Refactor nvfbc into abstract capture api

11 files changed, 525 insertions, 306 deletions

diff --git a/README.md b/README.md
index 41155b1..344b435 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ If you are running another distro then you can run `install.sh` as root: `sudo .
 You can also install gpu screen recorder ([the gtk gui version](https://git.dec05eba.com/gpu-screen-recorder-gtk/)) from [flathub](https://flathub.org/apps/details/com.dec05eba.gpu_screen_recorder).
 
 # Dependencies
-`libgl (libglvnd), ffmpeg, libx11, libxcomposite, libpulse`. You need to additionally have `libcuda.so` installed when you run `gpu-screen-recorder`.\
+`libgl (libglvnd), ffmpeg, libx11, libxcomposite, libxrandr, libpulse`. You need to additionally have `libcuda.so` installed when you run `gpu-screen-recorder`.\
 Recording monitors requires a gpu with NvFBC support (note: this is not required when recording a single window!). Normally only tesla and quadro gpus support this, but by using [nvidia-patch](https://github.com/keylase/nvidia-patch) or [nvlax](https://github.com/illnyang/nvlax) you can do this on all gpus that support nvenc as well (gpus as old as the nvidia 600 series), provided you are not using outdated gpu drivers.
 
 # How to use
@@ -57,7 +57,6 @@ FFMPEG only uses the GPU with CUDA when doing transcoding from an input video to
 # TODO
 * Support AMD and Intel, using VAAPI.
 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.
 * Implement opengl injection to capture texture. This fixes composition issues and (VRR) without having to use NvFBC direct capture.
diff --git a/build.sh b/build.sh
index 8b92d92..5d42a3c 100755
--- a/build.sh
+++ b/build.sh
@@ -1,9 +1,11 @@
 #!/bin/sh -e
 
