Take snapshot of video in Qt Multimedia - qt

Question

Is it possible to take snapshot of a video in Qt Multimedia? how?

Answer 1

It depends on the platform but what you can probably do is to use a QMediaPlayer, set a subclassed video surface via setVideoOutput, and get the frame data from the QVideoFrame passed in the present method. You'll then have to deal with the frame format and to map if those are not in CPU memory.
However, depending on your need, I would use ffmpeg/libav to get a frame from a specific position.

Answer 2

Try this (Documentation here: http://doc.qt.io/qt-5/qml-qtquick-item.html#grabToImage-method)
import QtQuick 2.5
import QtQuick.Window 2.2
import QtQuick.Controls 1.4
import QtQuick.Layouts 1.1
import QtMultimedia 5.0
Window {
id: mainWindow
visible: true
width: 480
height: 800
MediaPlayer {
id: player
source: "file:///location/of/some/video.mp4"
autoPlay: false
}
ColumnLayout {
anchors.fill: parent
VideoOutput {
id: output
source: player
Layout.fillHeight: true
Layout.fillWidth: true
}
Row {
id: buttonsRow
height: 100
spacing: 20
anchors.horizontalCenter: parent.horizontalCenter
Layout.margins: 10
Button {
id: playPauseButton
text: player.playbackState === MediaPlayer.PlayingState ? "Pause" : "Play"
onClicked: {
var playing = player.playbackState === MediaPlayer.PlayingState;
playing ? player.pause() : player.play();
}
}
Button {
text: "Snapshot"
onClicked: {
output.grabToImage(function(image) {
console.log("Called...", arguments)
image.saveToFile("screen.png"); // save happens here
});
}
}
}
}
}