implement live video preview and shutter attenuation, requires gphoto2, requires graphicsmagick for photo postprocessing

video-overlay-test.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 
 import sys, os
+import tempfile, subprocess
 import gi
 gi.require_version('Gtk', '3.0')
 gi.require_version('Gst', '1.0')
@@ -8,16 +9,28 @@ gi.require_version('GstVideo', '1.0')
 gi.require_version('GdkX11', '3.0')
 from gi.repository import Gst, GObject, Gtk, GdkX11, Gdk, GstVideo
 
-COUNTDOWN_SECONDS   = 4
+COUNTDOWN_SECONDS   = 3
 AUDIOFILE_COUNTDOWN = "beep.m4a"
 AUDIOFILE_SHUTTER   = "shutter.m4a"
 
+#Gst.debug_set_active(True)
+#Gst.debug_set_default_threshold(3)
 
 class GTK_Main:
 	def __init__(self):
+		cmd = ['gphoto2', '--set-config=/main/capturesettings/imagequality=1']
+		ret = subprocess.call(cmd)
+		if ret != 0:
+			exit()
+
+		self.moviecapture = None
+		tmpdir = tempfile.mkdtemp()
+		self.video_pipe_name = os.path.join(tmpdir, 'videopreview')
+		os.mkfifo(self.video_pipe_name)
+
 		window = Gtk.Window(Gtk.WindowType.TOPLEVEL)
 		window.set_title("Live Video Preview")
-		window.set_default_size(1024, 830)
+		window.set_default_size(1024, 768)
 		window.connect("destroy", Gtk.main_quit, "WM destroy")
 		Gtk.Window.fullscreen(window)
 
@@ -59,13 +72,27 @@ class GTK_Main:
 		self.overlay.show_all()
 		window.show_all()
 
+		self.gst_setup_live_preview()
+
+		self.countdown_timer = None
+		self.audioplayer = Gst.Pipeline.new("audioplayer")
+		self.audioplaybin = Gst.ElementFactory.make("playbin", "audioplaybin")
+		self.audioplayer.add(self.audioplaybin)
+
+	def gst_setup_live_preview(self):
 		self.videoplayer = Gst.Pipeline.new("player")
-		source = Gst.ElementFactory.make("videotestsrc", "file-source")
+		source = Gst.ElementFactory.make("filesrc", "filesrc")
-		source.set_property("pattern", 1)
+		source.set_property("location", self.video_pipe_name)
-		capsfilter = Gst.ElementFactory.make("capsfilter", "capsfilter")
+		mjpeg_filter = Gst.ElementFactory.make("capsfilter", "mjpeg_capsfilter")
-		caps = Gst.Caps.from_string("video/x-raw, width=1024, height=768")
+		caps = Gst.Caps.from_string("image/jpeg, width=640, height=424, framerate=30/1, pixel-aspect-ratio=1/1")
-		capsfilter.set_property("caps", caps)
+		mjpeg_filter.set_property("caps", caps)
+
+		jpegdec = Gst.ElementFactory.make("jpegdec", "jpegdec")
+		video_scale = Gst.ElementFactory.make("videoscale", "videoscale")
 		video_convert = Gst.ElementFactory.make("videoconvert", "video_convert")
+		capsfilter = Gst.ElementFactory.make("capsfilter", "capsfilter")
+		caps = Gst.Caps.from_string("video/x-raw, width=1076, height=708")
+		capsfilter.set_property("caps", caps)
 
 		png_source = Gst.ElementFactory.make("filesrc", "png-source")
 		png_source.set_property("location", os.path.realpath("overlay.png"))
@@ -78,12 +105,15 @@ class GTK_Main:
 		mix_convert = Gst.ElementFactory.make("videoconvert", "mix_convert")
 		videosink = Gst.ElementFactory.make("xvimagesink", "video-output")
 