-dependencies="libavcodec libavformat libavutil x11 xcomposite libpulse libswresample"
+dependencies="libavcodec libavformat libavutil x11 xcomposite xrandr libpulse libswresample"
 includes="$(pkg-config --cflags $dependencies)"
 libs="$(pkg-config --libs $dependencies) -ldl -pthread -lm"
+gcc -c src/capture/capture.c -O2 -g0 -DNDEBUG $includes
+gcc -c src/capture/nvfbc.c -O2 -g0 -DNDEBUG $includes
 g++ -c src/sound.cpp -O2 -g0 -DNDEBUG $includes
 g++ -c src/main.cpp -O2 -g0 -DNDEBUG $includes
-g++ -o gpu-screen-recorder -O2 sound.o main.o -s $libs
+g++ -o gpu-screen-recorder -O2 capture.o nvfbc.o sound.o main.o -s $libs
 echo "Successfully built gpu-screen-recorder"
\ No newline at end of file
diff --git a/include/NvFBCLibrary.hpp b/include/NvFBCLibrary.hpp
deleted file mode 100644
index 19b9bcc..0000000
--- a/include/NvFBCLibrary.hpp
+++ /dev/null
@@ -1,278 +0,0 @@
-#pragma once
-
-#include "../external/NvFBC.h"
-#include <dlfcn.h>
-#include <string.h>
-#include <stdio.h>
-#include <string.h>
-
-class NvFBCLibrary {
-public:
-    ~NvFBCLibrary() {
-        if(fbc_handle_created) {
-            NVFBC_DESTROY_CAPTURE_SESSION_PARAMS destroy_capture_params;
-            memset(&destroy_capture_params, 0, sizeof(destroy_capture_params));
-            destroy_capture_params.dwVersion = NVFBC_DESTROY_CAPTURE_SESSION_PARAMS_VER;
-            nv_fbc_function_list.nvFBCDestroyCaptureSession(nv_fbc_handle, &destroy_capture_params);
-
-            NVFBC_DESTROY_HANDLE_PARAMS destroy_params;
-            memset(&destroy_params, 0, sizeof(destroy_params));
-            destroy_params.dwVersion = NVFBC_DESTROY_HANDLE_PARAMS_VER;
-            nv_fbc_function_list.nvFBCDestroyHandle(nv_fbc_handle, &destroy_params);
-        }
-
-        if(library)
-            dlclose(library);
-    }
-
-    bool load() {
-        if(library)
-            return true;
-
-        dlerror(); // clear
-        void *lib = dlopen("libnvidia-fbc.so.1", RTLD_LAZY);
-        if(!lib) {
-            fprintf(stderr, "Error: failed to load libnvidia-fbc.so.1, error: %s\n", dlerror());
-            return false;
-        }
-
-        nv_fbc_create_instance = (PNVFBCCREATEINSTANCE)dlsym(lib, "NvFBCCreateInstance");
-        if(!nv_fbc_create_instance) {
-            fprintf(stderr, "Error: unable to resolve symbol 'NvFBCCreateInstance'\n");
-            dlclose(lib);
-            return false;
-        }
-
-        memset(&nv_fbc_function_list, 0, sizeof(nv_fbc_function_list));
-        nv_fbc_function_list.dwVersion = NVFBC_VERSION;
-        NVFBCSTATUS status = nv_fbc_create_instance(&nv_fbc_function_list);
-        if(status != NVFBC_SUCCESS) {
-            fprintf(stderr, "Error: failed to create NvFBC instance (status: %d)\n", status);
-            dlclose(lib);
-            return false;
-        }
-
-        library = lib;
-        return true;
-    }
-
-    // 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;
-
-        const bool capture_region = (x > 0 || y > 0 || width > 0 || height > 0);
-
-        NVFBCSTATUS status;
-        NVFBC_TRACKING_TYPE tracking_type;
-        bool capture_session_created = false;
-        uint32_t output_id = 0;
-        fbc_handle_created = false;
-
-        NVFBC_CREATE_HANDLE_PARAMS create_params;
-        memset(&create_params, 0, sizeof(create_params));
-        create_params.dwVersion = NVFBC_CREATE_HANDLE_PARAMS_VER;
-
-        status = nv_fbc_function_list.nvFBCCreateHandle(&nv_fbc_handle, &create_params);
-        if(status != NVFBC_SUCCESS) {
-            // Reverse engineering for interoperability
-            const uint8_t enable_key[] = { 0xac, 0x10, 0xc9, 0x2e, 0xa5, 0xe6, 0x87, 0x4f, 0x8f, 0x4b, 0xf4, 0x61, 0xf8, 0x56, 0x27, 0xe9 };
-            create_params.privateData = enable_key;
-            create_params.privateDataSize = 16;
-
-            status = nv_fbc_function_list.nvFBCCreateHandle(&nv_fbc_handle, &create_params);
-            if(status != NVFBC_SUCCESS) {
-                fprintf(stderr, "Error: %s\n", nv_fbc_function_list.nvFBCGetLastErrorStr(nv_fbc_handle));
-                return false;
-            }
-        }
-        fbc_handle_created = true;
-
-        NVFBC_GET_STATUS_PARAMS status_params;
-        memset(&status_params, 0, sizeof(status_params));
-        status_params.dwVersion = NVFBC_GET_STATUS_PARAMS_VER;
-
-        status = nv_fbc_function_list.nvFBCGetStatus(nv_fbc_handle, &status_params);
-        if(status != NVFBC_SUCCESS) {
-            fprintf(stderr, "Error: %s\n", nv_fbc_function_list.nvFBCGetLastErrorStr(nv_fbc_handle));
-            goto error_cleanup;
-        }
-
-        if(status_params.bCanCreateNow == NVFBC_FALSE) {
-            fprintf(stderr, "Error: it's not possible to create a capture session on this system\n");
-            goto error_cleanup;
-        }
-
-        tracking_type = strcmp(display_to_capture, "screen") == 0 ? NVFBC_TRACKING_SCREEN : NVFBC_TRACKING_OUTPUT;
-        if(tracking_type == NVFBC_TRACKING_OUTPUT) {
-            if(!status_params.bXRandRAvailable) {
-                fprintf(stderr, "Error: the xrandr extension is not available\n");
-                goto error_cleanup;
-            }
-
-            if(status_params.bInModeset) {
-                fprintf(stderr, "Error: the x server is in modeset, unable to record\n");
-                goto error_cleanup;
-            }
-
-            output_id = get_output_id_from_display_name(status_params.outputs, status_params.dwOutputNum, display_to_capture, display_width, display_height);
-            if(output_id == 0) {
-                fprintf(stderr, "Error: display '%s' not found\n", display_to_capture);
-                goto error_cleanup;
-            }
-        } else {
-            *display_width = status_params.screenSize.w;
-            *display_height = status_params.screenSize.h;
-        }
-
-        NVFBC_CREATE_CAPTURE_SESSION_PARAMS create_capture_params;
-        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 || driver_supports_direct_capture_cursor()) ? NVFBC_TRUE : NVFBC_FALSE;
-        if(capture_region) {
-            create_capture_params.captureBox = { x, y, width, height };
-            *display_width = width;
-            *display_height = height;
-        }
-        create_capture_params.eTrackingType = tracking_type;
-        create_capture_params.dwSamplingRateMs = 1000 / fps;
-        create_capture_params.bAllowDirectCapture = direct_capture ? NVFBC_TRUE : NVFBC_FALSE;
