Article Outline
Python pyqt (gui) example 'camera'
camera
Python pyqt example: camera
#!/usr/bin/env python
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
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## met:
## * Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
## * Redistributions in binary form must reproduce the above copyright
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## the documentation and/or other materials provided with the
## distribution.
## * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
## the names of its contributors may be used to endorse or promote
## products derived from this software without specific prior written
## permission.
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## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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## $QT_END_LICENSE$
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#############################################################################
from PyQt5.QtCore import QByteArray, qFuzzyCompare, Qt, QTimer
from PyQt5.QtGui import QPalette, QPixmap
from PyQt5.QtMultimedia import (QAudioEncoderSettings, QCamera,
QCameraImageCapture, QImageEncoderSettings, QMediaMetaData,
QMediaRecorder, QMultimedia, QVideoEncoderSettings)
from PyQt5.QtWidgets import (QAction, QActionGroup, QApplication, QDialog,
QMainWindow, QMessageBox)
from ui_camera import Ui_Camera
from ui_imagesettings import Ui_ImageSettingsUi
from ui_videosettings import Ui_VideoSettingsUi
class ImageSettings(QDialog):
def __init__(self, imageCapture, parent=None):
super(ImageSettings, self).__init__(parent)
self.ui = Ui_ImageSettingsUi()
self.imagecapture = imageCapture
self.ui.setupUi(self)
self.ui.imageCodecBox.addItem("Default image format", "")
for codecName in self.imagecapture.supportedImageCodecs():
description = self.imagecapture.imageCodecDescription(codecName)
self.ui.imageCodecBox.addItem(codecName + ": " + description,
codecName)
self.ui.imageQualitySlider.setRange(0, QMultimedia.VeryHighQuality)
self.ui.imageResolutionBox.addItem("Default resolution")
supportedResolutions, _ = self.imagecapture.supportedResolutions()
for resolution in supportedResolutions:
self.ui.imageResolutionBox.addItem(
"%dx%d" % (resolution.width(), resolution.height()),
resolution)
def imageSettings(self):
settings = self.imagecapture.encodingSettings()
settings.setCodec(self.boxValue(self.ui.imageCodecBox))
settings.setQuality(
QMultimedia.EncodingQuality(
self.ui.imageQualitySlider.value()))
settings.setResolution(self.boxValue(self.ui.imageResolutionBox))
return settings
def setImageSettings(self, settings):
self.selectComboBoxItem(self.ui.imageCodecBox, settings.codec())
self.selectComboBoxItem(self.ui.imageResolutionBox,
settings.resolution())
self.ui.imageQualitySlider.setValue(settings.quality())
@staticmethod
def boxValue(box):
idx = box.currentIndex()
if idx == -1:
return None
return box.itemData(idx)
@staticmethod
def selectComboBoxItem(box, value):
for i in range(box.count()):
if box.itemData(i) == value:
box.setCurrentIndex(i)
break
class VideoSettings(QDialog):
def __init__(self, mediaRecorder, parent=None):
super(VideoSettings, self).__init__(parent)
self.ui = Ui_VideoSettingsUi()
self.mediaRecorder = mediaRecorder
self.ui.setupUi(self)
self.ui.audioCodecBox.addItem("Default audio codec", "")
for codecName in self.mediaRecorder.supportedAudioCodecs():
description = self.mediaRecorder.audioCodecDescription(codecName)
self.ui.audioCodecBox.addItem(codecName + ": " + description,
codecName)
supportedSampleRates, _ = self.mediaRecorder.supportedAudioSampleRates()
for sampleRate in supportedSampleRates:
self.ui.audioSampleRateBox.addItem(str(sampleRate), sampleRate)
self.ui.audioQualitySlider.setRange(0, QMultimedia.VeryHighQuality)
self.ui.videoCodecBox.addItem("Default video codec", "")
