From 0b9f86685a8a32fafdb1a24394aa0a5e0bb9e7c3 Mon Sep 17 00:00:00 2001
From: Jan Svabenik <jan@svabi.ch>
Date: Mon, 23 Mar 2026 12:30:23 +0100
Subject: [PATCH] Add feed/process gap diagnostics for live audio

---
 cmd/sdrd/dsp_loop.go          |  4 ++++
 internal/recorder/streamer.go | 23 ++++++++++++++++++++---
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/cmd/sdrd/dsp_loop.go b/cmd/sdrd/dsp_loop.go
index 5d54d6c..a579752 100644
--- a/cmd/sdrd/dsp_loop.go
+++ b/cmd/sdrd/dsp_loop.go
@@ -13,6 +13,7 @@ import (
 	"sdr-wideband-suite/internal/config"
 	"sdr-wideband-suite/internal/detector"
 	"sdr-wideband-suite/internal/dsp"
+	"sdr-wideband-suite/internal/logging"
 	"sdr-wideband-suite/internal/pipeline"
 	"sdr-wideband-suite/internal/recorder"
 )
@@ -93,6 +94,7 @@ func runDSP(ctx context.Context, srcMgr *sourceManager, cfg config.Config, det *
 							continue
 						}
 						if j >= len(streamSnips) || len(streamSnips[j]) == 0 {
+							logging.Warn("gap", "snippet_empty", "signal", ds.ID)
 							continue
 						}
 						snipRate := rt.cfg.SampleRate
@@ -106,6 +108,8 @@ func runDSP(ctx context.Context, srcMgr *sourceManager, cfg config.Config, det *
 					}
 					if len(items) > 0 {
 						rec.FeedSnippets(items)
+					} else {
+						logging.Warn("gap", "feed_empty", "signals", len(streamSignals))
 					}
 				}
 				rt.maintenance(displaySignals, rec)
diff --git a/internal/recorder/streamer.go b/internal/recorder/streamer.go
index 7ba3d53..afb965f 100644
--- a/internal/recorder/streamer.go
+++ b/internal/recorder/streamer.go
@@ -170,6 +170,9 @@ type Streamer struct {
 	droppedFeed uint64
 	droppedPCM  uint64
 
+	lastFeedTS time.Time
+	lastProcTS time.Time
+
 	// pendingListens are subscribers waiting for a matching session.
 	pendingListens map[int64]*pendingListen
 }
@@ -260,6 +263,14 @@ func (st *Streamer) FeedSnippets(items []streamFeedItem) {
 	hasListeners := st.hasListenersLocked()
 	pending := len(st.pendingListens)
 	debugLiveAudio := st.policy.DebugLiveAudio
+	now := time.Now()
+	if !st.lastFeedTS.IsZero() {
+		gap := now.Sub(st.lastFeedTS)
+		if gap > 150*time.Millisecond {
+			logging.Warn("gap", "feed_gap", "gap_ms", gap.Milliseconds())
+		}
+	}
+	st.lastFeedTS = now
 	st.mu.Unlock()
 
 	if debugLiveAudio {
@@ -280,16 +291,22 @@ func (st *Streamer) FeedSnippets(items []streamFeedItem) {
 // processFeed runs in the worker goroutine.
 func (st *Streamer) processFeed(msg streamFeedMsg) {
 	st.mu.Lock()
-	defer st.mu.Unlock()
-
 	recEnabled := st.policy.Enabled && (st.policy.RecordAudio || st.policy.RecordIQ)
 	hasListeners := st.hasListenersLocked()
+	now := time.Now()
+	if !st.lastProcTS.IsZero() {
+		gap := now.Sub(st.lastProcTS)
+		if gap > 150*time.Millisecond {
+			logging.Warn("gap", "process_gap", "gap_ms", gap.Milliseconds())
+		}
+	}
+	st.lastProcTS = now
+	defer st.mu.Unlock()
 
 	if !recEnabled && !hasListeners {
 		return
 	}
 
-	now := time.Now()
 	seen := make(map[int64]bool, len(msg.items))
 
 	for i := range msg.items {