Rename CodexTest.cpp to CodecTest.cpp

CodexTest confuses me almost every time I try to open it. Renaming it
to what my brain thinks it should be called.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1897973004

Review URL: https://codereview.chromium.org/1897973004

1 files changed, 974 insertions, 0 deletions

diff --git a/tests/CodecTest.cpp b/tests/CodecTest.cpp
new file mode 100644
index 0000000000..bdb5e7792e
--- /dev/null
+++ b/tests/CodecTest.cpp
@@ -0,0 +1,974 @@
+/*
+ * 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 "SkAndroidCodec.h"
+#include "SkBitmap.h"
+#include "SkCodec.h"
+#include "SkCodecImageGenerator.h"
+#include "SkData.h"
+#include "SkFrontBufferedStream.h"
+#include "SkMD5.h"
+#include "SkRandom.h"
+#include "SkStream.h"
+#include "SkStreamPriv.h"
+#include "SkPngChunkReader.h"
+#include "Test.h"
+
+#include "png.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.
+ */
+template<typename Codec>
+static void test_info(skiatest::Reporter* r, Codec* 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;
+}
+
+template<typename Codec>
+static void test_codec(skiatest::Reporter* r, Codec* codec, SkBitmap& bm, const SkImageInfo& info,
+        const SkISize& size, SkCodec::Result expectedResult, SkMD5::Digest* digest,
+        const SkMD5::Digest* goodDigest) {
+
+    REPORTER_ASSERT(r, info.dimensions() == size);
+    bm.allocPixels(info);
+    SkAutoLockPixels autoLockPixels(bm);
+
+    SkCodec::Result result = codec->getPixels(info, bm.getPixels(), bm.rowBytes());
+    REPORTER_ASSERT(r, result == expectedResult);
+
+    md5(bm, digest);
+    if (goodDigest) {
+        REPORTER_ASSERT(r, *digest == *goodDigest);
+    }
+
+    {
+        // Test decoding to 565
+        SkImageInfo info565 = info.makeColorType(kRGB_565_SkColorType);
+        SkCodec::Result expected565 = info.alphaType() == kOpaque_SkAlphaType ?
+                expectedResult : SkCodec::kInvalidConversion;
+        test_info(r, codec, info565, expected565, 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, expectedResult, digest);
+
+    {
+        // Check alpha type conversions
+        if (info.alphaType() == kOpaque_SkAlphaType) {
+            test_info(r, codec, info.makeAlphaType(kUnpremul_SkAlphaType),
+                      expectedResult, digest);
+            test_info(r, codec, info.makeAlphaType(kPremul_SkAlphaType),
+                      expectedResult, digest);
+        } 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), expectedResult, nullptr);
+        }
+    }
+}
+
+static bool supports_partial_scanlines(const char path[]) {
+    static const char* const exts[] = {
+        "jpg", "jpeg", "png", "webp"
+        "JPG", "JPEG", "PNG", "WEBP"
+    };
+
+    for (uint32_t i = 0; i < SK_ARRAY_COUNT(exts); i++) {
+        if (SkStrEndsWith(path, exts[i])) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static void check(skiatest::Reporter* r,
+                  const char path[],
+                  SkISize size,
+                  bool supportsScanlineDecoding,
+                  bool supportsSubsetDecoding,
+                  bool supportsIncomplete = true) {
+
+    SkAutoTDelete<SkStream> stream(resource(path));
+    if (!stream) {
+        SkDebugf("Missing resource '%s'\n", path);
+        return;
+    }
+
+    SkAutoTDelete<SkCodec> codec(nullptr);
+    bool isIncomplete = supportsIncomplete;
+    if (isIncomplete) {
+        size_t size = stream->getLength();
+        SkAutoTUnref<SkData> data((SkData::NewFromStream(stream, 2 * size / 3)));
+        codec.reset(SkCodec::NewFromData(data));
+    } else {
+        codec.reset(SkCodec::NewFromStream(stream.release()));
+    }
+    if (!codec) {
+        ERRORF(r, "Unable to decode '%s'", path);
+        return;
+    }
+
+    // Test full image decodes with SkCodec
+    SkMD5::Digest codecDigest;
+    const SkImageInfo info = codec->getInfo().makeColorType(kN32_SkColorType);
+    SkBitmap bm;
+    SkCodec::Result expectedResult = isIncomplete ? SkCodec::kIncompleteInput : SkCodec::kSuccess;
+    test_codec(r, codec.get(), bm, info, size, expectedResult, &codecDigest, nullptr);
+
+    // Scanline decoding follows.
