playwright/browser_patches/firefox/juggler/screencast/nsScreencastService.cpp
Yury Semikhatsky 02aa31048c
browser(firefox): cross thread sync in screencast (#16320)
* nsIScreencastServiceClient is not thread safe refcounted so we make nsScreencastService::Session a thread safe refcounted object and keep it alive while there are inflight frames. Once such frames get handled on the main thread we check if the session has been stopped.
* Removed mCaptureCallbackCs in favor of atomic counter (mClient is not accessed only on the main thread).
* HeadlessWindowCapturer now holds RefPtr to the headless window object to avoid use after free when clearing it as a listener on the widget.
* ScreencastEncoder is not ref counted anymore.

Pretty-diff: 5f5042ff1e
2022-08-05 15:25:26 -07:00

379 lines
12 KiB
C++

/* 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 "nsScreencastService.h"
#include "ScreencastEncoder.h"
#include "HeadlessWidget.h"
#include "HeadlessWindowCapturer.h"
#include "mozilla/Base64.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/PresShell.h"
#include "mozilla/StaticPtr.h"
#include "nsIDocShell.h"
#include "nsIObserverService.h"
#include "nsIRandomGenerator.h"
#include "nsISupportsPrimitives.h"
#include "nsThreadManager.h"
#include "nsView.h"
#include "nsViewManager.h"
#include "modules/desktop_capture/desktop_capturer.h"
#include "modules/desktop_capture/desktop_capture_options.h"
#include "modules/desktop_capture/desktop_frame.h"
#include "modules/video_capture/video_capture.h"
#include "mozilla/widget/PlatformWidgetTypes.h"
#include "video_engine/desktop_capture_impl.h"
extern "C" {
#include "jpeglib.h"
}
#include <libyuv.h>
using namespace mozilla::widget;
namespace mozilla {
NS_IMPL_ISUPPORTS(nsScreencastService, nsIScreencastService)
namespace {
const int kMaxFramesInFlight = 1;
StaticRefPtr<nsScreencastService> gScreencastService;
rtc::scoped_refptr<webrtc::VideoCaptureModuleEx> CreateWindowCapturer(nsIWidget* widget) {
if (gfxPlatform::IsHeadless()) {
HeadlessWidget* headlessWidget = static_cast<HeadlessWidget*>(widget);
return HeadlessWindowCapturer::Create(headlessWidget);
}
uintptr_t rawWindowId = reinterpret_cast<uintptr_t>(widget->GetNativeData(NS_NATIVE_WINDOW_WEBRTC_DEVICE_ID));
if (!rawWindowId) {
fprintf(stderr, "Failed to get native window id\n");
return nullptr;
}
nsCString windowId;
windowId.AppendPrintf("%" PRIuPTR, rawWindowId);
bool captureCursor = false;
static int moduleId = 0;
return webrtc::DesktopCaptureImpl::Create(++moduleId, windowId.get(), CaptureDeviceType::Window, captureCursor);
}
nsresult generateUid(nsString& uid) {
nsresult rv = NS_OK;
nsCOMPtr<nsIRandomGenerator> rg = do_GetService("@mozilla.org/security/random-generator;1", &rv);
NS_ENSURE_SUCCESS(rv, rv);
uint8_t* buffer;
const int kLen = 16;
rv = rg->GenerateRandomBytes(kLen, &buffer);
NS_ENSURE_SUCCESS(rv, rv);
for (int i = 0; i < kLen; i++) {
uid.AppendPrintf("%02x", buffer[i]);
}
free(buffer);
return rv;
}
}
class nsScreencastService::Session : public rtc::VideoSinkInterface<webrtc::VideoFrame>,
public webrtc::RawFrameCallback {
Session(
nsIScreencastServiceClient* client,
rtc::scoped_refptr<webrtc::VideoCaptureModuleEx>&& capturer,
std::unique_ptr<ScreencastEncoder> encoder,
int width, int height,
int viewportWidth, int viewportHeight,
gfx::IntMargin margin,
uint32_t jpegQuality)
: mClient(client)
, mCaptureModule(std::move(capturer))
, mEncoder(std::move(encoder))
, mJpegQuality(jpegQuality)
, mWidth(width)
, mHeight(height)
, mViewportWidth(viewportWidth)
, mViewportHeight(viewportHeight)
, mMargin(margin) {
}
~Session() override = default;
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(Session)
static RefPtr<Session> Create(
nsIScreencastServiceClient* client,
rtc::scoped_refptr<webrtc::VideoCaptureModuleEx>&& capturer,
std::unique_ptr<ScreencastEncoder> encoder,
int width, int height,
int viewportWidth, int viewportHeight,
gfx::IntMargin margin,
uint32_t jpegQuality) {
return do_AddRef(new Session(client, std::move(capturer), std::move(encoder), width, height, viewportWidth, viewportHeight, margin, jpegQuality));
}
bool Start() {
webrtc::VideoCaptureCapability capability;
// The size is ignored in fact.
