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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
commit | 43a123c1ae6613b3efeed291fa552ecd909d3acf (patch) | |
tree | fd92518b7024bc74031f78a1cf9e454b65e73665 /src/image/gif | |
parent | Initial commit. (diff) | |
download | golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.tar.xz golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.zip |
Adding upstream version 1.20.14.upstream/1.20.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/image/gif')
-rw-r--r-- | src/image/gif/fuzz_test.go | 65 | ||||
-rw-r--r-- | src/image/gif/reader.go | 641 | ||||
-rw-r--r-- | src/image/gif/reader_test.go | 441 | ||||
-rw-r--r-- | src/image/gif/writer.go | 477 | ||||
-rw-r--r-- | src/image/gif/writer_test.go | 734 |
5 files changed, 2358 insertions, 0 deletions
diff --git a/src/image/gif/fuzz_test.go b/src/image/gif/fuzz_test.go new file mode 100644 index 0000000..a4bc06e --- /dev/null +++ b/src/image/gif/fuzz_test.go @@ -0,0 +1,65 @@ +// Copyright 2021 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" + "os" + "path/filepath" + "strings" + "testing" +) + +func FuzzDecode(f *testing.F) { + if testing.Short() { + f.Skip("Skipping in short mode") + } + + testdata, err := os.ReadDir("../testdata") + if err != nil { + f.Fatalf("failed to read testdata directory: %s", err) + } + for _, de := range testdata { + if de.IsDir() || !strings.HasSuffix(de.Name(), ".gif") { + continue + } + b, err := os.ReadFile(filepath.Join("../testdata", de.Name())) + if err != nil { + f.Fatalf("failed to read testdata: %s", err) + } + f.Add(b) + } + + f.Fuzz(func(t *testing.T, b []byte) { + cfg, _, err := image.DecodeConfig(bytes.NewReader(b)) + if err != nil { + return + } + if cfg.Width*cfg.Height > 1e6 { + return + } + img, typ, err := image.Decode(bytes.NewReader(b)) + if err != nil || typ != "gif" { + return + } + for q := 1; q <= 256; q++ { + var w bytes.Buffer + err := Encode(&w, img, &Options{NumColors: q}) + if err != nil { + t.Fatalf("failed to encode valid image: %s", err) + } + img1, err := Decode(&w) + if err != nil { + t.Fatalf("failed to decode roundtripped image: %s", err) + } + got := img1.Bounds() + want := img.Bounds() + if !got.Eq(want) { + t.Fatalf("roundtripped image bounds have changed, got: %v, want: %v", got, want) + } + } + }) +} diff --git a/src/image/gif/reader.go b/src/image/gif/reader.go new file mode 100644 index 0000000..0867b10 --- /dev/null +++ b/src/image/gif/reader.go @@ -0,0 +1,641 @@ +// Copyright 2011 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 implements a GIF image decoder and encoder. +// +// The GIF specification is at https://www.w3.org/Graphics/GIF/spec-gif89a.txt. +package gif + +import ( + "bufio" + "compress/lzw" + "errors" + "fmt" + "image" + "image/color" + "io" +) + +var ( + errNotEnough = errors.New("gif: not enough image data") + errTooMuch = errors.New("gif: too much image data") + errBadPixel = errors.New("gif: invalid pixel value") +) + +// If the io.Reader does not also have ReadByte, then decode will introduce its own buffering. +type reader interface { + io.Reader + io.ByteReader +} + +// Masks etc. +const ( + // Fields. + fColorTable = 1 << 7 + fInterlace = 1 << 6 + fColorTableBitsMask = 7 + + // Graphic control flags. + gcTransparentColorSet = 1 << 0 + gcDisposalMethodMask = 7 << 2 +) + +// Disposal Methods. +const ( + DisposalNone = 0x01 + DisposalBackground = 0x02 + DisposalPrevious = 0x03 +) + +// Section indicators. +const ( + sExtension = 0x21 + sImageDescriptor = 0x2C + sTrailer = 0x3B +) + +// Extensions. +const ( + eText = 0x01 // Plain Text + eGraphicControl = 0xF9 // Graphic Control + eComment = 0xFE // Comment + eApplication = 0xFF // Application +) + +func readFull(r io.Reader, b []byte) error { + _, err := io.ReadFull(r, b) + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return err +} + +func readByte(r io.ByteReader) (byte, error) { + b, err := r.ReadByte() + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return b, err +} + +// decoder is the type used to decode a GIF file. +type decoder struct { + r reader + + // From header. + vers string + width int + height int + loopCount int + delayTime int + backgroundIndex byte + disposalMethod byte + + // From image descriptor. + imageFields byte + + // From graphics control. + transparentIndex byte + hasTransparentIndex bool + + // Computed. + globalColorTable color.Palette + + // Used when decoding. + delay []int + disposal []byte + image []*image.Paletted + tmp [1024]byte // must be at least 768 so we can read color table +} + +// blockReader parses the block structure of GIF image data, which comprises +// (n, (n bytes)) blocks, with 1 <= n <= 255. It is the reader given to the +// LZW decoder, which is thus immune to the blocking. After the LZW decoder +// completes, there will be a 0-byte block remaining (0, ()), which is +// consumed when checking that the blockReader is exhausted. +// +// To avoid the allocation of a bufio.Reader for the lzw Reader, blockReader +// implements io.ByteReader and buffers blocks into the decoder's "tmp" buffer. +type blockReader struct { + d *decoder + i, j uint8 // d.tmp[i:j] contains the buffered bytes + err error +} + +func (b *blockReader) fill() { + if b.err != nil { + return + } + b.j, b.err = readByte(b.d.r) + if b.j == 0 && b.err == nil { + b.err = io.EOF + } + if b.err != nil { + return + } + + b.i = 0 + b.err = readFull(b.d.r, b.d.tmp[:b.j]) + if b.err != nil { + b.j = 0 + } +} + +func (b *blockReader) ReadByte() (byte, error) { + if b.i == b.j { + b.fill() + if b.err != nil { + return 0, b.err + } + } + + c := b.d.tmp[b.i] + b.i++ + return c, nil +} + +// blockReader must implement io.Reader, but its Read shouldn't ever actually +// be called in practice. The compress/lzw package will only call ReadByte. +func (b *blockReader) Read(p []byte) (int, error) { + if len(p) == 0 || b.err != nil { + return 0, b.err + } + if b.i == b.j { + b.fill() + if b.err != nil { + return 0, b.err + } + } + + n := copy(p, b.d.tmp[b.i:b.j]) + b.i += uint8(n) + return n, nil +} + +// close primarily detects whether or not a block terminator was encountered +// after reading a sequence of data sub-blocks. It allows at most one trailing +// sub-block worth of data. I.e., if some number of bytes exist in one sub-block +// following the end of LZW data, the very next sub-block must be the block +// terminator. If the very end of LZW data happened to fill one sub-block, at +// most one more sub-block of length 1 may exist before the block-terminator. +// These accommodations allow us to support GIFs created by less strict encoders. +// See https://golang.org/issue/16146. +func (b *blockReader) close() error { + if b.err == io.EOF { + // A clean block-sequence terminator was encountered while reading. + return nil + } else if b.err != nil { + // Some other error was encountered while reading. + return b.err + } + + if b.i == b.j { + // We reached the end of a sub block reading LZW data. We'll allow at + // most one more sub block of data with a length of 1 byte. + b.fill() + if b.err == io.EOF { + return nil + } else if b.err != nil { + return b.err + } else if b.j > 1 { + return errTooMuch + } + } + + // Part of a sub-block remains buffered. We expect that the next attempt to + // buffer a sub-block will reach the block terminator. + b.fill() + if b.err == io.EOF { + return nil + } else if b.err != nil { + return b.err + } + + return errTooMuch +} + +// decode reads a GIF image from r and stores the result in d. +func (d *decoder) decode(r io.Reader, configOnly, keepAllFrames bool) error { + // Add buffering if r does not provide ReadByte. + if rr, ok := r.(reader); ok { + d.r = rr + } else { + d.r = bufio.NewReader(r) + } + + d.loopCount = -1 + + err := d.readHeaderAndScreenDescriptor() + if err != nil { + return err + } + if configOnly { + return nil + } + + for { + c, err := readByte(d.r) + if err != nil { + return fmt.Errorf("gif: reading frames: %v", err) + } + switch c { + case sExtension: + if err = d.readExtension(); err != nil { + return err + } + + case sImageDescriptor: + if err = d.readImageDescriptor(keepAllFrames); err != nil { + return err + } + + if !keepAllFrames && len(d.image) == 1 { + return nil + } + + case sTrailer: + if len(d.image) == 0 { + return fmt.Errorf("gif: missing image data") + } + return nil + + default: + return fmt.Errorf("gif: unknown block type: 0x%.2x", c) + } + } +} + +func (d *decoder) readHeaderAndScreenDescriptor() error { + err := readFull(d.r, d.tmp[:13]) + if err != nil { + return fmt.Errorf("gif: reading header: %v", err) + } + d.vers = string(d.tmp[:6]) + if d.vers != "GIF87a" && d.vers != "GIF89a" { + return fmt.Errorf("gif: can't recognize format %q", d.vers) + } + d.width = int(d.tmp[6]) + int(d.tmp[7])<<8 + d.height = int(d.tmp[8]) + int(d.tmp[9])<<8 + if fields := d.tmp[10]; fields&fColorTable != 0 { + d.backgroundIndex = d.tmp[11] + // readColorTable overwrites the contents of d.tmp, but that's OK. + if d.globalColorTable, err = d.readColorTable(fields); err != nil { + return err + } + } + // d.tmp[12] is the Pixel Aspect Ratio, which is ignored. + return nil +} + +func (d *decoder) readColorTable(fields byte) (color.Palette, error) { + n := 1 << (1 + uint(fields&fColorTableBitsMask)) + err := readFull(d.r, d.tmp[:3*n]) + if err != nil { + return nil, fmt.Errorf("gif: reading color table: %s", err) + } + j, p := 0, make(color.Palette, n) + for i := range p { + p[i] = color.RGBA{d.tmp[j+0], d.tmp[j+1], d.tmp[j+2], 0xFF} + j += 3 + } + return p, nil +} + +func (d *decoder) readExtension() error { + extension, err := readByte(d.r) + if err != nil { + return fmt.Errorf("gif: reading extension: %v", err) + } + size := 0 + switch extension { + case eText: + size = 13 + case eGraphicControl: + return d.readGraphicControl() + case eComment: + // nothing to do but read the data. + case eApplication: + b, err := readByte(d.r) + if err != nil { + return fmt.Errorf("gif: reading extension: %v", err) + } + // The spec requires size be 11, but Adobe sometimes uses 10. + size = int(b) + default: + return fmt.Errorf("gif: unknown extension 0x%.2x", extension) + } + if size > 0 { + if err := readFull(d.r, d.tmp[:size]); err != nil { + return fmt.Errorf("gif: reading extension: %v", err) + } + } + + // Application Extension with "NETSCAPE2.0" as string and 1 in data means + // this extension defines a loop count. + if extension == eApplication && string(d.tmp[:size]) == "NETSCAPE2.0" { + n, err := d.readBlock() + if err != nil { + return fmt.Errorf("gif: reading extension: %v", err) + } + if n == 0 { + return nil + } + if n == 3 && d.tmp[0] == 1 { + d.loopCount = int(d.tmp[1]) | int(d.tmp[2])<<8 + } + } + for { + n, err := d.readBlock() + if err != nil { + return fmt.Errorf("gif: reading extension: %v", err) + } + if n == 0 { + return nil + } + } +} + +func (d *decoder) readGraphicControl() error { + if err := readFull(d.r, d.tmp[:6]); err != nil { + return fmt.Errorf("gif: can't read graphic control: %s", err) + } + if d.tmp[0] != 4 { + return fmt.Errorf("gif: invalid graphic control extension block size: %d", d.tmp[0]) + } + flags := d.tmp[1] + d.disposalMethod = (flags & gcDisposalMethodMask) >> 2 + d.delayTime = int(d.tmp[2]) | int(d.tmp[3])<<8 + if flags&gcTransparentColorSet != 0 { + d.transparentIndex = d.tmp[4] + d.hasTransparentIndex = true + } + if d.tmp[5] != 0 { + return fmt.Errorf("gif: invalid graphic control extension block terminator: %d", d.tmp[5]) + } + return nil +} + +func (d *decoder) readImageDescriptor(keepAllFrames bool) error { + m, err := d.newImageFromDescriptor() + if err != nil { + return err + } + useLocalColorTable := d.imageFields&fColorTable != 0 + if useLocalColorTable { + m.Palette, err = d.readColorTable(d.imageFields) + if err != nil { + return err + } + } else { + if d.globalColorTable == nil { + return errors.New("gif: no color table") + } + m.Palette = d.globalColorTable + } + if d.hasTransparentIndex { + if !useLocalColorTable { + // Clone the global color table. + m.Palette = append(color.Palette(nil), d.globalColorTable...) + } + if ti := int(d.transparentIndex); ti < len(m.Palette) { + m.Palette[ti] = color.RGBA{} + } else { + // The transparentIndex is out of range, which is an error + // according to the spec, but Firefox and Google Chrome + // seem OK with this, so we enlarge the palette with + // transparent colors. See golang.org/issue/15059. + p := make(color.Palette, ti+1) + copy(p, m.Palette) + for i := len(m.Palette); i < len(p); i++ { + p[i] = color.RGBA{} + } + m.Palette = p + } + } + litWidth, err := readByte(d.r) + if err != nil { + return fmt.Errorf("gif: reading image data: %v", err) + } + if litWidth < 2 || litWidth > 8 { + return fmt.Errorf("gif: pixel size in decode out of range: %d", litWidth) + } + // A wonderfully Go-like piece of magic. + br := &blockReader{d: d} + lzwr := lzw.NewReader(br, lzw.LSB, int(litWidth)) + defer lzwr.Close() + if err = readFull(lzwr, m.Pix); err != nil { + if err != io.ErrUnexpectedEOF { + return fmt.Errorf("gif: reading image data: %v", err) + } + return errNotEnough + } + // In theory, both lzwr and br should be exhausted. Reading from them + // should yield (0, io.EOF). + // + // The spec (Appendix F - Compression), says that "An End of + // Information code... must be the last code output by the encoder + // for an image". In practice, though, giflib (a widely used C + // library) does not enforce this, so we also accept lzwr returning + // io.ErrUnexpectedEOF (meaning that the encoded stream hit io.EOF + // before the LZW decoder saw an explicit end code), provided that + // the io.ReadFull call above successfully read len(m.Pix) bytes. + // See https://golang.org/issue/9856 for an example GIF. + if n, err := lzwr.Read(d.tmp[256:257]); n != 0 || (err != io.EOF && err != io.ErrUnexpectedEOF) { + if err != nil { + return fmt.Errorf("gif: reading image data: %v", err) + } + return errTooMuch + } + + // In practice, some GIFs have an extra byte in the data sub-block + // stream, which we ignore. See https://golang.org/issue/16146. + if err := br.close(); err == errTooMuch { + return errTooMuch + } else if err != nil { + return fmt.Errorf("gif: reading image data: %v", err) + } + + // Check that the color indexes are inside the palette. + if len(m.Palette) < 256 { + for _, pixel := range m.Pix { + if int(pixel) >= len(m.Palette) { + return errBadPixel + } + } + } + + // Undo the interlacing if necessary. + if d.imageFields&fInterlace != 0 { + uninterlace(m) + } + + if keepAllFrames || len(d.image) == 0 { + d.image = append(d.image, m) + d.delay = append(d.delay, d.delayTime) + d.disposal = append(d.disposal, d.disposalMethod) + } + // The GIF89a spec, Section 23 (Graphic Control Extension) says: + // "The scope of this extension is the first graphic rendering block + // to follow." We therefore reset the GCE fields to zero. + d.delayTime = 0 + d.hasTransparentIndex = false + return nil +} + +func (d *decoder) newImageFromDescriptor() (*image.Paletted, error) { + if err := readFull(d.r, d.tmp[:9]); err != nil { + return nil, fmt.Errorf("gif: can't read image descriptor: %s", err) + } + left := int(d.tmp[0]) + int(d.tmp[1])<<8 + top := int(d.tmp[2]) + int(d.tmp[3])<<8 + width := int(d.tmp[4]) + int(d.tmp[5])<<8 + height := int(d.tmp[6]) + int(d.tmp[7])<<8 + d.imageFields = d.tmp[8] + + // The GIF89a spec, Section 20 (Image Descriptor) says: "Each image must + // fit within the boundaries of the Logical Screen, as defined in the + // Logical Screen Descriptor." + // + // This is conceptually similar to testing + // frameBounds := image.Rect(left, top, left+width, top+height) + // imageBounds := image.Rect(0, 0, d.width, d.height) + // if !frameBounds.In(imageBounds) { etc } + // but the semantics of the Go image.Rectangle type is that r.In(s) is true + // whenever r is an empty rectangle, even if r.Min.X > s.Max.X. Here, we + // want something stricter. + // + // Note that, by construction, left >= 0 && top >= 0, so we only have to + // explicitly compare frameBounds.Max (left+width, top+height) against + // imageBounds.Max (d.width, d.height) and not frameBounds.Min (left, top) + // against imageBounds.Min (0, 0). + if left+width > d.width || top+height > d.height { + return nil, errors.New("gif: frame bounds larger than image bounds") + } + return image.NewPaletted(image.Rectangle{ + Min: image.Point{left, top}, + Max: image.Point{left + width, top + height}, + }, nil), nil +} + +func (d *decoder) readBlock() (int, error) { + n, err := readByte(d.r) + if n == 0 || err != nil { + return 0, err + } + if err := readFull(d.r, d.tmp[:n]); err != nil { + return 0, err + } + return int(n), nil +} + +// interlaceScan defines the ordering for a pass of the interlace algorithm. +type interlaceScan struct { + skip, start int +} + +// interlacing represents the set of scans in an interlaced GIF image. +var interlacing = []interlaceScan{ + {8, 0}, // Group 1 : Every 8th. row, starting with row 0. + {8, 4}, // Group 2 : Every 8th. row, starting with row 4. + {4, 2}, // Group 3 : Every 4th. row, starting with row 2. + {2, 1}, // Group 4 : Every 2nd. row, starting with row 1. +} + +// uninterlace rearranges the pixels in m to account for interlaced input. +func uninterlace(m *image.Paletted) { + var nPix []uint8 + dx := m.Bounds().Dx() + dy := m.Bounds().Dy() + nPix = make([]uint8, dx*dy) + offset := 0 // steps through the input by sequential scan lines. + for _, pass := range interlacing { + nOffset := pass.start * dx // steps through the output as defined by pass. + for y := pass.start; y < dy; y += pass.skip { + copy(nPix[nOffset:nOffset+dx], m.Pix[offset:offset+dx]) + offset += dx + nOffset += dx * pass.skip + } + } + m.Pix = nPix +} + +// Decode reads a GIF image from r and returns the first embedded +// image as an image.Image. +func Decode(r io.Reader) (image.Image, error) { + var d decoder + if err := d.decode(r, false, false); err != nil { + return nil, err + } + return d.image[0], nil +} + +// GIF represents the possibly multiple images stored in a GIF file. +type GIF struct { + Image []*image.Paletted // The successive images. + Delay []int // The successive delay times, one per