[feat](trx-backend-soapysdr): add wfm denoise levels

Co-authored-by: OpenAI Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js

@@ -1428,8 +1428,10 @@ function render(update) {
         saveSetting("wfmAudioMode", nextMode);
       }
     }
-    if (wfmDenoiseEl && typeof update.filter.wfm_denoise === "boolean") {
-      const nextDenoise = update.filter.wfm_denoise ? "on" : "off";
+    if (wfmDenoiseEl && (typeof update.filter.wfm_denoise === "string" || typeof update.filter.wfm_denoise === "boolean")) {
+      const nextDenoise = typeof update.filter.wfm_denoise === "string"
+        ? normalizeWfmDenoiseLevel(update.filter.wfm_denoise)
+        : (update.filter.wfm_denoise ? "auto" : "low");
       if (wfmDenoiseEl.value !== nextDenoise) {
         wfmDenoiseEl.value = nextDenoise;
         saveSetting("wfmDenoise", nextDenoise);
@@ -2990,6 +2992,13 @@ function levelFromChannels(channels, frameCount) {
   return Math.min(100, rms * 220);
 }
 
+function normalizeWfmDenoiseLevel(value) {
+  const next = String(value ?? "").toLowerCase();
+  if (next === "auto" || next === "low" || next === "medium" || next === "high") return next;
+  if (next === "off") return "low";
+  return "auto";
+}
+
 if (wfmAudioModeEl) {
   wfmAudioModeEl.value = loadSetting("wfmAudioMode", "stereo");
   wfmAudioModeEl.addEventListener("change", () => {
@@ -2999,11 +3008,12 @@ if (wfmAudioModeEl) {
   });
 }
 if (wfmDenoiseEl) {
-  wfmDenoiseEl.value = loadSetting("wfmDenoise", "on");
+  wfmDenoiseEl.value = normalizeWfmDenoiseLevel(loadSetting("wfmDenoise", "auto"));
   wfmDenoiseEl.addEventListener("change", () => {
-    saveSetting("wfmDenoise", wfmDenoiseEl.value);
-    const enabled = wfmDenoiseEl.value !== "off";
-    postPath(`/set_wfm_denoise?enabled=${enabled ? "true" : "false"}`).catch(() => {});
+    const level = normalizeWfmDenoiseLevel(wfmDenoiseEl.value);
+    wfmDenoiseEl.value = level;
+    saveSetting("wfmDenoise", level);
+    postPath(`/set_wfm_denoise?level=${encodeURIComponent(level)}`).catch(() => {});
   });
 }
 if (wfmDeemphasisEl) {

src/trx-client/trx-frontend/trx-frontend-http/src/api.rs

@@ -14,6 +14,7 @@ use tokio::time::{self, Duration};
 use tokio_stream::wrappers::{IntervalStream, WatchStream};
 
 use trx_core::radio::freq::Freq;
+use trx_core::rig::state::WfmDenoiseLevel;
 use trx_core::rig::{RigAccessMethod, RigCapabilities, RigInfo};
 use trx_core::{RigCommand, RigRequest, RigSnapshot, RigState};
 use trx_frontend::{FrontendRuntimeContext, RemoteRigEntry};
@@ -551,7 +552,7 @@ pub async fn set_wfm_stereo(
 
 #[derive(serde::Deserialize)]
 pub struct WfmDenoiseQuery {
-    pub enabled: bool,
+    pub level: WfmDenoiseLevel,
 }
 
 #[post("/set_wfm_denoise")]
@@ -559,7 +560,7 @@ pub async fn set_wfm_denoise(
     query: web::Query<WfmDenoiseQuery>,
     rig_tx: web::Data<mpsc::Sender<RigRequest>>,
 ) -> Result<HttpResponse, Error> {
-    send_command(&rig_tx, RigCommand::SetWfmDenoise(query.enabled)).await
+    send_command(&rig_tx, RigCommand::SetWfmDenoise(query.level)).await
 }
 