+    // Need to call startScanlineDecode() first.
+    REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
+            == 0);
+    REPORTER_ASSERT(r, codec->skipScanlines(1)
+            == 0);
+
+    const SkCodec::Result startResult = codec->startScanlineDecode(info);
+    if (supportsScanlineDecoding) {
+        bm.eraseColor(SK_ColorYELLOW);
+
+        REPORTER_ASSERT(r, startResult == SkCodec::kSuccess);
+
+        for (int y = 0; y < info.height(); y++) {
+            const int lines = codec->getScanlines(bm.getAddr(0, y), 1, 0);
+            if (!isIncomplete) {
+                REPORTER_ASSERT(r, 1 == lines);
+            }
+        }
+        // verify that scanline decoding gives the same result.
+        if (SkCodec::kTopDown_SkScanlineOrder == codec->getScanlineOrder()) {
+            compare_to_good_digest(r, codecDigest, bm);
+        }
+
+        // Cannot continue to decode scanlines beyond the end
+        REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
+                == 0);
+
+        // Interrupting a scanline decode with a full decode starts from
+        // scratch
+        REPORTER_ASSERT(r, codec->startScanlineDecode(info) == SkCodec::kSuccess);
+        const int lines = codec->getScanlines(bm.getAddr(0, 0), 1, 0);
+        if (!isIncomplete) {
+            REPORTER_ASSERT(r, lines == 1);
+        }
+        REPORTER_ASSERT(r, codec->getPixels(bm.info(), bm.getPixels(), bm.rowBytes())
+                == expectedResult);
+        REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
+                == 0);
+        REPORTER_ASSERT(r, codec->skipScanlines(1)
+                == 0);
+
+        // Test partial scanline decodes
+        if (supports_partial_scanlines(path) && info.width() >= 3) {
+            SkCodec::Options options;
+            int width = info.width();
+            int height = info.height();
+            SkIRect subset = SkIRect::MakeXYWH(2 * (width / 3), 0, width / 3, height);
+            options.fSubset = &subset;
+
+            const SkCodec::Result partialStartResult = codec->startScanlineDecode(info, &options,
+                    nullptr, nullptr);
+            REPORTER_ASSERT(r, partialStartResult == SkCodec::kSuccess);
+
+            for (int y = 0; y < height; y++) {
+                const int lines = codec->getScanlines(bm.getAddr(0, y), 1, 0);
+                if (!isIncomplete) {
+                    REPORTER_ASSERT(r, 1 == lines);
+                }
+            }
+        }
+    } else {
+        REPORTER_ASSERT(r, startResult == SkCodec::kUnimplemented);
+    }
+
+    // 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 == expectedResult);
+            // 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);
+        }
+    }
+
+    // SkAndroidCodec tests
+    if (supportsScanlineDecoding || supportsSubsetDecoding) {
+
+        SkAutoTDelete<SkStream> stream(resource(path));
+        if (!stream) {
+            SkDebugf("Missing resource '%s'\n", path);
+            return;
+        }
+
+        SkAutoTDelete<SkAndroidCodec> androidCodec(nullptr);
+        if (isIncomplete) {
+            size_t size = stream->getLength();
+            SkAutoTUnref<SkData> data((SkData::NewFromStream(stream, 2 * size / 3)));
+            androidCodec.reset(SkAndroidCodec::NewFromData(data));
+        } else {
+            androidCodec.reset(SkAndroidCodec::NewFromStream(stream.release()));
+        }
+        if (!androidCodec) {
+            ERRORF(r, "Unable to decode '%s'", path);
+            return;
+        }
+
+        SkBitmap bm;
+        SkMD5::Digest androidCodecDigest;
+        test_codec(r, androidCodec.get(), bm, info, size, expectedResult, &androidCodecDigest,
+                   &codecDigest);
+    }
+
+    if (!isIncomplete) {
