follow focused

1 files changed, 107 insertions, 84 deletions

diff --git a/src/capture/xcomposite_cuda.c b/src/capture/xcomposite_cuda.c
index d6c147b..6b2b72c 100644
--- a/src/capture/xcomposite_cuda.c
+++ b/src/capture/xcomposite_cuda.c
@@ -20,12 +20,12 @@ typedef struct {
     double window_resize_timer;
 
     vec2i window_size;
-    vec2i window_pos;
 
     unsigned int target_texture_id;
     vec2i texture_size;
-    Window composite_window;
+    Window window;
     WindowTexture window_texture;
+    Atom net_active_window_atom;
 
     CUgraphicsResource cuda_graphics_resource;
     CUarray mapped_array;
@@ -42,6 +42,20 @@ static int min_int(int a, int b) {
     return a < b ? a : b;
 }
 
+static Window get_focused_window(Display *display, Atom net_active_window_atom) {
+	Atom type;
+	int format = 0;
+	unsigned long num_items = 0;
+	unsigned long bytes_after = 0;
+	unsigned char *properties = NULL;
+	if(XGetWindowProperty(display, DefaultRootWindow(display), net_active_window_atom, 0, 1024, False, AnyPropertyType, &type, &format, &num_items, &bytes_after, &properties) == Success && properties) {
+		Window focused_window = *(unsigned long*)properties;
+		XFree(properties);
+		return focused_window;
+	}
+	return None;
+}
+
 static void gsr_capture_xcomposite_cuda_stop(gsr_capture *cap, AVCodecContext *video_codec_context);
 
 static bool cuda_register_opengl_texture(gsr_capture_xcomposite_cuda *cap_xcomp) {
@@ -58,6 +72,7 @@ static bool cuda_register_opengl_texture(gsr_capture_xcomposite_cuda *cap_xcomp)
                 "Error: cuGraphicsGLRegisterImage failed, error %s, texture "
                 "id: %u\n",
                 err_str, cap_xcomp->target_texture_id);
+        res = cap_xcomp->cuda.cuCtxPopCurrent_v2(&old_ctx);
         return false;
     }
 
@@ -122,13 +137,6 @@ static bool cuda_create_codec_context(gsr_capture_xcomposite_cuda *cap_xcomp, AV
 }
 
 static unsigned int gl_create_texture(gsr_capture_xcomposite_cuda *cap_xcomp, int width, int height) {
-    // Generating this second texture is needed because
-    // cuGraphicsGLRegisterImage cant be used with the texture that is mapped
-    // directly to the pixmap.
-    // TODO: Investigate if it's somehow possible to use the pixmap texture
-    // directly, this should improve performance since only less image copy is
-    // then needed every frame.
-    // Ignoring failure for now.. TODO: Show proper error
     unsigned int texture_id = 0;
     cap_xcomp->egl.glGenTextures(1, &texture_id);
     cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, texture_id);
@@ -136,8 +144,8 @@ static unsigned int gl_create_texture(gsr_capture_xcomposite_cuda *cap_xcomp, in
 
     cap_xcomp->egl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     cap_xcomp->egl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-    cap_xcomp->egl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-    cap_xcomp->egl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    cap_xcomp->egl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    cap_xcomp->egl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 
     cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, 0);
     return texture_id;
@@ -146,18 +154,34 @@ static unsigned int gl_create_texture(gsr_capture_xcomposite_cuda *cap_xcomp, in
 static int gsr_capture_xcomposite_cuda_start(gsr_capture *cap, AVCodecContext *video_codec_context) {
     gsr_capture_xcomposite_cuda *cap_xcomp = cap->priv;
 