-		for ele in (source, capsfilter, video_convert, png_source, png_decoder, alphacolor, png_convert, imagefreeze, mixer, mix_convert, videosink):
+		for ele in (source, jpegdec, mjpeg_filter, capsfilter, video_scale, video_convert, png_source, png_decoder, alphacolor, png_convert, imagefreeze, mixer, mix_convert, videosink):
 			self.videoplayer.add(ele)
-			
+
-		source.link(capsfilter)
+		source.link(mjpeg_filter)
-		capsfilter.link(video_convert)
+		mjpeg_filter.link(jpegdec)
-		video_convert.link(mixer)
+		jpegdec.link(video_scale)
+		video_scale.link(video_convert)
+		video_convert.link(capsfilter)
+		capsfilter.link(mixer)
 
 		png_source.link(png_decoder)
 		png_decoder.link(alphacolor)
@@ -99,23 +129,54 @@ class GTK_Main:
 		bus.enable_sync_message_emission()
 		bus.connect("message", self.on_message)
 		bus.connect("sync-message::element", self.on_sync_message)
-	
+
-		self.countdown_timer = None
+	def gst_setup_snapshot_preview(self):
-		self.soundplayer = Gst.Pipeline.new("soundplayer")
+		self.videoplayer = Gst.Pipeline.new("player")
-		self.audioplaybin = Gst.ElementFactory.make("playbin", "soundfile")
+		source = Gst.ElementFactory.make("filesrc", "filesrc")
+		source.set_property("location", "print.jpg")
+		jpegdec = Gst.ElementFactory.make("jpegdec", "jpegdec")
+		imagefreeze = Gst.ElementFactory.make("imagefreeze", "imagefreeze")
+		video_scale = Gst.ElementFactory.make("videoscale", "videoscale")
+		video_convert = Gst.ElementFactory.make("videoconvert", "video_convert")
+		capsfilter = Gst.ElementFactory.make("capsfilter", "capsfilter")
+		caps = Gst.Caps.from_string("video/x-raw, width=1076, height=708")
+		capsfilter.set_property("caps", caps)
+		videosink = Gst.ElementFactory.make("xvimagesink", "video-output")
+		for ele in (source, jpegdec, imagefreeze, capsfilter, video_scale, video_convert, videosink):
+			self.videoplayer.add(ele)
+		source.link(jpegdec)
+		jpegdec.link(imagefreeze)
+		imagefreeze.link(video_scale)
+		video_scale.link(video_convert)
+		video_convert.link(capsfilter)
+		capsfilter.link(videosink)
+		self.videoplayer.set_state(Gst.State.PLAYING)
+		bus = self.videoplayer.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_play.get_label() == "Start":
 			self.xid = self.movie_window.get_property('window').get_xid()
 			self.button_play.set_label("Stop")
+			self.gst_setup_live_preview()
+			if not self.moviecapture:
+				video_pipe = open(self.video_pipe_name,"w+")
+				print "video_pipe", video_pipe
+				cmd = ['gphoto2', '--capture-movie', '--stdout']
+				self.moviecapture = subprocess.Popen(cmd, stdout=video_pipe, stderr=subprocess.PIPE)
 			self.videoplayer.set_state(Gst.State.PLAYING)
 		else:
+			print "STOPPING..."
 			self.videoplayer.set_state(Gst.State.NULL)
+			GObject.timeout_add(10, self.stop_capture)
 			self.button_play.set_label("Start")
 
