Merge SkCodec with SkScanlineDecoder
Benefits:
- This mimics other decoding APIs (including the ones SkCodec relies
on, e.g. a png_struct, which can be used to decode an entire image or
one line at a time).
- It allows a client to ask us to do what we can do efficiently - i.e.
start from encoded data and either decode the whole thing or scanlines.
- It removes the duplicate methods which appeared in both SkCodec and
SkScanlineDecoder (some of which, e.g. in SkJpegScanlineDecoder, just
call fCodec->sameMethod()).
- It simplifies moving more checks into the base class (e.g. the
examples in skbug.com/4284).
BUG=skia:4175
BUG=skia:4284
=====================================================================
SkScanlineDecoder.h/.cpp:
Removed.
SkCodec.h/.cpp:
Add methods, enums, and variables which were previously in
SkScanlineDecoder.
Default fCurrScanline to -1, as a sentinel that start has not been
called.
General changes:
Convert SkScanlineDecoders to SkCodecs.
General changes in SkCodec subclasses:
Merge SkScanlineDecoder implementation into SkCodec. Most (all?) owned
an SkCodec, so they now call this-> instead of fCodec->.
SkBmpCodec.h/.cpp:
Replace the unused rowOrder method with an override for
onGetScanlineOrder.
Make getDstRow const, since it is called by onGetY, which is const.
SkCodec_libpng.h/.cpp:
Make SkPngCodec an abstract class, with two subclasses which handle
scanline decoding separately (they share code for decoding the entire
image). Reimplement onReallyHasAlpha so that it can return the most
recent result (e.g. after a scanline decode which only decoded part
of the image) or a better answer (e.g. if the whole image is known to
be opaque).
Compute fNumberPasses early, so we know which subclass to instantiate.
Make SkPngInterlaceScanlineDecoder use the base class' fCurrScanline
rather than a separate variable.
CodexTest.cpp:
Add tests for the state changes in SkCodec (need to call start before
decoding scanlines; calling getPixels means that start will need to
be called again before decoding more scanlines).
Add a test which decodes in stripes, currently only used for an
interlaced PNG.
TODO: Add tests for onReallyHasAlpha.
Review URL: https://codereview.chromium.org/1365313002
diff --git a/tests/CodexTest.cpp b/tests/CodexTest.cpp
index 2ea6eda..f1c5bba 100644
--- a/tests/CodexTest.cpp
+++ b/tests/CodexTest.cpp
@@ -11,7 +11,6 @@
#include "SkMD5.h"
#include "SkRandom.h"
#include "SkScaledCodec.h"
-#include "SkScanlineDecoder.h"
#include "Test.h"
static SkStreamAsset* resource(const char path[]) {
@@ -147,25 +146,44 @@
// Scanline decoding follows.
- stream.reset(resource(path));
- SkAutoTDelete<SkScanlineDecoder> scanlineDecoder(
- SkScanlineDecoder::NewFromStream(stream.detach()));
+ // Need to call start() first.
+ REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
+ == SkCodec::kScanlineDecodingNotStarted);
+ REPORTER_ASSERT(r, codec->skipScanlines(1)
+ == SkCodec::kScanlineDecodingNotStarted);
+
+ const SkCodec::Result startResult = codec->startScanlineDecode(info);
if (supportsScanlineDecoding) {
bm.eraseColor(SK_ColorYELLOW);
- REPORTER_ASSERT(r, scanlineDecoder);
- REPORTER_ASSERT(r, scanlineDecoder->start(info) == SkCodec::kSuccess);
+ REPORTER_ASSERT(r, startResult == SkCodec::kSuccess);
for (int y = 0; y < info.height(); y++) {
- result = scanlineDecoder->getScanlines(bm.getAddr(0, y), 1, 0);
+ result = codec->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()) {
+ if (SkCodec::kTopDown_SkScanlineOrder == codec->getScanlineOrder()) {
compare_to_good_digest(r, digest, bm);
}
+
+ // Cannot continue to decode scanlines beyond the end
+ REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
+ == SkCodec::kInvalidParameters);
+
+ // Interrupting a scanline decode with a full decode starts from
+ // scratch
+ REPORTER_ASSERT(r, codec->startScanlineDecode(info) == SkCodec::kSuccess);
+ REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
+ == SkCodec::kSuccess);
+ REPORTER_ASSERT(r, codec->getPixels(bm.info(), bm.getPixels(), bm.rowBytes())
+ == SkCodec::kSuccess);
+ REPORTER_ASSERT(r, codec->getScanlines(bm.getAddr(0, 0), 1, 0)
+ == SkCodec::kScanlineDecodingNotStarted);
+ REPORTER_ASSERT(r, codec->skipScanlines(1)
+ == SkCodec::kScanlineDecodingNotStarted);
} else {
- REPORTER_ASSERT(r, !scanlineDecoder);
+ REPORTER_ASSERT(r, startResult == SkCodec::kUnimplemented);
}
// The rest of this function tests decoding subsets, and will decode an arbitrary number of
@@ -247,10 +265,102 @@
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, "plane_interlaced.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);
}
+// 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.detach()));
+ 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
+ result = codec->skipScanlines(stripeHeight);
+ REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+ result = codec->getScanlines(bm.getAddr(0, i * stripeHeight), stripeHeight,
+ bm.rowBytes());
+ REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+ }
+
+ // Even stripes
+ result = codec->startScanlineDecode(info);
+ REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+ for (int i = 0; i < numStripes; i += 2) {
+ result = codec->getScanlines(bm.getAddr(0, i * stripeHeight), stripeHeight,
+ bm.rowBytes());
+ REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+ // Skip the odd stripes
+ if (i + 1 < numStripes) {
+ result = codec->skipScanlines(stripeHeight);
+ REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+ }
+ }
+
+ // Remainder at the end
+ if (remainingLines > 0) {
+ result = codec->startScanlineDecode(info);
+ REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+ result = codec->skipScanlines(height - remainingLines);
+ REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+
+ result = codec->getScanlines(bm.getAddr(0, height - remainingLines),
+ remainingLines, bm.rowBytes());
+ REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+ }
+
+ compare_to_good_digest(r, digest, bm);
+}
+
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.
@@ -369,13 +479,12 @@
SkDebugf("Missing resource '%s'\n", path);
return;
}
- SkAutoTDelete<SkScanlineDecoder> decoder(SkScanlineDecoder::NewFromStream(
- stream.detach()));
+ SkAutoTDelete<SkCodec> decoder(SkCodec::NewFromStream(stream.detach()));
// This should return kSuccess because kIndex8 is supported.
SkPMColor colorStorage[256];
int colorCount;
- SkCodec::Result result = decoder->start(
+ 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
@@ -385,10 +494,10 @@
// This should return kInvalidParameters because, in kIndex_8 mode, we must pass in a valid
// colorPtr and a valid colorCountPtr.
- result = decoder->start(
+ result = decoder->startScanlineDecode(
decoder->getInfo().makeColorType(kIndex_8_SkColorType), nullptr, nullptr, nullptr);
REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
- result = decoder->start(
+ result = decoder->startScanlineDecode(
decoder->getInfo().makeColorType(kIndex_8_SkColorType));
REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
}