gecko-dev/dom/media/webrtc/MediaEngineTabVideoSource.cpp

/* -*- 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 "MediaEngineTabVideoSource.h"

#include "mozilla/gfx/2D.h"
#include "mozilla/RefPtr.h"
#include "nsGlobalWindow.h"
#include "nsIDOMClientRect.h"
#include "nsIDocShell.h"
#include "nsIPresShell.h"
#include "nsPresContext.h"
#include "gfxContext.h"
#include "gfx2DGlue.h"
#include "ImageContainer.h"
#include "Layers.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIDOMDocument.h"
#include "nsITabSource.h"
#include "VideoUtils.h"
#include "nsServiceManagerUtils.h"
#include "nsIPrefService.h"
#include "MediaTrackConstraints.h"

namespace mozilla {

using namespace mozilla::gfx;

NS_IMPL_ISUPPORTS(MediaEngineTabVideoSource, nsIDOMEventListener, nsITimerCallback)

MediaEngineTabVideoSource::MediaEngineTabVideoSource()
: mData(NULL), mDataSize(0), mMonitor("MediaEngineTabVideoSource"), mTabSource(nullptr)
{
}

nsresult
MediaEngineTabVideoSource::StartRunnable::Run()
{
  mVideoSource->Draw();
  mVideoSource->mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
  mVideoSource->mTimer->InitWithCallback(mVideoSource, mVideoSource->mTimePerFrame, nsITimer:: TYPE_REPEATING_SLACK);
  if (mVideoSource->mTabSource) {
    mVideoSource->mTabSource->NotifyStreamStart(mVideoSource->mWindow);
  }
  return NS_OK;
}

nsresult
MediaEngineTabVideoSource::StopRunnable::Run()
{
  nsCOMPtr<nsPIDOMWindow> privateDOMWindow = do_QueryInterface(mVideoSource->mWindow);

  if (mVideoSource->mTimer) {
    mVideoSource->mTimer->Cancel();
    mVideoSource->mTimer = nullptr;
  }
  if (mVideoSource->mTabSource) {
    mVideoSource->mTabSource->NotifyStreamStop(mVideoSource->mWindow);
  }
  return NS_OK;
}

NS_IMETHODIMP
MediaEngineTabVideoSource::HandleEvent(nsIDOMEvent *event) {
  Draw();
  return NS_OK;
}

NS_IMETHODIMP
MediaEngineTabVideoSource::Notify(nsITimer*) {
  Draw();
  return NS_OK;
}
#define LOGTAG "TabVideo"

nsresult
MediaEngineTabVideoSource::InitRunnable::Run()
{
  if (mVideoSource->mWindowId != -1) {
    nsCOMPtr<nsPIDOMWindow> window  = nsGlobalWindow::GetOuterWindowWithId(mVideoSource->mWindowId);
    if (window) {
      mVideoSource->mWindow = window;
    }
  }
  if (!mVideoSource->mWindow) {
    nsresult rv;
    mVideoSource->mTabSource = do_GetService(NS_TABSOURCESERVICE_CONTRACTID, &rv);
    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<nsIDOMWindow> win;
    rv = mVideoSource->mTabSource->GetTabToStream(getter_AddRefs(win));
    NS_ENSURE_SUCCESS(rv, rv);
    if (!win)
      return NS_OK;

    mVideoSource->mWindow = win;
  }
  nsCOMPtr<nsIRunnable> start(new StartRunnable(mVideoSource));
  start->Run();
  return NS_OK;
}

void
MediaEngineTabVideoSource::GetName(nsAString_internal& aName)
{
  aName.AssignLiteral(MOZ_UTF16("&getUserMedia.videoSource.tabShare;"));
}

void
MediaEngineTabVideoSource::GetUUID(nsAString_internal& aUuid)
{
  aUuid.AssignLiteral(MOZ_UTF16("uuid"));
}

nsresult
MediaEngineTabVideoSource::Allocate(const dom::MediaTrackConstraints& aConstraints,
                                    const MediaEnginePrefs& aPrefs)
{
  // windowId and scrollWithPage are not proper constraints, so just read them.
  // They have no well-defined behavior in advanced, so ignore them there.

  mWindowId = aConstraints.mBrowserWindow.WasPassed() ?
              aConstraints.mBrowserWindow.Value() : -1;
  mScrollWithPage = aConstraints.mScrollWithPage.WasPassed() ?
                    aConstraints.mScrollWithPage.Value() : true;

  FlattenedConstraints c(aConstraints);

  mBufWidthMax = c.mWidth.Clamp(c.mWidth.mIdeal.WasPassed() ?
                                c.mWidth.mIdeal.Value() : aPrefs.GetWidth(false));
  mBufHeightMax = c.mHeight.Clamp(c.mHeight.mIdeal.WasPassed() ?
                                  c.mHeight.mIdeal.Value() : aPrefs.GetHeight(false));
  double frameRate = c.mFrameRate.Clamp(c.mFrameRate.mIdeal.WasPassed() ?
                                     c.mFrameRate.mIdeal.Value() : aPrefs.mFPS);
  mTimePerFrame = std::max(10, int(1000.0 / (frameRate > 0? frameRate : 1)));
  return NS_OK;
}

