From 99c7093a1a264422bde3f480ab3d5a9c3a605ab5 Mon Sep 17 00:00:00 2001
From: Jakob Ketterl <jakob.ketterl@gmx.de>
Date: Sun, 25 Jul 2021 19:31:56 +0200
Subject: [PATCH] pack the client audio processing into its own chain

---
 csdr/__init__.py          | 16 ++++++++++++++--
 csdr/chain/am.py          |  1 -
 csdr/chain/clientaudio.py | 14 ++++++++++++++
 csdr/chain/fm.py          |  1 -
 csdr/chain/ssb.py         |  1 -
 5 files changed, 28 insertions(+), 5 deletions(-)
 create mode 100644 csdr/chain/clientaudio.py

diff --git a/csdr/__init__.py b/csdr/__init__.py
index 757aead..3f8cbb8 100644
--- a/csdr/__init__.py
+++ b/csdr/__init__.py
@@ -41,6 +41,7 @@ from csdr.chain.demodulator import DemodulatorChain
 from csdr.chain.fm import Fm
 from csdr.chain.am import Am
 from csdr.chain.ssb import Ssb
+from csdr.chain.clientaudio import ClientAudioChain
 
 import logging
 
@@ -51,6 +52,7 @@ class Dsp(DirewolfConfigSubscriber):
     def __init__(self, output: Output):
         self.pycsdr_enabled = True
         self.pycsdr_chain = None
+        self.pycsdr_client_chain = None
         self.pycsdr_reader = None
         self.pycsdr_power_reader = None
         self.buffer = None
@@ -732,11 +734,19 @@ class Dsp(DirewolfConfigSubscriber):
                 self.set_squelch_level(self.squelch_level)
                 self.set_bpf(self.low_cut, self.high_cut)
                 self.set_offset_freq(self.offset_freq)
+
                 chain.setInput(self.buffer)
-                outputBuffer = Buffer(chain.getOutputFormat())
-                chain.setWriter(outputBuffer)
+
+                self.pycsdr_client_chain = ClientAudioChain(self.get_audio_rate(), self.get_output_rate(), self.audio_compression)
+                buffer = Buffer(chain.getOutputFormat())
+                chain.setWriter(buffer)
+                self.pycsdr_client_chain.setInput(buffer)
+
+                outputBuffer = Buffer(self.pycsdr_client_chain.getOutputFormat())
+                self.pycsdr_client_chain.setWriter(outputBuffer)
                 self.pycsdr_reader = outputBuffer.getReader()
                 self.output.send_output("audio", self.pycsdr_reader.read)
+
                 powerBuffer = Buffer(Format.FLOAT)
                 chain.setPowerWriter(powerBuffer)
                 self.pycsdr_power_reader = powerBuffer.getReader()
@@ -839,6 +849,8 @@ class Dsp(DirewolfConfigSubscriber):
                 self.pycsdr_reader = None
                 self.pycsdr_power_reader.stop()
                 self.pycsdr_power_reader = None
+                self.pycsdr_client_chain.stop()
+                self.pycsdr_client_chain = None
             if self.process is not None:
                 try:
                     os.killpg(os.getpgid(self.process.pid), signal.SIGTERM)
diff --git a/csdr/chain/am.py b/csdr/chain/am.py
index e57fa9a..74d40a7 100644
--- a/csdr/chain/am.py
+++ b/csdr/chain/am.py
@@ -12,7 +12,6 @@ class Am(Chain):
             AmDemod(),
             DcBlock(),
             agc,
-            Convert(Format.FLOAT, Format.SHORT),
         ]
 
         super().__init__(*workers)
diff --git a/csdr/chain/clientaudio.py b/csdr/chain/clientaudio.py
new file mode 100644
index 0000000..d331bf8
--- /dev/null
+++ b/csdr/chain/clientaudio.py
@@ -0,0 +1,14 @@
+from csdr.chain import Chain
+from pycsdr.modules import AudioResampler, Convert, AdpcmEncoder
+from pycsdr.types import Format
+
+
+class ClientAudioChain(Chain):
+    def __init__(self, inputRate: int, clientRate: int, compression: str):
+        workers = []
+        if inputRate != clientRate:
+            workers += [AudioResampler(inputRate, clientRate)]
+        workers += [Convert(Format.FLOAT, Format.SHORT)]
+        if compression == "adpcm":
+            workers += [AdpcmEncoder()]
+        super().__init__(*workers)
diff --git a/csdr/chain/fm.py b/csdr/chain/fm.py
index 150cce4..1254fd2 100644
--- a/csdr/chain/fm.py
+++ b/csdr/chain/fm.py
@@ -13,6 +13,5 @@ class Fm(Chain):
             Limit(),
             NfmDeemphasis(sampleRate),
             agc,
-            Convert(Format.FLOAT, Format.SHORT),
         ]
         super().__init__(*workers)
diff --git a/csdr/chain/ssb.py b/csdr/chain/ssb.py
index cf94d42..4034281 100644
--- a/csdr/chain/ssb.py
+++ b/csdr/chain/ssb.py
@@ -10,7 +10,6 @@ class Ssb(Chain):
             # empty chain as placeholder for the "last decimation"
             Chain(),
             Agc(Format.FLOAT),
-            Convert(Format.FLOAT, Format.SHORT),
         ]
         super().__init__(*workers)