frame, in 100ths of a second. + // LoopCount controls the number of times an animation will be + // restarted during display. + // A LoopCount of 0 means to loop forever. + // A LoopCount of -1 means to show each frame only once. + // Otherwise, the animation is looped LoopCount+1 times. + LoopCount int + // Disposal is the successive disposal methods, one per frame. For + // backwards compatibility, a nil Disposal is valid to pass to EncodeAll, + // and implies that each frame's disposal method is 0 (no disposal + // specified). + Disposal []byte + // Config is the global color table (palette), width and height. A nil or + // empty-color.Palette Config.ColorModel means that each frame has its own + // color table and there is no global color table. Each frame's bounds must + // be within the rectangle defined by the two points (0, 0) and + // (Config.Width, Config.Height). + // + // For backwards compatibility, a zero-valued Config is valid to pass to + // EncodeAll, and implies that the overall GIF's width and height equals + // the first frame's bounds' Rectangle.Max point. + Config image.Config + // BackgroundIndex is the background index in the global color table, for + // use with the DisposalBackground disposal method. + BackgroundIndex byte +} + +// DecodeAll reads a GIF image from r and returns the sequential frames +// and timing information. +func DecodeAll(r io.Reader) (*GIF, error) { + var d decoder + if err := d.decode(r, false, true); err != nil { + return nil, err + } + gif := &GIF{ + Image: d.image, + LoopCount: d.loopCount, + Delay: d.delay, + Disposal: d.disposal, + Config: image.Config{ + ColorModel: d.globalColorTable, + Width: d.width, + Height: d.height, + }, + BackgroundIndex: d.backgroundIndex, + } + return gif, nil +} + +// DecodeConfig returns the global color model and dimensions of a GIF image +// without decoding the entire image. +func DecodeConfig(r io.Reader) (image.Config, error) { + var d decoder + if err := d.decode(r, true, false); err != nil { + return image.Config{}, err + } + return image.Config{ + ColorModel: d.globalColorTable, + Width: d.width, + Height: d.height, + }, nil +} + +func init() { + image.RegisterFormat("gif", "GIF8?a", Decode, DecodeConfig) +} diff --git a/src/image/gif/reader_test.go b/src/image/gif/reader_test.go new file mode 100644 index 0000000..a7f943a --- /dev/null +++ b/src/image/gif/reader_test.go @@ -0,0 +1,441 @@ +// 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" + "compress/lzw" + "image" + "image/color" + "image/color/palette" + "io" + "os" + "reflect" + "runtime" + "runtime/debug" + "strings" + "testing" +) + +// header, palette and trailer are parts of a valid 2x1 GIF image. +const ( + headerStr = "GIF89a" + + "\x02\x00\x01\x00" + // width=2, height=1 + "\x80\x00\x00" // headerFields=(a color table of 2 pixels), backgroundIndex, aspect + paletteStr = "\x10\x20\x30\x40\x50\x60" // the color table, also known as a palette + trailerStr = "\x3b" +) + +// lzw.NewReader wants a io.ByteReader, this ensures we're compatible. +var _ io.ByteReader = (*blockReader)(nil) + +// lzwEncode returns an LZW encoding (with 2-bit literals) of in. +func lzwEncode(in []byte) []byte { + b := &bytes.Buffer{} + w := lzw.NewWriter(b, lzw.LSB, 2) + if _, err := w.Write(in); err != nil { + panic(err) + } + if err := w.Close(); err != nil { + panic(err) + } + return b.Bytes() +} + +func TestDecode(t *testing.T) { + // extra contains superfluous bytes to inject into the GIF, either at the end + // of an existing data sub-block (past the LZW End of Information code) or in + // a separate data sub-block. The 0x02 values are arbitrary. + const extra = "\x02\x02\x02\x02" + + testCases := []struct { + nPix int // The number of pixels in the image data. + // If non-zero, write this many extra bytes inside the data sub-block + // containing the LZW end code. + extraExisting int + // If non-zero, write an extra block of this many bytes. + extraSeparate int + wantErr error + }{ + {0, 0, 0, errNotEnough}, + {1, 0, 0, errNotEnough}, + {2, 0, 0, nil}, + // An extra data sub-block after the compressed section with 1 byte which we + // silently skip. + {2, 0, 1, nil}, + // An extra data sub-block after the compressed section with 2 bytes. In + // this case we complain that there is too much data. + {2, 0, 2, errTooMuch}, + // Too much pixel data. + {3, 0, 0, errTooMuch}, + // An extra byte after LZW data, but inside the same data sub-block. + {2, 1, 0, nil}, + // Two extra bytes after LZW data, but inside the same data sub-block. + {2, 2, 0, nil}, + // Extra data exists in the final sub-block with LZW data, AND there is + // a bogus sub-block following. + {2, 1, 1, errTooMuch}, + } + for _, tc := range testCases { + b := &bytes.Buffer{} + b.WriteString(headerStr) + b.WriteString(paletteStr) + // Write an image with bounds 2x1 but tc.nPix pixels. If tc.nPix != 2 + // then this should result in an invalid GIF image. First, write a + // magic 0x2c (image descriptor) byte, bounds=(0,0)-(2,1), a flags + // byte, and 2-bit LZW literals. + b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02") + if tc.nPix > 0 { + enc := lzwEncode(make([]byte, tc.nPix)) + if len(enc)+tc.extraExisting > 0xff { + t.Errorf("nPix=%d, extraExisting=%d, extraSeparate=%d: compressed length %d is too large", + tc.nPix, tc.extraExisting, tc.extraSeparate, len(enc)) + continue + } + + // Write the size of the data sub-block containing the LZW data. + b.WriteByte(byte(len(enc) + tc.extraExisting)) + + // Write the LZW data. + b.Write(enc) + + // Write extra bytes inside the same data sub-block where LZW data + // ended. Each arbitrarily 0x02. + b.WriteString(extra[:tc.extraExisting]) + } + + if tc.extraSeparate > 0 { + // Data sub-block size. This indicates how many extra bytes follow. + b.WriteByte(byte(tc.extraSeparate)) + b.WriteString(extra[:tc.extraSeparate]) + } + b.WriteByte(0x00) // An empty block signifies the end of the image data. + b.WriteString(trailerStr) + + got, err := Decode(b) + if err != tc.wantErr { + t.Errorf("nPix=%d, extraExisting=%d, extraSeparate=%d\ngot %v\nwant %v", + tc.nPix, tc.extraExisting, tc.extraSeparate, err, tc.wantErr) + } + + if tc.wantErr != nil { + continue + } + want := &image.Paletted{ + Pix: []uint8{0, 0}, + Stride: 2, + Rect: image.Rect(0, 0, 2, 1), + Palette: color.Palette{ + color.RGBA{0x10, 0x20, 0x30, 0xff}, + color.RGBA{0x40, 0x50, 0x60, 0xff}, + }, + } + if !reflect.DeepEqual(got, want) { + t.Errorf("nPix=%d, extraExisting=%d, extraSeparate=%d\ngot %v\nwant %v", + tc.nPix, tc.extraExisting, tc.extraSeparate, got, want) + } + } +} + +func TestTransparentIndex(t *testing.T) { + b := &bytes.Buffer{} + b.WriteString(headerStr) + b.WriteString(paletteStr) + for transparentIndex := 0; transparentIndex < 3; transparentIndex++ { + if transparentIndex < 2 { + // Write the graphic control for the transparent index. + b.WriteString("\x21\xf9\x04\x01\x00\x00") + b.WriteByte(byte(transparentIndex)) + b.WriteByte(0) + } + // Write an image with bounds 2x1, as per TestDecode. + b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02") + enc := lzwEncode([]byte{0x00, 0x00}) + if len(enc) > 0xff { + t.Fatalf("compressed length %d is too large", len(enc)) + } + b.WriteByte(byte(len(enc))) + b.Write(enc) + b.WriteByte(0x00) + } + b.WriteString(trailerStr) + + g, err := DecodeAll(b) + if err != nil { + t.Fatalf("DecodeAll: %v", err) + } + c0 := color.RGBA{paletteStr[0], paletteStr[1], paletteStr[2], 0xff} + c1 := color.RGBA{paletteStr[3], paletteStr[4], paletteStr[5], 0xff} + cz := color.RGBA{} + wants := []color.Palette{ + {cz, c1}, + {c0, cz}, + {c0, c1}, + } + if len(g.Image) != len(wants) { + t.Fatalf("got %d images, want %d", len(g.Image), len(wants)) + } + for i, want := range wants { + got := g.Image[i].Palette + if !reflect.DeepEqual(got, want) { + t.Errorf("palette #%d:\ngot %v\nwant %v", i, got, want) + } + } +} + +// testGIF is a simple GIF that we can modify to test different scenarios. +var testGIF = []byte{ + 'G', 'I', 'F', '8', '9', 'a', + 1, 0, 1, 0, // w=1, h=1 (6) + 128, 0, 0, // headerFields, bg, aspect (10) + 0, 0, 0, 1, 1, 1, // color table and graphics control (13) + 0x21, 0xf9, 0x04, 0x00, 0x00, 0x00, 0xff, 0x00, // (19) + // frame 1 (0,0 - 1,1) + 0x2c, + 0x00, 0x00, 0x00, 0x00, + 0x01, 0x00, 0x01, 0x00, // (32) + 0x00, + 0x02, 0x02, 0x4c, 0x01, 0x00, // lzw pixels + // trailer + 0x3b, +} + +func try(t *testing.T, b []byte, want string) { + _, err := DecodeAll(bytes.NewReader(b)) + var got string + if err != nil { + got = err.Error() + } + if got != want { + t.Fatalf("got %v, want %v", got, want) + } +} + +func TestBounds(t *testing.T) { + // Make a local copy of testGIF. + gif := make([]byte, len(testGIF)) + copy(gif, testGIF) + // Make the bounds too big, just by one. + gif[32] = 2 + want := "gif: frame bounds larger than image bounds" + try(t, gif, want) + + // Make the bounds too small; does not trigger bounds + // check, but now there's too much data. + gif[32] = 0 + want = "gif: too much image data" + try(t, gif, want) + gif[32] = 1 + + // Make the bounds really big, expect an error. + want = "gif: frame bounds larger than image bounds" + for i := 0; i < 4; i++ { + gif[32+i] = 0xff + } + try(t, gif, want) +} + +func TestNoPalette(t *testing.T) { + b := &bytes.Buffer{} + + // Manufacture a GIF with no palette, so any pixel at all + // will be invalid. + b.WriteString(headerStr[:len(headerStr)-3]) + b.WriteString("\x00\x00\x00") // No global palette. + + // Image descriptor: 2x1, no local palette, and 2-bit LZW literals. + b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02") + + // Encode the pixels: neither is in range, because there is no palette. + enc := lzwEncode([]byte{0x00, 0x03}) + b.WriteByte(byte(len(enc))) + b.Write(enc) + b.WriteByte(0x00) // An empty block signifies the end of the image data. + + b.WriteString(trailerStr) + + try(t, b.Bytes(), "gif: no color table") +} + +func TestPixelOutsidePaletteRange(t *testing.T) { + for _, pval := range []byte{0, 1, 2, 3} { + b := &bytes.Buffer{} + + // Manufacture a GIF with a 2 color palette. + b.WriteString(headerStr) + b.WriteString(paletteStr) + + // Image descriptor: 2x1, no local palette, and 2-bit LZW literals. + b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02") + + // Encode the pixels; some pvals trigger the expected error. + enc := lzwEncode([]byte{pval, pval}) + b.WriteByte(byte(len(enc))) + b.Write(enc) + b.WriteByte(0x00) // An empty block signifies the end of the image data. + + b.WriteString(trailerStr) + + // No error expected, unless the pixels are beyond the 2 color palette. + want := "" + if pval >= 2 { + want = "gif: invalid pixel value" + } + try(t, b.Bytes(), want) + } +} + +func TestTransparentPixelOutsidePaletteRange(t *testing.T) { + b := &bytes.Buffer{} + + // Manufacture a GIF with a 2 color palette. + b.WriteString(headerStr) + b.WriteString(paletteStr) + + // Graphic Control Extension: transparency, transparent color index = 3. + // + // This index, 3, is out of range of the global palette and there is no + // local palette in the subsequent image descriptor. This is an error + // according to the spec, but Firefox and Google Chrome seem OK with this. + // + // See golang.org/issue/15059. + b.WriteString("\x21\xf9\x04\x01\x00\x00\x03\x00") + + // Image descriptor: 2x1, no local palette, and 2-bit LZW literals. + b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02") + + // Encode the pixels. + enc := lzwEncode([]byte{0x03, 0x03}) + b.WriteByte(byte(len(enc))) + b.Write(enc) + b.WriteByte(0x00) // An empty block signifies the end of the image data. + + b.WriteString(trailerStr) + + try(t, b.Bytes(), "") +} + +func TestLoopCount(t *testing.T) { + testCases := []struct { + name string + data []byte + loopCount int + }{ + { + "loopcount-missing", + []byte("GIF89a000\x00000" + + ",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 0 descriptor & color table + "\x02\b\xf01u\xb9\xfdal\x05\x00;"), // image 0 image data & trailer + -1, + }, + { + "loopcount-0", + []byte("GIF89a000\x00000" + + "!