From ccc2b89c9cf879ccbd948e169a029917cc16f0ee Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <steinar+nageru@gunderson.no>
Date: Sun, 15 Aug 2021 15:06:34 +0200
Subject: [PATCH] Fix DeckLink capture using the 11.7 or newer drivers.

Reported by Marcus Nilsen.
---
 nageru/bmusb               | 2 +-
 nageru/decklink_capture.h  | 2 ++
 nageru/decklink_output.cpp | 6 ++----
 nageru/decklink_output.h   | 6 +++++-
 nageru/mixer.cpp           | 2 +-
 5 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/nageru/bmusb b/nageru/bmusb
index 0c0182f..327dca2 160000
--- a/nageru/bmusb
+++ b/nageru/bmusb
@@ -1 +1 @@
-Subproject commit 0c0182f453e8bc26e630615ea6d2a2f05e868fde
+Subproject commit 327dca2d848e4c4656be1bfb54a2edf2e6587a71
diff --git a/nageru/decklink_capture.h b/nageru/decklink_capture.h
index f940241..a2e25c8 100644
--- a/nageru/decklink_capture.h
+++ b/nageru/decklink_capture.h
@@ -26,6 +26,8 @@ public:
 	DeckLinkCapture(IDeckLink *card, int card_index);  // Takes ownership of <card>.
 	~DeckLinkCapture();
 
+	IDeckLinkInput *get_input() const { return input; }
+
 	// IDeckLinkInputCallback.
 	HRESULT STDMETHODCALLTYPE QueryInterface(REFIID, LPVOID *) override;
 	ULONG STDMETHODCALLTYPE AddRef() override;
diff --git a/nageru/decklink_output.cpp b/nageru/decklink_output.cpp
index da172af..20de922 100644
--- a/nageru/decklink_output.cpp
+++ b/nageru/decklink_output.cpp
@@ -82,11 +82,9 @@ DeckLinkOutput::DeckLinkOutput(ResourcePool *resource_pool, QSurface *surface, u
 	});
 }
 
-bool DeckLinkOutput::set_device(IDeckLink *decklink)
+bool DeckLinkOutput::set_device(IDeckLink *decklink, IDeckLinkInput *input_arg)
 {
-	if (decklink->QueryInterface(IID_IDeckLinkInput, (void**)&input) != S_OK) {
-		input = nullptr;
-	}
+	input_arg = input;
 	if (decklink->QueryInterface(IID_IDeckLinkOutput, (void**)&output) != S_OK) {
 		fprintf(stderr, "Warning: Card %u has no outputs\n", card_index);
 		return false;
diff --git a/nageru/decklink_output.h b/nageru/decklink_output.h
index f1b40f4..8213f49 100644
--- a/nageru/decklink_output.h
+++ b/nageru/decklink_output.h
@@ -39,7 +39,11 @@ class DeckLinkOutput : public IDeckLinkVideoOutputCallback {
 public:
 	DeckLinkOutput(movit::ResourcePool *resource_pool, QSurface *surface, unsigned width, unsigned height, unsigned card_index);
 
-	bool set_device(IDeckLink *output);
+	// The IDecklinkInput argument is to work around a bug
+	// in the 11.7 and newer drivers against older SDKs,
+	// where you get a freeze if querying an IDeckLinkInput interface
+	// on an already-started card.
+	bool set_device(IDeckLink *decklink, IDeckLinkInput *input_arg);
 	void start_output(uint32_t mode, int64_t base_pts);  // Mode comes from get_available_video_modes().
 	void end_output();
 
diff --git a/nageru/mixer.cpp b/nageru/mixer.cpp
index ce8a732..3a137d6 100644
--- a/nageru/mixer.cpp
+++ b/nageru/mixer.cpp
@@ -429,7 +429,7 @@ Mixer::Mixer(const QSurfaceFormat &format)
 
 				DeckLinkCapture *capture = new DeckLinkCapture(decklink, card_index);
 				DeckLinkOutput *output = new DeckLinkOutput(resource_pool.get(), decklink_output_surface, global_flags.width, global_flags.height, card_index);
-				if (!output->set_device(decklink)) {
+				if (!output->set_device(decklink, capture->get_input())) {
 					delete output;
 					output = nullptr;
 				}
-- 
2.39.2