libvlc+qwidget 在 Win64 上处理鼠标事件

Question

我正在使用 Qt 并使用 libVlc 2.1.5 版进行实时视频流。我想处理 vlc 帧上的鼠标按下事件。但是当我单击 vlc 时，它无法引发鼠标事件。 我试过了

libvlc_video_set_mouse_input(libvlcMediaPlayer,false);

但是它将鼠标隐藏在 vlc 上。 如果有人知道，请帮助我。

谢谢。

Answer 1

您还需要使用 libvlc_video_set_key_input 函数：

libvlc_video_set_mouse_input(media_player, 0);
libvlc_video_set_key_input(media_player, 0);

Answer 2

我在 Ubuntu 16 下使用了 libvlc 2.2.2，并设法通过以下方式在 vlc 视频区域上获取鼠标事件（仅提供与问题相关的代码）。在我的 VideoPlayer 类中，我有成员：

libvlc_media_player_t* vlcPlayer;
VideoWidget* widget;

，其中 VideoWidget 是我的自定义小部件类。在cpp中我设置libvlc_video_set_mouse_input(vlcPlayer, false);，创建widget实例，将它传递给我的用户界面，当调用“播放”视频时，我还将小部件传递给vlc libvlc_media_player_set_xwindow(vlcPlayer, widget->winId());

我的自定义 VideoWidget 类如下：

// header
class VideoWidget : public QFrame
{
public:
  VideoWidget(QWidget* parent = Q_NULLPTR);

protected:
  void mousePressEvent(QMouseEvent* event) override;
};

// cpp
VideoWidget::VideoWidget(QWidget* parent)
  : QFrame(parent)
{
}

void VideoWidget::mousePressEvent(QMouseEvent* event)
{
  qDebug() << "mouse press";
  QFrame::mousePressEvent(event);
}

所以想法是通过传递给 vlc 的 QWidget 来捕获鼠标事件。

Answer 3

Windows 上的三种解决方案

方案一：WS_EX_TRANSPARENT

注意：可能不适用于Windows 7 或以下版本。

# Created by BaiJiFeiLong@gmail.com at 2022/2/10 23:31
import vlc
import win32con
import win32gui
from PySide2 import QtWidgets, QtCore


def togglePlaying():
    player.get_state() == vlc.State.Ended and player.set_media(player.get_media())
    player.get_state() == vlc.State.Playing and player.pause()
    player.get_state() != vlc.State.Playing and player.play()


def onVideoOut(event):
    hwnd = win32gui.GetWindow(player.get_hwnd(), win32con.GW_CHILD)
    exStyle = win32gui.GetWindowLong(hwnd, win32con.GWL_EXSTYLE)
    exStyle |= win32con.WS_EX_LAYERED | win32con.WS_EX_TRANSPARENT
    win32gui.SetWindowLong(hwnd, win32con.GWL_EXSTYLE, exStyle)


app = QtWidgets.QApplication()
window = QtWidgets.QMainWindow()
window.setCentralWidget(QtWidgets.QWidget())
window.centralWidget().mousePressEvent = lambda *args: togglePlaying()
window.setWindowFlags(QtCore.Qt.WindowType.WindowCloseButtonHint)
window.resize(854, 480)
window.show()

filename = r"https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"
player = vlc.MediaPlayer(filename)
player.set_hwnd(window.centralWidget().winId())
player.event_manager().event_attach(vlc.EventType.MediaPlayerVout, onVideoOut)
player.play()

app.exec_()

方案二：低级鼠标挂钩

# Created by BaiJiFeiLong@gmail.com at 2022/2/10 23:31
from ctypes import WINFUNCTYPE, c_int, Structure, cast, POINTER, windll
from ctypes.wintypes import LPARAM, WPARAM, DWORD, PULONG, LONG

import vlc
import win32con
import win32gui
from PySide2 import QtWidgets, QtCore


def genStruct(name="Structure", **kwargs):
    return type(name, (Structure,), dict(
        _fields_=list(kwargs.items()),
        __str__=lambda self: "%s(%s)" % (name, ",".join("%s=%s" % (k, getattr(self, k)) for k in kwargs))
    ))


