[feat](trx-server): handle virtual channel bandwidth updates

Handle AUDIO_MSG_VCHAN_BW in the audio server path and apply per-channel filter bandwidth through the SoapySDR virtual channel manager.

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

src/trx-server/src/audio.rs

@@ -27,7 +27,8 @@ use trx_core::audio::{
     AUDIO_MSG_AIS_DECODE, AUDIO_MSG_APRS_DECODE, AUDIO_MSG_CW_DECODE, AUDIO_MSG_FT8_DECODE,
     AUDIO_MSG_HF_APRS_DECODE, AUDIO_MSG_HISTORY_COMPRESSED, AUDIO_MSG_RX_FRAME,
     AUDIO_MSG_STREAM_INFO, AUDIO_MSG_TX_FRAME, AUDIO_MSG_VCHAN_ALLOCATED,
-    AUDIO_MSG_VCHAN_DESTROYED, AUDIO_MSG_VCHAN_FREQ, AUDIO_MSG_VCHAN_MODE, AUDIO_MSG_VCHAN_REMOVE,
+    AUDIO_MSG_VCHAN_BW, AUDIO_MSG_VCHAN_DESTROYED, AUDIO_MSG_VCHAN_FREQ, AUDIO_MSG_VCHAN_MODE,
+    AUDIO_MSG_VCHAN_REMOVE,
     AUDIO_MSG_VCHAN_SUB, AUDIO_MSG_VCHAN_UNSUB, AUDIO_MSG_VDES_DECODE, AUDIO_MSG_WSPR_DECODE,
 };
 use trx_core::vchan::SharedVChanManager;
@@ -2183,6 +2184,20 @@ async fn handle_audio_client(
                     }
                 }
             }
+            Ok((AUDIO_MSG_VCHAN_BW, payload)) => {
+                if let Some(ref mgr) = vchan_manager {
+                    if let Ok(v) = serde_json::from_slice::<serde_json::Value>(&payload) {
+                        if let (Some(uuid), Some(bandwidth_hz)) = (
+                            v["uuid"].as_str().and_then(|s| s.parse::<Uuid>().ok()),
+                            v["bandwidth_hz"].as_u64().map(|b| b as u32),
+                        ) {
+                            if let Err(e) = mgr.set_channel_bandwidth(uuid, bandwidth_hz) {
+                                warn!("Audio vchan BW: {}", e);
+                            }
+                        }
+                    }
+                }
+            }
             Ok((AUDIO_MSG_VCHAN_REMOVE, payload)) => {
                 match parse_vchan_uuid_msg(&payload) {
                     Ok(uuid) => {

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

@@ -295,6 +295,20 @@ impl VirtualChannelManager for SdrVirtualChannelManager {
         Ok(())
     }
 
+    fn set_channel_bandwidth(&self, id: Uuid, bandwidth_hz: u32) -> Result<(), VChanError> {
+        let channels = self.channels.read().unwrap();
+        let ch = channels
+            .iter()
+            .find(|c| c.id == id)
+            .ok_or(VChanError::NotFound)?;
+
+        let dsps = self.pipeline.channel_dsps.read().unwrap();
+        if let Some(dsp_arc) = dsps.get(ch.pipeline_slot) {
+            dsp_arc.lock().unwrap().set_filter(bandwidth_hz, DEFAULT_FIR_TAPS);
+        }
+        Ok(())
+    }
+
     fn subscribe_pcm(&self, id: Uuid) -> Option<broadcast::Receiver<Vec<f32>>> {
         let channels = self.channels.read().unwrap();
         channels