我正在研究这个很好的例子,它在一个带有python和GStreamer的GTK小部件中显示了一个网络摄像头输出:
http://pygstdocs.berlios.de/pygst-tutorial/webcam-viewer.html 这是代码:
#!/usr/bin/env python
import sys, os
import pygtk, gtk, gobject
import pygst
pygst.require("0.10")
import gst
class GTK_Main:
def __init__(self):
window = gtk.Window(gtk.WINDOW_TOPLEVEL)
window.set_title("Webcam-Viewer")
window.set_default_size(500, 400)
window.connect("destroy", gtk.main_quit, "WM destroy")
vbox = gtk.VBox()
window.add(vbox)
self.movie_window = gtk.DrawingArea()
vbox.add(self.movie_window)
hbox = gtk.HBox()
vbox.pack_start(hbox, False)
hbox.set_border_width(10)
hbox.pack_start(gtk.Label())
self.button = gtk.Button("Start")
self.button.connect("clicked", self.start_stop)
hbox.pack_start(self.button, False)
self.button2 = gtk.Button("Quit")
self.button2.connect("clicked", self.exit)
hbox.pack_start(self.button2, False)
hbox.add(gtk.Label())
window.show_all()
# Set up the gstreamer pipeline
self.player = gst.parse_launch ("v4l2src ! autovideosink")
bus = self.player.get_bus()
bus.add_signal_watch()
bus.enable_sync_message_emission()
bus.connect("message", self.on_message)
bus.connect("sync-message::element", self.on_sync_message)
def start_stop(self, w):
if self.button.get_label() == "Start":
self.button.set_label("Stop")
self.player.set_state(gst.STATE_PLAYING)
else:
self.player.set_state(gst.STATE_NULL)
self.button.set_label("Start")
def exit(self, widget, data=None):
gtk.main_quit()
def on_message(self, bus, message):
t = message.type
if t == gst.MESSAGE_EOS:
self.player.set_state(gst.STATE_NULL)
self.button.set_label("Start")
elif t == gst.MESSAGE_ERROR:
err, debug = message.parse_error()
print "Error: %s" % err, debug
self.player.set_state(gst.STATE_NULL)
self.button.set_label("Start")
def on_sync_message(self, bus, message):
if message.structure is None:
return
message_name = message.structure.get_name()
if message_name == "prepare-xwindow-id":
# Assign the viewport
imagesink = message.src
imagesink.set_property("force-aspect-ratio", True)
imagesink.set_xwindow_id(self.movie_window.window.xid)
GTK_Main()
gtk.gdk.threads_init()
gtk.main()
我想要做的是获取当前帧的快照并保存到磁盘的方法。 我认为有两种方法可以做到: - 一些gstreamer方法(但我想我至少应该修改管道) - 用GTK本身以某种方式抓住图片
有什么暗示吗? 我没有使用gstreamer或gtk的经验,非常感谢任何帮助
非常感谢 莫罗
答案 0 :(得分:4)
感谢OpenCV,我设法用wxPython重写了所有内容(我比pyGTK更了解)。这是一个完整的工作示例(蒙特快照!),如果有人感兴趣的话。 另请查看OpenCV wiki:http://opencv.willowgarage.com/wiki/wxpython
import wx
import opencv.cv as cv
import opencv.highgui as gui
class CvMovieFrame(wx.Frame):
TIMER_PLAY_ID = 101
def __init__(self, parent):
wx.Frame.__init__(self, parent, -1,)
sizer = wx.BoxSizer(wx.VERTICAL)
self.capture = gui.cvCreateCameraCapture(0)
frame = gui.cvQueryFrame(self.capture)
cv.cvCvtColor(frame, frame, cv.CV_BGR2RGB)
self.SetSize((frame.width + 300, frame.height + 100))
self.bmp = wx.BitmapFromBuffer(frame.width, frame.height, frame.imageData)
self.displayPanel= wx.StaticBitmap(self, -1, bitmap=self.bmp)
sizer.Add(self.displayPanel, 0, wx.ALL, 10)
self.shotbutton = wx.Button(self,-1, "Shot")
sizer.Add(self.shotbutton,-1, wx.GROW)
self.retrybutton = wx.Button(self,-1, "Retry")
sizer.Add(self.retrybutton,-1, wx.GROW)
self.retrybutton.Hide()
#events
self.Bind(wx.EVT_BUTTON, self.onShot, self.shotbutton)
self.Bind(wx.EVT_BUTTON, self.onRetry, self.retrybutton)
self.Bind(wx.EVT_PAINT, self.onPaint)
self.Bind(wx.EVT_CLOSE, self.onClose)
self.playTimer = wx.Timer(self, self.TIMER_PLAY_ID)
wx.EVT_TIMER(self, self.TIMER_PLAY_ID, self.onNextFrame)
self.fps = 8;
self.SetSizer(sizer)
sizer.Layout()
self.startTimer()
def startTimer(self):
if self.fps!=0: self.playTimer.Start(1000/self.fps)#every X ms
else: self.playTimer.Start(1000/15)#assuming 15 fps
def onRetry(self, event):
frame = gui.cvQueryFrame(self.capture)
cv.cvCvtColor(frame, frame, cv.CV_BGR2RGB)
self.bmp = wx.BitmapFromBuffer(frame.width, frame.height, frame.imageData)
self.startTimer()
self.shotbutton.Show()
self.retrybutton.Hide()
self.hasPicture = False
self.Layout()
event.Skip()
def onShot(self, event):
frame = gui.cvQueryFrame(self.capture)
self.playTimer.Stop()
gui.cvSaveImage("foo.png", frame)
self.hasPicture = True
self.shotbutton.Hide()
self.retrybutton.Show()
self.Layout()
event.Skip()
def onClose(self, event):
try:
self.playTimer.Stop()
except:
pass
self.Show(False)
self.Destroy()
def onPaint(self, evt):
if self.bmp:
self.displayPanel.SetBitmap(self.bmp)
evt.Skip()
def onNextFrame(self, evt):
frame = gui.cvQueryFrame(self.capture)
if frame:
cv.cvCvtColor(frame, frame, cv.CV_BGR2RGB)
self.bmp = wx.BitmapFromBuffer(frame.width, frame.height, frame.imageData)
self.Refresh()
evt.Skip()
if __name__=="__main__":
app = wx.App()
f = CvMovieFrame(None)
f.Centre()
f.Show(True)
app.MainLoop()
答案 1 :(得分:2)
我很确定你能做到:
self.movie_window.window.get_image(0, 0, 500, 400)
使用网络摄像头的最后一帧获取GtkImage。 500和400是窗口的宽度和高度。