\xff\vNETSCAPE2.0\x03\x01\x00\x00\x00" + // loop count = 0 + ",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 0 descriptor & color table + "\x02\b\xf01u\xb9\xfdal\x05\x00" + // image 0 image data + ",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 1 descriptor & color table + "\x02\b\xf01u\xb9\xfdal\x05\x00;"), // image 1 image data & trailer + 0, + }, + { + "loopcount-1", + []byte("GIF89a000\x00000" + + "!\xff\vNETSCAPE2.0\x03\x01\x01\x00\x00" + // loop count = 1 + ",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 0 descriptor & color table + "\x02\b\xf01u\xb9\xfdal\x05\x00" + // image 0 image data + ",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 1 descriptor & color table + "\x02\b\xf01u\xb9\xfdal\x05\x00;"), // image 1 image data & trailer + 1, + }, + } + + for _, tc := range testCases { + t.Run(tc.name, func(t *testing.T) { + img, err := DecodeAll(bytes.NewReader(tc.data)) + if err != nil { + t.Fatal("DecodeAll:", err) + } + w := new(bytes.Buffer) + err = EncodeAll(w, img) + if err != nil { + t.Fatal("EncodeAll:", err) + } + img1, err := DecodeAll(w) + if err != nil { + t.Fatal("DecodeAll:", err) + } + if img.LoopCount != tc.loopCount { + t.Errorf("loop count mismatch: %d vs %d", img.LoopCount, tc.loopCount) + } + if img.LoopCount != img1.LoopCount { + t.Errorf("loop count failed round-trip: %d vs %d", img.LoopCount, img1.LoopCount) + } + }) + } +} + +func TestUnexpectedEOF(t *testing.T) { + for i := len(testGIF) - 1; i >= 0; i-- { + _, err := DecodeAll(bytes.NewReader(testGIF[:i])) + if err == errNotEnough { + continue + } + text := "" + if err != nil { + text = err.Error() + } + if !strings.HasPrefix(text, "gif:") || !strings.HasSuffix(text, ": unexpected EOF") { + t.Errorf("Decode(testGIF[:%d]) = %v, want gif: ...: unexpected EOF", i, err) + } + } +} + +// See golang.org/issue/22237 +func TestDecodeMemoryConsumption(t *testing.T) { + const frames = 3000 + img := image.NewPaletted(image.Rectangle{Max: image.Point{1, 1}}, palette.WebSafe) + hugeGIF := &GIF{ + Image: make([]*image.Paletted, frames), + Delay: make([]int, frames), + Disposal: make([]byte, frames), + } + for i := 0; i < frames; i++ { + hugeGIF.Image[i] = img + hugeGIF.Delay[i] = 60 + } + buf := new(bytes.Buffer) + if err := EncodeAll(buf, hugeGIF); err != nil { + t.Fatal("EncodeAll:", err) + } + s0, s1 := new(runtime.MemStats), new(runtime.MemStats) + runtime.GC() + defer debug.SetGCPercent(debug.SetGCPercent(5)) + runtime.ReadMemStats(s0) + if _, err := Decode(buf); err != nil { + t.Fatal("Decode:", err) + } + runtime.ReadMemStats(s1) + if heapDiff := int64(s1.HeapAlloc - s0.HeapAlloc); heapDiff > 30<<20 { + t.Fatalf("Decode of %d frames increased heap by %dMB", frames, heapDiff>>20) + } +} + +func BenchmarkDecode(b *testing.B) { + data, err := os.ReadFile("../testdata/video-001.gif") + if err != nil { + b.Fatal(err) + } + cfg, err := DecodeConfig(bytes.NewReader(data)) + if err != nil { + b.Fatal(err) + } + b.SetBytes(int64(cfg.Width * cfg.Height)) + b.ReportAllocs() + b.ResetTimer() + for i := 0; i < b.N; i++ { + Decode(bytes.NewReader(data)) + } +} diff --git a/src/image/gif/writer.go b/src/image/gif/writer.go new file mode 100644 index 0000000..7220446 --- /dev/null +++ b/src/image/gif/writer.go @@ -0,0 +1,477 @@ +// 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 ( + "bufio" + "bytes" + "compress/lzw" + "errors" + "image" + "image/color" + "image/color/palette" + "image/draw" + "io" +) + +// Graphic control extension fields. +const ( + gcLabel = 0xF9 + gcBlockSize = 0x04 +) + +var log2Lookup = [8]int{2, 4, 8, 16, 32, 64, 128, 256} + +func log2(x int) int { + for i, v := range log2Lookup { + if x <= v { + return i + } + } + return -1 +} + +// Little-endian. +func writeUint16(b []uint8, u uint16) { + b[0] = uint8(u) + b[1] = uint8(u >> 8) +} + +// writer is a buffered writer. +type writer interface { + Flush() error + io.Writer + io.ByteWriter +} + +// encoder encodes an image to the GIF format. +type encoder struct { + // w is the writer to write to. err is the first error encountered during + // writing. All attempted writes after the first error become no-ops. + w writer + err error + // g is a reference to the data that is being encoded. + g GIF + // globalCT is the size in bytes of the global color table. + globalCT int + // buf is a scratch buffer. It must be at least 256 for the blockWriter. + buf [256]byte + globalColorTable [3 * 256]byte + localColorTable [3 * 256]byte +} + +// blockWriter writes the block structure of GIF image data, which +// comprises (n, (n bytes)) blocks, with 1 <= n <= 255. It is the +// writer given to the LZW encoder, which is thus immune to the +// blocking. +type blockWriter struct { + e *encoder +} + +func (b blockWriter) setup() { + b.e.buf[0] = 0 +} + +func (b blockWriter) Flush() error { + return b.e.err +} + +func (b blockWriter) WriteByte(c byte) error { + if b.e.err != nil { + return b.e.err + } + + // Append c to buffered sub-block. + b.e.buf[0]++ + b.e.buf[b.e.buf[0]] = c + if b.e.buf[0] < 255 { + return nil + } + + // Flush block + b.e.write(b.e.buf[:256]) + b.e.buf[0] = 0 + return b.e.err +} + +// blockWriter must be an io.Writer for lzw.NewWriter, but this is never +// actually called. +func (b blockWriter) Write(data []byte) (int, error) { + for i, c := range data { + if err := b.WriteByte(c); err != nil { + return i, err + } + } + return len(data), nil +} + +func (b blockWriter) close() { + // Write the block terminator (0x00), either by itself, or along with a + // pending sub-block. + if b.e.buf[0] == 0 { + b.e.writeByte(0) + } else { + n := uint(b.e.buf[0]) + b.e.buf[n+1] = 0 + b.e.write(b.e.buf[:n+2]) + } + b.e.flush() +} + +func (e *encoder) flush() { + if e.err != nil { + return + } + e.err = e.w.Flush() +} + +func (e *encoder) write(p []byte) { + if e.err != nil { + return + } + _, e.err = e.w.Write(p) +} + +func (e *encoder) writeByte(b byte) { + if e.err != nil { + return + } + e.err = e.w.WriteByte(b) +} + +func (e *encoder) writeHeader() { + if e.err != nil { + return + } + _, e.err = io.WriteString(e.w, "GIF89a") + if e.err != nil { + return + } + + // Logical screen width and height. + writeUint16(e.buf[0:2], uint16(e.g.Config.Width)) + writeUint16(e.buf[2:4], uint16(e.g.Config.Height)) + e.write(e.buf[:4]) + + if p, ok := e.g.Config.ColorModel.