uhd: Moved USRP analog TV receiver examples to gr-uhd/examples. They seem to run with the UHD, but I can't really test them since there's no NTSC signals around...

2 files changed, 642 insertions, 0 deletions

diff --git a/gr-uhd/examples/usrp_tv_rcv.py b/gr-uhd/examples/usrp_tv_rcv.py
new file mode 100755
index 000000000..a68867365
--- /dev/null
+++ b/gr-uhd/examples/usrp_tv_rcv.py
@@ -0,0 +1,436 @@
+#!/usr/bin/env python
+#
+# Copyright 2005-2007,2011 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+# 
+
+"""
+Realtime capture and display of analog Tv stations.
+
+Can also use a file as source or sink
+
+When you use an output file you can show the results frame-by-frame
+using ImageMagick
+
+When you want to use the realtime sdl display window you must first
+install gr-video-sdl.
+
+When you use a file source, instead of the usrp, make sure you
+capture interleaved shorts.  (Use usrp_rx_file.py, or use
+usrp_rx_cfile.py --output-shorts if you have a recent enough
+usrp_rx_cfile.py)
+
+There is no synchronisation yet. The sync blocks are in development
+but not yet in cvs.
+"""
+
+from gnuradio import gr
+try:
+  from gnuradio import video_sdl
+except:
+  print "FYI: gr-video-sdl is not installed"
+  print "realtime SDL video output window will not be available"
+from gnuradio import uhd
+from gnuradio.eng_option import eng_option
+from gnuradio.wxgui import slider, powermate
+from gnuradio.wxgui import stdgui2, fftsink2, form
+from optparse import OptionParser
+import sys
+import wx
+
+
+class tv_rx_block (stdgui2.std_top_block):
+    def __init__(self,frame,panel,vbox,argv):
+        stdgui2.std_top_block.__init__ (self,frame,panel,vbox,argv)
+
+        usage="%prog: [options] [input_filename]. \n If you don't specify an input filename the usrp will be used as source\n " \
+              "Make sure your input capture file containes interleaved shorts not complex floats"
+        parser=OptionParser(option_class=eng_option, usage=usage)
+        parser.add_option("-a", "--address", type="string",
+                          default="addr=192.168.10.2",
+                          help="Address of UHD device, [default=%default]")
+        parser.add_option("-A", "--antenna", type="string", default=None,
+                          help="select Rx Antenna where appropriate")
+        parser.add_option("-s", "--samp-rate", type="eng_float", default=1e6,
+                          help="set sample rate")
+        parser.add_option("-f", "--freq", type="eng_float", default=519.25e6,
+                          help="set frequency to FREQ", metavar="FREQ")
+        parser.add_option("-g", "--gain", type="eng_float", default=None,
+                          help="set gain in dB (default is midpoint)")
+        parser.add_option("-c", "--contrast", type="eng_float", default=1.0,
+                          help="set contrast (default is 1.0)")
+        parser.add_option("-b", "--brightness", type="eng_float", default=0.0,
+                          help="set brightness (default is 0)")
+        parser.add_option("-p", "--pal", action="store_true", default=False,
+                          help="PAL video format (this is the default)")
+        parser.add_option("-n", "--ntsc", action="store_true", default=False,
+                          help="NTSC video format")
+        parser.add_option("-o", "--out-filename", type="string", default="sdl",
+                          help="For example out_raw_uchar.gray. If you don't specify an output filename you will get a video_sink_sdl realtime output window. You then need to have gr-video-sdl installed)")
+        parser.add_option("-r", "--repeat", action="store_false", default=True,
+                          help="repeat file in a loop")
+        parser.add_option("", "--freq-min", type="eng_float", default=50.25e6,
+                          help="Set a minimum frequency [default=%default]")
+        parser.add_option("", "--freq-max", type="eng_float", default=900.25e6,
+                          help="Set a maximum frequency [default=%default]")
+
+        (options, args) = parser.parse_args()
