main.qml

import QtQuick 2.14
import QtQuick.Controls 2.14
import QtMultimedia 5.14
import QtQuick.Dialogs 1.2

// import com.example 1.0  // Import your C++ module

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: "Qt + MLT Example"

    Rectangle {
        width: 640
        height: 480
        color: "black"

        // VideoOutput to display the video
        VideoOutput {
            id: videoOutput
            anchors.fill: parent
            // MediaPlayer for playing the video
            source: mediaPlayer
        }
        Row{
            anchors.bottom: parent
            spacing: 20
             Button {
                text: "视频合成"
                // anchors.bottom: parent.right
                anchors.horizontalCenter: parent.horizontalRight
                onClicked: {
                    // Open the file dialog to choose a video file
                    // fileDialog.open()
                    worker.doCompose()

                }
            }
                // Button to open FileDialog to select a video file
            Button {
                text: "Select Video"
                // anchors.top: parent.
                anchors.horizontalCenter: parent.horizontalLeft
                onClicked: {
                    // Open the file dialog to choose a video file
                    fileDialog.open()
                }
            }
        }

        // FileDialog to allow the user to select a video file
        FileDialog {
            id: fileDialog
            title: "Select a Video"
            folder: "file:///C:/"  // default folder (you can set this dynamically)
            nameFilters: ["Video Files (*.mp4 *.avi *.mov)"]  // File types
            onAccepted: {
                // When a file is selected, set it as the source of the MediaPlayer
                mediaPlayer.source = fileDialog.fileUrl
                // console.log("Open: ", mediaPlayer.source)
                mediaPlayer.play()
            }
        }

        // MediaPlayer to handle video playback
        MediaPlayer {
            id: mediaPlayer
            // source: "gst-pipeline: filesrc location=../main/main.mp4 ! qtdemux ! avdec_h264 ! qtvideosink"
            source: "../main/main.mp4"
            autoPlay: false  // Set to false since you control play via button click 
            onError: {
                console.log("Error: " + mediaPlayer.errorString)  // Log errors if any
            }
        }
    }
}