diff --git a/scripts/ci/video_downstream_gate.sh b/scripts/ci/video_downstream_gate.sh
new file mode 100755
index 0000000..44f7829
--- /dev/null
+++ b/scripts/ci/video_downstream_gate.sh
@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+# Guard downstream eye-video stability before pushing video-related changes.
+set -euo pipefail
+
+ROOT=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/../.." && pwd)
+cd "$ROOT"
+
+VIDEO_TESTS=(
+  --test video_downstream_feed_contract
+  --test server_video_include_contract
+  --test video_support_contract
+  --test client_output_video_include_contract
+  --test server_video_sinks_include_contract
+  --test server_video_sink_smoke_contract
+)
+
+VIDEO_IGNORE_REGEX='(/common/src/(hid|paste|process_metrics)\.rs|/server/src/(audio|camera|gadget|paste|runtime_support|uvc_runtime)\.rs)'
+
+cargo fmt --all -- --check
+cargo check -q --bin lesavka-client --bin lesavka-server
+cargo test -q -p lesavka_testing "${VIDEO_TESTS[@]}"
+
+cargo llvm-cov clean --workspace
+cargo llvm-cov --workspace "${VIDEO_TESTS[@]}" \
+  --ignore-filename-regex "$VIDEO_IGNORE_REGEX" \
+  --fail-under-lines 95 \
+  --summary-only
diff --git a/server/src/video.rs b/server/src/video.rs
index c5e87e7..0654d20 100644
--- a/server/src/video.rs
+++ b/server/src/video.rs
@@ -336,12 +336,17 @@ pub async fn eye_ball_with_request(
     let pipeline = gst::Pipeline::new();
     let (tx, rx) = tokio::sync::mpsc::channel(64);
 
-    let _ = tx.try_send(Ok(VideoPacket {
-        id: id.min(1),
-        pts: 0,
-        data: vec![0, 0, 0, 1, 0x65, 0x88, 0x84],
-        ..Default::default()
-    }));
+    for seq in 0..8 {
+        let _ = tx.try_send(Ok(VideoPacket {
+            id: id.min(1),
+            pts: seq * 16_666,
+            data: vec![0, 0, 0, 1, 0x65, 0x88, 0x84],
+            seq: seq + 1,
+            effective_fps: 60,
+            server_encoder_label: "coverage-testsrc".to_string(),
+            ..Default::default()
+        }));
+    }
 
     Ok(VideoStream {
         _pipeline: pipeline,
diff --git a/testing/tests/client_output_video_include_contract.rs b/testing/tests/client_output_video_include_contract.rs
index 3993f8b..a134d5a 100644
--- a/testing/tests/client_output_video_include_contract.rs
+++ b/testing/tests/client_output_video_include_contract.rs
@@ -95,6 +95,33 @@ mod video_include_contract {
         with_var("PATH", Some(merged), f);
     }
 
+    #[test]
+    #[serial]
+    fn h264_decoder_selection_honors_env_and_fallbacks() {
+        gst::init().expect("initialize gstreamer");
+        with_var("LESAVKA_H264_DECODER", Some("decodebin"), || {
+            assert_eq!(pick_h264_decoder(), "decodebin");
+        });
+        with_var("LESAVKA_H264_DECODER", Some("fakesink"), || {
+            assert_eq!(pick_h264_decoder(), "fakesink");
+        });
+        with_var(
+            "LESAVKA_H264_DECODER",
+            Some("definitely-not-a-decoder"),
+            || {
+                assert_ne!(pick_h264_decoder(), "definitely-not-a-decoder");
+            },
+        );
+        with_var("LESAVKA_H264_DECODER", Some("   "), || {
+            assert!(!pick_h264_decoder().trim().is_empty());
+        });
+        with_var("LESAVKA_H264_DECODER", None::<&str>, || {
+            assert!(!pick_h264_decoder().trim().is_empty());
+        });
+        assert!(buildable_decoder("fakesink"));
+        assert!(!buildable_decoder("definitely-not-a-real-gst-element"));
+    }
+
     #[test]
     #[serial]
     fn monitor_window_new_covers_x11_backend_path() {
diff --git a/testing/tests/server_video_include_contract.rs b/testing/tests/server_video_include_contract.rs
index 3cf0d07..eee5cbf 100644
--- a/testing/tests/server_video_include_contract.rs
+++ b/testing/tests/server_video_include_contract.rs
@@ -31,6 +31,30 @@ mod video_include_contract {
         let _ = gst::init();
     }
 
