skia2/tests/CodexTest.cpp
msarett 8ff6ca6e73 Disable dithering in libjpeg-turbo for 565 decodes
libjpeg-turbo turns on dithering by default.  When we
decode to RGBA, it uses Floyd-Steinberg dithering -
consistent with the libjpeg6b gold standard,

When we decode to 565, it uses ordered dithering.  Ordered
dithering for 565 is not part of the 6b standard (libjpeg6b
doesn't even support 565) and is causing us a number of
issues:
(1) Ordered dithering + nearest neighbor sampling is
causing checkerboard visual artifacts in some outputs.
(2) The ordered dither function in libjpeg-turbo actually
behaves differently depending on the alignment of the
memory that it decodes into.  This means that two image
decodes that should be identical may look different just
because they decode into different memory blocks.  This
was causing some diffs on Gold with the scanline_subset
test that were causing me some confusion.
(3) Maybe not the best evidence, but visually I can't tell
a difference with and without dithering (except when
nearest neighbor scaling causes the checkerboard artifact).
(4) Turning off dithering should be a more significant
performance improvement than you might expect.
libjpeg-turbo has SIMD color conversions to 565, but when
dithering is on, it defaults to scalar code.

This CL should make every jpeg decode to 565 on Gold look
slightly different.  Yay!

BUG=skia:

Review URL: https://codereview.chromium.org/1349563007
2015-09-18 12:06:04 -07:00

400 lines
16 KiB
C++

/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "Resources.h"
#include "SkBitmap.h"
#include "SkCodec.h"
#include "SkMD5.h"
#include "SkRandom.h"
#include "SkScaledCodec.h"
#include "SkScanlineDecoder.h"
#include "Test.h"
static SkStreamAsset* resource(const char path[]) {
SkString fullPath = GetResourcePath(path);
return SkStream::NewFromFile(fullPath.c_str());
}
static void md5(const SkBitmap& bm, SkMD5::Digest* digest) {
SkAutoLockPixels autoLockPixels(bm);
SkASSERT(bm.getPixels());
SkMD5 md5;
size_t rowLen = bm.info().bytesPerPixel() * bm.width();
for (int y = 0; y < bm.height(); ++y) {
md5.update(static_cast<uint8_t*>(bm.getAddr(0, y)), rowLen);
}
md5.finish(*digest);
}
/**
* Compute the digest for bm and compare it to a known good digest.
* @param r Reporter to assert that bm's digest matches goodDigest.
* @param goodDigest The known good digest to compare to.
* @param bm The bitmap to test.
*/
static void compare_to_good_digest(skiatest::Reporter* r, const SkMD5::Digest& goodDigest,
const SkBitmap& bm) {
SkMD5::Digest digest;
md5(bm, &digest);
REPORTER_ASSERT(r, digest == goodDigest);
}
/**
* Test decoding an SkCodec to a particular SkImageInfo.
*
* Calling getPixels(info) should return expectedResult, and if goodDigest is non nullptr,
* the resulting decode should match.
*/
static void test_info(skiatest::Reporter* r, SkCodec* codec, const SkImageInfo& info,
SkCodec::Result expectedResult, const SkMD5::Digest* goodDigest) {
SkBitmap bm;
bm.allocPixels(info);
SkAutoLockPixels autoLockPixels(bm);
SkCodec::Result result = codec->getPixels(info, bm.getPixels(), bm.rowBytes());
REPORTER_ASSERT(r, result == expectedResult);
if (goodDigest) {
compare_to_good_digest(r, *goodDigest, bm);
}
}
SkIRect generate_random_subset(SkRandom* rand, int w, int h) {
SkIRect rect;
do {
rect.fLeft = rand->nextRangeU(0, w);
rect.fTop = rand->nextRangeU(0, h);
rect.fRight = rand->nextRangeU(0, w);
rect.fBottom = rand->nextRangeU(0, h);
rect.sort();
} while (rect.isEmpty());
return rect;
}
static void check(skiatest::Reporter* r,
const char path[],
SkISize size,
bool supportsScanlineDecoding,
bool supportsSubsetDecoding,
bool supports565 = true) {
SkAutoTDelete<SkStream> stream(resource(path));
if (!stream) {
SkDebugf("Missing resource '%s'\n", path);
return;
}
SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
if (!codec) {
ERRORF(r, "Unable to decode '%s'", path);
return;
}
// This test is used primarily to verify rewinding works properly. Using kN32 allows
// us to test this without the added overhead of creating different bitmaps depending
// on the color type (ex: building a color table for kIndex8). DM is where we test
// decodes to all possible destination color types.