-        create_capture_params.bPushModel = direct_capture ? NVFBC_TRUE : NVFBC_FALSE;
-        if(tracking_type == NVFBC_TRACKING_OUTPUT)
-            create_capture_params.dwOutputId = output_id;
-
-        status = nv_fbc_function_list.nvFBCCreateCaptureSession(nv_fbc_handle, &create_capture_params);
-        if(status != NVFBC_SUCCESS) {
-            fprintf(stderr, "Error: %s\n", nv_fbc_function_list.nvFBCGetLastErrorStr(nv_fbc_handle));
-            goto error_cleanup;
-        }
-        capture_session_created = true;
-
-        NVFBC_TOCUDA_SETUP_PARAMS setup_params;
-        memset(&setup_params, 0, sizeof(setup_params));
-        setup_params.dwVersion = NVFBC_TOCUDA_SETUP_PARAMS_VER;
-        setup_params.eBufferFormat = NVFBC_BUFFER_FORMAT_BGRA;
-
-        status = nv_fbc_function_list.nvFBCToCudaSetUp(nv_fbc_handle, &setup_params);
-        if(status != NVFBC_SUCCESS) {
-            fprintf(stderr, "Error: %s\n", nv_fbc_function_list.nvFBCGetLastErrorStr(nv_fbc_handle));
-            goto error_cleanup;
-        }
-
-        return true;
-
-        error_cleanup:
-        if(fbc_handle_created) {
-            if(capture_session_created) {
-                NVFBC_DESTROY_CAPTURE_SESSION_PARAMS destroy_capture_params;
-                memset(&destroy_capture_params, 0, sizeof(destroy_capture_params));
-                destroy_capture_params.dwVersion = NVFBC_DESTROY_CAPTURE_SESSION_PARAMS_VER;
-                nv_fbc_function_list.nvFBCDestroyCaptureSession(nv_fbc_handle, &destroy_capture_params);
-            }
-
-            NVFBC_DESTROY_HANDLE_PARAMS destroy_params;
-            memset(&destroy_params, 0, sizeof(destroy_params));
-            destroy_params.dwVersion = NVFBC_DESTROY_HANDLE_PARAMS_VER;
-            nv_fbc_function_list.nvFBCDestroyHandle(nv_fbc_handle, &destroy_params);
-            fbc_handle_created = false;
-        }
-        output_id = 0;
-        return false;
-    }
-
-    bool capture(/*out*/ void *cu_device_ptr, uint32_t *byte_size) {
-        if(!library || !fbc_handle_created || !cu_device_ptr || !byte_size)
-            return false;
-
-        NVFBCSTATUS status;
-        NVFBC_FRAME_GRAB_INFO frame_info;
-        memset(&frame_info, 0, sizeof(frame_info));
-
-        NVFBC_TOCUDA_GRAB_FRAME_PARAMS grab_params;
-        memset(&grab_params, 0, sizeof(grab_params));
-        grab_params.dwVersion = NVFBC_TOCUDA_GRAB_FRAME_PARAMS_VER;
-        grab_params.dwFlags = NVFBC_TOCUDA_GRAB_FLAGS_NOWAIT | NVFBC_TOCUDA_GRAB_FLAGS_FORCE_REFRESH;
-        grab_params.pFrameGrabInfo = &frame_info;
-        grab_params.pCUDADeviceBuffer = cu_device_ptr;
-
-        status = nv_fbc_function_list.nvFBCToCudaGrabFrame(nv_fbc_handle, &grab_params);
-        if(status != NVFBC_SUCCESS) {
-            fprintf(stderr, "Error: %s\n", nv_fbc_function_list.nvFBCGetLastErrorStr(nv_fbc_handle));
-            return false;
-        }
-
-        *byte_size = frame_info.dwByteSize;
-        // TODO: Check bIsNewFrame
-        // TODO: Check dwWidth and dwHeight and update size in video output in ffmpeg. This can happen when xrandr is used to change monitor resolution
-
-        return true;
-    }
-private:
-    static char to_upper(char c) {
-        if(c >= 'a' && c <= 'z')
-            return c - 32;
-        else
-            return c;
-    }
-
-    static bool strcase_equals(const char *str1, const char *str2) {
-        for(;;) {
-            char c1 = to_upper(*str1);
-            char c2 = to_upper(*str2);
-            if(c1 != c2)
-                return false;
-            if(c1 == '\0' || c2 == '\0')
-                return true;
-            ++str1;
-            ++str2;       
-        }
-    }
-
-    // Returns 0 on failure
-    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;
-
-        for(uint32_t i = 0; i < num_outputs; ++i) {
-            if(strcase_equals(outputs[i].name, display_name)) {
-                *display_width = outputs[i].trackedBox.w;
-                *display_height = outputs[i].trackedBox.h;
-                return outputs[i].dwId;
-            }
-        }
-
-        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;
-    NVFBC_API_FUNCTION_LIST nv_fbc_function_list;
-    NVFBC_SESSION_HANDLE nv_fbc_handle;
-    bool fbc_handle_created = false;
-};
diff --git a/include/capture/capture.h b/include/capture/capture.h
new file mode 100644
index 0000000..9e23a23
--- /dev/null
+++ b/include/capture/capture.h
@@ -0,0 +1,25 @@
+#ifndef GSR_CAPTURE_CAPTURE_H
+#define GSR_CAPTURE_CAPTURE_H
+
+#include <stdbool.h>
+
+typedef struct AVFrame AVFrame;
+
+typedef struct gsr_capture gsr_capture;
+
+struct gsr_capture {
+    int (*start)(gsr_capture *cap);
+    void (*stop)(gsr_capture *cap);
+    int (*capture)(gsr_capture *cap, AVFrame *frame);
+    void (*destroy)(gsr_capture *cap);
+
+    void *priv;
+};
+
+int gsr_capture_start(gsr_capture *cap);
+void gsr_capture_stop(gsr_capture *cap);
+int gsr_capture_capture(gsr_capture *cap, AVFrame *frame);
+/* Calls |gsr_capture_stop| as well */
+void gsr_capture_destroy(gsr_capture *cap);
+
+#endif /* GSR_CAPTURE_CAPTURE_H */
diff --git a/include/capture/nvfbc.h b/include/capture/nvfbc.h
new file mode 100644
index 0000000..b749b87
--- /dev/null
+++ b/include/capture/nvfbc.h
@@ -0,0 +1,17 @@
+#ifndef GSR_CAPTURE_NVFBC_H
+#define GSR_CAPTURE_NVFBC_H
+
+#include "capture.h"
+#include "../vec2.h"
+
+typedef struct {
+    const char *display_to_capture; /* if this is "screen", then the entire x11 screen is captured (all displays) */
+    int fps;
+    vec2i pos;
+    vec2i size;
+    bool direct_capture; /* temporary disabled */
+} gsr_capture_nvfbc_params;
+
+gsr_capture* gsr_capture_nvfbc_create(const gsr_capture_nvfbc_params *params);
+
+#endif /* GSR_CAPTURE_NVFBC_H */
diff --git a/include/vec2.h b/include/vec2.h
new file mode 100644
index 0000000..d1957ef
--- /dev/null
+++ b/include/vec2.h
@@ -0,0 +1,8 @@
+#ifndef VEC2_H
+#define VEC2_H
+
+typedef struct {
+    int x, y;
+} vec2i;
+
+#endif /* VEC2_H */
\ No newline at end of file
diff --git a/install_ubuntu.sh b/install_ubuntu.sh
index 6a3bb4a..f414f50 100755
--- a/install_ubuntu.sh
+++ b/install_ubuntu.sh
@@ -8,7 +8,7 @@ cd "$script_dir"
 set -e
 apt-get -y install build-essential\
 	libswresample-dev libavformat-dev libavcodec-dev libavutil-dev\
-	libgl-dev libx11-dev libxcomposite-dev\
+	libgl-dev libx11-dev libxcomposite-dev libxrandr-dev\
 	libpulse-dev
 