+        // Test SkCodecImageGenerator
+        SkAutoTDelete<SkStream> stream(resource(path));
+        SkAutoTUnref<SkData> fullData(SkData::NewFromStream(stream, stream->getLength()));
+        SkAutoTDelete<SkImageGenerator> gen(SkCodecImageGenerator::NewFromEncodedCodec(fullData));
+        SkBitmap bm;
+        bm.allocPixels(info);
+        SkAutoLockPixels autoLockPixels(bm);
+        REPORTER_ASSERT(r, gen->getPixels(info, bm.getPixels(), bm.rowBytes()));
+        compare_to_good_digest(r, codecDigest, bm);
+
+        // Test using SkFrontBufferedStream, as Android does
+        SkStream* bufferedStream = SkFrontBufferedStream::Create(new SkMemoryStream(fullData),
+                SkCodec::MinBufferedBytesNeeded());
+        REPORTER_ASSERT(r, bufferedStream);
+        codec.reset(SkCodec::NewFromStream(bufferedStream));
+        REPORTER_ASSERT(r, codec);
+        if (codec) {
+            test_info(r, codec.get(), info, SkCodec::kSuccess, &codecDigest);
+        }
+    }
+
+    // If we've just tested incomplete decodes, let's run the same test again on full decodes.
+    if (isIncomplete) {
+        check(r, path, size, supportsScanlineDecoding, supportsSubsetDecoding, false);
+    }
+}
+
+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);
+    check(r, "rle.bmp", SkISize::Make(320, 240), true, false);
+
+    // ICO
+    // FIXME: We are not ready to test incomplete ICOs
+    // These two tests examine interestingly different behavior:
+    // Decodes an embedded BMP image
+    check(r, "color_wheel.ico", SkISize::Make(128, 128), true, false, false);
+    // Decodes an embedded PNG image
+    check(r, "google_chrome.ico", SkISize::Make(256, 256), true, false, false);
+
+    // GIF
+    // FIXME: We are not ready to test incomplete GIFs
+    check(r, "box.gif", SkISize::Make(200, 55), true, false, false);
+    check(r, "color_wheel.gif", SkISize::Make(128, 128), true, false, false);
+    // randPixels.gif is too small to test incomplete
+    check(r, "randPixels.gif", SkISize::Make(8, 8), true, false, false);
+
+    // JPG
+    check(r, "CMYK.jpg", SkISize::Make(642, 516), true, false);
+    check(r, "color_wheel.jpg", SkISize::Make(128, 128), true, false);
+    // grayscale.jpg is too small to test incomplete
+    check(r, "grayscale.jpg", SkISize::Make(128, 128), true, false, false);
+    check(r, "mandrill_512_q075.jpg", SkISize::Make(512, 512), true, false);
+    // randPixels.jpg is too small to test incomplete
+    check(r, "randPixels.jpg", SkISize::Make(8, 8), true, false, false);
+
+    // PNG
+    check(r, "arrow.png", SkISize::Make(187, 312), true, false, false);
+    check(r, "baby_tux.png", SkISize::Make(240, 246), true, false, false);
+    check(r, "color_wheel.png", SkISize::Make(128, 128), true, false, false);
+    check(r, "half-transparent-white-pixel.png", SkISize::Make(1, 1), true, false, false);
+    check(r, "mandrill_128.png", SkISize::Make(128, 128), true, false, false);
+    check(r, "mandrill_16.png", SkISize::Make(16, 16), true, false, false);
+    check(r, "mandrill_256.png", SkISize::Make(256, 256), true, false, false);
+    check(r, "mandrill_32.png", SkISize::Make(32, 32), true, false, false);
+    check(r, "mandrill_512.png", SkISize::Make(512, 512), true, false, false);
+    check(r, "mandrill_64.png", SkISize::Make(64, 64), true, false, false);
+    check(r, "plane.png", SkISize::Make(250, 126), true, false, false);
+    // FIXME: We are not ready to test incomplete interlaced pngs
+    check(r, "plane_interlaced.png", SkISize::Make(250, 126), true, false, false);
+    check(r, "randPixels.png", SkISize::Make(8, 8), true, false, false);
+    check(r, "yellow_rose.png", SkISize::Make(400, 301), true, false, false);
+
+    // RAW
+// Disable RAW tests for Win32.