+    if(cap_xcomp->params.follow_focused) {
+        cap_xcomp->net_active_window_atom = XInternAtom(cap_xcomp->dpy, "_NET_ACTIVE_WINDOW", False);
+        if(!cap_xcomp->net_active_window_atom) {
+            fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_start failed: failed to get _NET_ACTIVE_WINDOW atom\n");
+            return -1;
+        }
+        cap_xcomp->window = get_focused_window(cap_xcomp->dpy, cap_xcomp->net_active_window_atom);
+    } else {
+        cap_xcomp->window = cap_xcomp->params.window;
+    }
+
+    /* TODO: Do these in tick, and allow error if follow_focused */
+
     XWindowAttributes attr;
-    if(!XGetWindowAttributes(cap_xcomp->dpy, cap_xcomp->params.window, &attr)) {
-        fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_start failed: invalid window id: %lu\n", cap_xcomp->params.window);
+    attr.width = 0;
+    attr.height = 0;
+    if(!XGetWindowAttributes(cap_xcomp->dpy, cap_xcomp->window, &attr) && !cap_xcomp->params.follow_focused) {
+        fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_start failed: invalid window id: %lu\n", cap_xcomp->window);
         return -1;
     }
 
     cap_xcomp->window_size.x = max_int(attr.width, 0);
     cap_xcomp->window_size.y = max_int(attr.height, 0);
-    Window c;
-    XTranslateCoordinates(cap_xcomp->dpy, cap_xcomp->params.window, DefaultRootWindow(cap_xcomp->dpy), 0, 0, &cap_xcomp->window_pos.x, &cap_xcomp->window_pos.y, &c);
 
-    XSelectInput(cap_xcomp->dpy, cap_xcomp->params.window, StructureNotifyMask | ExposureMask);
+    if(cap_xcomp->params.follow_focused)
+        XSelectInput(cap_xcomp->dpy, DefaultRootWindow(cap_xcomp->dpy), PropertyChangeMask);
+
+    XSelectInput(cap_xcomp->dpy, cap_xcomp->window, StructureNotifyMask | ExposureMask);
 
     if(!gsr_egl_load(&cap_xcomp->egl, cap_xcomp->dpy)) {
         fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_start: failed to load opengl\n");
@@ -165,16 +189,16 @@ static int gsr_capture_xcomposite_cuda_start(gsr_capture *cap, AVCodecContext *v
     }
 
     cap_xcomp->egl.eglSwapInterval(cap_xcomp->egl.egl_display, 0);
-    // TODO: Fallback to composite window
-    if(window_texture_init(&cap_xcomp->window_texture, cap_xcomp->dpy, cap_xcomp->params.window, &cap_xcomp->egl) != 0) {
-        fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_start: failed get window texture for window %ld\n", cap_xcomp->params.window);
+    if(window_texture_init(&cap_xcomp->window_texture, cap_xcomp->dpy, cap_xcomp->window, &cap_xcomp->egl) != 0 && !cap_xcomp->params.follow_focused) {
+        fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_start: failed get window texture for window %ld\n", cap_xcomp->window);
         gsr_egl_unload(&cap_xcomp->egl);
         return -1;
     }
 
-    cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, window_texture_get_opengl_texture_id(&cap_xcomp->window_texture));
     cap_xcomp->texture_size.x = 0;
     cap_xcomp->texture_size.y = 0;
+
+    cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, window_texture_get_opengl_texture_id(&cap_xcomp->window_texture));
     cap_xcomp->egl.glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &cap_xcomp->texture_size.x);
     cap_xcomp->egl.glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &cap_xcomp->texture_size.y);
     cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, 0);
@@ -182,16 +206,21 @@ static int gsr_capture_xcomposite_cuda_start(gsr_capture *cap, AVCodecContext *v
     cap_xcomp->texture_size.x = max_int(2, cap_xcomp->texture_size.x & ~1);
     cap_xcomp->texture_size.y = max_int(2, cap_xcomp->texture_size.y & ~1);
 
