1 // Copyright 2019 Google LLC.
2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3
4 #include "include/core/SkICC.h"
5 #include "include/core/SkString.h"
6 #include "tools/HashAndEncode.h"
7
8 #include <png.h>
9
rec2020()10 static sk_sp<SkColorSpace> rec2020() {
11 return SkColorSpace::MakeRGB(SkNamedTransferFn::kRec2020, SkNamedGamut::kRec2020);
12 }
13
HashAndEncode(const SkBitmap & bitmap)14 HashAndEncode::HashAndEncode(const SkBitmap& bitmap) : fSize(bitmap.info().dimensions()) {
15 skcms_AlphaFormat srcAlpha;
16 switch (bitmap.alphaType()) {
17 case kUnknown_SkAlphaType: return;
18
19 case kOpaque_SkAlphaType:
20 case kUnpremul_SkAlphaType: srcAlpha = skcms_AlphaFormat_Unpremul; break;
21 case kPremul_SkAlphaType: srcAlpha = skcms_AlphaFormat_PremulAsEncoded; break;
22 }
23
24 skcms_PixelFormat srcFmt;
25 switch (bitmap.colorType()) {
26 case kUnknown_SkColorType: return;
27
28 case kAlpha_8_SkColorType: srcFmt = skcms_PixelFormat_A_8; break;
29 case kRGB_565_SkColorType: srcFmt = skcms_PixelFormat_BGR_565; break;
30 case kARGB_4444_SkColorType: srcFmt = skcms_PixelFormat_ABGR_4444; break;
31 case kRGBA_8888_SkColorType: srcFmt = skcms_PixelFormat_RGBA_8888; break;
32 case kBGRA_8888_SkColorType: srcFmt = skcms_PixelFormat_BGRA_8888; break;
33 case kSRGBA_8888_SkColorType: srcFmt = skcms_PixelFormat_RGBA_8888_sRGB; break;
34 case kRGBA_1010102_SkColorType: srcFmt = skcms_PixelFormat_RGBA_1010102; break;
35 case kBGRA_1010102_SkColorType: srcFmt = skcms_PixelFormat_BGRA_1010102; break;
36 case kGray_8_SkColorType: srcFmt = skcms_PixelFormat_G_8; break;
37 // skcms doesn't have R_8. Pretend it's G_8, but see below for color space trickery:
38 case kR8_unorm_SkColorType: srcFmt = skcms_PixelFormat_G_8; break;
39 case kRGBA_F16Norm_SkColorType: srcFmt = skcms_PixelFormat_RGBA_hhhh; break;
40 case kRGBA_F16_SkColorType: srcFmt = skcms_PixelFormat_RGBA_hhhh; break;
41 case kRGBA_F32_SkColorType: srcFmt = skcms_PixelFormat_RGBA_ffff; break;
42 case kR16G16B16A16_unorm_SkColorType: srcFmt = skcms_PixelFormat_RGBA_16161616LE; break;
43
44 case kRGB_888x_SkColorType: srcFmt = skcms_PixelFormat_RGBA_8888;
45 srcAlpha = skcms_AlphaFormat_Opaque; break;
46 case kRGB_101010x_SkColorType: srcFmt = skcms_PixelFormat_RGBA_1010102;
47 srcAlpha = skcms_AlphaFormat_Opaque; break;
48 case kBGR_101010x_SkColorType: srcFmt = skcms_PixelFormat_BGRA_1010102;
49 srcAlpha = skcms_AlphaFormat_Opaque; break;
50
51 case kR8G8_unorm_SkColorType: return;
52 case kR16G16_unorm_SkColorType: return;
53 case kR16G16_float_SkColorType: return;
54 case kA16_unorm_SkColorType: return;
55 case kA16_float_SkColorType: return;
56 }
57
58 skcms_ICCProfile srcProfile = *skcms_sRGB_profile();
59 if (auto cs = bitmap.colorSpace()) {
60 cs->toProfile(&srcProfile);
61 }
62
63 // NOTE: If the color type is R8, we told skcms it's actually G8 above. To get red PNGs,
64 // we tweak the source color space to throw away any green and blue:
65 if (bitmap.colorType() == kR8_unorm_SkColorType) {
66 srcProfile.toXYZD50.vals[0][1] = srcProfile.toXYZD50.vals[0][2] = 0;
67 srcProfile.toXYZD50.vals[1][1] = srcProfile.toXYZD50.vals[1][2] = 0;
68 srcProfile.toXYZD50.vals[2][1] = srcProfile.toXYZD50.vals[2][2] = 0;
69 }
70
71 // Our common format that can represent anything we draw and encode as a PNG:
72 // - 16-bit big-endian RGBA
73 // - unpremul
74 // - Rec. 2020 gamut and transfer function
75 skcms_PixelFormat dstFmt = skcms_PixelFormat_RGBA_16161616BE;
76 skcms_AlphaFormat dstAlpha = skcms_AlphaFormat_Unpremul;
77 skcms_ICCProfile dstProfile;
78 rec2020()->toProfile(&dstProfile);
79
80 int N = fSize.width() * fSize.height();
81 fPixels.reset(new uint64_t[N]);
82
83 const void* src = bitmap.getPixels();
84 void* dst = fPixels.get();
85 while (N > 0) {
86 int todo = std::min(N, 1<<27); // Keep todo*8 <= 1B; skcms requires N*bpp < MAX_INT.
