From: Steinar H. Gunderson <steinar+nageru@gunderson.no>
Date: Sun, 30 Aug 2020 17:23:43 +0000 (+0200)
Subject: In DeckLinkOutput, keep a list of all the scheduled frames instead of just a count.
X-Git-Tag: 2.0.2~15
X-Git-Url: https://git.sesse.net/?p=nageru;a=commitdiff_plain;h=cd1b6b6b8dd3d4d6f52d917cec3e5a152f87e822

In DeckLinkOutput, keep a list of all the scheduled frames instead of just a count.

This will be important when we want to track frames the driver inserts
on our behalf; we'll need to be able to adjust their estimated pts then.
---

diff --git a/nageru/decklink_output.cpp b/nageru/decklink_output.cpp
index 00d8043..da172af 100644
--- a/nageru/decklink_output.cpp
+++ b/nageru/decklink_output.cpp
@@ -255,7 +255,7 @@ void DeckLinkOutput::end_output()
 	// Wait until all frames are accounted for, and free them.
 	{
 		unique_lock<mutex> lock(frame_queue_mutex);
-		while (!(frame_freelist.empty() && num_frames_in_flight == 0)) {
+		while (!(frame_freelist.empty() && scheduled_frames.empty())) {
 			frame_queues_changed.wait(lock, [this]{ return !frame_freelist.empty(); });
 			frame_freelist.pop();
 		}
@@ -503,7 +503,8 @@ HRESULT DeckLinkOutput::ScheduledFrameCompleted(/* in */ IDeckLinkVideoFrame *co
 	{
 		lock_guard<mutex> lock(frame_queue_mutex);
 		frame_freelist.push(unique_ptr<Frame>(frame));
-		--num_frames_in_flight;
+		assert(scheduled_frames.front() == frame);
+		scheduled_frames.pop_front();
 		--metric_decklink_output_inflight_frames;
 	}
 
@@ -573,8 +574,6 @@ void DeckLinkOutput::present_thread_func()
 			}
 			frame = move(pending_video_frames.front());
 			pending_video_frames.pop();
-			++num_frames_in_flight;
-			++metric_decklink_output_inflight_frames;
 		}
 
 		for ( ;; ) {
@@ -601,15 +600,14 @@ void DeckLinkOutput::present_thread_func()
 		BMDTimeValue pts = frame->pts;
 		BMDTimeValue duration = frame->duration;
 		HRESULT res = output->ScheduleVideoFrame(frame.get(), pts, duration, TIMEBASE);
+		lock_guard<mutex> lock(frame_queue_mutex);
 		if (res == S_OK) {
-			frame.release();  // Owned by the driver now.
+			scheduled_frames.push_back(frame.release());  // Owned by the driver now.
+			++metric_decklink_output_inflight_frames;
 		} else {
 			fprintf(stderr, "Could not schedule video frame! (error=0x%08x)\n", res);
 
-			lock_guard<mutex> lock(frame_queue_mutex);
 			frame_freelist.push(move(frame));
-			--num_frames_in_flight;
-			--metric_decklink_output_inflight_frames;
 		}
 	}
 }
diff --git a/nageru/decklink_output.h b/nageru/decklink_output.h
index 2c07bc7..f1b40f4 100644
--- a/nageru/decklink_output.h
+++ b/nageru/decklink_output.h
@@ -7,6 +7,7 @@
 #include <atomic>
 #include <chrono>
 #include <condition_variable>
+#include <deque>
 #include <memory>
 #include <mutex>
 #include <queue>
@@ -133,7 +134,8 @@ private:
 	std::mutex frame_queue_mutex;
 	std::queue<std::unique_ptr<Frame>> pending_video_frames;  // Under <frame_queue_mutex>.
 	std::queue<std::unique_ptr<Frame>> frame_freelist;  // Under <frame_queue_mutex>.
-	int num_frames_in_flight = 0;  // Number of frames allocated but not on the freelist. Under <frame_queue_mutex>.
+	std::deque<Frame *> scheduled_frames;  // Owned by the driver, so no unique_ptr. Under <frame_queue_mutex>.
+
 	std::condition_variable frame_queues_changed;
 	bool playback_initiated = false, playback_started = false;
 	int64_t base_pts, frame_duration;