+#if defined(SK_CODEC_DECODES_RAW) && (!defined(_WIN32))
+    check(r, "sample_1mp.dng", SkISize::Make(600, 338), false, false, false);
+    check(r, "sample_1mp_rotated.dng", SkISize::Make(600, 338), false, false, false);
+    check(r, "dng_with_preview.dng", SkISize::Make(600, 338), true, false, false);
+#endif
+}
+
+// Test interlaced PNG in stripes, similar to DM's kStripe_Mode
+DEF_TEST(Codec_stripes, r) {
+    const char * path = "plane_interlaced.png";
+    SkAutoTDelete<SkStream> stream(resource(path));
+    if (!stream) {
+        SkDebugf("Missing resource '%s'\n", path);
+    }
+
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.release()));
+    REPORTER_ASSERT(r, codec);
+
+    if (!codec) {
+        return;
+    }
+
+    switch (codec->getScanlineOrder()) {
+        case SkCodec::kBottomUp_SkScanlineOrder:
+        case SkCodec::kOutOfOrder_SkScanlineOrder:
+            ERRORF(r, "This scanline order will not match the original.");
+            return;
+        default:
+            break;
+    }
+
+    // Baseline for what the image should look like, using N32.
+    const SkImageInfo info = codec->getInfo().makeColorType(kN32_SkColorType);
+
+    SkBitmap bm;
+    bm.allocPixels(info);
+    SkAutoLockPixels autoLockPixels(bm);
+    SkCodec::Result result = codec->getPixels(info, bm.getPixels(), bm.rowBytes());
+    REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+    SkMD5::Digest digest;
+    md5(bm, &digest);
+
+    // Now decode in stripes
+    const int height = info.height();
+    const int numStripes = 4;
+    int stripeHeight;
+    int remainingLines;
+    SkTDivMod(height, numStripes, &stripeHeight, &remainingLines);
+
+    bm.eraseColor(SK_ColorYELLOW);
+
+    result = codec->startScanlineDecode(info);
+    REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+    // Odd stripes
+    for (int i = 1; i < numStripes; i += 2) {
+        // Skip the even stripes
+        bool skipResult = codec->skipScanlines(stripeHeight);
+        REPORTER_ASSERT(r, skipResult);
+
+        int linesDecoded = codec->getScanlines(bm.getAddr(0, i * stripeHeight), stripeHeight,
+                                     bm.rowBytes());
+        REPORTER_ASSERT(r, linesDecoded == stripeHeight);
+    }
+
+    // Even stripes
+    result = codec->startScanlineDecode(info);
+    REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+    for (int i = 0; i < numStripes; i += 2) {
+        int linesDecoded = codec->getScanlines(bm.getAddr(0, i * stripeHeight), stripeHeight,
+                                     bm.rowBytes());
+        REPORTER_ASSERT(r, linesDecoded == stripeHeight);
+
+        // Skip the odd stripes
+        if (i + 1 < numStripes) {
+            bool skipResult = codec->skipScanlines(stripeHeight);
+            REPORTER_ASSERT(r, skipResult);
+        }
+    }
+
+    // Remainder at the end
+    if (remainingLines > 0) {
+        result = codec->startScanlineDecode(info);
+        REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+        bool skipResult = codec->skipScanlines(height - remainingLines);
+        REPORTER_ASSERT(r, skipResult);
+
+        int linesDecoded = codec->getScanlines(bm.getAddr(0, height - remainingLines),
+                                     remainingLines, bm.rowBytes());
+        REPORTER_ASSERT(r, linesDecoded == remainingLines);
+    }
+
+    compare_to_good_digest(r, digest, bm);
+}
+
+static void test_invalid_stream(skiatest::Reporter* r, const void* stream, size_t len) {
+    // Neither of these calls should return a codec. Bots should catch us if we leaked anything.