capability.width = 1280;
capability.height = 960;
capability.maxFPS = ScreencastEncoder::fps;
capability.videoType = webrtc::VideoType::kI420;
int error = mCaptureModule->StartCapture(capability);
if (error) {
fprintf(stderr, "StartCapture error %d\n", error);
return false;
}
if (mEncoder)
mCaptureModule->RegisterCaptureDataCallback(this);
else
mCaptureModule->RegisterRawFrameCallback(this);
return true;
}
void Stop() {
if (mStopped) {
fprintf(stderr, "Screencast session has already been stopped\n");
return;
}
mStopped = true;
if (mEncoder)
mCaptureModule->DeRegisterCaptureDataCallback(this);
else
mCaptureModule->DeRegisterRawFrameCallback(this);
int error = mCaptureModule->StopCapture();
if (error) {
fprintf(stderr, "StopCapture error %d\n", error);
}
if (mEncoder) {
mEncoder->finish([this, protect = RefPtr{this}] {
NS_DispatchToMainThread(NS_NewRunnableFunction(
"NotifyScreencastStopped", [this, protect = std::move(protect)]() -> void {
mClient->ScreencastStopped();
}));
});
} else {
mClient->ScreencastStopped();
}
}
void ScreencastFrameAck() {
if (mFramesInFlight.load() == 0) {
fprintf(stderr, "ScreencastFrameAck is called while there are no inflight frames\n");
return;
}
mFramesInFlight.fetch_sub(1);
}
// These callbacks end up running on the VideoCapture thread.
void OnFrame(const webrtc::VideoFrame& videoFrame) override {
if (!mEncoder)
return;
mEncoder->encodeFrame(videoFrame);
}
// These callbacks end up running on the VideoCapture thread.
void OnRawFrame(uint8_t* videoFrame, size_t videoFrameStride, const webrtc::VideoCaptureCapability& frameInfo) override {
int pageWidth = frameInfo.width - mMargin.LeftRight();
int pageHeight = frameInfo.height - mMargin.TopBottom();
// Frame size is 1x1 when browser window is minimized.
if (pageWidth <= 1 || pageHeight <= 1)
return;
// Headed Firefox brings sizes in sync slowly.
if (mViewportWidth && pageWidth > mViewportWidth)
pageWidth = mViewportWidth;
if (mViewportHeight && pageHeight > mViewportHeight)
pageHeight = mViewportHeight;
if (mFramesInFlight.load() >= kMaxFramesInFlight)
return;
int screenshotWidth = pageWidth;
int screenshotHeight = pageHeight;
int screenshotTopMargin = mMargin.TopBottom();
std::unique_ptr<uint8_t[]> canvas;
uint8_t* canvasPtr = videoFrame;
int canvasStride = videoFrameStride;
if (mWidth < pageWidth || mHeight < pageHeight) {
double scale = std::min(1., std::min((double)mWidth / pageWidth, (double)mHeight / pageHeight));
int canvasWidth = frameInfo.width * scale;
int canvasHeight = frameInfo.height * scale;
canvasStride = canvasWidth * 4;
screenshotWidth *= scale;
screenshotHeight *= scale;
screenshotTopMargin *= scale;
canvas.reset(new uint8_t[canvasWidth * canvasHeight * 4]);
canvasPtr = canvas.get();
libyuv::ARGBScale(videoFrame,
videoFrameStride,
frameInfo.width,
frameInfo.height,
canvasPtr,
canvasStride,
canvasWidth,
canvasHeight,
libyuv::kFilterBilinear);
}
jpeg_compress_struct info;
jpeg_error_mgr error;
info.err = jpeg_std_error(&error);
jpeg_create_compress(&info);
unsigned char* bufferPtr = nullptr;
unsigned long bufferSize;
jpeg_mem_dest(&info, &bufferPtr, &bufferSize);
info.image_width = screenshotWidth;
info.image_height = screenshotHeight;
#if MOZ_LITTLE_ENDIAN()
if (frameInfo.videoType == webrtc::VideoType::kARGB)
info.in_color_space = JCS_EXT_BGRA;
if (frameInfo.videoType == webrtc::VideoType::kBGRA)
info.in_color_space = JCS_EXT_ARGB;
#else
if (frameInfo.videoType == webrtc::VideoType::kARGB)
info.in_color_space = JCS_EXT_ARGB;
if (frameInfo.videoType == webrtc::VideoType::kBGRA)
info.in_color_space = JCS_EXT_BGRA;
#endif
// # of color components in input image
info.input_components = 4;
jpeg_set_defaults(&info);
jpeg_set_quality(&info, mJpegQuality, true);
jpeg_start_compress(&info, true);
while (info.next_scanline < info.image_height) {