+        if not ((len(args) == 1) or (len(args) == 0)):
+            parser.print_help()
+            sys.exit(1)
+        
+        if len(args) == 1:
+          filename = args[0]
+        else:
+          filename = None
+
+        self.frame = frame
+        self.panel = panel
+        
+        self.contrast = options.contrast
+        self.brightness = options.brightness
+        self.state = "FREQ"
+        self.freq = 0
+
+        self.tv_freq_min = options.freq_min
+        self.tv_freq_max = options.freq_max
+
+        # build graph
+        self.u=None
+
+        if not (options.out_filename=="sdl"):
+          options.repeat=False
+
+        usrp_rate = options.samp_rate
+
+        if not ((filename is None) or (filename=="usrp")):
+          # file is data source
+          self.filesource = gr.file_source(gr.sizeof_short,filename,options.repeat)
+          self.istoc = gr.interleaved_short_to_complex()
+          self.connect(self.filesource,self.istoc)
+          self.src=self.istoc
+
+          options.gain=0.0
+          self.gain=0.0
+
+        else: # use a UHD device
+          self.u = uhd.usrp_source(device_addr=options.address,
+                                   io_type=uhd.io_type.COMPLEX_FLOAT32,
+                                   num_channels=1)
+
+          self.u.set_samp_rate(usrp_rate)
+          dev_rate = self.u.get_samp_rate()
+
+          if options.gain is None:
+            # if no gain was specified, use the mid-point in dB
+            g = self.u.get_gain_range()
+            options.gain = float(g.start()+g.stop())/2.0
+
+          self.src=self.u
+
+        self.gain = options.gain
+
+        f2uc=gr.float_to_uchar()
+
+        # sdl window as final sink
+        if not (options.pal or options.ntsc):
+          options.pal=True #set default to PAL
+
+        if options.pal:
+          lines_per_frame=625.0
+          frames_per_sec=25.0
+          show_width=768
+
+        elif options.ntsc:
+          lines_per_frame=525.0
+          frames_per_sec=29.97002997
+          show_width=640
+
+        width=int(usrp_rate/(lines_per_frame*frames_per_sec))
+        height=int(lines_per_frame)
+
+        if (options.out_filename=="sdl"):
+          #Here comes the tv screen, you have to build and install
+          #gr-video-sdl for this (subproject of gnuradio, only in cvs
+          #for now)
+          try:
+            video_sink = video_sdl.sink_uc ( frames_per_sec, width, height, 0,
+                                             show_width, height)
+          except:
+            print "gr-video-sdl is not installed"
+            print "realtime \"sdl\" video output window is not available"
+            raise SystemExit, 1
+          self.dst=video_sink
+        else:
+          print "You can use the imagemagick display tool to show the resulting imagesequence"
+          print "use the following line to show the demodulated TV-signal:"
+          print "display -depth 8 -size " +str(width)+ "x" + str(height) \
+              + " gray:" + options.out_filename
+          print "(Use the spacebar to advance to next frames)" 
+          options.repeat=False
+          file_sink=gr.file_sink(gr.sizeof_char, options.out_filename)
+          self.dst =file_sink 
+
+        self.agc=gr.agc_cc(1e-7,1.0,1.0) #1e-7
+        self.am_demod = gr.complex_to_mag ()
+        self.set_blacklevel=gr.add_const_ff(0.0)
+        self.invert_and_scale = gr.multiply_const_ff (0.0) #-self.contrast *128.0*255.0/(200.0)
+
+        # now wire it all together
+        #sample_rate=options.width*options.height*options.framerate
+
+        process_type='do_no_sync'
+        if process_type=='do_no_sync':
+          self.connect (self.src, self.agc,self.am_demod,
+                        self.invert_and_scale, self.set_blacklevel,
+                        f2uc,self.dst)
+        elif process_type=='do_tv_sync_adv':
+          #defaults: gr.tv_sync_adv (double sampling_freq, unsigned
+          #int tv_format,bool output_active_video_only=false, bool
+          #do_invert=false, double wanted_black_level=0.0, double
+          #wanted_white_level=255.0, double avg_alpha=0.1, double
