implement wfm demodulator chain

csdr/csdr.py

@@ -165,6 +165,7 @@ class dsp(object):
     def __init__(self, output):
         self.samp_rate = 250000
         self.output_rate = 11025
+        self.hd_output_rate = 44100
         self.fft_size = 1024
         self.fft_fps = 5
         self.center_freq = 0
@@ -273,6 +274,13 @@ class dsp(object):
                 ]
             else:
                 chain += ["csdr convert_f_s16"]
+        elif which == "wfm":
+            chain += ["csdr fmdemod_quadri_cf", "csdr limit_ff"]
+            chain += last_decimation_block
+            chain += [
+                "csdr deemphasis_wfm_ff {audio_rate} 50e-6",
+                "csdr convert_f_s16"
+            ]
         elif self.isDigitalVoice(which):
             chain += ["csdr fmdemod_quadri_cf", "dc_block "]
             chain += last_decimation_block
@@ -305,7 +313,7 @@ class dsp(object):
             chain += ["csdr amdemod_cf", "csdr fastdcblock_ff"]
             chain += last_decimation_block
             chain += ["csdr agc_ff", "csdr limit_ff", "csdr convert_f_s16"]
-        elif which == "freedv":
+        elif self.isFreeDV(which):
             chain += ["csdr realpart_cf"]
             chain += last_decimation_block
             chain += [
@@ -585,13 +593,18 @@ class dsp(object):
     def get_output_rate(self):
         return self.output_rate
 
+    def get_hd_output_rate(self):
+        return self.hd_output_rate
+
     def get_audio_rate(self):
         if self.isDigitalVoice() or self.isPacket() or self.isPocsag():
             return 48000
         elif self.isWsjtMode() or self.isJs8():
             return 12000
-        elif self.get_demodulator() == "freedv":
+        elif self.isFreeDV():
             return 8000
+        elif self.isHdAudio():
+            return self.get_hd_output_rate()
         return self.get_output_rate()
 
     def isDigitalVoice(self, demodulator=None):
@@ -619,6 +632,16 @@ class dsp(object):
             demodulator = self.get_secondary_demodulator()
         return demodulator == "pocsag"
 
+    def isFreeDV(self, demodulator=None):
+        if demodulator is None:
+            demodulator = self.get_demodulator()
+        return demodulator == "freedv"
+
+    def isHdAudio(self, demodulator=None):
+        if demodulator is None:
+            demodulator = self.get_demodulator()
+        return demodulator == "wfm"
+
     def set_output_rate(self, output_rate):
         if self.output_rate == output_rate:
             return
@@ -626,6 +649,12 @@ class dsp(object):
         self.calculate_decimation()
         self.restart()
 
+    def set_hd_output_rate(self, hd_output_rate):
+        if self.hd_output_rate == hd_output_rate:
+            return
+        self.hd_output_rate = hd_output_rate
+        self.restart()
+
     def set_demodulator(self, demodulator):
         if demodulator in ["usb", "lsb", "cw"]:
             demodulator = "ssb"
@@ -685,7 +714,7 @@ class dsp(object):
     def set_squelch_level(self, squelch_level):
         self.squelch_level = squelch_level
         # no squelch required on digital voice modes
-        actual_squelch = -150 if self.isDigitalVoice() or self.isPacket() or self.isPocsag() or self.get_demodulator() == "freedv" else self.squelch_level
+        actual_squelch = -150 if self.isDigitalVoice() or self.isPacket() or self.isPocsag() or self.isFreeDV() else self.squelch_level
         if self.running:
             self.pipes["squelch_pipe"].write("%g\n" % (self.convertToLinear(actual_squelch)))
 
@@ -818,9 +847,10 @@ class dsp(object):
 
             threading.Thread(target=watch_thread).start()
 
-            if self.output.supports_type("audio"):
+            audio_type = "hd_audio" if self.isHdAudio() else "audio"
+            if self.output.supports_type(audio_type):
                 self.output.send_output(
-                    "audio",
+                    audio_type,
                     partial(
                         self.process.stdout.read,
                         self.get_fft_bytes_to_read() if self.demodulator == "fft" else self.get_audio_bytes_to_read(),

htdocs/lib/AudioEngine.js

@@ -238,6 +238,28 @@ AudioEngine.prototype.pushAudio = function(data) {
     }
 };
 
+AudioEngine.prototype.pushHdAudio = function(data) {
+    if (!this.audioNode) return;
+    this.audioBytes.add(data.byteLength);
+    var buffer;
+    if (this.compression === "adpcm") {
+        //resampling & ADPCM
+        buffer = this.audioCodec.decode(new Uint8Array(data));
+    } else {
+        buffer = new Int16Array(data);
+    }
+    buffer = this.hdResampler.process(buffer);
+    if (this.audioNode.port) {
+        // AudioWorklets supported
+        this.audioNode.port.postMessage(buffer);
+    } else {
+        // silently drop excess samples
+        if (this.getBuffersize() + buffer.length <= this.maxBufferSize) {
+            this.audioBuffers.push(buffer);
+        }
+    }
+}
+
 AudioEngine.prototype.setCompression = function(compression) {
     this.compression = compression;
 };

htdocs/openwebrx.js

@@ -829,6 +829,10 @@ function on_ws_recv(evt) {
                     secondary_demod_waterfall_add(waterfall_f32);
                 }
                 break;
+            case 4:
+                // hd audio data
+                audioEngine.pushHdAudio(data);
+                break;
             default:
                 console.warn('unknown type of binary message: ' + type)
         }

owrx/connection.py

@@ -299,6 +299,9 @@ class OpenWebRxReceiverClient(OpenWebRxClient):
     def write_dsp_data(self, data):
         self.send(bytes([0x02]) + data)
 
+    def write_hd_audio(self, data):
+        self.send(bytes([0x04]) + data)
+
     def write_s_meter_level(self, level):
         self.send({"type": "smeter", "value": level})
 

owrx/dsp.py

@@ -95,6 +95,7 @@ class DspManager(csdr.output):
             self.props.wireProperty("digimodes_fft_size", self.dsp.set_secondary_fft_size),
             self.props.wireProperty("samp_rate", self.dsp.set_samp_rate),
             self.props.wireProperty("output_rate", self.dsp.set_output_rate),
+            self.props.wireProperty("hd_output_rate", self.dsp.set_hd_output_rate),
             self.props.wireProperty("offset_freq", self.dsp.set_offset_freq),
             self.props.wireProperty("center_freq", self.dsp.set_center_freq),
             self.props.wireProperty("squelch_level", self.dsp.set_squelch_level),
@@ -147,6 +148,7 @@ class DspManager(csdr.output):
         logger.debug("adding new output of type %s", t)
         writers = {
             "audio": self.handler.write_dsp_data,
+            "hd_audio": self.handler.write_hd_audio,
             "smeter": self.handler.write_s_meter_level,
             "secondary_fft": self.handler.write_secondary_fft,
             "secondary_demod": self.handler.write_secondary_demod,

owrx/modes.py

@@ -40,6 +40,7 @@ class DigitalMode(Mode):
 class Modes(object):
     mappings = [
         AnalogMode("nfm", "FM", bandpass=Bandpass(-4000, 4000)),
+        AnalogMode("wfm", "WFM", bandpass=Bandpass(-16000, 16000)),
         AnalogMode("am", "AM", bandpass=Bandpass(-4000, 4000)),
         AnalogMode("lsb", "LSB", bandpass=Bandpass(-3000, -300)),
         AnalogMode("usb", "USB", bandpass=Bandpass(300, 3000)),