 ./install.sh
diff --git a/project.conf b/project.conf
index 8ac9d98..94da839 100644
--- a/project.conf
+++ b/project.conf
@@ -10,5 +10,6 @@ libavformat = ">=58"
 libavutil = ">=56.2"
 x11 = ">=1"
 xcomposite = ">=0.2"
+xrandr = ">=1"
 libpulse = ">=13"
 libswresample = ">=3"
diff --git a/src/capture/capture.c b/src/capture/capture.c
new file mode 100644
index 0000000..9755d6a
--- /dev/null
+++ b/src/capture/capture.c
@@ -0,0 +1,17 @@
+#include "../../include/capture/capture.h"
+
+int gsr_capture_start(gsr_capture *cap) {
+    return cap->start(cap);
+}
+
+void gsr_capture_stop(gsr_capture *cap) {
+    cap->stop(cap);
+}
+
+int gsr_capture_capture(gsr_capture *cap, AVFrame *frame) {
+    return cap->capture(cap, frame);
+}
+
+void gsr_capture_destroy(gsr_capture *cap) {
+    cap->destroy(cap);
+}
diff --git a/src/capture/nvfbc.c b/src/capture/nvfbc.c
new file mode 100644
index 0000000..a2648ef
--- /dev/null
+++ b/src/capture/nvfbc.c
@@ -0,0 +1,332 @@
+#include "../../include/capture/nvfbc.h"
+#include "../../external/NvFBC.h"
+#include <dlfcn.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <libavutil/frame.h>
+
+typedef struct {
+    gsr_capture_nvfbc_params params;
+    void *library;
+
+    NVFBC_SESSION_HANDLE nv_fbc_handle;
+    PNVFBCCREATEINSTANCE nv_fbc_create_instance;
+    NVFBC_API_FUNCTION_LIST nv_fbc_function_list;
+    bool fbc_handle_created;
+} gsr_capture_nvfbc;
+
+#if defined(_WIN64) || defined(__LP64__)
+typedef unsigned long long CUdeviceptr_v2;
+#else
+typedef unsigned int CUdeviceptr_v2;
+#endif
+typedef CUdeviceptr_v2 CUdeviceptr;
+
+static int max_int(int a, int b) {
+    return a > b ? a : b;
+}
+
+/* Returns 0 on failure */
+static uint32_t get_output_id_from_display_name(NVFBC_RANDR_OUTPUT_INFO *outputs, uint32_t num_outputs, const char *display_name) {
+    if(!outputs)
+        return 0;
+
+    for(uint32_t i = 0; i < num_outputs; ++i) {
+        if(strcmp(outputs[i].name, display_name) == 0) 
+            return outputs[i].dwId;
+    }
+
+    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;
+}
+
+static bool gsr_capture_nvfbc_load_library(gsr_capture *cap) {
+    gsr_capture_nvfbc *cap_nvfbc = cap->priv;
+
+    dlerror(); /* clear */
+    void *lib = dlopen("libnvidia-fbc.so.1", RTLD_LAZY);
+    if(!lib) {
+        fprintf(stderr, "gsr error: failed to load libnvidia-fbc.so.1, error: %s\n", dlerror());
+        return false;
+    }
+
+    cap_nvfbc->nv_fbc_create_instance = (PNVFBCCREATEINSTANCE)dlsym(lib, "NvFBCCreateInstance");
+    if(!cap_nvfbc->nv_fbc_create_instance) {
+        fprintf(stderr, "gsr error: unable to resolve symbol 'NvFBCCreateInstance'\n");
+        dlclose(lib);
+        return false;
+    }
+
+    memset(&cap_nvfbc->nv_fbc_function_list, 0, sizeof(cap_nvfbc->nv_fbc_function_list));
+    cap_nvfbc->nv_fbc_function_list.dwVersion = NVFBC_VERSION;
+    NVFBCSTATUS status = cap_nvfbc->nv_fbc_create_instance(&cap_nvfbc->nv_fbc_function_list);
+    if(status != NVFBC_SUCCESS) {
+        fprintf(stderr, "gsr error: failed to create NvFBC instance (status: %d)\n", status);
+        dlclose(lib);
+        return false;
+    }
+
+    cap_nvfbc->library = lib;
+    return true;
+}
+
+static int gsr_capture_nvfbc_start(gsr_capture *cap) {
+    gsr_capture_nvfbc *cap_nvfbc = cap->priv;
+    const uint32_t x = max_int(cap_nvfbc->params.pos.x, 0);
+    const uint32_t y = max_int(cap_nvfbc->params.pos.y, 0);
+    const uint32_t width = max_int(cap_nvfbc->params.size.x, 0);
+    const uint32_t height = max_int(cap_nvfbc->params.size.y, 0);
+
+    if(!cap_nvfbc->library || !cap_nvfbc->params.display_to_capture || cap_nvfbc->fbc_handle_created)
+        return -1;
+
+    const bool capture_region = (x > 0 || y > 0 || width > 0 || height > 0);
+
+    NVFBCSTATUS status;
+    NVFBC_TRACKING_TYPE tracking_type;
+    bool capture_session_created = false;
+    uint32_t output_id = 0;
+    cap_nvfbc->fbc_handle_created = false;
+
+    NVFBC_CREATE_HANDLE_PARAMS create_params;
+    memset(&create_params, 0, sizeof(create_params));
+    create_params.dwVersion = NVFBC_CREATE_HANDLE_PARAMS_VER;
+
+    status = cap_nvfbc->nv_fbc_function_list.nvFBCCreateHandle(&cap_nvfbc->nv_fbc_handle, &create_params);
+    if(status != NVFBC_SUCCESS) {
+        // Reverse engineering for interoperability
+        const uint8_t enable_key[] = { 0xac, 0x10, 0xc9, 0x2e, 0xa5, 0xe6, 0x87, 0x4f, 0x8f, 0x4b, 0xf4, 0x61, 0xf8, 0x56, 0x27, 0xe9 };
+        create_params.privateData = enable_key;
