input buffer

apps/RenderCadenceCompositor/RenderCadenceCompositor.cpp

@@ -12,9 +12,11 @@
 
 #include <windows.h>
 
+#include <chrono>
 #include <iostream>
 #include <sstream>
 #include <string>
+#include <thread>
 
 namespace
 {
@@ -41,6 +43,19 @@ private:
 	bool mInitialized = false;
 	HRESULT mResult = S_OK;
 };
+
+bool WaitForInputWarmup(InputFrameMailbox& mailbox, std::size_t targetReadyFrames, std::chrono::milliseconds timeout)
+{
+	const auto start = std::chrono::steady_clock::now();
+	while (std::chrono::steady_clock::now() - start < timeout)
+	{
+		const InputFrameMailboxMetrics metrics = mailbox.Metrics();
+		if (metrics.readyCount >= targetReadyFrames || metrics.submittedFrames >= targetReadyFrames)
+			return true;
+		std::this_thread::sleep_for(std::chrono::milliseconds(2));
+	}
+	return false;
+}
 }
 
 int main(int argc, char** argv)
@@ -123,6 +138,25 @@ int main(int argc, char** argv)
 		{
 			deckLinkInputStarted = true;
 			RenderCadenceCompositor::Log("app", "DeckLink input edge started for " + inputVideoMode.displayName + ".");
+			RenderCadenceCompositor::Log("app", "Waiting for DeckLink input warmup frames.");
+			constexpr std::size_t kInputWarmupFrames = 2;
+			constexpr std::chrono::milliseconds kInputWarmupTimeout(500);
+			if (WaitForInputWarmup(inputMailbox, kInputWarmupFrames, kInputWarmupTimeout))
+			{
+				const InputFrameMailboxMetrics metrics = inputMailbox.Metrics();
+				RenderCadenceCompositor::Log(
+					"app",
+					"DeckLink input warmup complete. ready=" + std::to_string(metrics.readyCount) +
+						" submitted=" + std::to_string(metrics.submittedFrames) + ".");
+			}
+			else
+			{
+				const InputFrameMailboxMetrics metrics = inputMailbox.Metrics();
+				RenderCadenceCompositor::LogWarning(
+					"app",
+					"DeckLink input warmup timed out; starting render cadence with current input buffer. ready=" +
+						std::to_string(metrics.readyCount) + " submitted=" + std::to_string(metrics.submittedFrames) + ".");
+			}
 		}
 		else
 		{