Drain receiver backlog before admitting new production and avoid double waiting

src/call/call_video_playout.c

@@ -58,7 +58,8 @@ enum call_video_playout_action call_video_playout_poll(struct call_video_playout
         p->audio_valid = !!audio_valid;
     }
     if (!audio_valid) { p->anchored = 0; p->clock_wait++; return CALL_VIDEO_PLAYOUT_WAIT; }
-    if (!f) return CALL_VIDEO_PLAYOUT_WAIT;
+    // Ожидание новых данных уже прошло в реальном времени: повторно добавлять этот интервал нельзя.
+    if (!f) { p->anchored = 0; return CALL_VIDEO_PLAYOUT_WAIT; }
     if (f->pts_us <= p->last_pts || f->received_us < 0 || f->received_us > now) {
         DEBUG_WARN(DEBUG_CATEGORY_CALL, "video playout invalid/order call=%llu pts=%lld last=%lld received=%lld now=%lld",
             (unsigned long long)p->call_id, (long long)f->pts_us, (long long)p->last_pts,

src/call/call_video_port.c

@@ -30,6 +30,7 @@ static struct {
     int64_t tx_wait_started;
     unsigned tx_retries;
     unsigned count, bytes;
+    int64_t rx_wait_started; // Полный FIFO возобновляет приём после drain, а не по одному освободившемуся месту.
     uint64_t decoded_generation;
     int decoded_pending, decoded_accepted;
 } port;
@@ -48,6 +49,7 @@ static void clear_frames(void) {
     port.tx_wait_started = 0; port.tx_retries = 0;
     for (unsigned i = 0; i < port.count; ++i) u_free((void *)port.rx[i].data);
     port.count = port.bytes = 0;
+    port.rx_wait_started = 0;
 }
 static void peer(void *arg, const struct call_video_caps *caps) {
     pthread_mutex_lock(&lock);
@@ -56,7 +58,20 @@ static void peer(void *arg, const struct call_video_caps *caps) {
 }
 static int ready(void *arg, uint32_t bytes) {
     pthread_mutex_lock(&lock);
-    int result = port.id == (uint64_t)(uintptr_t)arg && port.count < 8 && bytes <= 4u * 1024u * 1024u - port.bytes;
+    int result = 0;
+    if (port.id == (uint64_t)(uintptr_t)arg) {
+        if (port.rx_wait_started && !port.count) {
+            DEBUG_DEBUG(DEBUG_CATEGORY_CALL, "video port RX drained call=%llu wait_us=%lld; admission resumed",
+                (unsigned long long)port.id, (long long)(call_video_playout_now_us() - port.rx_wait_started));
+            port.rx_wait_started = 0;
+        }
+        result = !port.rx_wait_started && port.count < 8 && bytes <= 4u * 1024u * 1024u - port.bytes;
+        if (!result && !port.rx_wait_started) {
+            port.rx_wait_started = call_video_playout_now_us();
+            DEBUG_WARN(DEBUG_CATEGORY_CALL, "video port RX full call=%llu frames=%u bytes=%u next_bytes=%u; drain before resume",
+                (unsigned long long)port.id, port.count, port.bytes, bytes);
+        }
+    }
     pthread_mutex_unlock(&lock); return result;
 }
 static void frame(void *arg, const struct call_video_frame *f) {