 #[post("/toggle_aprs_decode")]

src/trx-core/src/lib.rs

@@ -13,5 +13,5 @@ pub type DynResult<T> = Result<T, Box<dyn std::error::Error + Send + Sync>>;
 pub use rig::command::RigCommand;
 pub use rig::request::RigRequest;
 pub use rig::response::{RigError, RigResult};
-pub use rig::state::{RdsData, RigFilterState, RigMode, RigSnapshot, RigState};
+pub use rig::state::{RdsData, RigFilterState, RigMode, RigSnapshot, RigState, WfmDenoiseLevel};
 pub use rig::AudioSource;

src/trx-core/src/rig/command.rs

@@ -3,6 +3,7 @@
 // SPDX-License-Identifier: BSD-2-Clause
 
 use crate::radio::freq::Freq;
+use crate::rig::state::WfmDenoiseLevel;
 use crate::RigMode;
 
 /// Internal command handled by the rig task.
@@ -36,6 +37,6 @@ pub enum RigCommand {
     SetSdrGain(f64),
     SetWfmDeemphasis(u32),
     SetWfmStereo(bool),
-    SetWfmDenoise(bool),
+    SetWfmDenoise(WfmDenoiseLevel),
     GetSpectrum,
 }

src/trx-core/src/rig/mod.rs

@@ -187,7 +187,7 @@ pub trait RigCat: Rig + Send {
 
     fn set_wfm_denoise<'a>(
         &'a mut self,
-        _enabled: bool,
+        _level: state::WfmDenoiseLevel,
     ) -> Pin<Box<dyn Future<Output = DynResult<()>> + Send + 'a>> {
         Box::pin(std::future::ready(Err(
             Box::new(response::RigError::not_supported("set_wfm_denoise"))

src/trx-core/src/rig/state.rs

@@ -277,8 +277,17 @@ pub struct RigFilterState {
     pub wfm_stereo: bool,
     #[serde(default)]
     pub wfm_stereo_detected: bool,
-    #[serde(default = "default_wfm_denoise")]
-    pub wfm_denoise: bool,
+    #[serde(default = "default_wfm_denoise_level")]
+    pub wfm_denoise: WfmDenoiseLevel,
+}
+
+#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+pub enum WfmDenoiseLevel {
+    Auto,
+    Low,
+    Medium,
+    High,
 }
 
 fn default_wfm_deemphasis_us() -> u32 {
@@ -289,8 +298,8 @@ fn default_wfm_stereo() -> bool {
     true
 }
 
-fn default_wfm_denoise() -> bool {
-    true
+fn default_wfm_denoise_level() -> WfmDenoiseLevel {
+    WfmDenoiseLevel::Auto
 }
 
 /// Spectrum data from SDR backends (FFT magnitude over the full capture bandwidth).

src/trx-protocol/src/mapping.rs

@@ -53,7 +53,7 @@ pub fn client_command_to_rig(cmd: ClientCommand) -> RigCommand {
             RigCommand::SetWfmDeemphasis(deemphasis_us)
         }
         ClientCommand::SetWfmStereo { enabled } => RigCommand::SetWfmStereo(enabled),
-        ClientCommand::SetWfmDenoise { enabled } => RigCommand::SetWfmDenoise(enabled),
+        ClientCommand::SetWfmDenoise { level } => RigCommand::SetWfmDenoise(level),
         ClientCommand::GetSpectrum => RigCommand::GetSpectrum,
     }
 }
@@ -100,7 +100,7 @@ pub fn rig_command_to_client(cmd: RigCommand) -> ClientCommand {
             ClientCommand::SetWfmDeemphasis { deemphasis_us }
         }
         RigCommand::SetWfmStereo(enabled) => ClientCommand::SetWfmStereo { enabled },
-        RigCommand::SetWfmDenoise(enabled) => ClientCommand::SetWfmDenoise { enabled },
+        RigCommand::SetWfmDenoise(level) => ClientCommand::SetWfmDenoise { level },
         RigCommand::GetSpectrum => ClientCommand::GetSpectrum,
     }
 }

src/trx-protocol/src/types.rs

@@ -7,6 +7,7 @@
 use serde::{Deserialize, Serialize};
 
 use trx_core::rig::state::RigSnapshot;
+use trx_core::WfmDenoiseLevel;
 