+        create_params.privateDataSize = 16;
+
+        status = cap_nvfbc->nv_fbc_function_list.nvFBCCreateHandle(&cap_nvfbc->nv_fbc_handle, &create_params);
+        if(status != NVFBC_SUCCESS) {
+            fprintf(stderr, "gsr error: gsr_capture_nvfbc_start failed: %s\n", cap_nvfbc->nv_fbc_function_list.nvFBCGetLastErrorStr(cap_nvfbc->nv_fbc_handle));
+            return -1;
+        }
+    }
+    cap_nvfbc->fbc_handle_created = true;
+
+    NVFBC_GET_STATUS_PARAMS status_params;
+    memset(&status_params, 0, sizeof(status_params));
+    status_params.dwVersion = NVFBC_GET_STATUS_PARAMS_VER;
+
+    status = cap_nvfbc->nv_fbc_function_list.nvFBCGetStatus(cap_nvfbc->nv_fbc_handle, &status_params);
+    if(status != NVFBC_SUCCESS) {
+        fprintf(stderr, "gsr error: gsr_capture_nvfbc_start failed: %s\n", cap_nvfbc->nv_fbc_function_list.nvFBCGetLastErrorStr(cap_nvfbc->nv_fbc_handle));
+        goto error_cleanup;
+    }
+
+    if(status_params.bCanCreateNow == NVFBC_FALSE) {
+        fprintf(stderr, "gsr error: gsr_capture_nvfbc_start failed: it's not possible to create a capture session on this system\n");
+        goto error_cleanup;
+    }
+
+    tracking_type = strcmp(cap_nvfbc->params.display_to_capture, "screen") == 0 ? NVFBC_TRACKING_SCREEN : NVFBC_TRACKING_OUTPUT;
+    if(tracking_type == NVFBC_TRACKING_OUTPUT) {
+        if(!status_params.bXRandRAvailable) {
+            fprintf(stderr, "gsr error: gsr_capture_nvfbc_start failed: the xrandr extension is not available\n");
+            goto error_cleanup;
+        }
+
+        if(status_params.bInModeset) {
+            fprintf(stderr, "gsr error: gsr_capture_nvfbc_start failed: the x server is in modeset, unable to record\n");
+            goto error_cleanup;
+        }
+
+        output_id = get_output_id_from_display_name(status_params.outputs, status_params.dwOutputNum, cap_nvfbc->params.display_to_capture);
+        if(output_id == 0) {
+            fprintf(stderr, "gsr error: gsr_capture_nvfbc_start failed: display '%s' not found\n", cap_nvfbc->params.display_to_capture);
+            goto error_cleanup;
+        }
+    }
+
+    NVFBC_CREATE_CAPTURE_SESSION_PARAMS create_capture_params;
+    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 = (!cap_nvfbc->params.direct_capture || driver_supports_direct_capture_cursor()) ? NVFBC_TRUE : NVFBC_FALSE;
+    if(capture_region)
+        create_capture_params.captureBox = (NVFBC_BOX){ x, y, width, height };
+    create_capture_params.eTrackingType = tracking_type;
+    create_capture_params.dwSamplingRateMs = 1000u / (uint32_t)cap_nvfbc->params.fps;
+    create_capture_params.bAllowDirectCapture = cap_nvfbc->params.direct_capture ? NVFBC_TRUE : NVFBC_FALSE;
+    create_capture_params.bPushModel = cap_nvfbc->params.direct_capture ? NVFBC_TRUE : NVFBC_FALSE;
+    if(tracking_type == NVFBC_TRACKING_OUTPUT)
+        create_capture_params.dwOutputId = output_id;
+
+    status = cap_nvfbc->nv_fbc_function_list.nvFBCCreateCaptureSession(cap_nvfbc->nv_fbc_handle, &create_capture_params);
+    if(status != NVFBC_SUCCESS) {
+        fprintf(stderr, "gsr error: gsr_capture_nvfbc_start failed: %s\n", cap_nvfbc->nv_fbc_function_list.nvFBCGetLastErrorStr(cap_nvfbc->nv_fbc_handle));
+        goto error_cleanup;
+    }
+    capture_session_created = true;
+
+    NVFBC_TOCUDA_SETUP_PARAMS setup_params;
+    memset(&setup_params, 0, sizeof(setup_params));
+    setup_params.dwVersion = NVFBC_TOCUDA_SETUP_PARAMS_VER;
+    setup_params.eBufferFormat = NVFBC_BUFFER_FORMAT_BGRA;
+
+    status = cap_nvfbc->nv_fbc_function_list.nvFBCToCudaSetUp(cap_nvfbc->nv_fbc_handle, &setup_params);
+    if(status != NVFBC_SUCCESS) {
+        fprintf(stderr, "gsr error: gsr_capture_nvfbc_start failed: %s\n", cap_nvfbc->nv_fbc_function_list.nvFBCGetLastErrorStr(cap_nvfbc->nv_fbc_handle));
+        goto error_cleanup;
+    }
+
+    return 0;
+
+    error_cleanup:
+    if(cap_nvfbc->fbc_handle_created) {
+        if(capture_session_created) {
+            NVFBC_DESTROY_CAPTURE_SESSION_PARAMS destroy_capture_params;
+            memset(&destroy_capture_params, 0, sizeof(destroy_capture_params));
+            destroy_capture_params.dwVersion = NVFBC_DESTROY_CAPTURE_SESSION_PARAMS_VER;
+            cap_nvfbc->nv_fbc_function_list.nvFBCDestroyCaptureSession(cap_nvfbc->nv_fbc_handle, &destroy_capture_params);
+        }
+
+        NVFBC_DESTROY_HANDLE_PARAMS destroy_params;
+        memset(&destroy_params, 0, sizeof(destroy_params));
