gecko-dev/dom/media/VideoFrameContainer.cpp

/* -*- 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 "VideoFrameContainer.h"

#include "mozilla/dom/HTMLMediaElement.h"
#include "mozilla/Telemetry.h"

#include "nsIFrame.h"
#include "nsDisplayList.h"
#include "SVGObserverUtils.h"

using namespace mozilla::layers;

namespace mozilla {
static LazyLogModule gVideoFrameContainerLog("VideoFrameContainer");
#define CONTAINER_LOG(type, msg) MOZ_LOG(gVideoFrameContainerLog, type, msg)

#define NS_DispatchToMainThread(...) CompileError_UseAbstractMainThreadInstead

namespace {
template<Telemetry::HistogramID ID>
class AutoTimer
{
  // Set a threshold to reduce performance overhead
  // for we're measuring hot spots.
  static const uint32_t sThresholdMS = 1000;
public:
  ~AutoTimer()
  {
    auto end = TimeStamp::Now();
    auto diff = uint32_t((end - mStart).ToMilliseconds());
    if (diff > sThresholdMS) {
      Telemetry::Accumulate(ID, diff);
    }
  }
private:
  const TimeStamp mStart = TimeStamp::Now();
};
}

VideoFrameContainer::VideoFrameContainer(
  dom::HTMLMediaElement* aElement,
  already_AddRefed<ImageContainer> aContainer)
  : mElement(aElement)
  , mImageContainer(aContainer)
  , mMutex("nsVideoFrameContainer")
  , mBlackImage(nullptr)
  , mFrameID(0)
  , mPendingPrincipalHandle(PRINCIPAL_HANDLE_NONE)
  , mFrameIDForPendingPrincipalHandle(0)
  , mMainThread(aElement->AbstractMainThread())
{
  NS_ASSERTION(aElement, "aElement must not be null");
  NS_ASSERTION(mImageContainer, "aContainer must not be null");
}

VideoFrameContainer::~VideoFrameContainer()
{}

PrincipalHandle VideoFrameContainer::GetLastPrincipalHandle()
{
  MutexAutoLock lock(mMutex);
  return GetLastPrincipalHandleLocked();
}

PrincipalHandle VideoFrameContainer::GetLastPrincipalHandleLocked()
{
  return mLastPrincipalHandle;
}

void VideoFrameContainer::UpdatePrincipalHandleForFrameID(const PrincipalHandle& aPrincipalHandle,
                                                          const ImageContainer::FrameID& aFrameID)
{
  MutexAutoLock lock(mMutex);
  UpdatePrincipalHandleForFrameIDLocked(aPrincipalHandle, aFrameID);
}

void VideoFrameContainer::UpdatePrincipalHandleForFrameIDLocked(const PrincipalHandle& aPrincipalHandle,
                                                                const ImageContainer::FrameID& aFrameID)
{
  if (mPendingPrincipalHandle == aPrincipalHandle) {
    return;
  }
  mPendingPrincipalHandle = aPrincipalHandle;
  mFrameIDForPendingPrincipalHandle = aFrameID;
}

static void
SetImageToBlackPixel(PlanarYCbCrImage* aImage)
{
  uint8_t blackPixel[] = { 0x10, 0x80, 0x80 };

  PlanarYCbCrData data;
  data.mYChannel = blackPixel;
  data.mCbChannel = blackPixel + 1;
  data.mCrChannel = blackPixel + 2;
  data.mYStride = data.mCbCrStride = 1;
  data.mPicSize = data.mYSize = data.mCbCrSize = gfx::IntSize(1, 1);
  aImage->CopyData(data);
}

class VideoFrameContainerInvalidateRunnable : public Runnable {
public:
  explicit VideoFrameContainerInvalidateRunnable(VideoFrameContainer* aVideoFrameContainer)
    : Runnable("VideoFrameContainerInvalidateRunnable")
    , mVideoFrameContainer(aVideoFrameContainer)
  {}
  NS_IMETHOD Run()
  {
    MOZ_ASSERT(NS_IsMainThread());

    mVideoFrameContainer->Invalidate();

    return NS_OK;
  }
private:
  RefPtr<VideoFrameContainer> mVideoFrameContainer;
};

void VideoFrameContainer::SetCurrentFrames(const VideoSegment& aSegment)
{
  if (aSegment.IsEmpty()) {
    return;
  }

  MutexAutoLock lock(mMutex);
  AutoTimer<Telemetry::VFC_SETVIDEOSEGMENT_LOCK_HOLD_MS> lockHold;

  // Collect any new frames produced in this iteration.
  AutoTArray<ImageContainer::NonOwningImage,4> newImages;
  PrincipalHandle lastPrincipalHandle = PRINCIPAL_HANDLE_NONE;

  VideoSegment::ConstChunkIterator iter(aSegment);
  while (!iter.IsEnded()) {
    VideoChunk chunk = *iter;

    const VideoFrame* frame = &chunk.mFrame;
    if (*frame == mLastPlayedVideoFrame) {
      iter.Next();
      continue;
    }