-    cap_xcomp->target_texture_id = gl_create_texture(cap_xcomp, cap_xcomp->texture_size.x, cap_xcomp->texture_size.y);
+    video_codec_context->width = cap_xcomp->texture_size.x;
+    video_codec_context->height = cap_xcomp->texture_size.y;
+
+    if(cap_xcomp->params.region_size.x > 0 && cap_xcomp->params.region_size.y) {
+        video_codec_context->width = cap_xcomp->params.region_size.x;
+        video_codec_context->height = cap_xcomp->params.region_size.y;
+    }
+
+    cap_xcomp->target_texture_id = gl_create_texture(cap_xcomp, video_codec_context->width, video_codec_context->height);
     if(cap_xcomp->target_texture_id == 0) {
         fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_start: failed to create opengl texture\n");
         gsr_capture_xcomposite_cuda_stop(cap, video_codec_context);
         return -1;
     }
 
-    video_codec_context->width = cap_xcomp->texture_size.x;
-    video_codec_context->height = cap_xcomp->texture_size.y;
-
     if(!gsr_cuda_load(&cap_xcomp->cuda)) {
         gsr_capture_xcomposite_cuda_stop(cap, video_codec_context);
         return -1;
@@ -221,13 +250,11 @@ static void gsr_capture_xcomposite_cuda_stop(gsr_capture *cap, AVCodecContext *v
         cap_xcomp->target_texture_id = 0;
     }
 
-    if(cap_xcomp->composite_window) {
-        XCompositeUnredirectWindow(cap_xcomp->dpy, cap_xcomp->composite_window, CompositeRedirectAutomatic);
-        cap_xcomp->composite_window = None;
-    }
-
-    av_buffer_unref(&video_codec_context->hw_device_ctx);
-    av_buffer_unref(&video_codec_context->hw_frames_ctx);
+    if(video_codec_context->hw_device_ctx)
+        av_buffer_unref(&video_codec_context->hw_device_ctx);
+    // Not needed because the above call to unref device ctx also frees this?
+    //if(video_codec_context->hw_frames_ctx)
+    //    av_buffer_unref(&video_codec_context->hw_frames_ctx);
 
     if(cap_xcomp->cuda.cu_ctx) {
         CUcontext old_ctx;
@@ -241,7 +268,6 @@ static void gsr_capture_xcomposite_cuda_stop(gsr_capture *cap, AVCodecContext *v
 
     gsr_egl_unload(&cap_xcomp->egl);
     if(cap_xcomp->dpy) {
-        // TODO: Why is this crashing?
         XCloseDisplay(cap_xcomp->dpy);
         cap_xcomp->dpy = NULL;
     }
@@ -268,22 +294,18 @@ static void gsr_capture_xcomposite_cuda_tick(gsr_capture *cap, AVCodecContext *v
         cap_xcomp->cuda.cuCtxPopCurrent_v2(&old_ctx);
     }
 
-    if(XCheckTypedWindowEvent(cap_xcomp->dpy, cap_xcomp->params.window, DestroyNotify, &cap_xcomp->xev)) {
+    if(!cap_xcomp->params.follow_focused && XCheckTypedWindowEvent(cap_xcomp->dpy, cap_xcomp->window, DestroyNotify, &cap_xcomp->xev)) {
         cap_xcomp->should_stop = true;
         cap_xcomp->stop_is_error = false;
     }
 
-    if(XCheckTypedWindowEvent(cap_xcomp->dpy, cap_xcomp->params.window, Expose, &cap_xcomp->xev) && cap_xcomp->xev.xexpose.count == 0) {
+    if(XCheckTypedWindowEvent(cap_xcomp->dpy, cap_xcomp->window, Expose, &cap_xcomp->xev) && cap_xcomp->xev.xexpose.count == 0) {
         cap_xcomp->window_resize_timer = clock_get_monotonic_seconds();
         cap_xcomp->window_resized = true;
     }
 