+        destroy_params.dwVersion = NVFBC_DESTROY_HANDLE_PARAMS_VER;
+        cap_nvfbc->nv_fbc_function_list.nvFBCDestroyHandle(cap_nvfbc->nv_fbc_handle, &destroy_params);
+        cap_nvfbc->fbc_handle_created = false;
+    }
+    output_id = 0;
+    return -1;
+}
+
+static void gsr_capture_nvfbc_stop(gsr_capture *cap) {
+    gsr_capture_nvfbc *cap_nvfbc = cap->priv;
+
+    /* Intentionally ignore failure on destroy */
+    if(!cap_nvfbc->nv_fbc_handle)
+        return;
+
+    NVFBC_DESTROY_CAPTURE_SESSION_PARAMS destroy_capture_params;
+    memset(&destroy_capture_params, 0, sizeof(destroy_capture_params));
+    destroy_capture_params.dwVersion = NVFBC_DESTROY_CAPTURE_SESSION_PARAMS_VER;
+    cap_nvfbc->nv_fbc_function_list.nvFBCDestroyCaptureSession(cap_nvfbc->nv_fbc_handle, &destroy_capture_params);
+
+    NVFBC_DESTROY_HANDLE_PARAMS destroy_params;
+    memset(&destroy_params, 0, sizeof(destroy_params));
+    destroy_params.dwVersion = NVFBC_DESTROY_HANDLE_PARAMS_VER;
+    cap_nvfbc->nv_fbc_function_list.nvFBCDestroyHandle(cap_nvfbc->nv_fbc_handle, &destroy_params);
+
+    cap_nvfbc->nv_fbc_handle = 0;
+}
+
+static int gsr_capture_nvfbc_capture(gsr_capture *cap, AVFrame *frame) {
+    gsr_capture_nvfbc *cap_nvfbc = cap->priv;
+    if(!cap_nvfbc->library || !cap_nvfbc->fbc_handle_created)
+        return -1;
+
+    CUdeviceptr cu_device_ptr = 0;
+
+    NVFBC_FRAME_GRAB_INFO frame_info;
+    memset(&frame_info, 0, sizeof(frame_info));
+
+    NVFBC_TOCUDA_GRAB_FRAME_PARAMS grab_params;
+    memset(&grab_params, 0, sizeof(grab_params));
+    grab_params.dwVersion = NVFBC_TOCUDA_GRAB_FRAME_PARAMS_VER;
+    grab_params.dwFlags = NVFBC_TOCUDA_GRAB_FLAGS_NOWAIT;/* | NVFBC_TOCUDA_GRAB_FLAGS_FORCE_REFRESH;*/
+    grab_params.pFrameGrabInfo = &frame_info;
+    grab_params.pCUDADeviceBuffer = &cu_device_ptr;
+
+    NVFBCSTATUS status = cap_nvfbc->nv_fbc_function_list.nvFBCToCudaGrabFrame(cap_nvfbc->nv_fbc_handle, &grab_params);
+    if(status != NVFBC_SUCCESS) {
+        fprintf(stderr, "gsr error: gsr_capture_nvfbc_capture failed: %s\n", cap_nvfbc->nv_fbc_function_list.nvFBCGetLastErrorStr(cap_nvfbc->nv_fbc_handle));
+        return -1;
+    }
+
+    /*
+        *byte_size = frame_info.dwByteSize;
+
+        TODO: Check bIsNewFrame
+        TODO: Check dwWidth and dwHeight and update size in video output in ffmpeg. This can happen when xrandr is used to change monitor resolution
+    */
+
+    frame->data[0] = (uint8_t*)cu_device_ptr;
+    frame->linesize[0] = frame->width * 4;
+    return 0;
+}
+
+static void gsr_capture_nvfbc_destroy(gsr_capture *cap) {
+    if(cap) {
+        gsr_capture_nvfbc *cap_nvfbc = cap->priv;
+        gsr_capture_nvfbc_stop(cap);
+        if(cap_nvfbc) {
+            dlclose(cap_nvfbc->library);
+            free((void*)cap_nvfbc->params.display_to_capture);
+            free(cap->priv);
+            cap->priv = NULL;
+        }
+        free(cap);
+    }
+}
+
+gsr_capture* gsr_capture_nvfbc_create(const gsr_capture_nvfbc_params *params) {
+    if(!params) {
+        fprintf(stderr, "gsr error: gsr_capture_nvfbc_create params is NULL\n");
+        return NULL;
+    }
+
+    gsr_capture *cap = calloc(1, sizeof(gsr_capture));
+    if(!cap)
+        return NULL;
+
+    gsr_capture_nvfbc *cap_nvfbc = calloc(1, sizeof(gsr_capture_nvfbc));
+    if(!cap_nvfbc) {
+        free(cap);
+        return NULL;
+    }
+
+    const char *display_to_capture = strdup(params->display_to_capture);
+    if(!display_to_capture) {
+        free(cap);
+        free(cap_nvfbc);
+        return NULL;
+    }
+
+    cap_nvfbc->params = *params;
+    cap_nvfbc->params.display_to_capture = display_to_capture;
+    cap_nvfbc->params.fps = max_int(cap_nvfbc->params.fps, 1);
+    
+    *cap = (gsr_capture) {
+        .start = gsr_capture_nvfbc_start,
+        .stop = gsr_capture_nvfbc_stop,
+        .capture = gsr_capture_nvfbc_capture,
+        .destroy = gsr_capture_nvfbc_destroy,
+        .priv = cap_nvfbc
+    };
+
+    if(!gsr_capture_nvfbc_load_library(cap)) {
+        gsr_capture_nvfbc_destroy(cap);
+        return NULL;
+    }
+
+    return cap;
+}
diff --git a/src/main.cpp b/src/main.cpp
index b449666..8e80797 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -15,6 +15,10 @@
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
+extern "C" {
+#include "../include/capture/nvfbc.h"
+}
+
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -31,11 +35,11 @@
 #include <fcntl.h>
 
