blob: 3737fdcf294afb8d67f6bf007dbd27be5cb03a35 [file] [log] [blame]
// Copyright 2019 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#include "include/core/SkICC.h"
#include "include/core/SkString.h"
#include "tools/HashAndEncode.h"
#include "png.h"
static sk_sp<SkColorSpace> rec2020() {
return SkColorSpace::MakeRGB(SkNamedTransferFn::kRec2020, SkNamedGamut::kRec2020);
HashAndEncode::HashAndEncode(const SkBitmap& bitmap) : fSize( {
skcms_AlphaFormat srcAlpha;
switch (bitmap.alphaType()) {
case kUnknown_SkAlphaType: return;
case kOpaque_SkAlphaType:
case kUnpremul_SkAlphaType: srcAlpha = skcms_AlphaFormat_Unpremul; break;
case kPremul_SkAlphaType: srcAlpha = skcms_AlphaFormat_PremulAsEncoded; break;
skcms_PixelFormat srcFmt;
switch (bitmap.colorType()) {
case kUnknown_SkColorType: return;
case kAlpha_8_SkColorType: srcFmt = skcms_PixelFormat_A_8; break;
case kRGB_565_SkColorType: srcFmt = skcms_PixelFormat_BGR_565; break;
case kARGB_4444_SkColorType: srcFmt = skcms_PixelFormat_ABGR_4444; break;
case kRGBA_8888_SkColorType: srcFmt = skcms_PixelFormat_RGBA_8888; break;
case kBGRA_8888_SkColorType: srcFmt = skcms_PixelFormat_BGRA_8888; break;
case kRGBA_1010102_SkColorType: srcFmt = skcms_PixelFormat_RGBA_1010102; break;
case kBGRA_1010102_SkColorType: srcFmt = skcms_PixelFormat_BGRA_1010102; break;
case kGray_8_SkColorType: srcFmt = skcms_PixelFormat_G_8; break;
case kRGBA_F16Norm_SkColorType: srcFmt = skcms_PixelFormat_RGBA_hhhh; break;
case kRGBA_F16_SkColorType: srcFmt = skcms_PixelFormat_RGBA_hhhh; break;
case kRGBA_F32_SkColorType: srcFmt = skcms_PixelFormat_RGBA_ffff; break;
case kR16G16B16A16_unorm_SkColorType: srcFmt = skcms_PixelFormat_RGBA_16161616LE; break;
case kRGB_888x_SkColorType: srcFmt = skcms_PixelFormat_RGBA_8888;
srcAlpha = skcms_AlphaFormat_Opaque; break;
case kRGB_101010x_SkColorType: srcFmt = skcms_PixelFormat_RGBA_1010102;
srcAlpha = skcms_AlphaFormat_Opaque; break;
case kBGR_101010x_SkColorType: srcFmt = skcms_PixelFormat_BGRA_1010102;
srcAlpha = skcms_AlphaFormat_Opaque; break;
case kR8G8_unorm_SkColorType: return;
case kR16G16_unorm_SkColorType: return;
case kR16G16_float_SkColorType: return;
case kA16_unorm_SkColorType: return;
case kA16_float_SkColorType: return;
skcms_ICCProfile srcProfile = *skcms_sRGB_profile();
if (auto cs = bitmap.colorSpace()) {
// Our common format that can represent anything we draw and encode as a PNG:
// - 16-bit big-endian RGBA
// - unpremul
// - Rec. 2020 gamut and transfer function
skcms_PixelFormat dstFmt = skcms_PixelFormat_RGBA_16161616BE;
skcms_AlphaFormat dstAlpha = skcms_AlphaFormat_Unpremul;
skcms_ICCProfile dstProfile;
int N = fSize.width() * fSize.height();
fPixels.reset(new uint64_t[N]);
if (!skcms_Transform(bitmap.getPixels(), srcFmt, srcAlpha, &srcProfile,
fPixels.get(), dstFmt, dstAlpha, &dstProfile, N)) {
void HashAndEncode::feedHash(SkWStream* st) const {
st->write(&fSize, sizeof(fSize));
if (const uint64_t* px = fPixels.get()) {
st->write(px, sizeof(*px) * fSize.width() * fSize.height());
// N.B. changing salt will change the hash of all images produced by DM,
// and will cause tens of thousands of new images to be uploaded to Gold.
int salt = 1;
st->write(&salt, sizeof(salt));
// NOTE: HashAndEncode uses libpng directly rather than through an abstraction
// like SkPngEncoder to make sure we get stable, portable results independent
// of any changes to Skia production encoder.
bool HashAndEncode::encodePNG(SkWStream* st,
const char* md5,
CommandLineFlags::StringArray key,
CommandLineFlags::StringArray properties) const {
if (!fPixels) {
return false;
png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
if (!png) {
return false;
png_infop info = png_create_info_struct(png);
if (!info) {
png_destroy_write_struct(&png, &info);
return false;
auto write_to_stream = +[](png_structp png, png_bytep ptr, png_size_t len) {
auto st = (SkWStream*)png_get_io_ptr(png);
if (!st->write(ptr, len)) {
png_error(png, "HashAndEncode::encodePNG() failed writing stream");
png_set_write_fn(png, st, write_to_stream, nullptr);
SkString description;
description.append("Key: ");
for (int i = 0; i < key.count(); i++) {
description.appendf("%s ", key[i]);
description.append("Properties: ");
for (int i = 0; i < properties.count(); i++) {
description.appendf("%s ", properties[i]);
description.appendf("MD5: %s", md5);
png_text text[2];
text[0].key = (png_charp)"Author";
text[0].text = (png_charp)"DM unified Rec.2020";
text[0].compression = PNG_TEXT_COMPRESSION_NONE;
text[1].key = (png_charp)"Description";
text[1].text = (png_charp)description.c_str();
text[1].compression = PNG_TEXT_COMPRESSION_NONE;
png_set_text(png, info, text, SK_ARRAY_COUNT(text));
png_set_IHDR(png, info, (png_uint_32)fSize.width()
, (png_uint_32)fSize.height()
, 16/*bits per channel*/
// Fastest encoding and decoding, at slight file size cost is no filtering, compression 1.
png_set_compression_level(png, 1);
static const sk_sp<SkData> profile =
SkWriteICCProfile(SkNamedTransferFn::kRec2020, SkNamedGamut::kRec2020);
png_set_iCCP(png, info,
0/*compression type... no idea what options are available here*/,
(png_uint_32) profile->size());
png_write_info(png, info);
for (int y = 0; y < fSize.height(); y++) {
png_write_row(png, (png_bytep)(fPixels.get() + y*fSize.width()));
png_write_end(png, info);
png_destroy_write_struct(&png, &info);
return true;