(color.Palette); ok && len(p) > 0 { + paddedSize := log2(len(p)) // Size of Global Color Table: 2^(1+n). + e.buf[0] = fColorTable | uint8(paddedSize) + e.buf[1] = e.g.BackgroundIndex + e.buf[2] = 0x00 // Pixel Aspect Ratio. + e.write(e.buf[:3]) + var err error + e.globalCT, err = encodeColorTable(e.globalColorTable[:], p, paddedSize) + if err != nil && e.err == nil { + e.err = err + return + } + e.write(e.globalColorTable[:e.globalCT]) + } else { + // All frames have a local color table, so a global color table + // is not needed. + e.buf[0] = 0x00 + e.buf[1] = 0x00 // Background Color Index. + e.buf[2] = 0x00 // Pixel Aspect Ratio. + e.write(e.buf[:3]) + } + + // Add animation info if necessary. + if len(e.g.Image) > 1 && e.g.LoopCount >= 0 { + e.buf[0] = 0x21 // Extension Introducer. + e.buf[1] = 0xff // Application Label. + e.buf[2] = 0x0b // Block Size. + e.write(e.buf[:3]) + _, err := io.WriteString(e.w, "NETSCAPE2.0") // Application Identifier. + if err != nil && e.err == nil { + e.err = err + return + } + e.buf[0] = 0x03 // Block Size. + e.buf[1] = 0x01 // Sub-block Index. + writeUint16(e.buf[2:4], uint16(e.g.LoopCount)) + e.buf[4] = 0x00 // Block Terminator. + e.write(e.buf[:5]) + } +} + +func encodeColorTable(dst []byte, p color.Palette, size int) (int, error) { + if uint(size) >= uint(len(log2Lookup)) { + return 0, errors.New("gif: cannot encode color table with more than 256 entries") + } + for i, c := range p { + if c == nil { + return 0, errors.New("gif: cannot encode color table with nil entries") + } + var r, g, b uint8 + // It is most likely that the palette is full of color.RGBAs, so they + // get a fast path. + if rgba, ok := c.(color.RGBA); ok { + r, g, b = rgba.R, rgba.G, rgba.B + } else { + rr, gg, bb, _ := c.RGBA() + r, g, b = uint8(rr>>8), uint8(gg>>8), uint8(bb>>8) + } + dst[3*i+0] = r + dst[3*i+1] = g + dst[3*i+2] = b + } + n := log2Lookup[size] + if n > len(p) { + // Pad with black. + fill := dst[3*len(p) : 3*n] + for i := range fill { + fill[i] = 0 + } + } + return 3 * n, nil +} + +func (e *encoder) colorTablesMatch(localLen, transparentIndex int) bool { + localSize := 3 * localLen + if transparentIndex >= 0 { + trOff := 3 * transparentIndex + return bytes.Equal(e.globalColorTable[:trOff], e.localColorTable[:trOff]) && + bytes.Equal(e.globalColorTable[trOff+3:localSize], e.localColorTable[trOff+3:localSize]) + } + return bytes.Equal(e.globalColorTable[:localSize], e.localColorTable[:localSize]) +} + +func (e *encoder) writeImageBlock(pm *image.Paletted, delay int, disposal byte) { + if e.err != nil { + return + } + + if len(pm.Palette) == 0 { + e.err = errors.New("gif: cannot encode image block with empty palette") + return + } + + b := pm.Bounds() + if b.Min.X < 0 || b.Max.X >= 1<<16 || b.Min.Y < 0 || b.Max.Y >= 1<<16 { + e.err = errors.New("gif: image block is too large to encode") + return + } + if !b.In(image.Rectangle{Max: image.Point{e.g.Config.Width, e.g.Config.Height}}) { + e.err = errors.New("gif: image block is out of bounds") + return + } + + transparentIndex := -1 + for i, c := range pm.Palette { + if c == nil { + e.err = errors.New("gif: cannot encode color table with nil entries") + return + } + if _, _, _, a := c.RGBA(); a == 0 { + transparentIndex = i + break + } + } + + if delay > 0 || disposal != 0 || transparentIndex != -1 { + e.buf[0] = sExtension // Extension Introducer. + e.buf[1] = gcLabel // Graphic Control Label. + e.buf[2] = gcBlockSize // Block Size. + if transparentIndex != -1 { + e.buf[3] = 0x01 | disposal<<2 + } else { + e.buf[3] = 0x00 | disposal<<2 + } + writeUint16(e.buf[4:6], uint16(delay)) // Delay Time (1/100ths of a second) + + // Transparent color index. + if transparentIndex != -1 { + e.buf[6] = uint8(transparentIndex) + } else { + e.buf[6] = 0x00 + } + e.buf[7] = 0x00 // Block Terminator. + e.write(e.buf[:8]) + } + e.buf[0] = sImageDescriptor + writeUint16(e.buf[1:3], uint16(b.Min.X)) + writeUint16(e.buf[3:5], uint16(b.Min.Y)) + writeUint16(e.buf[5:7], uint16(b.Dx())) + writeUint16(e.buf[7:9], uint16(b.Dy())) + e.write(e.buf[:9]) + + // To determine whether or not this frame's palette is the same as the + // global palette, we can check a couple things. First, do they actually + // point to the same []color.Color? If so, they are equal so long as the + // frame's palette is not longer than the global palette... + paddedSize := log2(len(pm.Palette)) // Size of Local Color Table: 2^(1+n). + if gp, ok := e.g.Config.ColorModel.(color.Palette); ok && len(pm.Palette) <= len(gp) && &gp[0] == &pm.Palette[0] { + e.writeByte(0) // Use the global color table. + } else { + ct, err := encodeColorTable(e.localColorTable[:], pm.Palette, paddedSize) + if err != nil { + if e.err == nil { + e.err = err + } + return + } + // This frame's palette is not the very same slice as the global + // palette, but it might be a copy, possibly with one value turned into + // transparency by DecodeAll. + if ct <= e.globalCT && e.colorTablesMatch(len(pm.Palette), transparentIndex) { + e.writeByte(0) // Use the global color table. + } else { + // Use a local color table. + e.writeByte(fColorTable | uint8(paddedSize)) + e.write(e.localColorTable[:ct]) + } + } + + litWidth := paddedSize + 1 + if litWidth < 2 { + litWidth = 2 + } + e.writeByte(uint8(litWidth)) // LZW Minimum Code Size. + + bw := blockWriter{e: e} + bw.setup() + lzww := lzw.NewWriter(bw, lzw.LSB, litWidth) + if dx := b.Dx(); dx == pm.Stride { + _, e.err = lzww.Write(pm.Pix[:dx*b.Dy()]) + if e.err != nil { + lzww.Close() + return + } + } else { + for i, y := 0, b.Min.Y; y < b.Max.Y; i, y = i+pm.Stride, y+1 { + _, e.err = lzww.Write(pm.Pix[i : i+dx]) + if e.err != nil { + lzww.Close() + return + } + } + } + lzww.Close() // flush to bw + bw.close() // flush to e.w +} + +// Options are the encoding parameters. +type Options struct { + // NumColors is the maximum number of colors used in the image. + // It ranges