nsresult
MediaEngineTabVideoSource::Deallocate()
{
  return NS_OK;
}

nsresult
MediaEngineTabVideoSource::Start(SourceMediaStream* aStream, TrackID aID)
{
  nsCOMPtr<nsIRunnable> runnable;
  if (!mWindow)
    runnable = new InitRunnable(this);
  else
    runnable = new StartRunnable(this);
  NS_DispatchToMainThread(runnable);
  aStream->AddTrack(aID, 0, new VideoSegment());

  return NS_OK;
}

void
MediaEngineTabVideoSource::NotifyPull(MediaStreamGraph*,
                                      SourceMediaStream* aSource,
                                      TrackID aID, StreamTime aDesiredTime)
{
  VideoSegment segment;
  MonitorAutoLock mon(mMonitor);

  // Note: we're not giving up mImage here
  nsRefPtr<layers::CairoImage> image = mImage;
  StreamTime delta = aDesiredTime - aSource->GetEndOfAppendedData(aID);
  if (delta > 0) {
    // nullptr images are allowed
    gfx::IntSize size = image ? image->GetSize() : IntSize(0, 0);
    segment.AppendFrame(image.forget().downcast<layers::Image>(), delta, size);
    // This can fail if either a) we haven't added the track yet, or b)
    // we've removed or finished the track.
    aSource->AppendToTrack(aID, &(segment));
  }
}

void
MediaEngineTabVideoSource::Draw() {
  nsCOMPtr<nsPIDOMWindow> win = do_QueryInterface(mWindow);

  if (!win) {
    return;
  }

  int32_t innerWidth, innerHeight;
  win->GetInnerWidth(&innerWidth);
  win->GetInnerHeight(&innerHeight);

  if (innerWidth == 0 || innerHeight == 0) {
    return;
  }

  IntSize size;
  // maintain source aspect ratio
  if (mBufWidthMax/innerWidth < mBufHeightMax/innerHeight) {
    // adjust width to be divisible by 4 to work around bug 1125393
    int32_t width = mBufWidthMax - (mBufWidthMax % 4);
    size = IntSize(width, (width * ((float) innerHeight/innerWidth)));
  } else {
    int32_t tmpWidth = (mBufHeightMax * ((float) innerWidth/innerHeight));
    int32_t width =  tmpWidth - (tmpWidth % 4);
    size = IntSize(width, (width * ((float) innerHeight/innerWidth)));
  }

  gfxImageFormat format = gfxImageFormat::RGB24;
  uint32_t stride = gfxASurface::FormatStrideForWidth(format, size.width);

  if (mDataSize < static_cast<size_t>(stride * size.height)) {
    mDataSize = stride * size.height;
    mData = static_cast<unsigned char*>(malloc(mDataSize));
  }

  if (!mData) {
    return;
  }

  nsRefPtr<nsPresContext> presContext;
  nsIDocShell* docshell = win->GetDocShell();
  if (docshell) {
    docshell->GetPresContext(getter_AddRefs(presContext));
  }
  if (!presContext) {
    return;
  }

  nscolor bgColor = NS_RGB(255, 255, 255);
  nsCOMPtr<nsIPresShell> presShell = presContext->PresShell();
  uint32_t renderDocFlags = 0;
  if (!mScrollWithPage) {
    renderDocFlags |= nsIPresShell::RENDER_IGNORE_VIEWPORT_SCROLLING;
  }
  nsRect r(0, 0, nsPresContext::CSSPixelsToAppUnits((float)innerWidth),
           nsPresContext::CSSPixelsToAppUnits((float)innerHeight));

  nsRefPtr<layers::ImageContainer> container = layers::LayerManager::CreateImageContainer();
  RefPtr<DrawTarget> dt =
    Factory::CreateDrawTargetForData(BackendType::CAIRO,
                                     mData.rwget(),
                                     size,
                                     stride,
                                     SurfaceFormat::B8G8R8X8);
  if (!dt) {
    return;
  }
  nsRefPtr<gfxContext> context = new gfxContext(dt);
  context->SetMatrix(context->CurrentMatrix().Scale((((float) size.width)/innerWidth),
                                                    (((float) size.height)/innerHeight)));

  NS_ENSURE_SUCCESS_VOID(presShell->RenderDocument(r, renderDocFlags, bgColor, context));

  RefPtr<SourceSurface> surface = dt->Snapshot();
  if (!surface) {
    return;
  }

  layers::CairoImage::Data cairoData;
  cairoData.mSize = size;
  cairoData.mSourceSurface = surface;

  nsRefPtr<layers::CairoImage> image = new layers::CairoImage();

  image->SetData(cairoData);

  MonitorAutoLock mon(mMonitor);
  mImage = image;
}

nsresult
MediaEngineTabVideoSource::Stop(mozilla::SourceMediaStream*, mozilla::TrackID)
{
  if (!mWindow)
    return NS_OK;

  NS_DispatchToMainThread(new StopRunnable(this));
  return NS_OK;
}

nsresult
MediaEngineTabVideoSource::Config(bool, uint32_t, bool, uint32_t, bool, uint32_t, int32_t)
{
  return NS_OK;
}

bool
MediaEngineTabVideoSource::IsFake()
{
  return false;
}

}