+    SkCodec* codec = SkCodec::NewFromStream(new SkMemoryStream(stream, len, false));
+    REPORTER_ASSERT(r, !codec);
+
+    SkAndroidCodec* androidCodec =
+            SkAndroidCodec::NewFromStream(new SkMemoryStream(stream, len, false));
+    REPORTER_ASSERT(r, !androidCodec);
+}
+
+// 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));
+}
+
+DEF_TEST(Codec_null, r) {
+    // Attempting to create an SkCodec or an SkAndroidCodec with null should not
+    // crash.
+    SkCodec* codec = SkCodec::NewFromStream(nullptr);
+    REPORTER_ASSERT(r, !codec);
+
+    SkAndroidCodec* androidCodec = SkAndroidCodec::NewFromStream(nullptr);
+    REPORTER_ASSERT(r, !androidCodec);
+}
+
+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<SkAndroidCodec> codec(SkAndroidCodec::NewFromStream(stream.release()));
+    if (!codec) {
+        ERRORF(r, "Unable to create codec '%s'", path);
+        return;
+    }
+
+    // Check that the decode is successful for a variety of scales
+    for (int sampleSize = 1; sampleSize < 32; sampleSize++) {
+        // Scale the output dimensions
+        SkISize scaledDims = codec->getSampledDimensions(sampleSize);
+        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);
+
+        SkAndroidCodec::AndroidOptions options;
+        options.fSampleSize = sampleSize;
+        SkCodec::Result result =
+                codec->getAndroidPixels(scaledInfo, pixels.get(), rowBytes, &options);
+        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");
+
+    // RAW
+// Disable RAW tests for Win32.
+#if defined(SK_CODEC_DECODES_RAW) && (!defined(_WIN32))
+    test_dimensions(r, "sample_1mp.dng");
+    test_dimensions(r, "sample_1mp_rotated.dng");
+    test_dimensions(r, "dng_with_preview.dng");
+#endif
+}
+
+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.release()));
+    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<SkCodec> decoder(SkCodec::NewFromStream(stream.release()));
+
+    // This should return kSuccess because kIndex8 is supported.
+    SkPMColor colorStorage[256];
+    int colorCount;
+    SkCodec::Result result = decoder->startScanlineDecode(
+        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->startScanlineDecode(
+        decoder->getInfo().makeColorType(kIndex_8_SkColorType), nullptr, nullptr, nullptr);
+    REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
+    result = decoder->startScanlineDecode(
+        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");
+}
+
+static void codex_test_write_fn(png_structp png_ptr, png_bytep data, png_size_t len) {
+    SkWStream* sk_stream = (SkWStream*)png_get_io_ptr(png_ptr);
+    if (!sk_stream->write(data, len)) {
+        png_error(png_ptr, "sk_write_fn Error!");
+    }
+}
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+DEF_TEST(Codec_pngChunkReader, r) {
+    // Create a dummy bitmap. Use unpremul RGBA for libpng.