+          #initial_gain=1.0, double initial_offset=0.0,bool
+          #debug=false)
+
+          #note, this block is not yet in cvs
+          self.tv_sync_adv=gr.tv_sync_adv(usrp_rate, 0, False, False,
+                                          0.0, 255.0, 0.01, 1.0, 0.0, False)
+          self.connect (self.src, self.am_demod, self.invert_and_scale,
+                        self.tv_sync_adv, s2f, f2uc, self.dst) 
+
+        elif process_type=='do_nullsink':
+          #self.connect (self.src, self.am_demod,self.invert_and_scale,f2uc,video_sink)
+          c2r=gr.complex_to_real()
+          nullsink=gr.null_sink(gr.sizeof_float)
+          self.connect (self.src, c2r,nullsink) #video_sink)
+        elif process_type=='do_tv_sync_corr':
+          frame_size=width*height #int(usrp_rate/25.0)
+          nframes=10# 32
+          search_window=20*nframes 
+          debug=False
+          video_alpha=0.3 #0.1
+          corr_alpha=0.3
+          
+          #Note: this block is not yet in cvs
+          tv_corr=gr.tv_correlator_ff(frame_size,nframes, search_window,
+                                      video_alpha, corr_alpha,debug) 
+          shift=gr.add_const_ff(-0.7)
+          
+          self.connect (self.src, self.agc, self.am_demod, tv_corr,
+                        self.invert_and_scale, self.set_blacklevel,
+                        f2uc, self.dst)
+        else: # process_type=='do_test_image':
+          src_vertical_bars = gr.sig_source_f (usrp_rate, gr.GR_SIN_WAVE,
+                                               10.0 *usrp_rate/320, 255,128)
+          self.connect(src_vertical_bars, f2uc, self.dst)
+
+        self._build_gui(vbox, usrp_rate, usrp_rate, usrp_rate)
+ 
+
+        frange = self.u.get_freq_range()
+        if(frange.start() > self.tv_freq_max or frange.stop() <  self.tv_freq_min):
+            sys.stderr.write("Radio does not support required frequency range.\n")
+            sys.exit(1)
+        if(options.freq < self.tv_freq_min or options.freq > self.tv_freq_max):
+            sys.stderr.write("Requested frequency is outside of required frequency range.\n")
+            sys.exit(1)
+
+        # set initial values
+        self.set_gain(options.gain)
+        self.set_contrast(self.contrast)
+        self.set_brightness(options.brightness)
+        if not(self.set_freq(options.freq)):
+            self._set_status_msg("Failed to set initial frequency")
+
+
+    def _set_status_msg(self, msg, which=0):
+        self.frame.GetStatusBar().SetStatusText(msg, which)
+
+
+    def _build_gui(self, vbox, usrp_rate, demod_rate, audio_rate):
+
+        def _form_set_freq(kv):
+            return self.set_freq(kv['freq'])
+
+
+        if 0:
+            self.src_fft = fftsink.fft_sink_c (self, self.panel, title="Data from USRP",
+                                               fft_size=512, sample_rate=usrp_rate)
+            self.connect (self.src, self.src_fft)
+            vbox.Add (self.src_fft.win, 4, wx.EXPAND)
+
+        if 0:
+            post_demod_fft = fftsink.fft_sink_f (self, self.panel, title="Post Demod",
+                                                  fft_size=512, sample_rate=demod_rate,
+                                                  y_per_div=10, ref_level=-40)
+            self.connect (self.am_demod, post_demod_fft)
+            vbox.Add (post_demod_fft.win, 4, wx.EXPAND)
+
+        if 0:
+            post_filt_fft = fftsink.fft_sink_f (self, self.panel, title="Post Filter", 
+                                                fft_size=512, sample_rate=audio_rate,
+                                                y_per_div=10, ref_level=-40)
+            self.connect (self.set_blacklevel, post_filt)
+            vbox.Add (fft_win4, 4, wx.EXPAND)
+
+        
+        # control area form at bottom
+        self.myform = myform = form.form()
+
+        if not (self.u is None):
+          hbox = wx.BoxSizer(wx.HORIZONTAL)
+          hbox.Add((5,0), 0)
+          myform['freq'] = form.float_field(
+            parent=self.panel, sizer=hbox, label="Freq", weight=1,
