1 files changed, 212 insertions, 0 deletions
diff --git a/dom/media/CanvasCaptureMediaStream.cpp b/dom/media/CanvasCaptureMediaStream.cpp
new file mode 100644
index 0000000000..377243540c
--- /dev/null
+++ b/dom/media/CanvasCaptureMediaStream.cpp
@@ -0,0 +1,212 @@
+/* -*- 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 "CanvasCaptureMediaStream.h"
+
+#include "DOMMediaStream.h"
+#include "ImageContainer.h"
+#include "MediaTrackGraph.h"
+#include "Tracing.h"
+#include "VideoSegment.h"
+#include "gfxPlatform.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/dom/CanvasCaptureMediaStreamBinding.h"
+#include "mozilla/gfx/2D.h"
+#include "nsContentUtils.h"
+
+using namespace mozilla::layers;
+using namespace mozilla::gfx;
+
+namespace mozilla::dom {
+
+OutputStreamDriver::OutputStreamDriver(SourceMediaTrack* aSourceStream,
+                                       const PrincipalHandle& aPrincipalHandle)
+    : mSourceStream(aSourceStream), mPrincipalHandle(aPrincipalHandle) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mSourceStream);
+}
+
+OutputStreamDriver::~OutputStreamDriver() {
+  MOZ_ASSERT(NS_IsMainThread());
+  EndTrack();
+}
+
+void OutputStreamDriver::EndTrack() {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!mSourceStream->IsDestroyed()) {
+    mSourceStream->Destroy();
+  }
+}
+
+void OutputStreamDriver::SetImage(RefPtr<layers::Image>&& aImage,
+                                  const TimeStamp& aTime) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  VideoSegment segment;
+  const auto size = aImage->GetSize();
+  segment.AppendFrame(aImage.forget(), size, mPrincipalHandle, false, aTime);
+  mSourceStream->AppendData(&segment);
+}
+
+// ----------------------------------------------------------------------
+
+class TimerDriver : public OutputStreamDriver {
+ public:
+  explicit TimerDriver(SourceMediaTrack* aSourceStream, const double& aFPS,
+                       const PrincipalHandle& aPrincipalHandle)
+      : OutputStreamDriver(aSourceStream, aPrincipalHandle),
+        mFrameInterval(aFPS == 0.0 ? TimeDuration::Forever()
+                                   : TimeDuration::FromSeconds(1.0 / aFPS)) {}
+
+  void RequestFrameCapture() override { mExplicitCaptureRequested = true; }
+
+  bool FrameCaptureRequested(const TimeStamp& aTime) const override {
+    if (mLastFrameTime.IsNull()) {
+      // All CanvasCaptureMediaStreams shall at least get one frame.
+      return true;
+    }
+
+    if (mExplicitCaptureRequested) {
+      return true;
+    }
+
+    if ((aTime - mLastFrameTime) >= mFrameInterval) {
+      return true;
+    }
+
+    return false;
+  }
+
+  void NewFrame(already_AddRefed<Image> aImage,
+                const TimeStamp& aTime) override {
+    nsCString str;
+    if (profiler_thread_is_being_profiled_for_markers()) {
+      TimeDuration sinceLast =
+          aTime - (mLastFrameTime.IsNull() ? aTime : mLastFrameTime);
+      str.AppendPrintf(
+          "TimerDriver %staking frame (%sexplicitly requested; after %.2fms; "
+          "interval cap %.2fms)",
+          sinceLast >= mFrameInterval ? "" : "NOT ",
+          mExplicitCaptureRequested ? "" : "NOT ", sinceLast.ToMilliseconds(),
+          mFrameInterval.ToMilliseconds());
+    }
+    AUTO_PROFILER_MARKER_TEXT("Canvas CaptureStream", MEDIA_RT, {}, str);
+
+    RefPtr<Image> image = aImage;
+
+    if (!FrameCaptureRequested(aTime)) {
+      return;
+    }
+
+    mLastFrameTime = aTime;
+    mExplicitCaptureRequested = false;
+    SetImage(std::move(image), aTime);