for codecName in self.mediaRecorder.supportedVideoCodecs():
description = self.mediaRecorder.videoCodecDescription(codecName)
self.ui.videoCodecBox.addItem(codecName + ": " + description,
codecName)
self.ui.videoQualitySlider.setRange(0, QMultimedia.VeryHighQuality)
self.ui.videoResolutionBox.addItem("Default")
supportedResolutions, _ = self.mediaRecorder.supportedResolutions()
for resolution in supportedResolutions:
self.ui.videoResolutionBox.addItem(
"%dx%d" % (resolution.width(), resolution.height()),
resolution)
self.ui.videoFramerateBox.addItem("Default")
supportedFrameRates, _ = self.mediaRecorder.supportedFrameRates()
for rate in supportedFrameRates:
self.ui.videoFramerateBox.addItem("%0.2f" % rate, rate)
self.ui.containerFormatBox.addItem("Default container", "")
for format in self.mediaRecorder.supportedContainers():
self.ui.containerFormatBox.addItem(
format + ":" + self.mediaRecorder.containerDescription(
format),
format)
def audioSettings(self):
settings = self.mediaRecorder.audioSettings()
settings.setCodec(self.boxValue(self.ui.audioCodecBox))
settings.setQuality(
QMultimedia.EncodingQuality(
self.ui.audioQualitySlider.value()))
settings.setSampleRate(self.boxValue(self.ui.audioSampleRateBox))
return settings
def setAudioSettings(self, settings):
self.selectComboBoxItem(self.ui.audioCodecBox, settings.codec())
self.selectComboBoxItem(self.ui.audioSampleRateBox,
settings.sampleRate())
self.ui.audioQualitySlider.setValue(settings.quality())
def videoSettings(self):
settings = self.mediaRecorder.videoSettings()
settings.setCodec(self.boxValue(self.ui.videoCodecBox))
settings.setQuality(
QMultimedia.EncodingQuality(
self.ui.videoQualitySlider.value()))
settings.setResolution(self.boxValue(self.ui.videoResolutionBox))
settings.setFrameRate(self.boxValue(self.ui.videoFramerateBox))
return settings
def setVideoSettings(self, settings):
self.selectComboBoxItem(self.ui.videoCodecBox, settings.codec())
self.selectComboBoxItem(self.ui.videoResolutionBox,
settings.resolution())
self.ui.videoQualitySlider.setValue(settings.quality())
for i in range(1, self.ui.videoFramerateBox.count()):
itemRate = self.ui.videoFramerateBox.itemData(i)
if qFuzzyCompare(itemRate, settings.frameRate()):
self.ui.videoFramerateBox.setCurrentIndex(i)
break
def format(self):
return self.boxValue(self.ui.containerFormatBox)
def setFormat(self, format):
self.selectComboBoxItem(self.ui.containerFormatBox, format)
@staticmethod
def boxValue(box):
idx = box.currentIndex()
if idx == -1:
return None
return box.itemData(idx)
@staticmethod
def selectComboBoxItem(box, value):
for i in range(box.count()):
if box.itemData(i) == value:
box.setCurrentIndex(i)
break
class Camera(QMainWindow):
def __init__(self, parent=None):
super(Camera, self).__init__(parent)
self.ui = Ui_Camera()
self.camera = None
self.imageCapture = None
self.mediaRecorder = None
self.isCapturingImage = False
self.applicationExiting = False
self.imageSettings = QImageEncoderSettings()
self.audioSettings = QAudioEncoderSettings()
self.videoSettings = QVideoEncoderSettings()
self.videoContainerFormat = ''
self.ui.setupUi(self)
cameraDevice = QByteArray()
videoDevicesGroup = QActionGroup(self)
videoDevicesGroup.setExclusive(True)
for deviceName in QCamera.availableDevices():
description = QCamera.deviceDescription(deviceName)
videoDeviceAction = QAction(description, videoDevicesGroup)
videoDeviceAction.setCheckable(True)
videoDeviceAction.setData(deviceName)
if cameraDevice.isEmpty():
cameraDevice = deviceName
videoDeviceAction.setChecked(True)
self.ui.menuDevices.addAction(videoDeviceAction)
videoDevicesGroup.triggered.connect(self.updateCameraDevice)
self.ui.captureWidget.currentChanged.connect(self.updateCaptureMode)
self.ui.lockButton.hide()
self.setCamera(cameraDevice)
def setCamera(self, cameraDevice):
if cameraDevice.isEmpty():
self.camera = QCamera()
else:
self.camera = QCamera(cameraDevice)