from 1 to 256. + NumColors int + + // Quantizer is used to produce a palette with size NumColors. + // palette.Plan9 is used in place of a nil Quantizer. + Quantizer draw.Quantizer + + // Drawer is used to convert the source image to the desired palette. + // draw.FloydSteinberg is used in place of a nil Drawer. + Drawer draw.Drawer +} + +// EncodeAll writes the images in g to w in GIF format with the +// given loop count and delay between frames. +func EncodeAll(w io.Writer, g *GIF) error { + if len(g.Image) == 0 { + return errors.New("gif: must provide at least one image") + } + + if len(g.Image) != len(g.Delay) { + return errors.New("gif: mismatched image and delay lengths") + } + + e := encoder{g: *g} + // The GIF.Disposal, GIF.Config and GIF.BackgroundIndex fields were added + // in Go 1.5. Valid Go 1.4 code, such as when the Disposal field is omitted + // in a GIF struct literal, should still produce valid GIFs. + if e.g.Disposal != nil && len(e.g.Image) != len(e.g.Disposal) { + return errors.New("gif: mismatched image and disposal lengths") + } + if e.g.Config == (image.Config{}) { + p := g.Image[0].Bounds().Max + e.g.Config.Width = p.X + e.g.Config.Height = p.Y + } else if e.g.Config.ColorModel != nil { + if _, ok := e.g.Config.ColorModel.(color.Palette); !ok { + return errors.New("gif: GIF color model must be a color.Palette") + } + } + + if ww, ok := w.(writer); ok { + e.w = ww + } else { + e.w = bufio.NewWriter(w) + } + + e.writeHeader() + for i, pm := range g.Image { + disposal := uint8(0) + if g.Disposal != nil { + disposal = g.Disposal[i] + } + e.writeImageBlock(pm, g.Delay[i], disposal) + } + e.writeByte(sTrailer) + e.flush() + return e.err +} + +// Encode writes the Image m to w in GIF format. +func Encode(w io.Writer, m image.Image, o *Options) error { + // Check for bounds and size restrictions. + b := m.Bounds() + if b.Dx() >= 1<<16 || b.Dy() >= 1<<16 { + return errors.New("gif: image is too large to encode") + } + + opts := Options{} + if o != nil { + opts = *o + } + if opts.NumColors < 1 || 256 < opts.NumColors { + opts.NumColors = 256 + } + if opts.Drawer == nil { + opts.Drawer = draw.FloydSteinberg + } + + pm, _ := m.(*image.Paletted) + if pm == nil { + if cp, ok := m.ColorModel().(color.Palette); ok { + pm = image.NewPaletted(b, cp) + for y := b.Min.Y; y < b.Max.Y; y++ { + for x := b.Min.X; x < b.Max.X; x++ { + pm.Set(x, y, cp.Convert(m.At(x, y))) + } + } + } + } + if pm == nil || len(pm.Palette) > opts.NumColors { + // Set pm to be a palettedized copy of m, including its bounds, which + // might not start at (0, 0). + // + // TODO: Pick a better sub-sample of the Plan 9 palette. + pm = image.NewPaletted(b, palette.Plan9[:opts.NumColors]) + if opts.Quantizer != nil { + pm.Palette = opts.Quantizer.Quantize(make(color.Palette, 0, opts.NumColors), m) + } + opts.Drawer.Draw(pm, b, m, b.Min) + } + + // When calling Encode instead of EncodeAll, the single-frame image is + // translated such that its top-left corner is (0, 0), so that the single + // frame completely fills the overall GIF's bounds. + if pm.Rect.Min != (image.Point{}) { + dup := *pm + dup.Rect = dup.Rect.Sub(dup.Rect.Min) + pm = &dup + } + + return EncodeAll(w, &GIF{ + Image: []*image.Paletted{pm}, + Delay: []int{0}, + Config: image.Config{ + ColorModel: pm.Palette, + Width: b.Dx(), + Height: b.Dy(), + }, + }) +} diff --git a/src/image/gif/writer_test.go b/src/image/gif/writer_test.go new file mode 100644 index 0000000..8dd2890 --- /dev/null +++ b/src/image/gif/writer_test.go @@ -0,0 +1,734 @@ +// 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/draw" + _ "image/png" + "io" + "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 +// calculated 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(io.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(io.Discard, g1); err == nil { + t.Error("expected error from mismatched disposal and image slice lengths") + } +} + +func TestEncodeZeroGIF(t *testing.T) { + if err := EncodeAll(io.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(io.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(io.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(io.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: Encode 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: Encode 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 BenchmarkEncodeRandomPaletted(b *testing.B) { + paletted := image.NewPaletted(image.Rect(0, 0, 640, 480), palette.Plan9) + rnd := rand.New(rand.NewSource(123)) + for i := range paletted.Pix { + paletted.Pix[i] = uint8(rnd.Intn(256)) + } + + b.SetBytes(640 * 480 * 1) + b.ReportAllocs() + b.ResetTimer() + for i := 0; i < b.N; i++ { + Encode(io.Discard, paletted, nil) + } +} + +func BenchmarkEncodeRandomRGBA(b *testing.B) { + rgba := image.NewRGBA(image.Rect(0, 0, 640, 480)) + bo := rgba.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++ { + rgba.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(io.Discard, rgba, nil) + } +} + +func BenchmarkEncodeRealisticPaletted(b *testing.B) { + img, err := readImg("../testdata/video-001.png") + if err != nil { + b.Fatalf("readImg: %v", err) + } + bo := img.Bounds() + paletted := image.NewPaletted(bo, palette.Plan9) + draw.Draw(paletted, bo, img, bo.Min, draw.Src) + + b.SetBytes(int64(bo.Dx() * bo.Dy() * 1)) + b.ReportAllocs() + b.ResetTimer() + for i := 0; i < b.N; i++ { + Encode(io.Discard, paletted, nil) + } +} + +func BenchmarkEncodeRealisticRGBA(b *testing.B) { + img, err := readImg("../testdata/video-001.png") + if err != nil { + b.Fatalf("readImg: %v", err) + } + bo := img.Bounds() + // Converting img to rgba is redundant for video-001.png, which is already + // in the RGBA format, but for those copy/pasting this benchmark (but + // changing the source image), the conversion ensures that we're still + // benchmarking encoding an RGBA image. + rgba := image.NewRGBA(bo) + draw.Draw(rgba, bo, img, bo.Min, draw.Src) + + b.SetBytes(int64(bo.Dx() * bo.Dy() * 4)) + b.ReportAllocs() + b.ResetTimer() + for i := 0; i < b.N; i++ { + Encode(io.Discard, rgba, nil) + } +} |