 	def snapshot(self, widget, event):
 		if event.button == 1 and self.videoplayer.get_state(0).state == Gst.State.PLAYING and not self.countdown_timer:
-			self.countdown_timer = GObject.timeout_add(1000, self.countdown_cb)
+			self.countdown_timer = GObject.timeout_add(100, self.countdown_cb)
 			self.snapshot_label = Gtk.Label(label="SNAPSHOT!", angle=25, halign=Gtk.Align.END)
 			self.snapshot_label.set_valign(Gtk.Align.CENTER)
 			self.snapshot_label.set_halign(Gtk.Align.CENTER)
@@ -123,35 +184,68 @@ class GTK_Main:
 			self.snapshot_label.get_style_context().add_class("snapshot_label")
 			uri = 'file://'+os.path.abspath(AUDIOFILE_COUNTDOWN)
 			self.audioplaybin.set_property('uri',uri)
-			self.soundplayer.add(self.audioplaybin)
+			self.audioplayer.set_state(Gst.State.PLAYING)
-			self.soundplayer.set_state(Gst.State.PLAYING)
 			self.overlay.add_overlay(self.snapshot_label)
 			self.overlay.show_all()
-			self.counter = COUNTDOWN_SECONDS
+			self.counter = COUNTDOWN_SECONDS*10
 
 	def countdown_cb(self):
 		self.counter -= 1
+		self.snapshot_label.set_text("SNAP IN %i" % self.counter)
 		if self.counter == 0:
+			self.countdown_timer = None
+			self.overlay.remove(self.snapshot_label)
 			self.snap()
 			return False
-		self.snapshot_label.set_text("SNAP IN %i" % self.counter)
 		return True
 
 	def snap(self):
-		print "TAKE SNAPSHOT!"
+		print "TAKE SNAPSHOT!", self.counter
-		self.countdown_timer = None
+		self.moviecapture.terminate()
-		self.soundplayer.set_state(Gst.State.READY)
+		out,err = self.moviecapture.communicate()
+		self.moviecapture = None
+		print "video capture terminated", out, err, self.counter
+		cmd = ['gphoto2', '--capture-image-and-download', '--force-overwrite']
+		photocapture = subprocess.Popen(cmd)
+		print "snashop taken", self.counter, out, err
+		self.audioplayer.set_state(Gst.State.READY)
 		uri = 'file://'+os.path.abspath(AUDIOFILE_SHUTTER)
 		self.audioplaybin.set_property('uri',uri)
-		self.soundplayer.set_state(Gst.State.PLAYING)
+		self.audioplayer.set_state(Gst.State.PLAYING)
-		self.overlay.remove(self.snapshot_label)
+		out,err = photocapture.communicate()
+		self.videoplayer.set_state(Gst.State.NULL)
+		cmd = ['gm', 'mogrify', '-resize', '2152x1417!', 'capt0000.jpg']
+		print "execute", cmd
+		subprocess.call(cmd)
+		cmd = ['gm', 'composite', '-compose', 'Over', 'overlay_print.png', 'capt0000.jpg', 'print.jpg']
+		print "execute", cmd
+		subprocess.call(cmd)
+		self.audioplayer.set_state(Gst.State.READY)
+		self.gst_setup_snapshot_preview()
 
-	def exit(self, widget, data=None):
+	def exit(self, widget=None, data=None):
+		print "EXIT"
+		self.stop_capture()
+		os.unlink(self.video_pipe_name)
 		Gtk.main_quit()
 
+	def stop_capture(self):
+		if self.moviecapture:
+			print "stop_capture...", self.moviecapture
+			self.moviecapture.terminate()
+			print "terminated...", self.moviecapture
+			video_pipe = open(self.video_pipe_name,"w+")
+			print "video_pipe=", video_pipe
+			#self.moviecapture.communicate()
+			bla = video_pipe.read(1)
+			print "bla=", bla
+			self.moviecapture = None
+		return False
+
 	def on_message(self, bus, message):
 		t = message.type
 		if t == Gst.MessageType.EOS:
+			print "EOS!"
 			self.videoplayer.set_state(Gst.State.NULL)
 			self.button_play.set_label("Start")
 		elif t == Gst.MessageType.ERROR:
@@ -159,6 +253,8 @@ class GTK_Main:
 			print "Error: %s" % err, debug
 			self.videoplayer.set_state(Gst.State.NULL)
 			self.button_play.set_label("Start")
+		#else:
+			#print "on_message", message, message.type
 
 	def on_sync_message(self, bus, message):
 		struct = message.get_structure()