self.camera.stateChanged.connect(self.updateCameraState)
self.camera.error.connect(self.displayCameraError)
self.mediaRecorder = QMediaRecorder(self.camera)
self.mediaRecorder.stateChanged.connect(self.updateRecorderState)
self.imageCapture = QCameraImageCapture(self.camera)
self.mediaRecorder.durationChanged.connect(self.updateRecordTime)
self.mediaRecorder.error.connect(self.displayRecorderError)
self.mediaRecorder.setMetaData(QMediaMetaData.Title, "Test Title")
self.ui.exposureCompensation.valueChanged.connect(
self.setExposureCompensation)
self.camera.setViewfinder(self.ui.viewfinder)
self.updateCameraState(self.camera.state())
self.updateLockStatus(self.camera.lockStatus(), QCamera.UserRequest)
self.updateRecorderState(self.mediaRecorder.state())
self.imageCapture.readyForCaptureChanged.connect(self.readyForCapture)
self.imageCapture.imageCaptured.connect(self.processCapturedImage)
self.imageCapture.imageSaved.connect(self.imageSaved)
self.camera.lockStatusChanged.connect(self.updateLockStatus)
self.ui.captureWidget.setTabEnabled(0,
self.camera.isCaptureModeSupported(QCamera.CaptureStillImage))
self.ui.captureWidget.setTabEnabled(1,
self.camera.isCaptureModeSupported(QCamera.CaptureVideo))
self.updateCaptureMode()
self.camera.start()
def keyPressEvent(self, event):
if event.isAutoRepeat():
return
if event.key() == Qt.Key_CameraFocus:
self.displayViewfinder()
self.camera.searchAndLock()
event.accept()
elif event.key() == Qt.Key_Camera:
if self.camera.captureMode() == QCamera.CaptureStillImage:
self.takeImage()
elif self.mediaRecorder.state() == QMediaRecorder.RecordingState:
self.stop()
else:
self.record()
event.accept()
else:
super(Camera, self).keyPressEvent(event)
def keyReleaseEvent(self, event):
if event.isAutoRepeat():
return
if event.key() == Qt.Key_CameraFocus:
self.camera.unlock()
else:
super(Camera, self).keyReleaseEvent(event)
def updateRecordTime(self):
msg = "Recorded %d sec" % (self.mediaRecorder.duration() // 1000)
self.ui.statusbar.showMessage(msg)
def processCapturedImage(self, requestId, img):
scaledImage = img.scaled(self.ui.viewfinder.size(), Qt.KeepAspectRatio,
Qt.SmoothTransformation)
self.ui.lastImagePreviewLabel.setPixmap(QPixmap.fromImage(scaledImage))
self.displayCapturedImage()
QTimer.singleShot(4000, self.displayViewfinder)
def configureCaptureSettings(self):
if self.camera.captureMode() == QCamera.CaptureStillImage:
self.configureImageSettings()
elif self.camera.captureMode() == QCamera.CaptureVideo:
self.configureVideoSettings()
def configureVideoSettings(self):
settingsDialog = VideoSettings(self.mediaRecorder)
settingsDialog.setAudioSettings(self.audioSettings)
settingsDialog.setVideoSettings(self.videoSettings)
settingsDialog.setFormat(self.videoContainerFormat)
if settingsDialog.exec_():
self.audioSettings = settingsDialog.audioSettings()
self.videoSettings = settingsDialog.videoSettings()
self.videoContainerFormat = settingsDialog.format()
self.mediaRecorder.setEncodingSettings(self.audioSettings,
self.videoSettings, self.videoContainerFormat)
def configureImageSettings(self):
settingsDialog = ImageSettings(self.imageCapture)
settingsDialog.setImageSettings(self.imageSettings)
if settingsDialog.exec_():
self.imageSettings = settingsDialog.imageSettings()
self.imageCapture.setEncodingSettings(self.imageSettings)
def record(self):
self.mediaRecorder.record()
self.updateRecordTime()
def pause(self):
self.mediaRecorder.pause()
def stop(self):
self.mediaRecorder.stop()
def setMuted(self, muted):
self.mediaRecorder.setMuted(muted)
def toggleLock(self):
if self.camera.lockStatus() in (QCamera.Searching, QCamera.Locked):
self.camera.unlock()
elif self.camera.lockStatus() == QCamera.Unlocked:
self.camera.searchAndLock()
def updateLockStatus(self, status, reason):
indicationColor = Qt.black
if status == QCamera.Searching:
self.ui.statusbar.showMessage("Focusing...")
