feat: cw decoder

internal/audio/cwtap.go

@@ -0,0 +1,17 @@
+package audio
+
+// SampleRate is the fixed capture rate (mono 16-bit PCM). Exported so consumers
+// like the CW decoder can configure their DSP to match.
+const SampleRate = sampleRate
+
+// StreamCapture captures from deviceID and calls onSamples with mono 16-bit PCM
+// frames (as int16) until stop closes. A thin wrapper over the internal capture
+// loop for live consumers (the CW decoder) that want samples, not raw bytes.
+func StreamCapture(deviceID string, stop <-chan struct{}, onSamples func([]int16)) error {
+	return captureStream(deviceID, stop, func(chunk []byte) {
+		if len(chunk) == 0 {
+			return
+		}
+		onSamples(bytesToInt16(chunk))
+	})
+}