From fd26acca68e103349cc28a0fa718fffad7d5f948 Mon Sep 17 00:00:00 2001
From: Jakob Ketterl <jakob.ketterl@gmx.de>
Date: Sat, 8 May 2021 00:37:30 +0200
Subject: [PATCH 1/3] don't resample when there's only one service

---
 owrx/service/__init__.py | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/owrx/service/__init__.py b/owrx/service/__init__.py
index eac8c254..a4062caf 100644
--- a/owrx/service/__init__.py
+++ b/owrx/service/__init__.py
@@ -193,21 +193,25 @@ class ServiceHandler(SdrSourceEventClient):
                     self.services.append(self.setupService(dial["mode"], dial["frequency"], self.source))
             else:
                 for group in groups:
-                    cf = self.get_center_frequency(group)
-                    bw = self.get_bandwidth(group)
-                    logger.debug("group center frequency: {0}, bandwidth: {1}".format(cf, bw))
-                    resampler_props = PropertyLayer()
-                    resampler_props["center_freq"] = cf
-                    resampler_props["samp_rate"] = bw
-                    resampler = Resampler(resampler_props, self.source)
-                    resampler.start()
+                    if len(group) > 1:
+                        cf = self.get_center_frequency(group)
+                        bw = self.get_bandwidth(group)
+                        logger.debug("group center frequency: {0}, bandwidth: {1}".format(cf, bw))
+                        resampler_props = PropertyLayer()
+                        resampler_props["center_freq"] = cf
+                        resampler_props["samp_rate"] = bw
+                        resampler = Resampler(resampler_props, self.source)
+                        resampler.start()
 
-                    for dial in group:
-                        self.services.append(self.setupService(dial["mode"], dial["frequency"], resampler))
+                        for dial in group:
+                            self.services.append(self.setupService(dial["mode"], dial["frequency"], resampler))
 
-                    # resampler goes in after the services since it must not be shutdown as long as the services are
-                    # still running
-                    self.services.append(resampler)
+                        # resampler goes in after the services since it must not be shutdown as long as the services are
+                        # still running
+                        self.services.append(resampler)
+                    else:
+                        dial = group[0]
+                        self.services.append(self.setupService(dial["mode"], dial["frequency"], self.source))
 
     def get_min_max(self, group):
         frequencies = sorted(group, key=lambda f: f["frequency"])

From 093ad6cd0da1624b5cb2166262d4def703a62c02 Mon Sep 17 00:00:00 2001
From: Jakob Ketterl <jakob.ketterl@gmx.de>
Date: Sat, 8 May 2021 00:38:00 +0200
Subject: [PATCH 2/3] improve oversampling for resampling

---
 owrx/service/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/owrx/service/__init__.py b/owrx/service/__init__.py
index a4062caf..00afe186 100644
--- a/owrx/service/__init__.py
+++ b/owrx/service/__init__.py
@@ -228,7 +228,7 @@ class ServiceHandler(SdrSourceEventClient):
     def get_bandwidth(self, group):
         minFreq, maxFreq = self.get_min_max(group)
         # minimum bandwidth for a resampler: 25kHz
-        return max(maxFreq - minFreq, 25000)
+        return max((maxFreq - minFreq) * 1.15, 25000)
 
     def optimizeResampling(self, freqs, bandwidth):
         freqs = sorted(freqs, key=lambda f: f["frequency"])

From dc848a7006273ab4c9abd05c9aa4c5c6659dbda2 Mon Sep 17 00:00:00 2001
From: Jakob Ketterl <jakob.ketterl@gmx.de>
Date: Sat, 8 May 2021 00:59:57 +0200
Subject: [PATCH 3/3] fix bandwidth calculation for single-service groups

---
 owrx/service/__init__.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/owrx/service/__init__.py b/owrx/service/__init__.py
index 00afe186..2206924c 100644
--- a/owrx/service/__init__.py
+++ b/owrx/service/__init__.py
@@ -254,7 +254,10 @@ class ServiceHandler(SdrSourceEventClient):
             groups.append([f for f in freqs if previous < f["frequency"]])
 
             def get_total_bandwidth(group):
-                return bandwidth + len(group) * self.get_bandwidth(group)
+                if len(group) > 1:
+                    return bandwidth + len(group) * self.get_bandwidth(group)
+                else:
+                    return bandwidth
 
             total_bandwidth = sum([get_total_bandwidth(group) for group in groups])
             return {