    Image* image = frame->GetImage();
    CONTAINER_LOG(LogLevel::Verbose,
                  ("VideoFrameContainer %p writing video frame %p (%d x %d)",
                  this, image, frame->GetIntrinsicSize().width,
                  frame->GetIntrinsicSize().height));

    if (frame->GetForceBlack()) {
      if (!mBlackImage) {
        mBlackImage = GetImageContainer()->CreatePlanarYCbCrImage();
        if (mBlackImage) {
          // Sets the image to a single black pixel, which will be scaled to
          // fill the rendered size.
          SetImageToBlackPixel(mBlackImage->AsPlanarYCbCrImage());
        }
      }
      if (mBlackImage) {
        image = mBlackImage;
      }
    }
    // Don't append null image to the newImages.
    if (!image) {
      iter.Next();
      continue;
    }
    newImages.AppendElement(ImageContainer::NonOwningImage(image, chunk.mTimeStamp));

    lastPrincipalHandle = chunk.GetPrincipalHandle();

    mLastPlayedVideoFrame = *frame;
    iter.Next();
  }

  // Don't update if there are no changes.
  if (newImages.IsEmpty()) {
    return;
  }

  AutoTArray<ImageContainer::NonOwningImage,4> images;

  bool principalHandleChanged =
     lastPrincipalHandle != PRINCIPAL_HANDLE_NONE &&
     lastPrincipalHandle != GetLastPrincipalHandleLocked();

  // Add the frames from this iteration.
  for (auto& image : newImages) {
    image.mFrameID = NewFrameID();
    images.AppendElement(image);
  }

  if (principalHandleChanged) {
    UpdatePrincipalHandleForFrameIDLocked(lastPrincipalHandle,
                                          newImages.LastElement().mFrameID);
  }

  SetCurrentFramesLocked(mLastPlayedVideoFrame.GetIntrinsicSize(), images);
  nsCOMPtr<nsIRunnable> event =
    new VideoFrameContainerInvalidateRunnable(this);
  mMainThread->Dispatch(event.forget());

  images.ClearAndRetainStorage();
}

void VideoFrameContainer::ClearFrames()
{
  ClearFutureFrames();
}

void VideoFrameContainer::SetCurrentFrame(const gfx::IntSize& aIntrinsicSize,
                                          Image* aImage,
                                          const TimeStamp& aTargetTime)
{
  if (aImage) {
    MutexAutoLock lock(mMutex);
    AutoTimer<Telemetry::VFC_SETCURRENTFRAME_LOCK_HOLD_MS> lockHold;
    AutoTArray<ImageContainer::NonOwningImage,1> imageList;
    imageList.AppendElement(
        ImageContainer::NonOwningImage(aImage, aTargetTime, ++mFrameID));
    SetCurrentFramesLocked(aIntrinsicSize, imageList);
  } else {
    ClearCurrentFrame(aIntrinsicSize);
  }
}

void VideoFrameContainer::SetCurrentFrames(const gfx::IntSize& aIntrinsicSize,
                                           const nsTArray<ImageContainer::NonOwningImage>& aImages)
{
  MutexAutoLock lock(mMutex);
  AutoTimer<Telemetry::VFC_SETIMAGES_LOCK_HOLD_MS> lockHold;
  SetCurrentFramesLocked(aIntrinsicSize, aImages);
}

void VideoFrameContainer::SetCurrentFramesLocked(const gfx::IntSize& aIntrinsicSize,
                                                 const nsTArray<ImageContainer::NonOwningImage>& aImages)
{
  mMutex.AssertCurrentThreadOwns();

  if (aIntrinsicSize != mIntrinsicSize) {
    mIntrinsicSize = aIntrinsicSize;
    RefPtr<VideoFrameContainer> self = this;
    mMainThread->Dispatch(NS_NewRunnableFunction(
      "IntrinsicSizeChanged", [this, self, aIntrinsicSize]() {
        mMainThreadState.mIntrinsicSize = aIntrinsicSize;
        mMainThreadState.mIntrinsicSizeChanged = true;
      }));
  }

  gfx::IntSize oldFrameSize = mImageContainer->GetCurrentSize();

  // When using the OMX decoder, destruction of the current image can indirectly
  //  block on main thread I/O. If we let this happen while holding onto
  //  |mImageContainer|'s lock, then when the main thread then tries to
  //  composite it can then block on |mImageContainer|'s lock, causing a
  //  deadlock. We use this hack to defer the destruction of the current image
  //  until it is safe.
  nsTArray<ImageContainer::OwningImage> oldImages;
  mImageContainer->GetCurrentImages(&oldImages);