+  }
+
+ protected:
+  virtual ~TimerDriver() = default;
+
+ private:
+  const TimeDuration mFrameInterval;
+  bool mExplicitCaptureRequested = false;
+  TimeStamp mLastFrameTime;
+};
+
+// ----------------------------------------------------------------------
+
+class AutoDriver : public OutputStreamDriver {
+ public:
+  explicit AutoDriver(SourceMediaTrack* aSourceStream,
+                      const PrincipalHandle& aPrincipalHandle)
+      : OutputStreamDriver(aSourceStream, aPrincipalHandle) {}
+
+  void RequestFrameCapture() override {}
+
+  bool FrameCaptureRequested(const TimeStamp& aTime) const override {
+    return true;
+  }
+
+  void NewFrame(already_AddRefed<Image> aImage,
+                const TimeStamp& aTime) override {
+    AUTO_PROFILER_MARKER_TEXT("Canvas CaptureStream", MEDIA_RT, {},
+                              "AutoDriver taking frame"_ns);
+
+    RefPtr<Image> image = aImage;
+    SetImage(std::move(image), aTime);
+  }
+
+ protected:
+  virtual ~AutoDriver() = default;
+};
+
+// ----------------------------------------------------------------------
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(CanvasCaptureMediaStream, DOMMediaStream,
+                                   mCanvas)
+
+NS_IMPL_ADDREF_INHERITED(CanvasCaptureMediaStream, DOMMediaStream)
+NS_IMPL_RELEASE_INHERITED(CanvasCaptureMediaStream, DOMMediaStream)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CanvasCaptureMediaStream)
+NS_INTERFACE_MAP_END_INHERITING(DOMMediaStream)
+
+CanvasCaptureMediaStream::CanvasCaptureMediaStream(nsPIDOMWindowInner* aWindow,
+                                                   HTMLCanvasElement* aCanvas)
+    : DOMMediaStream(aWindow), mCanvas(aCanvas) {}
+
+CanvasCaptureMediaStream::~CanvasCaptureMediaStream() = default;
+
+JSObject* CanvasCaptureMediaStream::WrapObject(
+    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
+  return dom::CanvasCaptureMediaStream_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void CanvasCaptureMediaStream::RequestFrame() {
+  if (mOutputStreamDriver) {
+    mOutputStreamDriver->RequestFrameCapture();
+  }
+}
+
+nsresult CanvasCaptureMediaStream::Init(const dom::Optional<double>& aFPS,
+                                        nsIPrincipal* aPrincipal) {
+  MediaTrackGraph* graph = MediaTrackGraph::GetInstance(
+      MediaTrackGraph::SYSTEM_THREAD_DRIVER, GetOwner(),
+      MediaTrackGraph::REQUEST_DEFAULT_SAMPLE_RATE,
+      MediaTrackGraph::DEFAULT_OUTPUT_DEVICE);
+  SourceMediaTrack* source = graph->CreateSourceTrack(MediaSegment::VIDEO);
+  PrincipalHandle principalHandle = MakePrincipalHandle(aPrincipal);
+  if (!aFPS.WasPassed()) {
+    mOutputStreamDriver = new AutoDriver(source, principalHandle);
+  } else if (aFPS.Value() < 0) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  } else {
+    // Cap frame rate to 60 FPS for sanity
+    double fps = std::min(60.0, aFPS.Value());
+    mOutputStreamDriver = new TimerDriver(source, fps, principalHandle);
+  }
+  return NS_OK;
+}
+
+FrameCaptureListener* CanvasCaptureMediaStream::FrameCaptureListener() {
+  return mOutputStreamDriver;
+}
+
+void CanvasCaptureMediaStream::StopCapture() {
+  if (!mOutputStreamDriver) {
+    return;
+  }
+
+  mOutputStreamDriver->EndTrack();
+  mOutputStreamDriver = nullptr;
+}
+
+SourceMediaTrack* CanvasCaptureMediaStream::GetSourceStream() const {
+  if (!mOutputStreamDriver) {
+    return nullptr;
+  }
+  return mOutputStreamDriver->mSourceStream;
+}
+
+}  // namespace mozilla::dom