+    SkBitmap bm;
+    const int w = 1;
+    const int h = 1;
+    const SkImageInfo bmInfo = SkImageInfo::Make(w, h, kRGBA_8888_SkColorType,
+                                                 kUnpremul_SkAlphaType);
+    bm.setInfo(bmInfo);
+    bm.allocPixels();
+    bm.eraseColor(SK_ColorBLUE);
+    SkMD5::Digest goodDigest;
+    md5(bm, &goodDigest);
+
+    // Write to a png file.
+    png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
+    REPORTER_ASSERT(r, png);
+    if (!png) {
+        return;
+    }
+
+    png_infop info = png_create_info_struct(png);
+    REPORTER_ASSERT(r, info);
+    if (!info) {
+        png_destroy_write_struct(&png, nullptr);
+        return;
+    }
+
+    if (setjmp(png_jmpbuf(png))) {
+        ERRORF(r, "failed writing png");
+        png_destroy_write_struct(&png, &info);
+        return;
+    }
+
+    SkDynamicMemoryWStream wStream;
+    png_set_write_fn(png, (void*) (&wStream), codex_test_write_fn, nullptr);
+
+    png_set_IHDR(png, info, (png_uint_32)w, (png_uint_32)h, 8,
+                 PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
+                 PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+    // Create some chunks that match the Android framework's use.
+    static png_unknown_chunk gUnknowns[] = {
+        { "npOl", (png_byte*)"outline", sizeof("outline"), PNG_HAVE_IHDR },
+        { "npLb", (png_byte*)"layoutBounds", sizeof("layoutBounds"), PNG_HAVE_IHDR },
+        { "npTc", (png_byte*)"ninePatchData", sizeof("ninePatchData"), PNG_HAVE_IHDR },
+    };
+
+    png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS, (png_byte*)"npOl\0npLb\0npTc\0", 3);
+    png_set_unknown_chunks(png, info, gUnknowns, SK_ARRAY_COUNT(gUnknowns));
+#if PNG_LIBPNG_VER < 10600
+    /* Deal with unknown chunk location bug in 1.5.x and earlier */
+    png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR);
+    png_set_unknown_chunk_location(png, info, 1, PNG_HAVE_IHDR);
+#endif
+
+    png_write_info(png, info);
+
+    for (int j = 0; j < h; j++) {
+        png_bytep row = (png_bytep)(bm.getAddr(0, j));
+        png_write_rows(png, &row, 1);
+    }
+    png_write_end(png, info);
+    png_destroy_write_struct(&png, &info);
+
+    class ChunkReader : public SkPngChunkReader {
+    public:
+        ChunkReader(skiatest::Reporter* r)
+            : fReporter(r)
+        {
+            this->reset();
+        }
+
+        bool readChunk(const char tag[], const void* data, size_t length) override {
+            for (size_t i = 0; i < SK_ARRAY_COUNT(gUnknowns); ++i) {
+                if (!strcmp(tag, (const char*) gUnknowns[i].name)) {
+                    // Tag matches. This should have been the first time we see it.
+                    REPORTER_ASSERT(fReporter, !fSeen[i]);
+                    fSeen[i] = true;
+
+                    // Data and length should match
+                    REPORTER_ASSERT(fReporter, length == gUnknowns[i].size);
+                    REPORTER_ASSERT(fReporter, !strcmp((const char*) data,
+                                                       (const char*) gUnknowns[i].data));
+                    return true;
+                }
+            }
+            ERRORF(fReporter, "Saw an unexpected unknown chunk.");
+            return true;
+        }
+
+        bool allHaveBeenSeen() {
+            bool ret = true;
+            for (auto seen : fSeen) {
+                ret &= seen;
+            }
+            return ret;
+        }
+
+        void reset() {
+            sk_bzero(fSeen, sizeof(fSeen));
+        }
+
+    private:
+        skiatest::Reporter* fReporter;  // Unowned
+        bool fSeen[3];
+    };
+
+    ChunkReader chunkReader(r);
+
+    // Now read the file with SkCodec.
