x0e\x12\x11\x10\x13\x18" +
223		"\x28\x1a\x18\x16\x16\x18\x31\x23\x25\x1d\x28\x3a\x33\x3d\x3c\x39" +
224		"\x33\x38\x37\x40\x48\x5c\x4e\x40\x44\x57\x45\x37\x38\x50\x6d\x51" +
225		"\x57\x5f\x62\x67\x68\x67\x3e\x4d\x71\x79\x70\x64\x78\x5c\x65\x67" +
226		"\x63\xff\xc0\x00\x0b\x08\x20\x00\x20\x00\x01\x01\x11\x00\xff\xc4" +
227		"\x00\x1f\x00\x00\x01\x05\x01\x01\x01\x01\x01\x01\x00\x00\x00\x00" +
228		"\x00\x00\x00\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\xff" +
229		"\xc4\x00\xb5\x10\x00\x02\x01\x03\x03\x02\x04\x03\x05\x05\x04\x04" +
230		"\x00\x00\x01\x7d\x01\x02\x03\x00\x04\x11\x05\x12\x21\x31\x01\x06" +
231		"\x13\x51\x61\x07\x22\x71\x14\x32\x81\x91\xa1\x08\x23\xd8\xff\xdd" +
232		"\x42\xb1\xc1\x15\x52\xd1\xf0\x24\x33\x62\x72\x82\x09\x0a\x16\x17" +
233		"\x18\x19\x1a\x25\x26\x27\x28\x29\x2a\x34\x35\x36\x37\x38\x39\x3a" +
234		"\x43\x44\x45\x46\x47\x48\x49\x4a\x53\x54\x55\x56\x57\x58\x59\x5a" +
235		"\x00\x63\x64\x65\x66\x67\x68\x69\x6a\x73\x74\x75\x76\x77\x78\x79" +
236		"\x7a\x83\x84\x85\x86\x87\x88\x89\x8a\x92\x93\x94\x95\x96\x97\x98" +
237		"\x99\x9a\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xb2\xb3\xb4\xb5\xb6" +
238		"\xb7\xb8\xb9\xba\xc2\xc3\xc4\xc5\xc6\xc7\xff\xd8\xff\xe0\x00\x10" +
239		"\x4a\x46\x49\x46\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00\xff\xdb" +
240		"\x00\x43\x00\x10\x0b\x0c\x0e\x0c\x0a\x10\x0e\x0d\x0e\x12\x11\x10" +
241		"\x13\x18\x28\x1a\x18\x16\x16\x18\x31\x23\x25\x1d\xc8\xc9\xca\xd2" +
242		"\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8" +
243		"\xe9\xea\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xff\xda\x00\x08" +
244		"\x01\x01\x00\x00\x3f\x00\xb9\xeb\x50\xb0\xdb\xc8\xa8\xe4\x63\x80" +
245		"\xdd\x31\xd6\x9d\xbb\xf2\xc5\x42\x1f\x6c\x6f\xf4\x34\xdd\x3c\xfc" +
246		"\xac\xe7\x3d\x80\xa9\xcc\x87\x34\xb3\x37\xfa\x2b\x9f\x6a\xad\x63" +
247		"\x20\x36\x9f\x78\x64\x75\xe6\xab\x7d\xb2\xde\x29\x70\xd3\x20\x27" +
248		"\xde\xaf\xa4\xf0\xca\x9f\x24\xa8\xdf\x46\xa8\x24\x84\x96\xe3\x77" +
249		"\xf9\x2e\xe0\x0a\x62\x7f\xdf\xd9"
250	c := make(chan error, 1)
251	go func() {
252		_, err := Decode(strings.NewReader(input))
253		c <- err
254	}()
255	select {
256	case err := <-c:
257		if err == nil {
258			t.Fatalf("got nil error, want non-nil")
259		}
260	case <-time.After(3 * time.Second):
261		t.Fatalf("timed out")
262	}
263}
264
265func TestExtraneousData(t *testing.T) {
266	// Encode a 1x1 red image.
267	src := image.NewRGBA(image.Rect(0, 0, 1, 1))
268	src.Set(0, 0, color.RGBA{0xff, 0x00, 0x00, 0xff})
269	buf := new(bytes.Buffer)
270	if err := Encode(buf, src, nil); err != nil {
271		t.Fatalf("encode: %v", err)
272	}
273	enc := buf.String()
274	// Sanity check that the encoded JPEG is long enough, that it ends in a
275	// "\xff\xd9" EOI marker, and that it contains a "\xff\xda" SOS marker
276	// somewhere in the final 64 bytes.
277	if len(enc) < 64 {
278		t.Fatalf("encoded JPEG is too short: %d bytes", len(enc))
279	}
280	if got, want := enc[len(enc)-2:], "\xff\xd9"; got != want {
281		t.Fatalf("encoded JPEG ends with %q, want %q", got, want)
282	}
283	if s := enc[len(enc)-64:]; !strings.Contains(s, "\xff\xda") {
284		t.Fatalf("encoded JPEG does not contain a SOS marker (ff da) near the end: % x", s)
285	}
286	// Test that adding some random junk between the SOS marker and the
287	// EOI marker does not affect the decoding.
288	rnd := rand.New(rand.NewSource(1))
289	for i, nerr := 0, 0; i < 1000 && nerr < 10; i++ {
290		buf.Reset()
291		// Write all but the trailing "\xff\xd9" EOI marker.
292		buf.WriteString(enc[:len(enc)-2])
293		// Write some random extraneous data.
294		for n := rnd.Intn(10); n > 0; n-- {
295			if x := byte(rnd.Intn(256)); x != 0xff {
296				buf.WriteByte(x)
297			} else {
298				// The JPEG format escapes a SOS 0xff data byte as "\xff\x00".
299				buf.WriteString("\xff\x00")
300			}
301		}
302		// Write the "\xff\xd9" EOI marker.
303		buf.WriteString("\xff\xd9")
304
305		// Check that we can still decode the resultant image.
306		got, err := Decode(buf)
307		if err != nil {
308			t.Errorf("could not decode image #%d: %v", i, err)
309			nerr++
310			continue
311		}
312		if got.Bounds() != src.Bounds() {
313			t.Errorf("image #%d, bounds differ: %v and %v", i, got.Bounds(), src.Bounds())
314			nerr++
315			continue
316		}
317		if averageDelta(got, src) > 2<<8 {
318			t.Errorf("image #%d changed too much after a round trip", i)
319			nerr++
320			continue
321		}
322	}
323}
324
325func benchmarkDecode(b *testing.B, filename string) {
326	b.StopTimer()
327	data, err := ioutil.ReadFile(filename)
328	if err != nil {
329		b.Fatal(err)
330	}
331	cfg, err := DecodeConfig(bytes.NewReader(data))
332	if err != nil {
333		b.Fatal(err)
334	}
335	b.SetBytes(int64(cfg.Width * cfg.Height * 4))
336	b.StartTimer()
337	for i := 0; i < b.N; i++ {
338		Decode(bytes.NewReader(data))
339	}
340}
341
342func BenchmarkDecodeBaseline(b *testing.B) {
343	benchmarkDecode(b, "../testdata/video-001.jpeg")
344}
345
346func BenchmarkDecodeProgressive(b *testing.B) {
347	benchmarkDecode(b, "../testdata/video-001.progressive.jpeg")
348}
349