+            callback=myform.check_input_and_call(_form_set_freq, self._set_status_msg))
+
+          hbox.Add((5,0), 0)
+          myform['freq_slider'] = \
+              form.quantized_slider_field(parent=self.panel, sizer=hbox, weight=3,
+                                        range=(self.tv_freq_min, self.tv_freq_max, 0.25e6),
+                                        callback=self.set_freq)
+          hbox.Add((5,0), 0)
+          vbox.Add(hbox, 0, wx.EXPAND)
+
+        hbox = wx.BoxSizer(wx.HORIZONTAL)
+        hbox.Add((5,0), 0)
+
+        myform['contrast'] = \
+            form.quantized_slider_field(parent=self.panel, sizer=hbox, label="Contrast",
+                                        weight=3, range=(-2.0, 2.0, 0.1),
+                                        callback=self.set_contrast)
+        hbox.Add((5,0), 1)
+
+        myform['brightness'] = \
+            form.quantized_slider_field(parent=self.panel, sizer=hbox, label="Brightness",
+                                        weight=3, range=(-255.0, 255.0, 1.0),
+                                        callback=self.set_brightness)
+        hbox.Add((5,0), 0)
+
+        if not (self.u is None):
+          g = self.u.get_gain_range()
+          myform['gain'] = \
+              form.quantized_slider_field(parent=self.panel, sizer=hbox, label="Gain",
+                                        weight=3, range=(g.start(), g.stop(), g.step()),
+                                        callback=self.set_gain)
+          hbox.Add((5,0), 0)
+        vbox.Add(hbox, 0, wx.EXPAND)
+
+        try:
+            self.knob = powermate.powermate(self.frame)
+            self.rot = 0
+            powermate.EVT_POWERMATE_ROTATE (self.frame, self.on_rotate)
+            powermate.EVT_POWERMATE_BUTTON (self.frame, self.on_button)
+        except:
+            print "FYI: No Powermate or Contour Knob found"
+
+
+    def on_rotate (self, event):
+        self.rot += event.delta
+        if (self.state == "FREQ"):
+            if self.rot >= 3:
+                self.set_freq(self.freq + .1e6)
+                self.rot -= 3
+            elif self.rot <=-3:
+                self.set_freq(self.freq - .1e6)
+                self.rot += 3
+        elif (self.state == "CONTRAST"):
+            step = 0.1
+            if self.rot >= 3:
+                self.set_contrast(self.contrast + step)
+                self.rot -= 3
+            elif self.rot <=-3:
+                self.set_contrast(self.contrast - step)
+                self.rot += 3
+        else:
+            step = 1
+            if self.rot >= 3:
+                self.set_brightness(self.brightness + step)
+                self.rot -= 3
+            elif self.rot <=-3:
+                self.set_brightness(self.brightness - step)
+                self.rot += 3
+            
+    def on_button (self, event):
+        if event.value == 0:        # button up
+            return
+        self.rot = 0
+        if self.state == "FREQ":
+            self.state = "CONTRAST"
+        elif self.state == "CONTRAST":
+            self.state = "BRIGHTNESS"
+        else:
+            self.state = "FREQ"
+        self.update_status_bar ()
+        
+
+    def set_contrast (self, contrast):
+        self.contrast = contrast
+        self.invert_and_scale.set_k(-self.contrast *128.0*255.0/(200.0))
+        self.myform['contrast'].set_value(self.contrast)
+        self.update_status_bar ()
+
+    def set_brightness (self, brightness):
+        self.brightness = brightness
+        self.set_blacklevel.set_k(self.brightness +255.0)
+        self.myform['brightness'].set_value(self.brightness)
+        self.update_status_bar ()
+                                        
+    def set_freq(self, target_freq):
+        """
+        Set the center frequency we're interested in.
+
+        @param target_freq: frequency in Hz
+        @rypte: bool
+
+        Tuning is a two step process.  First we ask the front-end to
+        tune as close to the desired frequency as it can.  Then we use
+        the result of that operation and our target_frequency to
+        determine the value for the digital down converter.
