3 files changed, 420 insertions, 0 deletions
diff --git a/image/encoders/webp/moz.build b/image/encoders/webp/moz.build
new file mode 100644
index 0000000000..4363caa79f
--- /dev/null
+++ b/image/encoders/webp/moz.build
@@ -0,0 +1,15 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+SOURCES += [
+    "nsWebPEncoder.cpp",
+]
+
+LOCAL_INCLUDES += [
+    "/image",
+]
+
+FINAL_LIBRARY = "xul"
diff --git a/image/encoders/webp/nsWebPEncoder.cpp b/image/encoders/webp/nsWebPEncoder.cpp
new file mode 100644
index 0000000000..72ac1388e9
--- /dev/null
+++ b/image/encoders/webp/nsWebPEncoder.cpp
@@ -0,0 +1,342 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// #include "ImageLogging.h"
+#include "nsCRT.h"
+#include "nsWebPEncoder.h"
+#include "nsStreamUtils.h"
+#include "nsString.h"
+#include "prprf.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/UniquePtrExtensions.h"
+
+using namespace mozilla;
+
+// static LazyLogModule sWEBPEncoderLog("WEBPEncoder");
+
+NS_IMPL_ISUPPORTS(nsWebPEncoder, imgIEncoder, nsIInputStream,
+                  nsIAsyncInputStream)
+
+nsWebPEncoder::nsWebPEncoder()
+    : mFinished(false),
+      mImageBuffer(nullptr),
+      mImageBufferSize(0),
+      mImageBufferUsed(0),
+      mImageBufferReadPoint(0),
+      mCallback(nullptr),
+      mCallbackTarget(nullptr),
+      mNotifyThreshold(0),
+      mReentrantMonitor("nsWebPEncoder.mReentrantMonitor") {}
+
+nsWebPEncoder::~nsWebPEncoder() {
+  if (mImageBuffer) {
+    WebPFree(mImageBuffer);
+    mImageBuffer = nullptr;
+    mImageBufferSize = 0;
+    mImageBufferUsed = 0;
+    mImageBufferReadPoint = 0;
+  }
+}
+
+// nsWebPEncoder::InitFromData
+//
+//    One output option is supported: "quality=X" where X is an integer in the
+//    range 0-100. Higher values for X give better quality.
+
+NS_IMETHODIMP
+nsWebPEncoder::InitFromData(const uint8_t* aData,
+                            uint32_t aLength,  // (unused, req'd by JS)
+                            uint32_t aWidth, uint32_t aHeight, uint32_t aStride,
+                            uint32_t aInputFormat,
+                            const nsAString& aOutputOptions) {
+  NS_ENSURE_ARG(aData);
+
+  // validate input format
+  if (aInputFormat != INPUT_FORMAT_RGB && aInputFormat != INPUT_FORMAT_RGBA &&
+      aInputFormat != INPUT_FORMAT_HOSTARGB)
+    return NS_ERROR_INVALID_ARG;
+
+  // Stride is the padded width of each row, so it better be longer (I'm afraid
+  // people will not understand what stride means, so check it well)
+  if ((aInputFormat == INPUT_FORMAT_RGB && aStride < aWidth * 3) ||
+      ((aInputFormat == INPUT_FORMAT_RGBA ||
+        aInputFormat == INPUT_FORMAT_HOSTARGB) &&
+       aStride < aWidth * 4)) {
+    NS_WARNING("Invalid stride for InitFromData");
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // can't initialize more than once
+  if (mImageBuffer != nullptr) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  // options: we only have one option so this is easy
+  int quality = 92;
+  if (aOutputOptions.Length() > 0) {
+    // have options string
+    const nsString qualityPrefix(u"quality="_ns);
+    if (aOutputOptions.Length() > qualityPrefix.Length() &&
+        StringBeginsWith(aOutputOptions, qualityPrefix)) {
+      // have quality string
+      nsCString value = NS_ConvertUTF16toUTF8(
+          Substring(aOutputOptions, qualityPrefix.Length()));
+      int newquality = -1;
+      if (PR_sscanf(value.get(), "%d", &newquality) == 1) {
+        if (newquality >= 0 && newquality <= 100) {
+          quality = newquality;
+        } else {
+          NS_WARNING(
+              "Quality value out of range, should be 0-100,"
+              " using default");
+        }
+      } else {
+        NS_WARNING(
+            "Quality value invalid, should be integer 0-100,"
+            " using default");
+      }
+    } else {
+      return NS_ERROR_INVALID_ARG;
+    }
+  }
+
+  size_t size = 0;
+
+  CheckedInt32 width = CheckedInt32(aWidth);
+  CheckedInt32 height = CheckedInt32(aHeight);
+  CheckedInt32 stride = CheckedInt32(aStride);
+  if (!width.isValid() || !height.isValid() || !stride.isValid() ||
+      !(CheckedUint32(aStride) * CheckedUint32(aHeight)).isValid()) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  if (aInputFormat == INPUT_FORMAT_RGB) {
+    size = quality == 100
+               ? WebPEncodeLosslessRGB(aData, width.value(), height.value(),
+                                       stride.value(), &mImageBuffer)
+               : WebPEncodeRGB(aData, width.value(), height.value(),
+                               stride.value(), quality, &mImageBuffer);
+  } else if (aInputFormat == INPUT_FORMAT_RGBA) {