87 if (!skcms_Transform(src, srcFmt, srcAlpha, &srcProfile,
88 dst, dstFmt, dstAlpha, &dstProfile, todo)) {
89 SkASSERT(false);
90 fPixels.reset(nullptr);
91 break;
92 }
93 src = (char*)src + todo*SkColorTypeBytesPerPixel(bitmap.colorType());
94 dst = (char*)dst + todo*sizeof(uint64_t);
95 N -= todo;
96 }
97 }
98
feedHash(SkWStream * st) const99 void HashAndEncode::feedHash(SkWStream* st) const {
100 st->write(&fSize, sizeof(fSize));
101 if (const uint64_t* px = fPixels.get()) {
102 st->write(px, sizeof(*px) * fSize.width() * fSize.height());
103 }
104
105 // N.B. changing salt will change the hash of all images produced by DM,
106 // and will cause tens of thousands of new images to be uploaded to Gold.
107 int salt = 1;
108 st->write(&salt, sizeof(salt));
109 }
110
111 // NOTE: HashAndEncode uses libpng directly rather than through an abstraction
112 // like SkPngEncoder to make sure we get stable, portable results independent
113 // of any changes to Skia production encoder.
114
encodePNG(SkWStream * st,const char * md5,CommandLineFlags::StringArray key,CommandLineFlags::StringArray properties) const115 bool HashAndEncode::encodePNG(SkWStream* st,
116 const char* md5,
117 CommandLineFlags::StringArray key,
118 CommandLineFlags::StringArray properties) const {
119 if (!fPixels) {
120 return false;
121 }
122
123 png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
124 if (!png) {
125 return false;
126 }
127
128 png_infop info = png_create_info_struct(png);
129 if (!info) {
130 png_destroy_write_struct(&png, &info);
131 return false;
132 }
133 auto write_to_stream = +[](png_structp png, png_bytep ptr, png_size_t len) {
134 auto st = (SkWStream*)png_get_io_ptr(png);
135 if (!st->write(ptr, len)) {
136 png_error(png, "HashAndEncode::encodePNG() failed writing stream");
137 }
138 };
139 png_set_write_fn(png, st, write_to_stream, nullptr);
140
141 SkString description;
142 description.append("Key: ");
143 for (int i = 0; i < key.count(); i++) {
144 description.appendf("%s ", key[i]);
145 }
146 description.append("Properties: ");
147 for (int i = 0; i < properties.count(); i++) {
148 description.appendf("%s ", properties[i]);
149 }
150 description.appendf("MD5: %s", md5);
151
152 png_text text[2];
153 text[0].key = (png_charp)"Author";
154 text[0].text = (png_charp)"DM unified Rec.2020";
155 text[0].compression = PNG_TEXT_COMPRESSION_NONE;
156 text[1].key = (png_charp)"Description";
157 text[1].text = (png_charp)description.c_str();
158 text[1].compression = PNG_TEXT_COMPRESSION_NONE;
159 png_set_text(png, info, text, SK_ARRAY_COUNT(text));
160
161 png_set_IHDR(png, info, (png_uint_32)fSize.width()
162 , (png_uint_32)fSize.height()
163 , 16/*bits per channel*/
164 , PNG_COLOR_TYPE_RGB_ALPHA
165 , PNG_INTERLACE_NONE
166 , PNG_COMPRESSION_TYPE_DEFAULT
167 , PNG_FILTER_TYPE_DEFAULT);
168
169 // Fastest encoding and decoding, at slight file size cost is no filtering, compression 1.
170 png_set_filter(png, PNG_FILTER_TYPE_BASE, PNG_FILTER_NONE);
171 png_set_compression_level(png, 1);
172
173 static const sk_sp<SkData> profile =
174 SkWriteICCProfile(SkNamedTransferFn::kRec2020, SkNamedGamut::kRec2020);
175 png_set_iCCP(png, info,
176 "Rec.2020",
177 0/*compression type... no idea what options are available here*/,
178 (png_const_bytep)profile->data(),
179 (png_uint_32) profile->size());
180
181 png_write_info(png, info);
182 for (int y = 0; y < fSize.height(); y++) {
183 png_write_row(png, (png_bytep)(fPixels.get() + y*fSize.width()));
184 }
185 png_write_end(png, info);
186
187 png_destroy_write_struct(&png, &info);
188 return true;
189 }
190
191