+        """
+        if not (self.u is None):
+          r = self.u.set_center_freq(target_freq)
+          if r:
+              self.freq = target_freq
+              self.myform['freq'].set_value(target_freq)         # update displayed value
+              self.myform['freq_slider'].set_value(target_freq)  # update displayed value
+              self.update_status_bar()
+              self._set_status_msg("OK", 0)
+              return True
+
+        self._set_status_msg("Failed", 0)
+        return False
+
+    def set_gain(self, gain):
+      if not (self.u is None):
+        self.gain=gain
+        self.myform['gain'].set_value(gain)     # update displayed value
+        self.u.set_gain(gain)
+        self.update_status_bar()
+        
+    def update_status_bar (self):
+      msg = "Setting:%s Contrast:%r Brightness:%r Gain: %r" % \
+          (self.state, self.contrast,self.brightness,self.gain)
+      self._set_status_msg(msg, 1)
+        #self.src_fft.set_baseband_freq(self.freq)
+        
+
+if __name__ == '__main__':
+    app = stdgui2.stdapp (tv_rx_block, "USRP TV RX black-and-white")
+    app.MainLoop ()
diff --git a/gr-uhd/examples/usrp_tv_rcv_nogui.py b/gr-uhd/examples/usrp_tv_rcv_nogui.py
new file mode 100755
index 000000000..a44e20d39
--- /dev/null
+++ b/gr-uhd/examples/usrp_tv_rcv_nogui.py
@@ -0,0 +1,206 @@
+#!/usr/bin/env python
+#
+# Copyright 2005-2007,2011 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+# 
+
+"""
+Reads from a file and generates PAL TV pictures in black and white
+which can be displayed using ImageMagick or realtime using
+gr-video-sdl (To capture the input file Use usrp_rx_file.py, or use
+usrp_rx_cfile.py --output-shorts if you have a recent enough
+usrp_rx_cfile.py)
+
+Can also use usrp directly as capture source, but then you need a
+higher decimation factor (64) and thus get a lower horizontal
+resulution.  There is no synchronisation yet. The sync blocks are in
+development but not yet in cvs.
+
+"""
+
+from gnuradio import gr, eng_notation
+from gnuradio import audio
+from gnuradio import uhd
+from gnuradio.eng_option import eng_option
+from optparse import OptionParser
+import sys
+
+try:
+  from gnuradio import video_sdl
+except:
+  print "FYI: gr-video-sdl is not installed"
+  print "realtime \"sdl\" video output window will not be available"
+
+
+class my_top_block(gr.top_block):
+
+    def __init__(self):
+        gr.top_block.__init__(self)
+
+        usage=("%prog: [options] output_filename.\nSpecial output_filename" + \
+            "\"sdl\" will use video_sink_sdl as realtime output window. " + \
+            "You then need to have gr-video-sdl installed.\n" +\
+            "Make sure your input capture file containes interleaved " + \
+            "shorts not complex floats")
+        parser = OptionParser(option_class=eng_option, usage=usage)
+        parser.add_option("-a", "--address", type="string",
+                          default="addr=192.168.10.2",
+                          help="Address of UHD device, [default=%default]")
+        parser.add_option("-A", "--antenna", type="string", default=None,
+                          help="select Rx Antenna where appropriate")
+        parser.add_option("-s", "--samp-rate", type="eng_float", default=1e6,
+                          help="set sample rate")
+        parser.add_option("-c", "--contrast", type="eng_float", default=1.0,
+                          help="set contrast (default is 1.0)")
+        parser.add_option("-b", "--brightness", type="eng_float", default=0.0,
+                          help="set brightness (default is 0)")
+        parser.add_option("-i", "--in-filename", type="string", default=None,
+                          help="Use input file as source. samples must be " + \
+                            "interleaved shorts \n Use usrp_rx_file.py or " + \
+                            "usrp_rx_cfile.py --output-shorts.\n Special " + \
+                            "name \"usrp\" results in realtime capturing " + \
+                            "and processing using usrp.\n" + \
+                            "You then probably need a decimation factor of 64 or higher.")