SkImageInfo info = codec->getInfo().makeColorType(kN32_SkColorType);
REPORTER_ASSERT(r, info.dimensions() == size);
SkBitmap bm;
bm.allocPixels(info);
SkAutoLockPixels autoLockPixels(bm);
SkCodec::Result result =
codec->getPixels(info, bm.getPixels(), bm.rowBytes(), nullptr, nullptr, nullptr);
REPORTER_ASSERT(r, result == SkCodec::kSuccess);
SkMD5::Digest digest;
md5(bm, &digest);
{
// Test decoding to 565
SkImageInfo info565 = info.makeColorType(kRGB_565_SkColorType);
SkCodec::Result expected = (supports565 && info.alphaType() == kOpaque_SkAlphaType) ?
SkCodec::kSuccess : SkCodec::kInvalidConversion;
test_info(r, codec, info565, expected, nullptr);
}
// Verify that re-decoding gives the same result. It is interesting to check this after
// a decode to 565, since choosing to decode to 565 may result in some of the decode
// options being modified. These options should return to their defaults on another
// decode to kN32, so the new digest should match the old digest.
test_info(r, codec, info, SkCodec::kSuccess, &digest);
{
// Check alpha type conversions
if (info.alphaType() == kOpaque_SkAlphaType) {
test_info(r, codec, info.makeAlphaType(kUnpremul_SkAlphaType),
SkCodec::kInvalidConversion, nullptr);
test_info(r, codec, info.makeAlphaType(kPremul_SkAlphaType),
SkCodec::kInvalidConversion, nullptr);
} else {
// Decoding to opaque should fail
test_info(r, codec, info.makeAlphaType(kOpaque_SkAlphaType),
SkCodec::kInvalidConversion, nullptr);
SkAlphaType otherAt = info.alphaType();
if (kPremul_SkAlphaType == otherAt) {
otherAt = kUnpremul_SkAlphaType;
} else {
otherAt = kPremul_SkAlphaType;
}
// The other non-opaque alpha type should always succeed, but not match.
test_info(r, codec, info.makeAlphaType(otherAt), SkCodec::kSuccess, nullptr);
}
}
// Scanline decoding follows.
stream.reset(resource(path));
SkAutoTDelete<SkScanlineDecoder> scanlineDecoder(
SkScanlineDecoder::NewFromStream(stream.detach()));
if (supportsScanlineDecoding) {
bm.eraseColor(SK_ColorYELLOW);
REPORTER_ASSERT(r, scanlineDecoder);
REPORTER_ASSERT(r, scanlineDecoder->start(info) == SkCodec::kSuccess);
for (int y = 0; y < info.height(); y++) {
result = scanlineDecoder->getScanlines(bm.getAddr(0, y), 1, 0);
REPORTER_ASSERT(r, result == SkCodec::kSuccess);
}
// verify that scanline decoding gives the same result.
if (SkScanlineDecoder::kTopDown_SkScanlineOrder == scanlineDecoder->getScanlineOrder()) {
compare_to_good_digest(r, digest, bm);
}
} else {
REPORTER_ASSERT(r, !scanlineDecoder);
}
// The rest of this function tests decoding subsets, and will decode an arbitrary number of
// random subsets.
// Do not attempt to decode subsets of an image of only once pixel, since there is no
// meaningful subset.
if (size.width() * size.height() == 1) {
return;
}
SkRandom rand;
SkIRect subset;
SkCodec::Options opts;
opts.fSubset = &subset;
for (int i = 0; i < 5; i++) {
subset = generate_random_subset(&rand, size.width(), size.height());
SkASSERT(!subset.isEmpty());
const bool supported = codec->getValidSubset(&subset);
REPORTER_ASSERT(r, supported == supportsSubsetDecoding);
SkImageInfo subsetInfo = info.makeWH(subset.width(), subset.height());
SkBitmap bm;
bm.allocPixels(subsetInfo);
const SkCodec::Result result = codec->getPixels(bm.info(), bm.getPixels(), bm.rowBytes(),
&opts, nullptr, nullptr);
if (supportsSubsetDecoding) {
REPORTER_ASSERT(r, result == SkCodec::kSuccess);
// Webp is the only codec that supports subsets, and it will have modified the subset
// to have even left/top.
REPORTER_ASSERT(r, SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
} else {
// No subsets will work.
