add fifisdr support (no frequency tuning)

owrx/feature.py

@@ -31,6 +31,7 @@ class FeatureDetector(object):
         "digital_voice_dsd": ["dsd", "sox", "digiham"],
         "wsjt-x": ["wsjtx", "sox"],
         "packet": ["direwolf", "sox"],
+        "fifi_sdr": ["alsa"],
     }
 
     def feature_availability(self):
@@ -262,3 +263,10 @@ class FeatureDetector(object):
         on how to build from source.
         """
         return reduce(and_, map(self.command_is_runnable, ["jt9", "wsprd"]), True)
+
+    def has_alsa(self):
+        """
+        Some SDR receivers are identifying themselves as a soundcard. In order to read their data, OpenWebRX relies
+        on the Alsa library. It is available as a package for most Linux distributions.
+        """
+        return self.command_is_runnable("arecord --help")

owrx/source.py

@@ -460,6 +460,14 @@ class Resampler(SdrSource):
         pass
 
 
+class FifiSdrSource(SdrSource):
+    def getCommand(self):
+        return "arecord -D hw:2,0 -f S16_LE -r {samp_rate} -c2 -"
+
+    def getFormatConversion(self):
+        return "csdr convert_s16_f | csdr gain_ff 30"
+
+
 class ConnectorSource(SdrSource):
     def __init__(self, id, props, port):
         super().__init__(id, props, port)