 #include "../include/sound.hpp"
-#include "../include/NvFBCLibrary.hpp"
 #include "../include/CudaLibrary.hpp"
 #include "../include/GlLibrary.hpp"
 
 #include <X11/extensions/Xcomposite.h>
+#include <X11/extensions/Xrandr.h>
 //#include <X11/Xatom.h>
 
 extern "C" {
@@ -66,6 +70,75 @@ static thread_local char av_error_buffer[AV_ERROR_MAX_STRING_SIZE];
 static Cuda cuda;
 static GlLibrary gl;
 
+static const XRRModeInfo* get_mode_info(const XRRScreenResources *sr, RRMode id) {
+    for(int i = 0; i < sr->nmode; ++i) {
+        if(sr->modes[i].id == id)
+            return &sr->modes[i];
+    }    
+    return nullptr;
+}
+
+typedef void (*active_monitor_callback)(const XRROutputInfo *output_info, const XRRCrtcInfo *crt_info, const XRRModeInfo *mode_info, void *userdata);
+
+static void for_each_active_monitor_output(Display *display, active_monitor_callback callback, void *userdata) {
+    XRRScreenResources *screen_res = XRRGetScreenResources(display, DefaultRootWindow(display));
+    if(!screen_res)
+        return;
+
+    for(int i = 0; i < screen_res->noutput; ++i) {
+        XRROutputInfo *out_info = XRRGetOutputInfo(display, screen_res, screen_res->outputs[i]);
+        if(out_info && out_info->crtc && out_info->connection == RR_Connected) {
+            XRRCrtcInfo *crt_info = XRRGetCrtcInfo(display, screen_res, out_info->crtc);
+            if(crt_info && crt_info->mode) {
+                const XRRModeInfo *mode_info = get_mode_info(screen_res, crt_info->mode);
+                if(mode_info)
+                    callback(out_info, crt_info, mode_info, userdata);
+            }
+            if(crt_info)
+                XRRFreeCrtcInfo(crt_info);
+        }
+        if(out_info)
+            XRRFreeOutputInfo(out_info);
+    }    
+
+    XRRFreeScreenResources(screen_res);
+}
+
+typedef struct {
+    vec2i pos;
+    vec2i size;
+} gsr_monitor;
+
+typedef struct {
+    const char *name;
+    int name_len;
+    gsr_monitor *monitor;
+    bool found_monitor;
+} get_monitor_by_name_userdata;
+
+static void get_monitor_by_name_callback(const XRROutputInfo *output_info, const XRRCrtcInfo *crt_info, const XRRModeInfo *mode_info, void *userdata) {
+    get_monitor_by_name_userdata *data = (get_monitor_by_name_userdata*)userdata;
+    if(!data->found_monitor && data->name_len == output_info->nameLen && memcmp(data->name, output_info->name, data->name_len) == 0) {
+        data->monitor->pos = { crt_info->x, crt_info->y };
+        data->monitor->size = { (int)crt_info->width, (int)crt_info->height };
+        data->found_monitor = true;
+    }
+}
+
+static bool get_monitor_by_name(Display *display, const char *name, gsr_monitor *monitor) {
+    get_monitor_by_name_userdata userdata;
+    userdata.name = name;
+    userdata.name_len = strlen(name);
+    userdata.monitor = monitor;
+    userdata.found_monitor = false;
+    for_each_active_monitor_output(display, get_monitor_by_name_callback, &userdata);
+    return userdata.found_monitor;
+}
+
+static void monitor_output_callback_print(const XRROutputInfo *output_info, const XRRCrtcInfo *crt_info, const XRRModeInfo *mode_info, void *userdata) {
+    fprintf(stderr, "    \"%.*s\"    (%dx%d+%d+%d)\n", output_info->nameLen, output_info->name, (int)crt_info->width, (int)crt_info->height, crt_info->x, crt_info->y);
+}
+
 static char* av_error_to_string(int err) {
     if(av_strerror(err, av_error_buffer, sizeof(av_error_buffer)) < 0)
         strcpy(av_error_buffer, "Unknown error");
@@ -1216,7 +1289,7 @@ int main(int argc, char **argv) {
         }
 
         if(!match) {
-            fprintf(stderr, "Error: Audio input device '%s' is not a valid audio device. Expected one of:\n", request_audio_input.name.c_str());
+            fprintf(stderr, "Error: Audio input device '%s' is not a valid audio device, expected one of:\n", request_audio_input.name.c_str());
             for(const auto &existing_audio_input : audio_inputs) {
                 fprintf(stderr, "    %s\n", existing_audio_input.name.c_str());
             }
@@ -1318,6 +1391,15 @@ int main(int argc, char **argv) {
         return 1;
     }
 