 /// Command received from network clients (JSON).
 #[derive(Debug, Serialize, Deserialize)]
@@ -41,7 +42,7 @@ pub enum ClientCommand {
     SetSdrGain { gain_db: f64 },
     SetWfmDeemphasis { deemphasis_us: u32 },
     SetWfmStereo { enabled: bool },
-    SetWfmDenoise { enabled: bool },
+    SetWfmDenoise { level: WfmDenoiseLevel },
     GetSpectrum,
 }
 

src/trx-server/src/rig_task.rs

@@ -480,12 +480,12 @@ async fn process_command(
             let _ = ctx.state_tx.send(ctx.state.clone());
             return snapshot_from(ctx.state);
         }
-        RigCommand::SetWfmDenoise(enabled) => {
-            if let Err(e) = ctx.rig.set_wfm_denoise(enabled).await {
+        RigCommand::SetWfmDenoise(level) => {
+            if let Err(e) = ctx.rig.set_wfm_denoise(level).await {
                 return Err(RigError::communication(format!("set_wfm_denoise: {e}")));
             }
             if let Some(f) = ctx.state.filter.as_mut() {
-                f.wfm_denoise = enabled;
+                f.wfm_denoise = level;
             }
             let _ = ctx.state_tx.send(ctx.state.clone());
             return snapshot_from(ctx.state);

src/trx-server/trx-backend/trx-backend-soapysdr/src/demod/wfm.rs

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: BSD-2-Clause
 
 use num_complex::Complex;
-use trx_core::rig::state::RdsData;
+use trx_core::rig::state::{RdsData, WfmDenoiseLevel};
 use trx_rds::RdsDecoder;
 
 use super::{math::demod_fm_with_prev, DcBlocker};
@@ -387,7 +387,7 @@ impl DenoiseSubband {
 #[derive(Debug, Clone)]
 struct StereoDenoise {
     bands: [DenoiseSubband; DENOISE_BANDS],
-    enabled: bool,
+    level: WfmDenoiseLevel,
 }
 
 impl StereoDenoise {
@@ -397,16 +397,12 @@ impl StereoDenoise {
         });
         Self {
             bands,
-            enabled: true,
+            level: WfmDenoiseLevel::Auto,
         }
     }
 
     #[inline]
     fn process(&mut self, sum: f32, diff_i: f32, diff_q: f32) -> f32 {
-        if !self.enabled {
-            return diff_i;
-        }
-
         let mut gain_sum = 0.0_f32;
         let mut weight_sum = 0.0_f32;
         for band in &mut self.bands {
@@ -420,7 +416,16 @@ impl StereoDenoise {
         } else {
             1.0
         };
-        diff_i * broadband_gain
+        let effective_gain = match self.level {
+            WfmDenoiseLevel::Auto => {
+                let strength = (0.3 + (1.0 - broadband_gain) * 0.7).clamp(0.3, 1.0);
+                1.0 - (1.0 - broadband_gain) * strength
+            }
+            WfmDenoiseLevel::Low => 1.0 - (1.0 - broadband_gain) * 0.35,
+            WfmDenoiseLevel::Medium => 1.0 - (1.0 - broadband_gain) * 0.65,
+            WfmDenoiseLevel::High => broadband_gain,
+        };
+        diff_i * effective_gain.clamp(0.0, 1.0)
     }
 
     fn reset(&mut self) {
@@ -489,6 +494,7 @@ impl WfmStereoDecoder {
         output_channels: usize,
         stereo_enabled: bool,
         deemphasis_us: u32,
+        denoise_level: WfmDenoiseLevel,
     ) -> Self {
         let composite_rate_f = composite_rate.max(1) as f32;
         let output_phase_inc = audio_rate.max(1) as f64 / composite_rate.max(1) as f64;
@@ -538,7 +544,11 @@ impl WfmStereoDecoder {
             diff_hist: [0.0; WFM_RESAMP_TAPS],
             diff_q_hist: [0.0; WFM_RESAMP_TAPS],
             hist_pos: 0,
-            denoise: StereoDenoise::new(audio_rate.max(1) as f32),
+            denoise: {
+                let mut denoise = StereoDenoise::new(audio_rate.max(1) as f32);
+                denoise.level = denoise_level;
+                denoise
+            },
             prev_blend: 0.0,
             output_phase_inc,
             output_phase: 0.0,
@@ -768,8 +778,8 @@ impl WfmStereoDecoder {
         self.output_phase = 0.0;
     }
 
