Reject large audio timestamp jumps before narrowing PLC packet counts

src/stream/stream_playback_audio.cpp

@@ -118,12 +118,16 @@ int stream_playback_audio_feed(struct stream_playback_audio* a, int64_t pts, con
         DEBUG_WARN(DEBUG_CATEGORY_STREAM, "playback audio late packet pts=%lld expected=%lld", (long long)pts, (long long)a->expectedPts);
         return 1;
     }
-    int missing = a->expectedPts < 0 ? 0 : (int)((pts - a->expectedPts + 10000) / 20000);
-    if (missing > 5) {
-        DEBUG_WARN(DEBUG_CATEGORY_STREAM, "playback audio discontinuity pts=%lld expected=%lld missing=%d",
-                   (long long)pts, (long long)a->expectedPts, missing); return -2;
+    int64_t difference = a->expectedPts < 0 ? 0 : pts - a->expectedPts;
+    if (difference >= 110000) {
+        DEBUG_WARN(DEBUG_CATEGORY_STREAM, "playback audio discontinuity pts=%lld expected=%lld gap_us=%lld",
+                   (long long)pts, (long long)a->expectedPts, (long long)difference); return -2;
     }
+    int missing = a->expectedPts < 0 ? 0 : (int)((difference + 10000) / 20000);
     int64_t effectivePts = a->expectedPts < 0 ? pts : a->expectedPts + missing * 20000;
+    if (effectivePts > INT64_MAX - 20000) {
+        DEBUG_ERROR(DEBUG_CATEGORY_STREAM, "playback audio normalized PTS overflow pts=%lld", (long long)effectivePts); return -1;
+    }
     for (int i = 0; i < missing; i++) if (feedPcm(a, a->expectedPts + i * 20000, nullptr, 0) < 0) return -1;
     if (feedPcm(a, effectivePts, packet, (int)length) < 0) return -1;
     a->expectedPts = effectivePts + 20000;

tools/chatgui/tests/test_stream_audio.cpp

@@ -68,6 +68,9 @@ static void test_silence_clock() {
         int length = opus_codec_encode(encoder, pcm, 960, packet, sizeof(packet)); CHECK(length > 0);
         CHECK(stream_playback_audio_feed(audio, 1000000 + i * 20000, packet, (size_t)length) == 0);
     }
+    int length = opus_codec_encode(encoder, pcm, 960, packet, sizeof(packet)); CHECK(length > 0);
+    CHECK(stream_playback_audio_feed(audio, INT64_MAX - 20000, packet, (size_t)length) == -2);
+    CHECK(stream_playback_audio_feed(audio, 1080000, packet, (size_t)length) == 0);
     int got = stream_playback_audio_pull(audio, out, 960, INT64_MAX); CHECK(got > 0);
     uint64_t before = stream_playback_audio_written(audio);
     int64_t pts = stream_playback_audio_position(audio, before);