Processing frames from camera

This example shows how to run a camera widget using QVideoFrame-based processing pipeline.

Frame-based camera widget with Gaussian blurring process

PySide6PyQt6

"""
Camera example with blurring pipeline on QVideoframe.

The processor receives video frame from the video sink of media capture session,
and emits processed video frame.

"""

import cv2  # type: ignore[import]
import numpy as np
from PySide6.QtCore import Slot
from PySide6.QtWidgets import QMainWindow
from PySide6.QtMultimedia import QCamera, QMediaCaptureSession, QVideoFrame, QVideoSink
from PySide6.QtMultimediaWidgets import QVideoWidget
from araviq6 import VideoFrameWorker, VideoFrameProcessor


class BlurWorker(VideoFrameWorker):
    def processArray(self, array: np.ndarray) -> np.ndarray:
        return cv2.GaussianBlur(array, (0, 0), 25)


class Window(QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self._camera = QCamera()
        self._captureSession = QMediaCaptureSession()
        self._cameraVideoSink = QVideoSink()
        self._frameProcessor = VideoFrameProcessor()
        self._blurWorker = BlurWorker()
        self._videoWidget = QVideoWidget()

        # set up the pipeline
        self._captureSession.setCamera(self._camera)
        self._captureSession.setVideoSink(self._cameraVideoSink)
        self._cameraVideoSink.videoFrameChanged.connect(
            self._frameProcessor.processVideoFrame
        )
        self._frameProcessor.videoFrameProcessed.connect(self.displayVideoFrame)

        self._frameProcessor.setWorker(self._blurWorker)
        self.setCentralWidget(self._videoWidget)

        self._camera.start()

    @Slot(QVideoFrame)
    def displayVideoFrame(self, frame: QVideoFrame):
        self._videoWidget.videoSink().setVideoFrame(frame)

    def closeEvent(self, event):
        self._frameProcessor.stop()
        super().closeEvent(event)


if __name__ == "__main__":
    from PySide6.QtWidgets import QApplication
    import sys

    app = QApplication(sys.argv)
    window = Window()
    window.show()
    app.exec()
    app.quit()