JSAMPROW row = canvasPtr + (screenshotTopMargin + info.next_scanline) * canvasStride;
if (jpeg_write_scanlines(&info, &row, 1) != 1) {
fprintf(stderr, "JPEG library failed to encode line\n");
break;
}
}
jpeg_finish_compress(&info);
jpeg_destroy_compress(&info);
nsCString base64;
nsresult rv = mozilla::Base64Encode(reinterpret_cast<char *>(bufferPtr), bufferSize, base64);
free(bufferPtr);
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
mFramesInFlight.fetch_add(1);
NS_DispatchToMainThread(NS_NewRunnableFunction(
"NotifyScreencastFrame", [this, protect = RefPtr{this}, base64, pageWidth, pageHeight]() -> void {
if (mStopped)
return;
NS_ConvertUTF8toUTF16 utf16(base64);
mClient->ScreencastFrame(utf16, pageWidth, pageHeight);
}));
}
private:
RefPtr<nsIScreencastServiceClient> mClient;
rtc::scoped_refptr<webrtc::VideoCaptureModuleEx> mCaptureModule;
std::unique_ptr<ScreencastEncoder> mEncoder;
uint32_t mJpegQuality;
bool mStopped = false;
std::atomic<uint32_t> mFramesInFlight = 0;
int mWidth;
int mHeight;
int mViewportWidth;
int mViewportHeight;
gfx::IntMargin mMargin;
};
// static
already_AddRefed<nsIScreencastService> nsScreencastService::GetSingleton() {
if (gScreencastService) {
return do_AddRef(gScreencastService);
}
gScreencastService = new nsScreencastService();
// ClearOnShutdown(&gScreencastService);
return do_AddRef(gScreencastService);
}
nsScreencastService::nsScreencastService() = default;
nsScreencastService::~nsScreencastService() {
}
nsresult nsScreencastService::StartVideoRecording(nsIScreencastServiceClient* aClient, nsIDocShell* aDocShell, bool isVideo, const nsACString& aVideoFileName, uint32_t width, uint32_t height, uint32_t quality, uint32_t viewportWidth, uint32_t viewportHeight, uint32_t offsetTop, nsAString& sessionId) {
MOZ_RELEASE_ASSERT(NS_IsMainThread(), "Screencast service must be started on the Main thread.");
PresShell* presShell = aDocShell->GetPresShell();
if (!presShell)
return NS_ERROR_UNEXPECTED;
nsViewManager* viewManager = presShell->GetViewManager();
if (!viewManager)
return NS_ERROR_UNEXPECTED;
nsView* view = viewManager->GetRootView();
if (!view)
return NS_ERROR_UNEXPECTED;
nsIWidget* widget = view->GetWidget();
rtc::scoped_refptr<webrtc::VideoCaptureModuleEx> capturer = CreateWindowCapturer(widget);
if (!capturer)
return NS_ERROR_FAILURE;
gfx::IntMargin margin;
auto bounds = widget->GetScreenBounds().ToUnknownRect();
auto clientBounds = widget->GetClientBounds().ToUnknownRect();
// Crop the image to exclude frame (if any).
margin = bounds - clientBounds;
// Crop the image to exclude controls.
margin.top += offsetTop;
nsCString error;
std::unique_ptr<ScreencastEncoder> encoder;
if (isVideo) {
encoder = ScreencastEncoder::create(error, PromiseFlatCString(aVideoFileName), width, height, margin);
if (!encoder) {
fprintf(stderr, "Failed to create ScreencastEncoder: %s\n", error.get());
return NS_ERROR_FAILURE;
}
}
nsString uid;
nsresult rv = generateUid(uid);
NS_ENSURE_SUCCESS(rv, rv);
sessionId = uid;
auto session = Session::Create(aClient, std::move(capturer), std::move(encoder), width, height, viewportWidth, viewportHeight, margin, isVideo ? 0 : quality);
if (!session->Start())
return NS_ERROR_FAILURE;
mIdToSession.emplace(sessionId, std::move(session));
return NS_OK;
}
nsresult nsScreencastService::StopVideoRecording(const nsAString& aSessionId) {
nsString sessionId(aSessionId);
auto it = mIdToSession.find(sessionId);
if (it == mIdToSession.end())
return NS_ERROR_INVALID_ARG;
it->second->Stop();
mIdToSession.erase(it);
return NS_OK;
}
nsresult nsScreencastService::ScreencastFrameAck(const nsAString& aSessionId) {
nsString sessionId(aSessionId);
auto it = mIdToSession.find(sessionId);
if (it == mIdToSession.end())
return NS_ERROR_INVALID_ARG;
it->second->ScreencastFrameAck();
return NS_OK;
}
} // namespace mozilla