[feat](trx-rs): add AIS decoder mode and frontend

Add dual-channel AIS decode support across the SoapySDR backend, server decode pipeline, and frontend plugins, including the new AIS tab, live bar, and map filtering.

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

src/trx-core/src/audio.rs

@@ -15,6 +15,7 @@ pub const AUDIO_MSG_APRS_DECODE: u8 = 0x03;
 pub const AUDIO_MSG_CW_DECODE: u8 = 0x04;
 pub const AUDIO_MSG_FT8_DECODE: u8 = 0x05;
 pub const AUDIO_MSG_WSPR_DECODE: u8 = 0x06;
+pub const AUDIO_MSG_AIS_DECODE: u8 = 0x07;
 
 /// Maximum payload size (1 MB) to reject bogus frames early.
 const MAX_PAYLOAD_SIZE: u32 = 1_048_576;

src/trx-core/src/decode.rs

@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: BSD-2-Clause
 
-//! Shared types for server-side decoded messages (APRS, CW).
+//! Shared types for server-side decoded messages (APRS, AIS, CW).
 
 use serde::{Deserialize, Serialize};
 
@@ -10,6 +10,8 @@ use serde::{Deserialize, Serialize};
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(tag = "type")]
 pub enum DecodedMessage {
+    #[serde(rename = "ais")]
+    Ais(AisMessage),
     #[serde(rename = "aprs")]
     Aprs(AprsPacket),
     #[serde(rename = "cw")]
@@ -20,6 +22,37 @@ pub enum DecodedMessage {
     Wspr(WsprMessage),
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AisMessage {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub ts_ms: Option<i64>,
+    pub channel: String,
+    pub message_type: u8,
+    pub repeat: u8,
+    pub mmsi: u32,
+    pub crc_ok: bool,
+    pub bit_len: usize,
+    pub raw_bytes: Vec<u8>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub lat: Option<f64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub lon: Option<f64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub sog_knots: Option<f32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub cog_deg: Option<f32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub heading_deg: Option<u16>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub nav_status: Option<u8>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub vessel_name: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub callsign: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub destination: Option<String>,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct AprsPacket {
     #[serde(skip_serializing_if = "Option::is_none")]

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

@@ -72,6 +72,18 @@ pub trait AudioSource: Send + Sync {
     /// Subscribe to demodulated PCM audio from the primary channel.
     /// Returns a broadcast receiver that yields 20ms frames of mono f32 PCM.
     fn subscribe_pcm(&self) -> tokio::sync::broadcast::Receiver<Vec<f32>>;
+
+    /// Subscribe to PCM from a specific backend channel when available.
+    /// Channel `0` is always the primary channel.
+    fn subscribe_pcm_channel(&self, channel_idx: usize) -> tokio::sync::broadcast::Receiver<Vec<f32>> {
+        if channel_idx == 0 {
+            self.subscribe_pcm()
+        } else {
+            let (tx, rx) = tokio::sync::broadcast::channel(1);
+            drop(tx);
+            rx
+        }
+    }
 }
 
 /// Common interface for rig backends.

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

@@ -70,6 +70,7 @@ pub enum RigMode {
     AM,
     WFM,
     FM,
+    AIS,
     DIG,
     PKT,
     Other(String),