如何更改在 QML 中具有多个音轨的视频的音轨

Question

我们如何更改具有多个音轨的视频的音轨？例如，我有一个包含印地语和英语音频的电影的 .mkv 文件。但是当我使用 GNOME 视频播放器播放它时，它会默认播放印地语。Gnome Video 具有更改音轨的选项。当涉及到 QML 时，我们如何指定需要以哪种语言播放视频。我正在使用 QML QtMultimedia 视频组件。这就是它的样子Video {    id: video    width : 800    height : 600    source: "video.mkv"    language: "English"    MouseArea {        anchors.fill: parent        onClicked: {            video.play()        }    }    focus: true    Keys.onSpacePressed: video.playbackState == MediaPlayer.PlayingState ? video.pause() : video.play()    Keys.onLeftPressed: video.seek(video.position - 5000)    Keys.onRightPressed: video.seek(video.position + 5000)}

Answer 1

基本上这个问题与本文中的问题相同，因此我将忽略解释（要完全理解答案，您必须先阅读我的另一个答案的解释）并且只提供代码。

考虑到上述情况，有必要访问媒体播放器，但不幸的是项目视频不允许它，所以必须使用 VideoOuput + MediaPlayer

PyQt5：

from PyQt5 import QtCore, QtGui, QtQml, QtMultimedia

import sip

class PlayerHelper(QtCore.QObject):

    qmlplayerChanged = QtCore.pyqtSignal()

    def __init__(self, parent=None):

        super().__init__(parent)

        self.qml_player = None

    @QtCore.pyqtProperty(QtCore.QObject, notify=qmlplayerChanged)

    def qmlplayer(self):

        return self.qmlplayer

    @qmlplayer.setter

    def qmlplayer(self, player):

        self.qml_player = player

        self.qmlplayerChanged.emit()

    @staticmethod

    def get_stream_control(qmlplayer):

        mediaObject = qmlplayer.property("mediaObject")

        player = sip.cast(mediaObject, QtMultimedia.QMediaPlayer)

        control = player.service().requestControl(

            "org.qt-project.qt.mediastreamscontrol/5.0"

        )

        return sip.cast(control, QtMultimedia.QMediaStreamsControl)

    @QtCore.pyqtSlot(result=int)

    def audioCount(self):

        if not self.qml_player:

            return -1

        stream_control = self.get_stream_control(self.qml_player)

        count = 0

        for i in range(stream_control.streamCount()):

            if (

                stream_control.streamType(i)

                == QtMultimedia.QMediaStreamsControl.AudioStream

            ):

                count += 1

        return count

    @QtCore.pyqtSlot(int)

    def setAudioActive(self, index):

        if not self.qml_player:

            return

        stream_control = self.get_stream_control(self.qml_player)

        count = 0

        for i in range(stream_control.streamCount()):

            if (

                stream_control.streamType(i)

                == QtMultimedia.QMediaStreamsControl.AudioStream

            ):

                if index == count:

                    stream_control.setActive(i, True)

                    return

                count += 1

    @QtCore.pyqtSlot(result=int)

    def audioActive(self):

        if not self.qml_player:

            return -1

        stream_control = self.get_stream_control(self.qml_player)

        count = 0

        for i in range(stream_control.streamCount()):

            if (

                stream_control.streamType(i)

                == QtMultimedia.QMediaStreamsControl.AudioStream

            ):

                if stream_control.isActive(i):

                    return count

                count += 1

        return -1

if __name__ == "__main__":

    import os

    import sys

    app = QtGui.QGuiApplication(sys.argv)

    QtQml.qmlRegisterType(PlayerHelper, "AudioHelper", 1, 0, "PlayerHelper")

    engine = QtQml.QQmlApplicationEngine()

    file = os.path.join(os.path.dirname(os.path.realpath(__file__)), "main.qml")

    engine.load(QtCore.QUrl.fromLocalFile(file))

    if not engine.rootObjects():

        sys.exit(-1)

    sys.exit(app.exec())

main.qml

import QtQuick 2.14

import QtQuick.Controls 2.14

import QtMultimedia 5.14

import AudioHelper 1.0

ApplicationWindow {

    visible: true

    width: 640

    height: 480

    MediaPlayer {

        id: player

        source: "video.mkv"

    }

    PlayerHelper{

        id: playerhelper

        qmlplayer: player

    }

    VideoOutput {

        id: videoOutput

        source: player

        anchors.fill: parent

        focus: true

        Keys.onSpacePressed: player.playbackState == MediaPlayer.PlayingState ? player.pause() : player.play()

        Keys.onLeftPressed: player.seek(player.position - 5000)

        Keys.onRightPressed: player.seek(player.position + 5000)

        MouseArea{

            anchors.fill: parent

            acceptedButtons: Qt.LeftButton | Qt.RightButton

            onClicked: {

                if (mouse.button == Qt.LeftButton){

                    player.play()

                }

                else{

                    var count = playerhelper.audioCount()

                    var index = playerhelper.audioActive()

                    while(context_menu.count){

                        var it = context_menu.takeItem(0)

                        it.destroy()

                    }

                    for(var i = 0; i < count; ++i){

                        var item = Qt.createQmlObject('import QtQuick 2.13; import QtQuick.Controls 2.13; MenuItem {}', context_menu)

                        item.text = "Audio " + i;

                        item.checkable = true

                        item.checked = i == index 

                        var f = function(it, i){ 

                            it.triggered.connect(function (){ 

                                playerhelper.setAudioActive(i)

                            }

                        )}

                        f(item, i)

                        context_menu.addItem(item)

                    }

                    context_menu.popup(mouseX, mouseY)

                }

            }

        }

        Menu {

            id: context_menu

        }

    }

}