+    #[test]
+    fn eye_profile_and_telemetry_helpers_are_stable() {
+        assert_eq!(eye_source_profile(), (1920, 1080, 60));
+
+        let metric = server_process_cpu_metric();
+        metric.store(123, std::sync::atomic::Ordering::Relaxed);
+        assert_eq!(metric.load(std::sync::atomic::Ordering::Relaxed), 123);
+
+        let last_window = AtomicU64::new(5);
+        let source_gap = AtomicU32::new(99);
+        let send_gap = AtomicU32::new(88);
+        let queue_peak = AtomicU32::new(77);
+
+        reset_stream_telemetry_window(&last_window, 5, &source_gap, &send_gap, &queue_peak);
+        assert_eq!(source_gap.load(Ordering::Relaxed), 99);
+        assert_eq!(send_gap.load(Ordering::Relaxed), 88);
+        assert_eq!(queue_peak.load(Ordering::Relaxed), 77);
+
+        reset_stream_telemetry_window(&last_window, 6, &source_gap, &send_gap, &queue_peak);
+        assert_eq!(source_gap.load(Ordering::Relaxed), 0);
+        assert_eq!(send_gap.load(Ordering::Relaxed), 0);
+        assert_eq!(queue_peak.load(Ordering::Relaxed), 0);
+    }
+
     #[tokio::test]
     async fn video_stream_forwards_inner_packets() {
         init_gst();
@@ -248,4 +272,24 @@ mod video_include_contract {
             });
         });
     }
+
+    #[test]
+    #[serial]
+    fn wait_for_eye_device_reports_non_character_paths() {
+        let rt = tokio::runtime::Runtime::new().expect("runtime");
+        let dir = tempfile::tempdir().expect("tempdir");
+        let regular_file = dir.path().join("not-a-video-device");
+        std::fs::write(&regular_file, "not a device").expect("write marker file");
+        with_var("LESAVKA_EYE_DEVICE_WAIT_MS", Some("50"), || {
+            with_var("LESAVKA_EYE_DEVICE_POLL_MS", Some("25"), || {
+                rt.block_on(async {
+                    let err = wait_for_eye_device(regular_file.to_str().expect("utf8 path"), "l")
+                        .await
+                        .expect_err("regular files should not count as eye devices");
+                    let rendered = format!("{err:#}");
+                    assert!(rendered.contains("not a character device"));
+                });
+            });
+        });
+    }
 }
diff --git a/testing/tests/video_downstream_feed_contract.rs b/testing/tests/video_downstream_feed_contract.rs
index 020b999..ef32cfc 100644
--- a/testing/tests/video_downstream_feed_contract.rs
+++ b/testing/tests/video_downstream_feed_contract.rs
@@ -49,6 +49,22 @@ fn native_downstream_eye_modes_stay_widescreen_and_square_pixel() {
             (mode.width, mode.height)
         );
     }
+    assert_eq!(
+        display_size_for_source_mode(EyeSourceMode {
+            width: 720,
+            height: 576,
+            fps: 50,
+        }),
+        (1024, 576)
+    );
+    assert_eq!(
+        display_size_for_source_mode(EyeSourceMode {
+            width: 720,
+            height: 480,
+            fps: 60,
+        }),
+        (854, 480)
+    );
 }
 
 #[test]
diff --git a/testing/tests/video_support_contract.rs b/testing/tests/video_support_contract.rs
index 2f9aa0b..b37436e 100644
--- a/testing/tests/video_support_contract.rs
+++ b/testing/tests/video_support_contract.rs
@@ -29,6 +29,7 @@ fn contains_idr_handles_short_and_multi_nal_annex_b_streams() {
     assert!(contains_idr(&[0, 0, 1, 0x65, 0x00]));
     assert!(contains_idr(&[0, 0, 0, 1, 0x41, 0x00, 0, 0, 1, 0x65, 0x00]));
     assert!(!contains_idr(&[0, 0, 0, 1, 0x41, 0x00, 0x00]));
+    assert!(!contains_idr(&[0, 0, 2, 0x65, 0, 0, 0, 2, 0x65]));
 }
 
 #[test]