From dbe7ff470004e57b12c85243d4ca7a7664cf4f77 Mon Sep 17 00:00:00 2001
From: Silvano Seva <silseva@fastwebnet.it>
Date: Wed, 10 Jan 2024 19:01:54 +0100
Subject: [PATCH] M17: activate speaker only when a valid transmission is
 received

Audio path from codec2 to speaker is now set up only when an incoming stream
with matching CAN and destination callsign is received. Speaker is then turned
off when the demodulator goes back in unlocked state.
---
 openrtx/src/rtx/OpMode_M17.cpp | 45 +++++++++++++---------------------
 1 file changed, 17 insertions(+), 28 deletions(-)

diff --git a/openrtx/src/rtx/OpMode_M17.cpp b/openrtx/src/rtx/OpMode_M17.cpp
index 1f8fdbcd..e55de1be 100644
--- a/openrtx/src/rtx/OpMode_M17.cpp
+++ b/openrtx/src/rtx/OpMode_M17.cpp
@@ -78,17 +78,6 @@ void OpMode_M17::disable()
 
 void OpMode_M17::update(rtxStatus_t *const status, const bool newCfg)
 {
-    //
-    // FIXME: workaround to avoid UI glitches when a new dst callsign is set.
-    //
-    // When a new dst callsign is set, the rtx configuration data structure is
-    // updated and this may trigger false setting of the lsfOk variable to true,
-    // causing the M17 info screen to appear for a very small, but noticeable,
-    // amount of time.
-    //
-    if(newCfg)
-        status->lsfOk = false;
-
     #if defined(PLATFORM_MD3x0) || defined(PLATFORM_MDUV3x0)
     //
     // Invert TX phase for all MDx models.
@@ -154,9 +143,7 @@ void OpMode_M17::offState(rtxStatus_t *const status)
 {
     radio_disableRtx();
 
-    codec_stop(rxAudioPath);
     codec_stop(txAudioPath);
-    audioPath_release(rxAudioPath);
     audioPath_release(txAudioPath);
 
     if(startRx)
@@ -201,18 +188,6 @@ void OpMode_M17::rxState(rtxStatus_t *const status)
 
     if(locked)
     {
-        // Check RX audio path status, open it if necessary
-        uint8_t pthSts = audioPath_getStatus(rxAudioPath);
-        if(pthSts == PATH_CLOSED)
-        {
-            rxAudioPath = audioPath_request(SOURCE_MCU, SINK_SPK, PRIO_RX);
-            pthSts = audioPath_getStatus(rxAudioPath);
-        }
-
-        // Start codec2 module if not already up
-        if(codec_running() == false)
-            codec_startDecode(rxAudioPath);
-
         // Process new data
         if(newData)
         {
@@ -272,10 +247,21 @@ void OpMode_M17::rxState(rtxStatus_t *const status)
                 // matches with ours
                 bool callMatch = compareCallsigns(std::string(status->source_address), dst);
 
-                // Extract audio data
-                if((type == M17FrameType::STREAM) && (pthSts == PATH_OPEN) &&
-                   (canMatch == true)             && (callMatch == true))
+                // Open audio path only if CAN and callsign match
+                uint8_t pthSts = audioPath_getStatus(rxAudioPath);
+                if((pthSts == PATH_CLOSED) && (canMatch == true) && (callMatch == true))
                 {
+                    rxAudioPath = audioPath_request(SOURCE_MCU, SINK_SPK, PRIO_RX);
+                    pthSts = audioPath_getStatus(rxAudioPath);
+                }
+
+                // Extract audio data and sent it to codec
+                if((type == M17FrameType::STREAM) && (pthSts == PATH_OPEN))
+                {
+                    // (re)start codec2 module if not already up
+                    if(codec_running() == false)
+                        codec_startDecode(rxAudioPath);
+
                     M17StreamFrame sf = decoder.getStreamFrame();
                     codec_pushFrame(sf.payload().data(),     false);
                     codec_pushFrame(sf.payload().data() + 8, false);
@@ -301,6 +287,9 @@ void OpMode_M17::rxState(rtxStatus_t *const status)
         extendedCall  = false;
         status->M17_link[0] = '\0';
         status->M17_refl[0] = '\0';
+
+        codec_stop(rxAudioPath);
+        audioPath_release(rxAudioPath);
     }
 }