test(compositor): fix flaky runtime format change test on GPU runner

The test consistently got only 1 output frame instead of ≥ 2 on the
self-hosted GPU runner.  Root cause: when compiled with --features gpu
and gpu_mode Auto (the default), the compositor OS thread blocks on
GpuContext::try_init() before processing any compositing work.  On the
GPU runner with many tests competing for the device, init can exceed
the total sleep budget (800ms).  By the time it finishes, both input
frames have been drained to just the latest (Dynamic mode behaviour),
producing a single output.

Fix: set gpu_mode: "cpu" explicitly.  This test validates runtime
output_format switching via UpdateParams, not GPU compositing — GPU
init is unnecessary overhead that creates the race.

Also reduces sleep durations to 200/100/200ms (from 300/200/300ms)
since without GPU init the compositor thread starts processing
immediately.

Signed-off-by: Devin AI <devin@streamkit.dev>
Signed-off-by: StreamKit Devin <devin@streamkit.dev>
Co-Authored-By: Claudio Costa <cstcld91@gmail.com>

Author: streamkit-devin

crates/nodes/src/video/compositor/tests.rs

@@ -2502,7 +2502,16 @@ async fn test_compositor_output_format_runtime_change() {
     };
 
     // Start with no output_format (RGBA8).
-    let config = CompositorConfig { width: 4, height: 4, ..Default::default() };
+    // Force CPU mode so the test isn't blocked by GpuContext::try_init()
+    // competing for the GPU with other parallel tests on the self-hosted
+    // runner.  This test validates runtime output_format switching, not
+    // GPU compositing.
+    let config = CompositorConfig {
+        width: 4,
+        height: 4,
+        gpu_mode: Some("cpu".to_string()),
+        ..Default::default()
+    };
     let node = CompositorNode::new(config, GlobalCompositorConfig::default());
 
     let node_handle = tokio::spawn(async move { Box::new(node).run(context).await });
@@ -2513,21 +2522,17 @@ async fn test_compositor_output_format_runtime_change() {
     // Send a frame — should come out as RGBA8.
     let frame = make_rgba_frame(2, 2, 255, 0, 0, 255);
     input_tx.send(Packet::Video(frame)).await.unwrap();
-    // Give the compositor enough ticks to process the frame.  On the
-    // self-hosted GPU runner many tests run in parallel, so the
-    // compositor thread may be starved for CPU.  300ms ≈ 9 ticks at
-    // 30 fps — generous enough even under heavy load.
-    tokio::time::sleep(tokio::time::Duration::from_millis(300)).await;
+    tokio::time::sleep(tokio::time::Duration::from_millis(200)).await;
 
     // Send UpdateParams to switch output_format to NV12.
     let update = serde_json::json!({ "output_format": "nv12" });
     ctrl_tx.send(NodeControlMessage::UpdateParams(update)).await.unwrap();
-    tokio::time::sleep(tokio::time::Duration::from_millis(200)).await;
+    tokio::time::sleep(tokio::time::Duration::from_millis(100)).await;
 
     // Send another frame — should come out as NV12.
     let frame2 = make_rgba_frame(2, 2, 0, 255, 0, 255);
     input_tx.send(Packet::Video(frame2)).await.unwrap();
-    tokio::time::sleep(tokio::time::Duration::from_millis(300)).await;
+    tokio::time::sleep(tokio::time::Duration::from_millis(200)).await;
 
     drop(input_tx);
     drop(ctrl_tx);