I'm working with PyQt and trying to get video from a webcam to play within a QT widget. I've found tutorials for C and Qt, and for python and gtk, but NOTHING for this combo of pyQt and gstreamer. Anybody get this working?
This plays the video fine, but in a separate window:
self.gcam = gst.parse_launch('v4l2src device=/dev/video0 ! autovideosink')
self.gcam.set_state(gst.STATE_PLAYING)
what I need is to get the overlay working so it's displayed within a widget on my GUI. Thanks, Gurus of the internet!
ok, so I've gotten a lot farther, but still in need of some help. I'm actually writing this for Maemo, but the following code works fine on my linux laptop:
class Vid:
def __init__(self, windowId):
self.player = gst.Pipeline("player")
self.source = gst.element_factory_make("v4l2src", "vsource")
self.sink = gst.element_factory_make("autovideosink", "outsink")
self.source.set_property("device", "/dev/video0")
self.scaler = gst.element_factory_make("videoscale", "vscale")
self.window_id = None
self.windowId = windowId
self.player.add(self.source, self.scaler, self.sink)
gst.element_link_many(self.source,self.scaler, self.sink)
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 on_message(self, bus, message):
t = message.type
if t == gst.MESSAGE_EOS:
self.player.set_state(gst.STATE_NULL)
elif t == gst.MESSAGE_ERROR:
err, debug = message.parse_error()
print "Error: %s" % err, debug
self.player.set_state(gst.STATE_NULL)
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":
win_id = self.windowId
assert win_id
imagesink = message.src
imagesink.set_property("force-aspect-ratio", True)
imagesink.set_xwindow_id(win_id)
def startPrev(self):
self.player.set_state(gst.STATE_PLAYING)
print "should be playing"
vidStream = Vid(wId)
vidStream.startPrev()
where wId is the window id of the widget im trying to get to display the output in. When I run this on the N900, the screen goes black and blinks. Any ideas? I'm dying here!
EDIT: I've been asked to post the full code, and though I still need to clean it up a bit, here's the relevant part:
self.cameraWindow = QtGui.QWidget(self)
self.cameraWindow.setGeometry(QtCore.QRect(530, 20, 256, 192))
self.cameraWindow.setObjectName("cameraWindow")
self.cameraWindow.setAttribute(0, 1); # AA_ImmediateWidgetCreation == 0
self.cameraWindow.setAttribute(3, 1); # AA_NativeWindow == 3
global wId
wId = self.cameraWindow.winId()
self.camera = Vid(wId)
self.camera.startPrev()
class Vid:
def __init__(self, windowId):
self.player = gst.Pipeline("player")
self.source = gst.element_factory_make("v4l2src", "vsource")
self.sink = gst.element_factory_make("autovideosink", "outsink")
self.source.set_property("device", "/dev/video0")
#self.scaler = gst.element_factory_make("videoscale", "vscale")
self.fvidscale = gst.element_factory_make("videoscale", "fvidscale")
self.fvidscale_cap = gst.element_factory_make("capsfilter", "fvidscale_cap")
self.fvidscale_cap.set_property('caps', gst.caps_from_string('video/x-raw-yuv, width=256, height=192'))
self.window_id = None
self.windowId = windowId
print windowId
self.player.add(self.source, self.fvidscale, self.fvidscale_cap, self.sink)
gst.element_link_many(self.source,self.fvidscale, self.fvidscale_cap, self.sink)
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 on_message(self, bus, message):
t = message.type
if t == gst.MESSAGE_EOS:
self.player.set_state(gst.STATE_NULL)
elif t == gst.MESSAGE_ERROR:
err, debug = message.parse_error()
print "Error: %s" % err, debug
self.player.set_state(gst.STATE_NULL)
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":
win_id = self.windowId
assert win_id
imagesink = message.src
imagesink.set_property("force-aspect-ratio", True)
imagesink.set_xwindow_id(win_id)
def startPrev(self):
self.player.set_state(gst.STATE_PLAYING)
def pausePrev(self):
self.player.set_state(gst.STATE_NULL)
This is piecing together a few bits, and I can't test it right now, but maybe it will be helpful to someone. Good luck!
Got it! It appears I needed to force the resolution of the pipeline to match the resolution of the widget where I was pumping the video to:
self.fvidscale_cap = gst.element_factory_make("capsfilter", "fvidscale_cap") self.fvidscale_cap.set_property('caps', gst.caps_from_string('video/x-raw-yuv, width=256, height=192'))
Then just add those to the pipeline like the other elements, and it works great. Man, it seems so easy looking at it now, but when I was pounding my head against the wall for a few days it wasn't so obvious...