1 files changed, 332 insertions, 0 deletions
diff --git a/image/encoders/webp/nsWebPEncoder.cpp b/image/encoders/webp/nsWebPEncoder.cpp
new file mode 100644
index 0000000000..a5ea813417
--- /dev/null
+++ b/image/encoders/webp/nsWebPEncoder.cpp
@@ -0,0 +1,332 @@
+/* -*- 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"
+
+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 = MakeUnique<uint8_t[]>(aStride * aHeight);
+
+    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::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);
+  }
+}