Updates the gyp file.

src/codec/SkRawCodec.cpp

+/*
+ * 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 "SkCodec.h"
+#include "SkRawCodec.h"
+#include "SkCodecPriv.h"
+#include "SkColorPriv.h"
+#include "SkStream.h"
+#include "SkTemplates.h"
+#include "SkTypes.h"
+#include "SkSwizzler.h"
+
+#include "dng_color_space.h"
+#include "dng_exceptions.h"
+#include "dng_host.h"
+#include "dng_info.h"
+#include "dng_render.h"
+
+namespace {
+
+class SkDngStream : public dng_stream {
+   public:
+    explicit SkDngStream(SkStream* stream)
+        : fData(stream->getMemoryBase())
+        , fDataSize(stream->getLength()) {}
+    ~SkDngStream() override {}
+
+   protected:
+    uint64 DoGetLength() override { return fDataSize; }
+    void DoRead(void* data, uint32 count, uint64 offset) override {
+        if (fDataSize < offset + count) {
+            ThrowReadFile();
+        }
+
+        memcpy(data, reinterpret_cast<const uint8*>(fData) + offset, count);
+    }
+
+   private:
+    const void* fData;
+    size_t fDataSize;
+};
+
+bool IsDng(SkStream* data) {

[scroggo, 2015/11/24 14:46:05]

Is it possible to do less work here? It appears you're doing a lot of work here
to determine whether it is a valid DNG (I'm not familiar with DNG though; how
much of the image does Parse parse?), but the point of this method is basically
to know that this is *not* some other type of file.

For example, in PNG, we just check the first few bytes for a magic signature. If
those bytes do not match, we return and check the other formats. If they do
match, we assume that it is a PNG file. If it turns out the image is corrupt in
some way, we will fail later on, but won't need to check if the stream matches
another format.

Does DNG have a magic signature?

[ebrauer, 2016/01/07 10:07:36]

To identify a valid DNG we would require this code, but we have a better
solution in https://codereview.chromium.org/1520403003/

+    try {
+        SkDngStream stream(data);
+        dng_host host;
+        dng_info info;
+        info.Parse(host, stream);
+        info.PostParse(host);
+        return info.IsValidDNG();
+    } catch (...) {  // Handle all kinds of exceptions as "false".
+        return false;
+    }
+}
+
+bool ReadDng(dng_stream* stream, dng_host* host, dng_info* info, 
+             std::unique_ptr<dng_negative>* negative) {
+    const uint32 kPreferredSize = 0;
+    const uint32 kMinimumSize = 0;
+    const uint32 kMaximumSize = 0;
+    try {
+        host->SetPreferredSize(kPreferredSize);
+        host->SetMinimumSize(kMinimumSize);
+        host->SetMaximumSize(kMaximumSize);
+
+        host->ValidateSizes();
+
+        // Read stage 1 image into the negative.
+        {
+            info->Parse(*host, *stream);
+            info->PostParse(*host);
+
+            if (!info->IsValidDNG()) {
+                return false;
+            }
+
+            negative->reset(host->Make_dng_negative());
+            (*negative)->Parse(*host, *stream, *info);
+            (*negative)->PostParse(*host, *stream, *info);
+        }
+
+        (*negative)->SynchronizeMetadata();
+    } catch (const dng_exception& exception) {
+        return false;
+    } catch (...) {
+        return false;
+    }
+
+    return true;
+}
+
+bool PrepareStage3(dng_stream* stream, dng_host* host, dng_info* info,
+                   dng_negative* negative) {
+    if (negative->Stage3Image() == nullptr) {
+        negative->ReadStage1Image(*host, *stream, *info);
+
+        if (info->fMaskIndex != -1) {
+            negative->ReadTransparencyMask(*host, *stream, *info);
+        }
+
+        negative->ValidateRawImageDigest(*host);
+        if (negative->IsDamaged()) {
+            return false;
+        }
+
+        const int32 kMosaicPlane = -1;
+        negative->BuildStage2Image(*host);
+        negative->BuildStage3Image(*host, kMosaicPlane);
+    }
+
+    return true;
+}
+
+}  // namespace
+
+bool SkRawCodec::IsRaw(SkStream* stream) {
+    return IsDng(stream);

[scroggo, 2015/11/24 14:46:05]

Why didn't you just put the code for IsDng here? It looks like it is not used
elsewhere?