-    pub fn set_denoise_enabled(&mut self, enabled: bool) {
-        self.denoise.enabled = enabled;
+    pub fn set_denoise_level(&mut self, level: WfmDenoiseLevel) {
+        self.denoise.level = level;
     }
 
     pub fn stereo_detected(&self) -> bool {
@@ -815,7 +825,8 @@ mod tests {
             iq.push(Complex::from_polar(1.0, phase));
         }
 
-        let mut decoder = WfmStereoDecoder::new(composite_rate, audio_rate, 2, true, 50);
+        let mut decoder =
+            WfmStereoDecoder::new(composite_rate, audio_rate, 2, true, 50, WfmDenoiseLevel::Auto);
         let output = decoder.process_iq(&iq);
 
         let skip_samples = (0.2 * audio_rate as f32) as usize;
@@ -883,7 +894,14 @@ mod tests {
                 iq.push(Complex::from_polar(1.0, phase));
             }
 
-            let mut decoder = WfmStereoDecoder::new(composite_rate, audio_rate, 2, true, 50);
+            let mut decoder = WfmStereoDecoder::new(
+                composite_rate,
+                audio_rate,
+                2,
+                true,
+                50,
+                WfmDenoiseLevel::Auto,
+            );
             let output = decoder.process_iq(&iq);
 
             let skip_samples = (0.3 * audio_rate as f32) as usize;
@@ -947,7 +965,8 @@ mod tests {
             iq.push(Complex::from_polar(1.0, phase));
         }
 
-        let mut decoder = WfmStereoDecoder::new(composite_rate, audio_rate, 2, true, 50);
+        let mut decoder =
+            WfmStereoDecoder::new(composite_rate, audio_rate, 2, true, 50, WfmDenoiseLevel::Auto);
         let output = decoder.process_iq(&iq);
 
         assert!(!decoder.stereo_detected());
@@ -1031,12 +1050,16 @@ mod tests {
     }
 
     #[test]
-    fn test_denoise_bypass_when_disabled() {
-        let mut denoise = StereoDenoise::new(48_000.0);
-        denoise.enabled = false;
+    fn test_denoise_low_preserves_more_than_high() {
+        let mut low = StereoDenoise::new(48_000.0);
+        low.level = WfmDenoiseLevel::Low;
+        let mut high = StereoDenoise::new(48_000.0);
+        high.level = WfmDenoiseLevel::High;
 
         for &value in &[0.0_f32, 0.5, -0.3, 1.0, -1.0, 0.001] {
-            assert_eq!(denoise.process(0.1, value, 0.2), value);
+            let low_out = low.process(0.1, value, 0.2).abs();
+            let high_out = high.process(0.1, value, 0.2).abs();
+            assert!(low_out + 0.000_001 >= high_out);
         }
     }
 
@@ -1115,7 +1138,8 @@ mod tests {
             iq.push(Complex::from_polar(1.0, phase));
         }
 
-        let mut decoder = WfmStereoDecoder::new(composite_rate, audio_rate, 2, true, 50);
+        let mut decoder =
+            WfmStereoDecoder::new(composite_rate, audio_rate, 2, true, 50, WfmDenoiseLevel::Auto);
         let output = decoder.process_iq(&iq);
 
         let skip_samples = (0.2 * audio_rate as f32) as usize;

src/trx-server/trx-backend/trx-backend-soapysdr/src/dsp/channel.rs

@@ -4,7 +4,7 @@
 
 use num_complex::Complex;
 use tokio::sync::broadcast;
-use trx_core::rig::state::{RdsData, RigMode};
+use trx_core::rig::state::{RdsData, RigMode, WfmDenoiseLevel};
 
 use crate::demod::{DcBlocker, Demodulator, SoftAgc, WfmStereoDecoder};
 