  PrincipalHandle principalHandle = PRINCIPAL_HANDLE_NONE;
  ImageContainer::FrameID lastFrameIDForOldPrincipalHandle =
    mFrameIDForPendingPrincipalHandle - 1;
  if (mPendingPrincipalHandle != PRINCIPAL_HANDLE_NONE &&
       ((!oldImages.IsEmpty() &&
          oldImages.LastElement().mFrameID >= lastFrameIDForOldPrincipalHandle) ||
        (!aImages.IsEmpty() &&
          aImages[0].mFrameID > lastFrameIDForOldPrincipalHandle))) {
    // We are releasing the last FrameID prior to `lastFrameIDForOldPrincipalHandle`
    // OR
    // there are no FrameIDs prior to `lastFrameIDForOldPrincipalHandle` in the new
    // set of images.
    // This means that the old principal handle has been flushed out and we can
    // notify our video element about this change.
    principalHandle = mPendingPrincipalHandle;
    mLastPrincipalHandle = mPendingPrincipalHandle;
    mPendingPrincipalHandle = PRINCIPAL_HANDLE_NONE;
    mFrameIDForPendingPrincipalHandle = 0;
  }

  if (aImages.IsEmpty()) {
    mImageContainer->ClearAllImages();
  } else {
    mImageContainer->SetCurrentImages(aImages);
  }
  gfx::IntSize newFrameSize = mImageContainer->GetCurrentSize();
  bool imageSizeChanged = (oldFrameSize != newFrameSize);

  if (principalHandle != PRINCIPAL_HANDLE_NONE || imageSizeChanged) {
    RefPtr<VideoFrameContainer> self = this;
    mMainThread->Dispatch(NS_NewRunnableFunction(
      "PrincipalHandleOrImageSizeChanged",
      [this, self, principalHandle, imageSizeChanged]() {
        mMainThreadState.mImageSizeChanged = imageSizeChanged;
        if (mElement && principalHandle != PRINCIPAL_HANDLE_NONE) {
          mElement->PrincipalHandleChangedForVideoFrameContainer(
            this, principalHandle);
        }
      }));
  }
}

void VideoFrameContainer::ClearCurrentFrame()
{
  MutexAutoLock lock(mMutex);
  AutoTimer<Telemetry::VFC_CLEARCURRENTFRAME_LOCK_HOLD_MS> lockHold;

  // See comment in SetCurrentFrame for the reasoning behind
  // using a kungFuDeathGrip here.
  nsTArray<ImageContainer::OwningImage> kungFuDeathGrip;
  mImageContainer->GetCurrentImages(&kungFuDeathGrip);

  mImageContainer->ClearAllImages();
  mImageContainer->ClearCachedResources();
}

void VideoFrameContainer::ClearFutureFrames()
{
  MutexAutoLock lock(mMutex);
  AutoTimer<Telemetry::VFC_CLEARFUTUREFRAMES_LOCK_HOLD_MS> lockHold;

  // See comment in SetCurrentFrame for the reasoning behind
  // using a kungFuDeathGrip here.
  nsTArray<ImageContainer::OwningImage> kungFuDeathGrip;
  mImageContainer->GetCurrentImages(&kungFuDeathGrip);

  if (!kungFuDeathGrip.IsEmpty()) {
    nsTArray<ImageContainer::NonOwningImage> currentFrame;
    const ImageContainer::OwningImage& img = kungFuDeathGrip[0];
    currentFrame.AppendElement(ImageContainer::NonOwningImage(img.mImage,
        img.mTimeStamp, img.mFrameID, img.mProducerID));
    mImageContainer->SetCurrentImages(currentFrame);
  }
}

void
VideoFrameContainer::ClearCachedResources()
{
  mImageContainer->ClearCachedResources();
}

ImageContainer* VideoFrameContainer::GetImageContainer() {
  return mImageContainer;
}


double VideoFrameContainer::GetFrameDelay()
{
  return mImageContainer->GetPaintDelay().ToSeconds();
}

void VideoFrameContainer::InvalidateWithFlags(uint32_t aFlags)
{
  NS_ASSERTION(NS_IsMainThread(), "Must call on main thread");

  if (!mElement) {
    // Element has been destroyed
    return;
  }

  nsIFrame* frame = mElement->GetPrimaryFrame();
  bool invalidateFrame = mMainThreadState.mImageSizeChanged;
  mMainThreadState.mImageSizeChanged = false;

  if (mMainThreadState.mIntrinsicSizeChanged) {
    mElement->UpdateMediaSize(mMainThreadState.mIntrinsicSize);
    mMainThreadState.mIntrinsicSizeChanged = false;
    if (frame) {
      nsPresContext* presContext = frame->PresContext();
      nsIPresShell* presShell = presContext->PresShell();
      presShell->FrameNeedsReflow(
        frame, nsIPresShell::eStyleChange, NS_FRAME_IS_DIRTY);
    }
  }

  bool asyncInvalidate = mImageContainer &&
                         mImageContainer->IsAsync() &&
                         !(aFlags & INVALIDATE_FORCE);

  if (frame) {
    if (invalidateFrame) {
      frame->InvalidateFrame();
    } else {
      frame->InvalidateLayer(DisplayItemType::TYPE_VIDEO, nullptr, nullptr,
                             asyncInvalidate ? nsIFrame::UPDATE_IS_ASYNC : 0);
    }
  }

  SVGObserverUtils::InvalidateDirectRenderingObservers(mElement);
}

} // namespace mozilla

#undef NS_DispatchToMainThread