Fix call gap tone to follow 500ms of missing jitter PCM

src/call/call_audio.c

@@ -25,7 +25,7 @@
 
 #define CALL_AUDIO_ID    "call_audio"
 #define CALL_AUDIO_BITRATE 32000
-#define CALL_STALL_TB       5000   /* 500мс без медиа и недобор PCM → глитч-тон */
+#define CALL_STALL_SAMPLES (CALL_AUDIO_SAMPLE_RATE / 2) /* 500мс без PCM из jitter → глитч-тон */
 #define CALL_AEC_FILTER_SAMPLES 14400  /* хвост эха 300мс @48кГц */
 #define CALL_AEC_DELAY_FRAMES   2       /* desktop: минимальная задержка duplex */
 
@@ -36,7 +36,7 @@ static int                     g_ending = 0;
 static int                     g_glitch_started = 0; /* только аудиопоток */
 static int                     g_ended_started = 0;  /* только аудио-поток: тон завершения запущен */
 static uint64_t                g_call_id = 0;
-static uint64_t                g_last_media_tb = 0;
+static int                     g_gap_samples = 0; /* только аудиопоток; насыщение на пороге */
 static opus_codec_encoder_t*   g_encoder = NULL;
 static opus_codec_decoder_t*   g_decoder = NULL;
 static struct call_jitter*              g_vj = NULL;
@@ -85,7 +85,6 @@ void call_audio_on_media(struct UTUN_INSTANCE* inst, uint64_t call_id,
     pthread_mutex_lock(&g_mtx);
     if (g_active && call_id == g_call_id && g_vj && opus && len > 0) {
         call_jitter_push(g_vj, opus, len);
-        g_last_media_tb = get_time_tb();
     }
     pthread_mutex_unlock(&g_mtx);
 }
@@ -185,7 +184,7 @@ int call_audio_start(uint64_t call_id) {
     g_ending = 0;
     g_ended_started = 0;
     g_glitch_started = 0;
-    g_last_media_tb = 0;
+    g_gap_samples = 0;
     pthread_mutex_unlock(&g_mtx);
 
     DEBUG_INFO(DEBUG_CATEGORY_CALL, "%s: started call=0x%016llx aec=%d delay=%d compressor=%s gain=%d", CALL_AUDIO_ID,
@@ -220,7 +219,7 @@ void call_audio_release(uint64_t call_id) {
         g_ending = 0;
         g_ended_started = 0;
         g_call_id = 0;
-        g_last_media_tb = 0;
+        g_gap_samples = 0;
         enc = g_encoder; g_encoder = NULL;
         dec = g_decoder; g_decoder = NULL;
         j = g_vj;       g_vj = NULL;
@@ -347,7 +346,6 @@ int call_audio_pull_pcm(uint64_t call_id, int16_t* out, int max_samples) {
     int active = 0, ending = 0;
     struct call_jitter* j = NULL;
     struct call_tones* tones = NULL;
-    uint64_t last_media = 0;
 
     pthread_mutex_lock(&g_mtx);
     if (g_active && call_id == g_call_id) {
@@ -355,7 +353,6 @@ int call_audio_pull_pcm(uint64_t call_id, int16_t* out, int max_samples) {
         ending = g_ending;
         j = g_vj;
         tones = g_tones;
-        last_media = g_last_media_tb;
     }
     pthread_mutex_unlock(&g_mtx);
 
@@ -375,21 +372,36 @@ int call_audio_pull_pcm(uint64_t call_id, int16_t* out, int max_samples) {
             n = call_tones_render(tones, out, max_samples);
     } else {
         n = call_jitter_pull(j, out, max_samples);
-        uint64_t now = get_time_tb();
-        int stalled = n < max_samples && last_media != 0 && now - last_media >= CALL_STALL_TB;
-        if (stalled != g_glitch_started) {
-            g_glitch_started = stalled;
-            DEBUG_INFO(DEBUG_CATEGORY_CALL, "%s: gap tone %s call=%016llx media_gap=%llums pcm=%d/%d",
-                       CALL_AUDIO_ID, stalled ? "started" : "stopped", (unsigned long long)call_id,
-                       (unsigned long long)((now - last_media) / 10), n, max_samples);
-        }
-        if (stalled) {
-            call_tones_glitch_start(tones);
-            n += call_tones_render(tones, out + n, max_samples - n);
-        } else {
+        int previous_gap = g_gap_samples;
+        if (n > 0) g_gap_samples = 0;
+        int missing = max_samples - n;
+        int quiet = CALL_STALL_SAMPLES - g_gap_samples;
+        if (quiet > missing) quiet = missing;
+        int tone_samples = missing - quiet;
+        if (n > 0 && previous_gap > 0)
+            DEBUG_DEBUG(DEBUG_CATEGORY_CALL, "%s: PCM resumed call=%016llx gap=%dms pcm=%d/%d", CALL_AUDIO_ID,
+                        (unsigned long long)call_id, previous_gap * 1000 / CALL_AUDIO_SAMPLE_RATE, n, max_samples);
+        if (missing > 0 && g_gap_samples == 0)
+            DEBUG_DEBUG(DEBUG_CATEGORY_CALL, "%s: PCM gap started call=%016llx pcm=%d/%d", CALL_AUDIO_ID,
+                        (unsigned long long)call_id, n, max_samples);
+        g_gap_samples += quiet;
+        /* Новый PCM прерывает предыдущий цикл тона, даже если хвост блока снова пуст. */
+        if (g_glitch_started && (n > 0 || tone_samples == 0)) {
+            g_glitch_started = 0;
             call_tones_glitch_stop(tones);
+            DEBUG_INFO(DEBUG_CATEGORY_CALL, "%s: gap tone stopped call=%016llx pcm=%d/%d", CALL_AUDIO_ID,
+                       (unsigned long long)call_id, n, max_samples);
+        }
+        memset(out + n, 0, (size_t)quiet * sizeof(*out));
+        if (tone_samples > 0) {
+            if (!g_glitch_started) {
+                g_glitch_started = 1;
+                DEBUG_INFO(DEBUG_CATEGORY_CALL, "%s: gap tone started call=%016llx pcm_gap=500ms pcm=%d/%d", CALL_AUDIO_ID,
+                           (unsigned long long)call_id, n, max_samples);
+            }
+            call_tones_glitch_start(tones);
+            call_tones_render(tones, out + n + quiet, tone_samples);
         }
-        for (int i = n; i < max_samples; i++) out[i] = 0;
         n = max_samples;
     }