1 files changed, 197 insertions, 0 deletions
diff --git a/dom/media/imagecapture/CaptureTask.cpp b/dom/media/imagecapture/CaptureTask.cpp
new file mode 100644
index 0000000000..d83de76f5e
--- /dev/null
+++ b/dom/media/imagecapture/CaptureTask.cpp
@@ -0,0 +1,197 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "CaptureTask.h"
+#include "gfxUtils.h"
+#include "mozilla/dom/BlobImpl.h"
+#include "mozilla/dom/ImageCapture.h"
+#include "mozilla/dom/ImageCaptureError.h"
+#include "mozilla/dom/ImageEncoder.h"
+#include "mozilla/dom/MediaStreamTrack.h"
+#include "mozilla/dom/VideoStreamTrack.h"
+#include "mozilla/SchedulerGroup.h"
+#include "nsThreadUtils.h"
+#include "VideoSegment.h"
+
+namespace mozilla {
+
+class CaptureTask::MediaTrackEventListener : public MediaTrackListener {
+ public:
+  explicit MediaTrackEventListener(CaptureTask* aCaptureTask)
+      : mCaptureTask(aCaptureTask){};
+
+  // MediaTrackListener methods.
+  void NotifyEnded(MediaTrackGraph* aGraph) override {
+    mCaptureTask->PostTrackEndEvent();
+  }
+
+ private:
+  CaptureTask* mCaptureTask;
+};
+
+CaptureTask::CaptureTask(dom::ImageCapture* aImageCapture)
+    : mImageCapture(aImageCapture),
+      mEventListener(new MediaTrackEventListener(this)),
+      mImageGrabbedOrTrackEnd(false),
+      mPrincipalChanged(false) {}
+
+nsresult CaptureTask::TaskComplete(already_AddRefed<dom::BlobImpl> aBlobImpl,
+                                   nsresult aRv) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  DetachTrack();
+
+  nsresult rv;
+  RefPtr<dom::BlobImpl> blobImpl(aBlobImpl);
+
+  // We have to set the parent because the blob has been generated with a valid
+  // one.
+  RefPtr<dom::Blob> blob;
+  if (blobImpl) {
+    blob = dom::Blob::Create(mImageCapture->GetOwnerGlobal(), blobImpl);
+    if (NS_WARN_IF(!blob)) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  if (mPrincipalChanged) {
+    aRv = NS_ERROR_DOM_SECURITY_ERR;
+    IC_LOG("MediaStream principal should not change during TakePhoto().");
+  }
+
+  if (NS_SUCCEEDED(aRv)) {
+    rv = mImageCapture->PostBlobEvent(blob);
+  } else {
+    rv =
+        mImageCapture->PostErrorEvent(dom::ImageCaptureError::PHOTO_ERROR, aRv);
+  }
+
+  // Ensure ImageCapture dereference on main thread here because the TakePhoto()
+  // sequences stopped here.
+  mImageCapture = nullptr;
+
+  return rv;
+}
+
+void CaptureTask::AttachTrack() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  dom::MediaStreamTrack* track = mImageCapture->GetVideoStreamTrack();
+  track->AddPrincipalChangeObserver(this);
+  track->AddListener(mEventListener.get());
+  track->AddDirectListener(this);
+}
+
+void CaptureTask::DetachTrack() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  dom::MediaStreamTrack* track = mImageCapture->GetVideoStreamTrack();
+  track->RemovePrincipalChangeObserver(this);
+  track->RemoveListener(mEventListener.get());
+  track->RemoveDirectListener(this);
+}
+
+void CaptureTask::PrincipalChanged(dom::MediaStreamTrack* aMediaStreamTrack) {
+  MOZ_ASSERT(NS_IsMainThread());
+  mPrincipalChanged = true;
+}
+
+void CaptureTask::NotifyRealtimeTrackData(MediaTrackGraph* aGraph,
+                                          TrackTime aTrackOffset,
+                                          const MediaSegment& aMedia) {
+  MOZ_ASSERT(aMedia.GetType() == MediaSegment::VIDEO);
+  const VideoSegment& video = static_cast<const VideoSegment&>(aMedia);
+
+  // Callback for encoding complete, it calls on main thread.
+  class EncodeComplete : public dom::EncodeCompleteCallback {
+   public:
+    explicit EncodeComplete(CaptureTask* aTask) : mTask(aTask) {}
+
+    bool CanBeDeletedOnAnyThread() override {
+      // EncodeComplete is used from the main thread only.
+      return false;
+    }
+
+    nsresult ReceiveBlobImpl(
+        already_AddRefed<dom::BlobImpl> aBlobImpl) override {
+      MOZ_ASSERT(NS_IsMainThread());
+      RefPtr<dom::BlobImpl> blobImpl(aBlobImpl);
+      mTask->TaskComplete(blobImpl.forget(), NS_OK);
+      mTask = nullptr;
+      return NS_OK;
+    }
+
+   protected:
+    RefPtr<CaptureTask> mTask;
+  };
+
+  for (VideoSegment::ConstChunkIterator iter(video); !iter.IsEnded();
+       iter.Next()) {
+    VideoChunk chunk = *iter;
+
+    // Extract the first valid video frame.
+    VideoFrame frame;
+    if (chunk.IsNull()) {
+      continue;
+    }
+
+    RefPtr<layers::Image> image;
+    if (chunk.mFrame.GetForceBlack()) {
+      // Create a black image.
+      image = VideoFrame::CreateBlackImage(chunk.mFrame.GetIntrinsicSize());
+    } else {
+      image = chunk.mFrame.GetImage();
+    }
+    if (!image) {
+      MOZ_ASSERT(image);
+      continue;
+    }
+
+    bool wasGrabbed = mImageGrabbedOrTrackEnd.exchange(true);
+    if (wasGrabbed) {
+      return;
+    }
+
+    // Encode image.
+    nsresult rv;
+    nsAutoString type(u"image/jpeg"_ns);
+    nsAutoString options;
+    rv = dom::ImageEncoder::ExtractDataFromLayersImageAsync(
+        type, options, false, image, false, new EncodeComplete(this));
+    if (NS_FAILED(rv)) {
+      PostTrackEndEvent();
+    }
+  }
+}
+
+void CaptureTask::PostTrackEndEvent() {
+  bool wasGrabbed = mImageGrabbedOrTrackEnd.exchange(true);
+  if (wasGrabbed) {
+    return;
+  }
+
+  // Got track end or finish event, stop the task.
+  class TrackEndRunnable : public Runnable {
+   public:
+    explicit TrackEndRunnable(CaptureTask* aTask)
+        : mozilla::Runnable("TrackEndRunnable"), mTask(aTask) {}
+
+    NS_IMETHOD Run() override {
+      mTask->TaskComplete(nullptr, NS_ERROR_FAILURE);
+      mTask = nullptr;
+      return NS_OK;
+    }
+
+   protected:
+    RefPtr<CaptureTask> mTask;
+  };
+
+  IC_LOG("Got MediaTrack track removed or finished event.");
+  nsCOMPtr<nsIRunnable> event = new TrackEndRunnable(this);
+  SchedulerGroup::Dispatch(TaskCategory::Other, event.forget());
+}
+
+}  // namespace mozilla