+    SkAutoTUnref<SkData> data(wStream.copyToData());
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(data, &chunkReader));
+    REPORTER_ASSERT(r, codec);
+    if (!codec) {
+        return;
+    }
+
+    // Now compare to the original.
+    SkBitmap decodedBm;
+    decodedBm.setInfo(codec->getInfo());
+    decodedBm.allocPixels();
+    SkCodec::Result result = codec->getPixels(codec->getInfo(), decodedBm.getPixels(),
+                                              decodedBm.rowBytes());
+    REPORTER_ASSERT(r, SkCodec::kSuccess == result);
+
+    if (decodedBm.colorType() != bm.colorType()) {
+        SkBitmap tmp;
+        bool success = decodedBm.copyTo(&tmp, bm.colorType());
+        REPORTER_ASSERT(r, success);
+        if (!success) {
+            return;
+        }
+
+        tmp.swap(decodedBm);
+    }
+
+    compare_to_good_digest(r, goodDigest, decodedBm);
+    REPORTER_ASSERT(r, chunkReader.allHaveBeenSeen());
+
+    // Decoding again will read the chunks again.
+    chunkReader.reset();
+    REPORTER_ASSERT(r, !chunkReader.allHaveBeenSeen());
+    result = codec->getPixels(codec->getInfo(), decodedBm.getPixels(), decodedBm.rowBytes());
+    REPORTER_ASSERT(r, SkCodec::kSuccess == result);
+    REPORTER_ASSERT(r, chunkReader.allHaveBeenSeen());
+}
+#endif // PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+
+// Stream that can only peek up to a limit
+class LimitedPeekingMemStream : public SkStream {
+public:
+    LimitedPeekingMemStream(SkData* data, size_t limit)
+        : fStream(data)
+        , fLimit(limit) {}
+
+    size_t peek(void* buf, size_t bytes) const override {
+        return fStream.peek(buf, SkTMin(bytes, fLimit));
+    }
+    size_t read(void* buf, size_t bytes) override {
+        return fStream.read(buf, bytes);
+    }
+    bool rewind() override {
+        return fStream.rewind();
+    }
+    bool isAtEnd() const override {
+        return false;
+    }
+private:
+    SkMemoryStream fStream;
+    const size_t   fLimit;
+};
+
+// Stream that is not an asset stream (!hasPosition() or !hasLength())
+class NotAssetMemStream : public SkStream {
+public:
+    NotAssetMemStream(SkData* data) : fStream(data) {}
+
+    bool hasPosition() const override {
+        return false;
+    }
+
+    bool hasLength() const override {
+        return false;
+    }
+
+    size_t peek(void* buf, size_t bytes) const override {
+        return fStream.peek(buf, bytes);
+    }
+    size_t read(void* buf, size_t bytes) override {
+        return fStream.read(buf, bytes);
+    }
+    bool rewind() override {
+        return fStream.rewind();
+    }
+    bool isAtEnd() const override {
+        return fStream.isAtEnd();
+    }
+private:
+    SkMemoryStream fStream;
+};
+
+// Disable RAW tests for Win32.
+#if defined(SK_CODEC_DECODES_RAW) && (!defined(_WIN32))
+// Test that the RawCodec works also for not asset stream. This will test the code path using
+// SkRawBufferedStream instead of SkRawAssetStream.
+DEF_TEST(Codec_raw_notseekable, r) {
+    const char* path = "dng_with_preview.dng";
+    SkString fullPath(GetResourcePath(path));
+    SkAutoTUnref<SkData> data(SkData::NewFromFileName(fullPath.c_str()));
+    if (!data) {
+        SkDebugf("Missing resource '%s'\n", path);
+        return;
+    }
+
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(new NotAssetMemStream(data)));
+    REPORTER_ASSERT(r, codec);
+
+    test_info(r, codec.get(), codec->getInfo(), SkCodec::kSuccess, nullptr);
+}
+#endif
+
+// Test that even if webp_parse_header fails to peek enough, it will fall back to read()
+// + rewind() and succeed.
