WIP: Browser image decoding using Mojo.

chrome/utility/image_decoder_impl.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#include "chrome/utility/image_decoder_impl.h"
+
+#include <string.h>
+
+#include "base/base64.h"
+#include "base/memory/ref_counted.h"
+#include "base/time/time.h"
+#include "chrome/common/chrome_utility_messages.h"
+#include "content/child/child_process.h"
+#include "content/public/child/image_decoder_utils.h"
+#include "content/public/common/content_switches.h"
+#include "skia/ext/image_operations.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/gfx/codec/jpeg_codec.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace mojo {
+
+// TODO(amistry): Move somewhere else.
+template <>
+struct TypeConverter<content::ImageDataPtr, SkBitmap> {
+  static content::ImageDataPtr Convert(const SkBitmap& bitmap) {
+    content::ImageDataPtr result = content::ImageData::New();
+    const SkImageInfo& info = bitmap.info();
+    result->color_type = info.fColorType;
+    result->alpha_type = info.fAlphaType;
+    result->width = info.fWidth;
+    result->height = info.fHeight;
+    SkAutoLockPixels lock(bitmap);
+    size_t size = bitmap.getSize();
+    result->pixels = mojo::Array<uint8_t>::New(size);
+    memcpy(&result->pixels[0], bitmap.getPixels(), size);
+    return result.Pass();
+  }
+};
+
+}  // namespace mojo
+
+namespace content {
+
+ImageDecoderImpl::ImageDecoderImpl() {
+}
+
+ImageDecoderImpl::~ImageDecoderImpl() {
+  // TODO(amistry): Single process mode.
+  // TODO(amistry): This is the wrong place to do this.
+  LOG(INFO) << "Possibly destroying utility process";
+  content::ChildProcess::current()->ReleaseProcess();
+}
+
+void ImageDecoderImpl::DecodeImage(
+    mojo::Array<uint8_t> encoded_data,
+    bool use_robust_jpeg,
+    bool shrink_to_fit,
+    const mojo::Callback<void(bool, ImageDataPtr)>& callback) {
+  LOG(INFO) << "ImageDecoderImpl::DecodeImage: " << encoded_data.size()
+            << ", " << use_robust_jpeg << ", " << shrink_to_fit;
+  if (use_robust_jpeg) {
+    // Our robust jpeg decoding is using IJG libjpeg.
+    if (gfx::JPEGCodec::JpegLibraryVariant() == gfx::JPEGCodec::IJG_LIBJPEG &&
+        encoded_data.size()) {
+      scoped_ptr<SkBitmap> decoded_image(gfx::JPEGCodec::Decode(
+          &encoded_data[0], encoded_data.size()));
+      if (decoded_image.get() && !decoded_image->empty()) {
+        ImageDataPtr image = ImageData::From(*decoded_image);
+        LOG(INFO) << "............Done decoding image";
+        callback.Run(true, image.Pass());
+        return;
+      }
+    }
+    LOG(ERROR) << "Unable to do robust JPEG decode";
+    callback.Run(false, ImageDataPtr());
+  } else {
+    SkBitmap decoded_image = content::DecodeImage(&encoded_data[0],
+                                                  gfx::Size(),
+                                                  encoded_data.size());
+
+    ImageDataPtr image = ImageData::From(decoded_image);
+    // TODO(amistry): Do this!
+    // TODO(amistry): Resizing is (should be) orthogonal to decoding.
+    if (GetSerializedSize_(image) > 32*1024*1024) {
+      if (shrink_to_fit) {
+        LOG(ERROR) << "Resize currently unsupported";
+      } else {
+        // Image too big for IPC message, but caller didn't request resize;
+        LOG(ERROR) << "Decoded image too large for IPC message";
+      }
+      callback.Run(false, ImageDataPtr());
+      return;
+    }
+
+    callback.Run(true, image.Pass());
+  }
+  LOG(INFO) << "............Done decoding image";
+/*
+  int64_t struct_size = sizeof(ChromeUtilityHostMsg_DecodeImage_Succeeded);
+  int64_t image_size = decoded_image.computeSize64();
+  int halves = 0;
+  while (struct_size + (image_size >> 2*halves) > max_ipc_message_size_)
+    halves++;
+  if (halves) {
+    if (shrink_to_fit) {
+      // If decoded image is too large for IPC message, shrink it by halves.
+      // This prevents quality loss, and should never overshrink on displays
+      // smaller than 3600x2400.
+      // TODO (Issue 416916): Instead of shrinking, return via shared memory
+      decoded_image = skia::ImageOperations::Resize(
+          decoded_image, skia::ImageOperations::RESIZE_LANCZOS3,
+          decoded_image.width() >> halves, decoded_image.height() >> halves);
+    } else {
+      decoded_image.reset();
+    }
+  }
+  return decoded_image;
+*/
+}
+
+void ImageDecoderImpl::DecodeImageBase64(
+    const mojo::String& encoded_data,
+    const mojo::Callback<void(bool, ImageDataPtr)>& callback) {
+  std::string decoded_data;
+  if (!base::Base64Decode(encoded_data.get(), &decoded_data)) {
+    LOG(ERROR) << "Unable to base64 decode image";
+    callback.Run(false, ImageDataPtr());
+    return;
+  }
+
+  mojo::Array<uint8_t> decoded_array(decoded_data.size());
+  // TODO(amistry): This seems wrong.
+  memcpy(&decoded_array[0], decoded_data.data(), decoded_data.size());
+  DecodeImage(decoded_array.Pass(), false, false, callback);
+}
+
+}  // namespace content