From 8ee5edc9f243c0ad4da889f01e980e25a4132741 Mon Sep 17 00:00:00 2001
From: Jakob Ketterl <jakob.ketterl@gmx.de>
Date: Wed, 16 Aug 2023 17:07:18 +0200
Subject: [PATCH] add a lowpass to improve decoding performance

---
 csdr/chain/digimodes.py              | 10 +++++++---
 docker/scripts/install-owrx-tools.sh |  8 ++++----
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/csdr/chain/digimodes.py b/csdr/chain/digimodes.py
index a399c58d..015624be 100644
--- a/csdr/chain/digimodes.py
+++ b/csdr/chain/digimodes.py
@@ -3,7 +3,7 @@ from csdr.module.msk144 import Msk144Module, ParserAdapter
 from owrx.audio.chopper import AudioChopper, AudioChopperParser
 from owrx.aprs.kiss import KissDeframer
 from owrx.aprs import Ax25Parser, AprsParser
-from pycsdr.modules import Convert, FmDemod, Agc, TimingRecovery, DBPskDecoder, VaricodeDecoder, RttyDecoder, BaudotDecoder
+from pycsdr.modules import Convert, FmDemod, Agc, TimingRecovery, DBPskDecoder, VaricodeDecoder, RttyDecoder, BaudotDecoder, Lowpass
 from pycsdr.types import Format
 from owrx.aprs.module import DirewolfModule
 
@@ -94,10 +94,12 @@ class RttyDemodulator(SecondaryDemodulator, SecondarySelectorChain):
         # this is an assumption, we will adjust in setSampleRate
         self.sampleRate = 12000
         secondary_samples_per_bit = int(round(self.sampleRate / self.baudRate))
+        cutoff = self.baudRate / self.sampleRate
         workers = [
             Agc(Format.COMPLEX_FLOAT),
             FmDemod(),
-            TimingRecovery(Format.FLOAT, secondary_samples_per_bit, 0.5, 2),
+            Lowpass(Format.FLOAT, cutoff),
+            TimingRecovery(Format.FLOAT, secondary_samples_per_bit, 5, 2),
             RttyDecoder(invert),
             BaudotDecoder(),
         ]
@@ -111,4 +113,6 @@ class RttyDemodulator(SecondaryDemodulator, SecondarySelectorChain):
             return
         self.sampleRate = sampleRate
         secondary_samples_per_bit = int(round(self.sampleRate / self.baudRate))
-        self.replace(2, TimingRecovery(Format.FLOAT, secondary_samples_per_bit, 0.5, 2))
+        cutoff = self.baudRate / self.sampleRate
+        self.replace(2, Lowpass(Format.FLOAT, cutoff))
+        self.replace(3, TimingRecovery(Format.FLOAT, secondary_samples_per_bit, 5, 2))
diff --git a/docker/scripts/install-owrx-tools.sh b/docker/scripts/install-owrx-tools.sh
index 7938b5f5..bc1d1c5c 100755
--- a/docker/scripts/install-owrx-tools.sh
+++ b/docker/scripts/install-owrx-tools.sh
@@ -32,13 +32,13 @@ popd
 rm -rf js8py
 
 git clone https://github.com/jketterl/csdr.git
-# latest develop as of 2023-08-15 (rtty and baudot)
-cmakebuild csdr 8966688f748d04486560e973a599c26ed4297f34
+# latest develop as of 2023-08-16 (added lowpass)
+cmakebuild csdr 64a1603c4433e79f4b6a449711bfd86f977a997b
 
 git clone https://github.com/jketterl/pycsdr.git
 cd pycsdr
-# latest develop as of 2023-08-15 (rtty and baudot)
-git checkout 4e30b6c6a4d73ab4cf99698847c4df68e8206f73
+# latest develop as of 2023-08-16 (added lowpass)
+git checkout eec718ae365583ebf5f315ae45967d2f635ff209
 ./setup.py install install_headers
 cd ..
 rm -rf pycsdr