[ebrauer, 2016/01/07 10:07:36]

We are going to rework this as part of
https://codereview.chromium.org/1520403003/

+}
+
+SkCodec* SkRawCodec::NewFromStream(SkStream* data) {
+    SkDngStream stream(data);
+    dng_host host;
+    dng_info info;
+    std::unique_ptr<dng_negative> negative;
+    if (!ReadDng(&stream, &host, &info, &negative) &&
+        !PrepareStage3(&stream, &host, &info, negative.get())) {
+        return nullptr;
+    }
+    const SkImageInfo& imageInfo = SkImageInfo::Make(
+            negative->DefaultCropSizeH().As_real64(),
+            negative->DefaultCropSizeV().As_real64(), kRGBA_8888_SkColorType,

[msarett, 2015/11/25 15:15:23]

We would normally recommend kN32_SkColorType here (which is equivalent to kBGRA
or kRGBA depending on the platform).  Is there a reason to always recommend
RGBA?

[ebrauer, 2016/01/07 10:07:36]

We changed it in https://codereview.chromium.org/1520403003/

+            kOpaque_SkAlphaType);
+    return new SkRawCodec(imageInfo, data);
+}
+
+SkCodec::Result SkRawCodec::onGetPixels(const SkImageInfo& requestedInfo, void* dst,
+                                        size_t dstRowBytes, const Options& options,
+                                        SkPMColor ctable[], int* ctableCount,
+                                        int* rowsDecoded) {
+    const int width = requestedInfo.width();
+    const int height = requestedInfo.height();
+    std::unique_ptr<dng_image> finalDngImage;
+    try {
+        SkDngStream stream(this->stream());
+        dng_host host;
+        dng_info info;
+        std::unique_ptr<dng_negative> negative;
+        if (!ReadDng(&stream, &host, &info, &negative) ||
+            !PrepareStage3(&stream, &host, &info, negative.get())) {
+            return kInvalidInput;
+        }
+
+        dng_render render(host, *negative);
+        render.SetFinalSpace(dng_space_sRGB::Get());
+        render.SetFinalPixelType(ttByte);
+
+        finalDngImage.reset(render.Render());
+    } catch (const dng_exception& exception) {
+        return kInvalidInput;
+    } catch (...) {  
+        return kInvalidInput;
+    }
+
+    void* dstRow = dst;
+    uint8 srcRow[width * 3];
+    std::unique_ptr<SkSwizzler> swizzler(SkSwizzler::CreateSwizzler(

[msarett, 2015/11/25 15:15:23]

Is the swizzler now working as you expect?

[ebrauer, 2016/01/07 10:07:36]

It does what I expect, thanks.

+            SkSwizzler::kRGB, nullptr, requestedInfo, options));
+    if (!swizzler) {
+        return kInvalidInput;
+    }
+    for (int i = 0; i < height; ++i) {
+        dng_pixel_buffer buffer;
+        buffer.fData = &srcRow[0];
+        buffer.fArea = dng_rect(i, 0, i + 1, width);
+        buffer.fPlane = 0;
+        buffer.fPlanes = 3;
+        buffer.fColStep = buffer.fPlanes;
+        buffer.fPlaneStep = 1;
+        buffer.fPixelType = ttByte;
+        buffer.fPixelSize = sizeof(uint8);
+        buffer.fRowStep = sizeof(srcRow);
+        finalDngImage->Get(buffer, dng_image::edge_zero);
+        swizzler->swizzle(dstRow, &srcRow[0]);
+        dstRow = SkTAddOffset<void>(dstRow, dstRowBytes);
+    }
+    return kSuccess;
+}
+
+SkRawCodec::SkRawCodec(const SkImageInfo& srcInfo, SkStream* stream)
+    : INHERITED(srcInfo, stream) {}
+