+    size = quality == 100
+               ? WebPEncodeLosslessRGBA(aData, width.value(), height.value(),
+                                        stride.value(), &mImageBuffer)
+               : WebPEncodeRGBA(aData, width.value(), height.value(),
+                                stride.value(), quality, &mImageBuffer);
+  } else if (aInputFormat == INPUT_FORMAT_HOSTARGB) {
+    UniquePtr<uint8_t[]> aDest =
+        MakeUniqueFallible<uint8_t[]>(aStride * aHeight);
+    if (NS_WARN_IF(!aDest)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    for (uint32_t y = 0; y < aHeight; y++) {
+      for (uint32_t x = 0; x < aWidth; x++) {
+        const uint32_t& pixelIn =
+            ((const uint32_t*)(aData))[y * aStride / 4 + x];
+        uint8_t* pixelOut = &aDest[y * aStride + x * 4];
+
+        uint8_t alpha = (pixelIn & 0xff000000) >> 24;
+        pixelOut[3] = alpha;
+        if (alpha == 255) {
+          pixelOut[0] = (pixelIn & 0xff0000) >> 16;
+          pixelOut[1] = (pixelIn & 0x00ff00) >> 8;
+          pixelOut[2] = (pixelIn & 0x0000ff);
+        } else if (alpha == 0) {
+          pixelOut[0] = pixelOut[1] = pixelOut[2] = 0;
+        } else {
+          pixelOut[0] =
+              (((pixelIn & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
+          pixelOut[1] = (((pixelIn & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
+          pixelOut[2] = (((pixelIn & 0x0000ff)) * 255 + alpha / 2) / alpha;
+        }
+      }
+    }
+
+    size =
+        quality == 100
+            ? WebPEncodeLosslessRGBA(aDest.get(), width.value(), height.value(),
+                                     stride.value(), &mImageBuffer)
+            : WebPEncodeRGBA(aDest.get(), width.value(), height.value(),
+                             stride.value(), quality, &mImageBuffer);
+  }
+
+  mFinished = true;
+
+  if (size == 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mImageBufferUsed = size;
+
+  return NS_OK;
+}
+
+// nsWebPEncoder::StartImageEncode
+//
+//
+// See ::InitFromData for other info.
+NS_IMETHODIMP
+nsWebPEncoder::StartImageEncode(uint32_t aWidth, uint32_t aHeight,
+                                uint32_t aInputFormat,
+                                const nsAString& aOutputOptions) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+// Returns the number of bytes in the image buffer used.
+NS_IMETHODIMP
+nsWebPEncoder::GetImageBufferUsed(uint32_t* aOutputSize) {
+  NS_ENSURE_ARG_POINTER(aOutputSize);
+  *aOutputSize = mImageBufferUsed;
+  return NS_OK;
+}
+
+// Returns a pointer to the start of the image buffer
+NS_IMETHODIMP
+nsWebPEncoder::GetImageBuffer(char** aOutputBuffer) {
+  NS_ENSURE_ARG_POINTER(aOutputBuffer);
+  *aOutputBuffer = reinterpret_cast<char*>(mImageBuffer);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::AddImageFrame(const uint8_t* aData,
+                             uint32_t aLength,  // (unused, req'd by JS)
+                             uint32_t aWidth, uint32_t aHeight,
+                             uint32_t aStride, uint32_t aInputFormat,
+                             const nsAString& aFrameOptions) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::EndImageEncode() { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP
+nsWebPEncoder::Close() {
+  if (mImageBuffer) {
+    WebPFree(mImageBuffer);
+    mImageBuffer = nullptr;
+    mImageBufferSize = 0;
+    mImageBufferUsed = 0;
+    mImageBufferReadPoint = 0;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::Available(uint64_t* _retval) {
+  if (!mImageBuffer) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  *_retval = mImageBufferUsed - mImageBufferReadPoint;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::StreamStatus() {
+  return mImageBuffer ? NS_OK : NS_BASE_STREAM_CLOSED;
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::Read(char* aBuf, uint32_t aCount, uint32_t* _retval) {
+  return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                            uint32_t aCount, uint32_t* _retval) {
+  // Avoid another thread reallocing the buffer underneath us
+  ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
+
+  uint32_t maxCount = mImageBufferUsed - mImageBufferReadPoint;
+  if (maxCount == 0) {
+    *_retval = 0;
+    return mFinished ? NS_OK : NS_BASE_STREAM_WOULD_BLOCK;
+  }
+
+  if (aCount > maxCount) {
+    aCount = maxCount;
+  }
+  nsresult rv = aWriter(
+      this, aClosure,
+      reinterpret_cast<const char*>(mImageBuffer + mImageBufferReadPoint), 0,
+      aCount, _retval);
+  if (NS_SUCCEEDED(rv)) {
+    NS_ASSERTION(*_retval <= aCount, "bad write count");
+    mImageBufferReadPoint += *_retval;
+  }
+
+  // errors returned from the writer end here!