+        parser.add_option("-f", "--freq", type="eng_float", default=519.25e6,
+                          help="set frequency to FREQ.\nNote that the frequency of the video carrier is not at the middle of the TV channel", metavar="FREQ")
+        parser.add_option("-g", "--gain", type="eng_float", default=None,
+                          help="set gain in dB (default is midpoint)")
+        parser.add_option("-p", "--pal", action="store_true", default=False,
+                          help="PAL video format (this is the default)")
+        parser.add_option("-n", "--ntsc", action="store_true", default=False,
+                          help="NTSC video format")
+        parser.add_option("-r", "--repeat", action="store_false", default=True,
+                          help="repeat in_file in a loop")
+        parser.add_option("-N", "--nframes", type="eng_float", default=None,
+                          help="number of frames to collect [default=+inf]")
+        parser.add_option("", "--freq-min", type="eng_float", default=50.25e6,
+                          help="Set a minimum frequency [default=%default]")
+        parser.add_option("", "--freq-max", type="eng_float", default=900.25e6,
+                          help="Set a maximum frequency [default=%default]")
+        (options, args) = parser.parse_args ()
+        if not (len(args) == 1):
+            parser.print_help()
+            sys.stderr.write('You must specify the output. FILENAME or sdl \n');
+            sys.exit(1)
+        
+        filename = args[0]
+
+        self.tv_freq_min = options.freq_min
+        self.tv_freq_max = options.freq_max
+
+        if options.in_filename is None:
+            parser.print_help()
+            sys.stderr.write('You must specify the input -i FILENAME or -i usrp\n');
+            raise SystemExit, 1
+
+        if not (filename=="sdl"):
+          options.repeat=False
+
+        input_rate = options.samp_rate
+        print "video sample rate %s" % (eng_notation.num_to_str(input_rate))
+
+        if not (options.in_filename=="usrp"):
+          # file is data source, capture with usr_rx_csfile.py
+          self.filesource = gr.file_source(gr.sizeof_short,
+                                           options.in_filename,
+                                           options.repeat) 
+          self.istoc = gr.interleaved_short_to_complex()
+          self.connect(self.filesource,self.istoc)
+          self.src=self.istoc
+        else:
+          if options.freq is None:
+            parser.print_help()
+            sys.stderr.write('You must specify the frequency with -f FREQ\n');
+            raise SystemExit, 1
+
+          # build the graph
+          self.u = uhd.usrp_source(device_addr=options.address,
+                                   io_type=uhd.io_type.COMPLEX_FLOAT32,
+                                   num_channels=1)
+
+          self.u.set_samp_rate(input_rate)
+          dev_rate = self.u.get_samp_rate()
+
+          self.src=self.u
+
+          if options.gain is None:
+              # if no gain was specified, use the mid-point in dB
+              g = self.u.get_gain_range()
+              options.gain = float(g.start()+g.stop())/2.0
+          self.u.set_gain(options.gain)
+
+          r = self.u.set_center_freq(options.freq)
+          if not r:
+              sys.stderr.write('Failed to set frequency\n')
+              raise SystemExit, 1
+
+        self.agc = gr.agc_cc(1e-7,1.0,1.0) #1e-7
+        self.am_demod = gr.complex_to_mag ()
+        self.set_blacklevel = gr.add_const_ff(options.brightness +255.0)
+        self.invert_and_scale = gr.multiply_const_ff (-options.contrast *128.0*255.0/(200.0))
+        self.f2uc = gr.float_to_uchar()
+
+        # sdl window as final sink
+        if not (options.pal or options.ntsc):
+          options.pal=True #set default to PAL
+        if options.pal:
+          lines_per_frame=625.0
+          frames_per_sec=25.0
+          show_width=768
+        elif options.ntsc:
+          lines_per_frame=525.0
+          frames_per_sec=29.97002997
+          show_width=640
+        width=int(input_rate/(lines_per_frame*frames_per_sec))
+        height=int(lines_per_frame)
+
+        if filename=="sdl":
+          #Here comes the tv screen, you have to build and install
+          #gr-video-sdl for this (subproject of gnuradio, only in cvs
+          #for now)
+          try:
+            video_sink = video_sdl.sink_uc(frames_per_sec, width, height, 0,
+                                           show_width,height)
+          except:
+            print "gr-video-sdl is not installed"
+            print "realtime \"sdl\" video output window is not available"
+            raise SystemExit, 1
+          self.dst=video_sink
+        else:
+          print "You can use the imagemagick display tool to show the resulting imagesequence"
+          print "use the following line to show the demodulated TV-signal:"
+          print "display -depth 8 -size " +str(width)+ "x" + str(height) + " gray:" +filename
+          print "(Use the spacebar to advance to next frames)" 
+          file_sink=gr.file_sink(gr.sizeof_char, filename)
+          self.dst =file_sink 
+
+        if options.nframes is None:
+            self.connect(self.src, self.agc)
+        else:
+            self.head = gr.head(gr.sizeof_gr_complex, int(options.nframes*width*height))
+            self.connect(self.src, self.head, self.agc)
+
+        self.connect (self.agc, self.am_demod, self.invert_and_scale,
+                      self.set_blacklevel, self.f2uc, self.dst)
+
+if __name__ == '__main__':
+    try:
+        my_top_block().run()
+    except KeyboardInterrupt:
+        pass