self.ui.lockButton.setText("Focusing...")
indicationColor = Qt.yellow
elif status == QCamera.Locked:
self.ui.lockButton.setText("Unlock")
self.ui.statusbar.showMessage("Focused", 2000)
indicationColor = Qt.darkGreen
elif status == QCamera.Unlocked:
self.ui.lockButton.setText("Focus")
if reason == QCamera.LockFailed:
self.ui.statusbar.showMessage("Focus Failed", 2000)
indicationColor = Qt.red
palette = self.ui.lockButton.palette()
palette.setColor(QPalette.ButtonText, indicationColor)
self.ui.lockButton.setPalette(palette)
def takeImage(self):
self.isCapturingImage = True
self.imageCapture.capture()
def startCamera(self):
self.camera.start()
def stopCamera(self):
self.camera.stop()
def updateCaptureMode(self):
tabIndex = self.ui.captureWidget.currentIndex()
captureMode = QCamera.CaptureStillImage if tabIndex == 0 else QCamera.CaptureVideo
if self.camera.isCaptureModeSupported(captureMode):
self.camera.setCaptureMode(captureMode)
def updateCameraState(self, state):
if state == QCamera.ActiveState:
self.ui.actionStartCamera.setEnabled(False)
self.ui.actionStopCamera.setEnabled(True)
self.ui.captureWidget.setEnabled(True)
self.ui.actionSettings.setEnabled(True)
elif state in (QCamera.UnloadedState, QCamera.LoadedState):
self.ui.actionStartCamera.setEnabled(True)
self.ui.actionStopCamera.setEnabled(False)
self.ui.captureWidget.setEnabled(False)
self.ui.actionSettings.setEnabled(False)
def updateRecorderState(self, state):
if state == QMediaRecorder.StoppedState:
self.ui.recordButton.setEnabled(True)
self.ui.pauseButton.setEnabled(True)
self.ui.stopButton.setEnabled(False)
elif state == QMediaRecorder.PausedState:
self.ui.recordButton.setEnabled(True)
self.ui.pauseButton.setEnabled(False)
self.ui.stopButton.setEnabled(True)
elif state == QMediaRecorder.RecordingState:
self.ui.recordButton.setEnabled(False)
self.ui.pauseButton.setEnabled(True)
self.ui.stopButton.setEnabled(True)
def setExposureCompensation(self, index):
self.camera.exposure().setExposureCompensation(index * 0.5)
def displayRecorderError(self):
QMessageBox.warning(self, "Capture error",
self.mediaRecorder.errorString())
def displayCameraError(self):
QMessageBox.warning(self, "Camera error", self.camera.errorString())
def updateCameraDevice(self, action):
self.setCamera(action.data())
def displayViewfinder(self):
self.ui.stackedWidget.setCurrentIndex(0)
def displayCapturedImage(self):
self.ui.stackedWidget.setCurrentIndex(1)
def readyForCapture(self, ready):
self.ui.takeImageButton.setEnabled(ready)
def imageSaved(self, id, fileName):
self.isCapturingImage = False
if self.applicationExiting:
self.close()
def closeEvent(self, event):
if self.isCapturingImage:
self.setEnabled(False)
self.applicationExiting = True
event.ignore()
else:
event.accept()
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
camera = Camera()
camera.show()
sys.exit(app.exec_())
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/