usrp_tv_rcv.py

这是用python语言写的一个数字广播的信号处理工具包。利用它

        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
          tv_corr=gr.tv_correlator_ff(frame_size,nframes, search_window, video_alpha, corr_alpha,debug) #Note: this block is not yet in cvs
          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) #self.agc,
        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)

   
        if abs(options.freq) < 1e6:
            options.freq *= 1e6

        # 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=(50.25e6, 900.25e6, 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):
          myform['gain'] = \
              form.quantized_slider_field(parent=self.panel, sizer=hbox, label="Gain",
                                        weight=3, range=self.subdev.gain_range(),
                                        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 = usrp.tune(self.u, 0, self.subdev, 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.subdev.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 ()