@WINFUNCTYPE(LPARAM, c_int, WPARAM, LPARAM)
def hookProc(nCode, wParam, lParam):
    msg = cast(lParam, POINTER(HookStruct))[0]
    hwnd = win32gui.WindowFromPoint((msg.pt.x, msg.pt.y))
    if hwnd in vlcHwnds:
        win32gui.PostMessage(widget.winId(), wParam, wParam, (msg.pt.y << 16) + msg.pt.x)
    return windll.user32.CallNextHookEx(None, nCode, WPARAM(wParam), LPARAM(lParam))


def togglePlaying():
    print("toggle")
    player.get_state() == vlc.State.Ended and player.set_media(player.get_media())
    player.get_state() == vlc.State.Playing and player.pause()
    player.get_state() != vlc.State.Playing and player.play()


def onVideoOut(event):
    hwnd1 = win32gui.GetWindow(player.get_hwnd(), win32con.GW_CHILD)
    hwnd2 = win32gui.GetWindow(hwnd1, win32con.GW_CHILD)
    vlcHwnds.append(hwnd1)
    vlcHwnds.append(hwnd2)
    print("vlcHwnds", vlcHwnds)


app = QtWidgets.QApplication()
widget = QtWidgets.QWidget()
widget.mouseReleaseEvent = lambda *args: togglePlaying()
window = QtWidgets.QMainWindow()
window.setCentralWidget(widget)
window.setWindowFlags(QtCore.Qt.WindowType.WindowCloseButtonHint)
window.resize(854, 480)
window.show()
vlcHwnds = []

HookStruct = genStruct(
    "Hook", pt=genStruct("Point", x=LONG, y=LONG), mouseData=DWORD, flags=DWORD, time=DWORD, dwExtraInfo=PULONG)
msgDict = {v: k for k, v in win32con.__dict__.items() if k.startswith("WM_")}
windll.user32.SetWindowsHookExW(win32con.WH_MOUSE_LL, hookProc, None, 0)

filename = r"https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"
player = vlc.MediaPlayer(filename)
player.set_hwnd(widget.winId())
player.event_manager().event_attach(vlc.EventType.MediaPlayerVout, onVideoOut)
player.play()
app.exec_()

解决方案三：进程内鼠标钩

# Created by BaiJiFeiLong@gmail.com at 2022/2/10 23:31
from ctypes import WINFUNCTYPE, c_int, Structure, cast, POINTER, windll
from ctypes.wintypes import LPARAM, WPARAM, DWORD, PULONG, LONG, HINSTANCE

import vlc
import win32api
import win32con
import win32gui
from PySide2 import QtWidgets, QtCore


def genStruct(name="Structure", **kwargs):
    return type(name, (Structure,), dict(
        _fields_=list(kwargs.items()),
        __str__=lambda self: "%s(%s)" % (name, ",".join("%s=%s" % (k, getattr(self, k)) for k in kwargs))
    ))


@WINFUNCTYPE(LPARAM, c_int, WPARAM, LPARAM)
def hookProc(nCode, wParam, lParam):
    msg = cast(lParam, POINTER(HookStruct))[0]
    win32gui.PostMessage(widget.winId(), wParam, wParam, (msg.pt.y << 16) + msg.pt.x)
    return windll.user32.CallNextHookEx(None, nCode, WPARAM(wParam), LPARAM(lParam))


def togglePlaying():
    player.get_state() == vlc.State.Ended and player.set_media(player.get_media())
    player.get_state() == vlc.State.Playing and player.pause()
    player.get_state() != vlc.State.Playing and player.play()


def onVideoOut(event):
    hwnd1 = win32gui.GetWindow(player.get_hwnd(), win32con.GW_CHILD)
    processId = win32api.GetModuleHandle()
    threadId = windll.user32.GetWindowThreadProcessId(hwnd1, None)
    windll.user32.SetWindowsHookExW(win32con.WH_MOUSE, hookProc, HINSTANCE(processId), threadId)


app = QtWidgets.QApplication()
window = QtWidgets.QMainWindow()
widget = QtWidgets.QWidget()
widget.mouseReleaseEvent = lambda *args: togglePlaying()
window.setCentralWidget(widget)
window.setWindowFlags(QtCore.Qt.WindowType.WindowCloseButtonHint)
window.resize(854, 480)
window.show()

HookStruct = genStruct(
    "Hook", pt=genStruct("Point", x=LONG, y=LONG), mouseData=DWORD, flags=DWORD, time=DWORD, dwExtraInfo=PULONG)
msgDict = {v: k for k, v in win32con.__dict__.items() if k.startswith("WM_")}
filename = r"https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"
player = vlc.MediaPlayer(filename)
player.set_hwnd(widget.winId())
player.event_manager().event_attach(vlc.EventType.MediaPlayerVout, onVideoOut)
player.play()

app.exec_()