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::IsNonBlocking(bool* _retval) {
+  *_retval = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::AsyncWait(nsIInputStreamCallback* aCallback, uint32_t aFlags,
+                         uint32_t aRequestedCount, nsIEventTarget* aTarget) {
+  if (aFlags != 0) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  if (mCallback || mCallbackTarget) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  mCallbackTarget = aTarget;
+  // 0 means "any number of bytes except 0"
+  mNotifyThreshold = aRequestedCount;
+  if (!aRequestedCount) {
+    mNotifyThreshold = 1024;  // 1 KB seems good.  We don't want to
+                              // notify incessantly
+  }
+
+  // We set the callback absolutely last, because NotifyListener uses it to
+  // determine if someone needs to be notified.  If we don't set it last,
+  // NotifyListener might try to fire off a notification to a null target
+  // which will generally cause non-threadsafe objects to be used off the
+  // main thread
+  mCallback = aCallback;
+
+  // What we are being asked for may be present already
+  NotifyListener();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebPEncoder::CloseWithStatus(nsresult aStatus) { return Close(); }
+
+void nsWebPEncoder::NotifyListener() {
+  // We might call this function on multiple threads (any threads that call
+  // AsyncWait and any that do encoding) so we lock to avoid notifying the
+  // listener twice about the same data (which generally leads to a truncated
+  // image).
+  ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
+
+  if (mCallback &&
+      (mImageBufferUsed - mImageBufferReadPoint >= mNotifyThreshold ||
+       mFinished)) {
+    nsCOMPtr<nsIInputStreamCallback> callback;
+    if (mCallbackTarget) {
+      callback = NS_NewInputStreamReadyEvent("nsWebPEncoder::NotifyListener",
+                                             mCallback, mCallbackTarget);
+    } else {
+      callback = mCallback;
+    }
+
+    NS_ASSERTION(callback, "Shouldn't fail to make the callback");
+    // Null the callback first because OnInputStreamReady could reenter
+    // AsyncWait
+    mCallback = nullptr;
+    mCallbackTarget = nullptr;
+    mNotifyThreshold = 0;
+
+    callback->OnInputStreamReady(this);
+  }
+}
diff --git a/image/encoders/webp/nsWebPEncoder.h b/image/encoders/webp/nsWebPEncoder.h
new file mode 100644
index 0000000000..8628d12388
--- /dev/null
+++ b/image/encoders/webp/nsWebPEncoder.h
@@ -0,0 +1,63 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_encoders_webp_nsWebPEncoder_h
+#define mozilla_image_encoders_webp_nsWebPEncoder_h
+
+#include "webp/encode.h"
+
+#include "imgIEncoder.h"
+#include "nsCOMPtr.h"
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ReentrantMonitor.h"
+
+#define NS_WEBPENCODER_CID                           \
+  { /* a8e5a8e5-bebf-4512-9f50-e41e4748ce28 */       \
+    0xa8e5a8e5, 0xbebf, 0x4512, {                    \
+      0x9f, 0x50, 0xe4, 0x1e, 0x47, 0x48, 0xce, 0x28 \
+    }                                                \
+  }
+
+// Provides WEBP encoding functionality. Use InitFromData() to do the
+// encoding. See that function definition for encoding options.
+
+class nsWebPEncoder final : public imgIEncoder {
+  typedef mozilla::ReentrantMonitor ReentrantMonitor;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_IMGIENCODER
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+
+  nsWebPEncoder();
+
+ protected:
+  ~nsWebPEncoder();
+
+  void NotifyListener();
+
+  bool mFinished;
+
+  // image buffer
+  uint8_t* mImageBuffer;
+  uint32_t mImageBufferSize;
+  uint32_t mImageBufferUsed;
+
+  uint32_t mImageBufferReadPoint;
+
+  nsCOMPtr<nsIInputStreamCallback> mCallback;
+  nsCOMPtr<nsIEventTarget> mCallbackTarget;
+  uint32_t mNotifyThreshold;
+
+  // nsWebPEncoder is designed to allow one thread to pump data into it while
+  // another reads from it.  We lock to ensure that the buffer remains
+  // append-only while we read from it (that it is not realloced) and to
+  // ensure that only one thread dispatches a callback for each call to
+  // AsyncWait.
+  ReentrantMonitor mReentrantMonitor MOZ_UNANNOTATED;
+};
+#endif  // mozilla_image_encoders_webp_nsWebPEncoder_h