From 270a8636aed52ddb97242bcf1a77f9d36206cf36 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Mon, 3 Oct 2022 17:29:13 +0200
Subject: [PATCH] Capture cursor in direct capture mode if supported by the
 driver (driver version >= 515.57)

---
 README.md                |  2 +-
 include/NvFBCLibrary.hpp | 32 +++++++++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 867c15c..4f20586 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,6 @@ FFMPEG only uses the GPU with CUDA when doing transcoding from an input video to
 libraries at compile-time.
 * Clean up the code!
 * Dynamically change bitrate/resolution to match desired fps. This would be helpful when streaming for example, where the encode output speed also depends on upload speed to the streaming service.
-* Show cursor when recording. Currently the cursor is not visible when recording a window and it's disabled when recording screen-direct to allow direct nvfbc capture for fullscreen windows, which allows for better performance and variable refresh rate monitors to work.
+* Show cursor when recording. Currently the cursor is not visible when recording a window.
 * Implement opengl injection to capture texture. This fixes composition issues and (VRR) without having to use NvFBC direct capture.
 * Always use direct capture with NvFBC once the capture issue in mpv fullscreen has been resolved (maybe detect if direct capture fails in nvfbc and switch to non-direct recording. NvFBC says if direct capture fails).
diff --git a/include/NvFBCLibrary.hpp b/include/NvFBCLibrary.hpp
index 6ce6635..3a642f4 100644
--- a/include/NvFBCLibrary.hpp
+++ b/include/NvFBCLibrary.hpp
@@ -4,6 +4,7 @@
 #include <dlfcn.h>
 #include <string.h>
 #include <stdio.h>
+#include <string.h>
 
 class NvFBCLibrary {
 public:
@@ -55,7 +56,7 @@ public:
         return true;
     }
 
-    // If |display_to_capture| is "screen", then the entire x11 screen is captured (all displays)
+    // If |display_to_capture| is "screen", then the entire x11 screen is captured (all displays).
     bool create(const char *display_to_capture, uint32_t fps, /*out*/ uint32_t *display_width, /*out*/ uint32_t *display_height, uint32_t x = 0, uint32_t y = 0, uint32_t width = 0, uint32_t height = 0, bool direct_capture = false) {
         if(!library || !display_to_capture || !display_width || !display_height || fbc_handle_created)
             return false;
@@ -120,7 +121,7 @@ public:
         memset(&create_capture_params, 0, sizeof(create_capture_params));
         create_capture_params.dwVersion = NVFBC_CREATE_CAPTURE_SESSION_PARAMS_VER;
         create_capture_params.eCaptureType = NVFBC_CAPTURE_SHARED_CUDA;
-        create_capture_params.bWithCursor = direct_capture ? NVFBC_FALSE : NVFBC_TRUE;
+        create_capture_params.bWithCursor = (!direct_capture || driver_supports_direct_capture_cursor()) ? NVFBC_TRUE : NVFBC_FALSE;
         if(capture_region) {
             create_capture_params.captureBox = { x, y, width, height };
             *display_width = width;
@@ -221,7 +222,7 @@ private:
     }
 
     // Returns 0 on failure
-    uint32_t get_output_id_from_display_name(NVFBC_RANDR_OUTPUT_INFO *outputs, uint32_t num_outputs, const char *display_name, uint32_t *display_width, uint32_t *display_height) {
+    static uint32_t get_output_id_from_display_name(NVFBC_RANDR_OUTPUT_INFO *outputs, uint32_t num_outputs, const char *display_name, uint32_t *display_width, uint32_t *display_height) {
         if(!outputs)
             return 0;
 
@@ -235,6 +236,31 @@ private:
 
         return 0;
     }
+
+    // TODO: Test with optimus and open kernel modules
+    static bool driver_supports_direct_capture_cursor() {
+        FILE *f = fopen("/proc/driver/nvidia/version", "rb");
+        if(!f)
+            return false;
+
+        char buffer[2048];
+        size_t bytes_read = fread(buffer, 1, sizeof(buffer) - 1, f);
+        buffer[bytes_read] = '\0';
+
+        bool supports_cursor = false;
+        const char *p = strstr(buffer, "Kernel Module");
+        if(p) {
+            p += 13;
+            int driver_major_version = 0, driver_minor_version = 0;
+            if(sscanf(p, "%d.%d", &driver_major_version, &driver_minor_version) == 2) {
+                if(driver_major_version > 515 || (driver_major_version == 515 && driver_minor_version >= 57))
+                    supports_cursor = true;
+            }
+        }
+
+        fclose(f);
+        return supports_cursor;
+    }
 private:
     void *library = nullptr;
     PNVFBCCREATEINSTANCE nv_fbc_create_instance = nullptr;