@@ -59,7 +59,7 @@ pub struct ChannelDsp {
     fir_taps: usize,
     wfm_deemphasis_us: u32,
     wfm_stereo: bool,
-    wfm_denoise: bool,
+    wfm_denoise: WfmDenoiseLevel,
     pub decim_factor: usize,
     output_channels: usize,
     pub frame_buf: Vec<f32>,
@@ -153,6 +153,7 @@ impl ChannelDsp {
                     self.output_channels,
                     self.wfm_stereo,
                     self.wfm_deemphasis_us,
+                    self.wfm_denoise,
                 ));
             }
         } else {
@@ -214,7 +215,7 @@ impl ChannelDsp {
             fir_taps: taps,
             wfm_deemphasis_us,
             wfm_stereo,
-            wfm_denoise: true,
+            wfm_denoise: WfmDenoiseLevel::Auto,
             decim_factor,
             output_channels,
             frame_buf: Vec::with_capacity(frame_size + output_channels),
@@ -242,6 +243,7 @@ impl ChannelDsp {
                     output_channels,
                     wfm_stereo,
                     wfm_deemphasis_us,
+                    WfmDenoiseLevel::Auto,
                 ))
             } else {
                 None
@@ -279,10 +281,10 @@ impl ChannelDsp {
         }
     }
 
-    pub fn set_wfm_denoise(&mut self, enabled: bool) {
-        self.wfm_denoise = enabled;
+    pub fn set_wfm_denoise(&mut self, level: WfmDenoiseLevel) {
+        self.wfm_denoise = level;
         if let Some(decoder) = &mut self.wfm_decoder {
-            decoder.set_denoise_enabled(enabled);
+            decoder.set_denoise_level(level);
         }
     }
 

src/trx-server/trx-backend/trx-backend-soapysdr/src/lib.rs

@@ -11,7 +11,7 @@ use std::sync::{Arc, Mutex};
 
 use trx_core::radio::freq::{Band, Freq};
 use trx_core::rig::response::RigError;
-use trx_core::rig::state::{RigFilterState, SpectrumData};
+use trx_core::rig::state::{RigFilterState, SpectrumData, WfmDenoiseLevel};
 use trx_core::rig::{
     AudioSource, Rig, RigAccessMethod, RigCapabilities, RigCat, RigInfo, RigStatusFuture,
 };
@@ -42,7 +42,7 @@ pub struct SoapySdrRig {
     /// Whether WFM stereo decode is enabled.
     wfm_stereo: bool,
     /// Whether WFM stereo denoise is enabled.
-    wfm_denoise: bool,
+    wfm_denoise: WfmDenoiseLevel,
     /// Requested hardware gain setting in dB.
     gain_db: f64,
     /// Optional hard ceiling for the applied hardware gain in dB.
@@ -206,7 +206,7 @@ impl SoapySdrRig {
             retune_cmd,
             wfm_deemphasis_us,
             wfm_stereo: true,
-            wfm_denoise: true,
+            wfm_denoise: WfmDenoiseLevel::Auto,
             gain_db,
             max_gain_db,
         })
@@ -526,12 +526,12 @@ impl RigCat for SoapySdrRig {
 
     fn set_wfm_denoise<'a>(
         &'a mut self,
-        enabled: bool,
+        level: WfmDenoiseLevel,
     ) -> Pin<Box<dyn std::future::Future<Output = DynResult<()>> + Send + 'a>> {
         Box::pin(async move {
-            self.wfm_denoise = enabled;
+            self.wfm_denoise = level;
             if let Some(dsp_arc) = self.pipeline.channel_dsps.get(self.primary_channel_idx) {
-                dsp_arc.lock().unwrap().set_wfm_denoise(enabled);
+                dsp_arc.lock().unwrap().set_wfm_denoise(level);
             }
             Ok(())
         })