REPORTER_ASSERT(r, result == SkCodec::kUnimplemented);
}
}
}
DEF_TEST(Codec, r) {
// WBMP
check(r, "mandrill.wbmp", SkISize::Make(512, 512), true, false);
// WEBP
check(r, "baby_tux.webp", SkISize::Make(386, 395), false, true);
check(r, "color_wheel.webp", SkISize::Make(128, 128), false, true);
check(r, "yellow_rose.webp", SkISize::Make(400, 301), false, true);
// BMP
check(r, "randPixels.bmp", SkISize::Make(8, 8), true, false);
// ICO
// These two tests examine interestingly different behavior:
// Decodes an embedded BMP image
check(r, "color_wheel.ico", SkISize::Make(128, 128), false, false);
// Decodes an embedded PNG image
check(r, "google_chrome.ico", SkISize::Make(256, 256), false, false);
// GIF
check(r, "box.gif", SkISize::Make(200, 55), true, false);
check(r, "color_wheel.gif", SkISize::Make(128, 128), true, false);
check(r, "randPixels.gif", SkISize::Make(8, 8), true, false);
// JPG
check(r, "CMYK.jpg", SkISize::Make(642, 516), true, false, false);
check(r, "color_wheel.jpg", SkISize::Make(128, 128), true, false);
check(r, "grayscale.jpg", SkISize::Make(128, 128), true, false);
check(r, "mandrill_512_q075.jpg", SkISize::Make(512, 512), true, false);
check(r, "randPixels.jpg", SkISize::Make(8, 8), true, false);
// PNG
check(r, "arrow.png", SkISize::Make(187, 312), true, false);
check(r, "baby_tux.png", SkISize::Make(240, 246), true, false);
check(r, "color_wheel.png", SkISize::Make(128, 128), true, false);
check(r, "half-transparent-white-pixel.png", SkISize::Make(1, 1), true, false);
check(r, "mandrill_128.png", SkISize::Make(128, 128), true, false);
check(r, "mandrill_16.png", SkISize::Make(16, 16), true, false);
check(r, "mandrill_256.png", SkISize::Make(256, 256), true, false);
check(r, "mandrill_32.png", SkISize::Make(32, 32), true, false);
check(r, "mandrill_512.png", SkISize::Make(512, 512), true, false);
check(r, "mandrill_64.png", SkISize::Make(64, 64), true, false);
check(r, "plane.png", SkISize::Make(250, 126), true, false);
check(r, "randPixels.png", SkISize::Make(8, 8), true, false);
check(r, "yellow_rose.png", SkISize::Make(400, 301), true, false);
}
static void test_invalid_stream(skiatest::Reporter* r, const void* stream, size_t len) {
SkCodec* codec = SkCodec::NewFromStream(new SkMemoryStream(stream, len, false));
// We should not have gotten a codec. Bots should catch us if we leaked anything.
REPORTER_ASSERT(r, !codec);
}
// Ensure that SkCodec::NewFromStream handles freeing the passed in SkStream,
// even on failure. Test some bad streams.
DEF_TEST(Codec_leaks, r) {
// No codec should claim this as their format, so this tests SkCodec::NewFromStream.
const char nonSupportedStream[] = "hello world";
// The other strings should look like the beginning of a file type, so we'll call some
// internal version of NewFromStream, which must also delete the stream on failure.