+DEF_TEST(Codec_webp_peek, r) {
+    const char* path = "baby_tux.webp";
+    SkString fullPath(GetResourcePath(path));
+    auto data = SkData::MakeFromFileName(fullPath.c_str());
+    if (!data) {
+        SkDebugf("Missing resource '%s'\n", path);
+        return;
+    }
+
+    // The limit is less than webp needs to peek or read.
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(
+                                 new LimitedPeekingMemStream(data.get(), 25)));
+    REPORTER_ASSERT(r, codec);
+
+    test_info(r, codec.get(), codec->getInfo(), SkCodec::kSuccess, nullptr);
+
+    // Similarly, a stream which does not peek should still succeed.
+    codec.reset(SkCodec::NewFromStream(new LimitedPeekingMemStream(data.get(), 0)));
+    REPORTER_ASSERT(r, codec);
+
+    test_info(r, codec.get(), codec->getInfo(), SkCodec::kSuccess, nullptr);
+}
+
+// SkCodec's wbmp decoder was initially unnecessarily restrictive.
+// It required the second byte to be zero. The wbmp specification allows
+// a couple of bits to be 1 (so long as they do not overlap with 0x9F).
+// Test that SkCodec now supports an image with these bits set.
+DEF_TEST(Codec_wbmp, r) {
+    const char* path = "mandrill.wbmp";
+    SkAutoTDelete<SkStream> stream(resource(path));
+    if (!stream) {
+        SkDebugf("Missing resource '%s'\n", path);
+        return;
+    }
+
+    // Modify the stream to contain a second byte with some bits set.
+    auto data = SkCopyStreamToData(stream);
+    uint8_t* writeableData = static_cast<uint8_t*>(data->writable_data());
+    writeableData[1] = static_cast<uint8_t>(~0x9F);
+
+    // SkCodec should support this.
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(data.get()));
+    REPORTER_ASSERT(r, codec);
+    if (!codec) {
+        return;
+    }
+    test_info(r, codec.get(), codec->getInfo(), SkCodec::kSuccess, nullptr);
+}
+
+// wbmp images have a header that can be arbitrarily large, depending on the
+// size of the image. We cap the size at 65535, meaning we only need to look at
+// 8 bytes to determine whether we can read the image. This is important
+// because SkCodec only passes 14 bytes to SkWbmpCodec to determine whether the
+// image is a wbmp.
+DEF_TEST(Codec_wbmp_max_size, r) {
+    const unsigned char maxSizeWbmp[] = { 0x00, 0x00,           // Header
+                                          0x83, 0xFF, 0x7F,     // W: 65535
+                                          0x83, 0xFF, 0x7F };   // H: 65535
+    SkAutoTDelete<SkStream> stream(new SkMemoryStream(maxSizeWbmp, sizeof(maxSizeWbmp), false));
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.release()));
+
+    REPORTER_ASSERT(r, codec);
+    if (!codec) return;
+
+    REPORTER_ASSERT(r, codec->getInfo().width() == 65535);
+    REPORTER_ASSERT(r, codec->getInfo().height() == 65535);
+
+    // Now test an image which is too big. Any image with a larger header (i.e.
+    // has bigger width/height) is also too big.
+    const unsigned char tooBigWbmp[] = { 0x00, 0x00,           // Header
+                                         0x84, 0x80, 0x00,     // W: 65536
+                                         0x84, 0x80, 0x00 };   // H: 65536
+    stream.reset(new SkMemoryStream(tooBigWbmp, sizeof(tooBigWbmp), false));
+    codec.reset(SkCodec::NewFromStream(stream.release()));
+
+    REPORTER_ASSERT(r, !codec);
+}