+    Display *dpy = XOpenDisplay(nullptr);
+    if (!dpy) {
+        fprintf(stderr, "Error: Failed to open display\n");
+        return 1;
+    }
+
+    XSetErrorHandler(x11_error_handler);
+    XSetIOErrorHandler(x11_io_error_handler);
+
     const char *record_area = args["-s"].value();
 
     uint32_t window_width = 0;
@@ -1325,7 +1407,7 @@ int main(int argc, char **argv) {
     int window_x = 0;
     int window_y = 0;
 
-    NvFBCLibrary nv_fbc_library;
+    gsr_capture *capture = nullptr;
 
     const char *window_str = args["-w"].value();
     Window src_window_id = None;
@@ -1335,9 +1417,6 @@ int main(int argc, char **argv) {
             usage();
         }
 
-        if(!nv_fbc_library.load())
-            return 1;
-
         const char *capture_target = window_str;
         bool direct_capture = strcmp(window_str, "screen-direct") == 0;
         if(direct_capture) {
@@ -1347,7 +1426,36 @@ int main(int argc, char **argv) {
             fprintf(stderr, "Warning: screen-direct has temporary been disabled as it causes stuttering. This is likely a NvFBC bug. Falling back to \"screen\".\n");
         }
 
-        if(!nv_fbc_library.create(capture_target, fps, &window_width, &window_height, region_x, region_y, region_width, region_height, direct_capture))
+        gsr_capture_nvfbc_params nvfbc_params;
+        nvfbc_params.display_to_capture = capture_target;
+        nvfbc_params.fps = fps;
+        nvfbc_params.pos = { (int)region_x, (int)region_y };
+        nvfbc_params.size = { (int)region_width, (int)region_height };
+        nvfbc_params.direct_capture = direct_capture;
+        capture = gsr_capture_nvfbc_create(&nvfbc_params);
+        if(!capture)
+            return 1;
+
+        // TODO: Set window_width and window_height to the nvfbc blalba
+        if(strcmp(capture_target, "screen") == 0) {
+            window_width = WidthOfScreen(DefaultScreenOfDisplay(dpy));
+            window_height = HeightOfScreen(DefaultScreenOfDisplay(dpy));
+        } else {
+            gsr_monitor gmon;
+            if(!get_monitor_by_name(dpy, capture_target, &gmon)) {
+                fprintf(stderr, "gsr error: display \"%s\" not found, expected one of:\n", capture_target);
+                fprintf(stderr, "    \"screen\"    (%dx%d+%d+%d)\n", WidthOfScreen(DefaultScreenOfDisplay(dpy)), HeightOfScreen(DefaultScreenOfDisplay(dpy)), 0, 0);
+                fprintf(stderr, "    \"screen-direct\"    (%dx%d+%d+%d)\n", WidthOfScreen(DefaultScreenOfDisplay(dpy)), HeightOfScreen(DefaultScreenOfDisplay(dpy)), 0, 0);
+                for_each_active_monitor_output(dpy, monitor_output_callback_print, NULL);
+                return 1;
+            }
+
+            window_width = gmon.size.x;
+            window_height = gmon.size.y;
+        }
+
+        // TODO: Move down
+        if(gsr_capture_start(capture) != 0)
             return 1;
     } else {
         errno = 0;
@@ -1387,15 +1495,6 @@ int main(int argc, char **argv) {
 
     const double target_fps = 1.0 / (double)fps;
 
-    Display *dpy = XOpenDisplay(nullptr);
-    if (!dpy) {
-        fprintf(stderr, "Error: Failed to open display\n");
-        return 1;
-    }
-
-    XSetErrorHandler(x11_error_handler);
-    XSetIOErrorHandler(x11_io_error_handler);
-
     WindowPixmap window_pixmap;
     Window window = None;
     if(src_window_id) {
@@ -1993,13 +2092,7 @@ int main(int argc, char **argv) {
 
                     frame_captured = true;
                 } else {
-                    // TODO: Check when src_cu_device_ptr changes and re-register resource
-                    frame->linesize[0] = frame->width * 4;
-
-                    uint32_t byte_size = 0;
-                    CUdeviceptr src_cu_device_ptr = 0;
-                    frame_captured = nv_fbc_library.capture(&src_cu_device_ptr, &byte_size);
-                    frame->data[0] = (uint8_t*)src_cu_device_ptr;
+                    gsr_capture_capture(capture, frame);
                 }
                 // res = cuda.cuCtxPopCurrent_v2(&old_ctx);
             }
@@ -2059,6 +2152,9 @@ int main(int argc, char **argv) {
     if(replay_buffer_size_secs == -1 && !(output_format->flags & AVFMT_NOFILE))
         avio_close(av_format_context->pb);
 
+    if(capture)
+        gsr_capture_destroy(capture);
+
     if(dpy)
         XCloseDisplay(dpy);