const unsigned char emptyPng[] = { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a };
const unsigned char emptyJpeg[] = { 0xFF, 0xD8, 0xFF };
const char emptyWebp[] = "RIFF1234WEBPVP";
const char emptyBmp[] = { 'B', 'M' };
const char emptyIco[] = { '\x00', '\x00', '\x01', '\x00' };
const char emptyGif[] = "GIFVER";
test_invalid_stream(r, nonSupportedStream, sizeof(nonSupportedStream));
test_invalid_stream(r, emptyPng, sizeof(emptyPng));
test_invalid_stream(r, emptyJpeg, sizeof(emptyJpeg));
test_invalid_stream(r, emptyWebp, sizeof(emptyWebp));
test_invalid_stream(r, emptyBmp, sizeof(emptyBmp));
test_invalid_stream(r, emptyIco, sizeof(emptyIco));
test_invalid_stream(r, emptyGif, sizeof(emptyGif));
}
static void test_dimensions(skiatest::Reporter* r, const char path[]) {
// Create the codec from the resource file
SkAutoTDelete<SkStream> stream(resource(path));
if (!stream) {
SkDebugf("Missing resource '%s'\n", path);
return;
}
SkAutoTDelete<SkCodec> codec(SkScaledCodec::NewFromStream(stream.detach()));
if (!codec) {
ERRORF(r, "Unable to create codec '%s'", path);
return;
}
// Check that the decode is successful for a variety of scales
for (float scale = 0.05f; scale < 2.0f; scale += 0.05f) {
// Scale the output dimensions
SkISize scaledDims = codec->getScaledDimensions(scale);
SkImageInfo scaledInfo = codec->getInfo()
.makeWH(scaledDims.width(), scaledDims.height())
.makeColorType(kN32_SkColorType);
// Set up for the decode
size_t rowBytes = scaledDims.width() * sizeof(SkPMColor);
size_t totalBytes = scaledInfo.getSafeSize(rowBytes);
SkAutoTMalloc<SkPMColor> pixels(totalBytes);
SkCodec::Result result =
codec->getPixels(scaledInfo, pixels.get(), rowBytes, nullptr, nullptr, nullptr);
REPORTER_ASSERT(r, SkCodec::kSuccess == result);
}
}
// Ensure that onGetScaledDimensions returns valid image dimensions to use for decodes
DEF_TEST(Codec_Dimensions, r) {
// JPG
test_dimensions(r, "CMYK.jpg");
test_dimensions(r, "color_wheel.jpg");
test_dimensions(r, "grayscale.jpg");
test_dimensions(r, "mandrill_512_q075.jpg");
test_dimensions(r, "randPixels.jpg");
// Decoding small images with very large scaling factors is a potential
// source of bugs and crashes. We disable these tests in Gold because
// tiny images are not very useful to look at.
// Here we make sure that we do not crash or access illegal memory when
// performing scaled decodes on small images.
test_dimensions(r, "1x1.png");
test_dimensions(r, "2x2.png");
test_dimensions(r, "3x3.png");
test_dimensions(r, "3x1.png");
test_dimensions(r, "1x1.png");
test_dimensions(r, "16x1.png");
test_dimensions(r, "1x16.png");
test_dimensions(r, "mandrill_16.png");
}
static void test_invalid(skiatest::Reporter* r, const char path[]) {
SkAutoTDelete<SkStream> stream(resource(path));
if (!stream) {
SkDebugf("Missing resource '%s'\n", path);
return;
}
SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
REPORTER_ASSERT(r, nullptr == codec);
}
DEF_TEST(Codec_Empty, r) {
// Test images that should not be able to create a codec
test_invalid(r, "empty_images/zero-dims.gif");
test_invalid(r, "empty_images/zero-embedded.ico");
test_invalid(r, "empty_images/zero-width.bmp");
test_invalid(r, "empty_images/zero-height.bmp");
test_invalid(r, "empty_images/zero-width.jpg");
test_invalid(r, "empty_images/zero-height.jpg");
test_invalid(r, "empty_images/zero-width.png");
test_invalid(r, "empty_images/zero-height.png");
test_invalid(r, "empty_images/zero-width.wbmp");
test_invalid(r, "empty_images/zero-height.wbmp");
// This image is an ico with an embedded mask-bmp. This is illegal.
test_invalid(r, "invalid_images/mask-bmp-ico.ico");
}
static void test_invalid_parameters(skiatest::Reporter* r, const char path[]) {
SkAutoTDelete<SkStream> stream(resource(path));
if (!stream) {
SkDebugf("Missing resource '%s'\n", path);
return;
}
SkAutoTDelete<SkScanlineDecoder> decoder(SkScanlineDecoder::NewFromStream(
stream.detach()));
// This should return kSuccess because kIndex8 is supported.
SkPMColor colorStorage[256];
int colorCount;
SkCodec::Result result = decoder->start(
decoder->getInfo().makeColorType(kIndex_8_SkColorType), nullptr, colorStorage, &colorCount);
REPORTER_ASSERT(r, SkCodec::kSuccess == result);
// The rest of the test is uninteresting if kIndex8 is not supported
if (SkCodec::kSuccess != result) {
return;
}
// This should return kInvalidParameters because, in kIndex_8 mode, we must pass in a valid
// colorPtr and a valid colorCountPtr.
result = decoder->start(
decoder->getInfo().makeColorType(kIndex_8_SkColorType), nullptr, nullptr, nullptr);
REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
result = decoder->start(
decoder->getInfo().makeColorType(kIndex_8_SkColorType));
REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
}
DEF_TEST(Codec_Params, r) {
test_invalid_parameters(r, "index8.png");
test_invalid_parameters(r, "mandrill.wbmp");
}