-    if(XCheckTypedWindowEvent(cap_xcomp->dpy, cap_xcomp->params.window, ConfigureNotify, &cap_xcomp->xev) && cap_xcomp->xev.xconfigure.window == cap_xcomp->params.window) {
-        while(XCheckTypedWindowEvent(cap_xcomp->dpy, cap_xcomp->params.window, ConfigureNotify, &cap_xcomp->xev)) {}
-        Window c;
-        XTranslateCoordinates(cap_xcomp->dpy, cap_xcomp->params.window, DefaultRootWindow(cap_xcomp->dpy), 0, 0, &cap_xcomp->xev.xconfigure.x, &cap_xcomp->xev.xconfigure.y, &c);
-        cap_xcomp->window_pos.x = cap_xcomp->xev.xconfigure.x;
-        cap_xcomp->window_pos.y = cap_xcomp->xev.xconfigure.y;
+    if(XCheckTypedWindowEvent(cap_xcomp->dpy, cap_xcomp->window, ConfigureNotify, &cap_xcomp->xev) && cap_xcomp->xev.xconfigure.window == cap_xcomp->window) {
+        while(XCheckTypedWindowEvent(cap_xcomp->dpy, cap_xcomp->window, ConfigureNotify, &cap_xcomp->xev)) {}
 
         /* Window resize */
         if(cap_xcomp->xev.xconfigure.width != cap_xcomp->window_size.x || cap_xcomp->xev.xconfigure.height != cap_xcomp->window_size.y) {
@@ -294,10 +316,31 @@ static void gsr_capture_xcomposite_cuda_tick(gsr_capture *cap, AVCodecContext *v
         }
     }
 
+    if(cap_xcomp->params.follow_focused && XCheckTypedWindowEvent(cap_xcomp->dpy, DefaultRootWindow(cap_xcomp->dpy), PropertyNotify, &cap_xcomp->xev) && cap_xcomp->xev.xproperty.atom == cap_xcomp->net_active_window_atom) {
+        Window focused_window = get_focused_window(cap_xcomp->dpy, cap_xcomp->net_active_window_atom);
+        if(focused_window != cap_xcomp->window) {
+            XSelectInput(cap_xcomp->dpy, cap_xcomp->window, 0);
+            cap_xcomp->window = focused_window;
+            XSelectInput(cap_xcomp->dpy, cap_xcomp->window, StructureNotifyMask | ExposureMask);
+
+            XWindowAttributes attr;
+            attr.width = 0;
+            attr.height = 0;
+            if(!XGetWindowAttributes(cap_xcomp->dpy, cap_xcomp->window, &attr))
+                fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_start failed: invalid window id: %lu\n", cap_xcomp->window);
+
+            cap_xcomp->window_size.x = max_int(attr.width, 0);
+            cap_xcomp->window_size.y = max_int(attr.height, 0);
+            cap_xcomp->window_resized = true;
+
+            window_texture_deinit(&cap_xcomp->window_texture);
+            window_texture_init(&cap_xcomp->window_texture, cap_xcomp->dpy, cap_xcomp->window, &cap_xcomp->egl); // TODO: Do not do the below window_texture_on_resize after this
+        }
+    }
+
     const double window_resize_timeout = 1.0; // 1 second
     if(cap_xcomp->window_resized && clock_get_monotonic_seconds() - cap_xcomp->window_resize_timer >= window_resize_timeout) {
         cap_xcomp->window_resized = false;
-        fprintf(stderr, "Resize window!\n");
         if(window_texture_on_resize(&cap_xcomp->window_texture) != 0) {
             fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_tick: window_texture_on_resize failed\n");
             cap_xcomp->should_stop = true;
@@ -305,9 +348,10 @@ static void gsr_capture_xcomposite_cuda_tick(gsr_capture *cap, AVCodecContext *v
             return;
         }
 
-        cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, window_texture_get_opengl_texture_id(&cap_xcomp->window_texture));
         cap_xcomp->texture_size.x = 0;
         cap_xcomp->texture_size.y = 0;
+
+        cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, window_texture_get_opengl_texture_id(&cap_xcomp->window_texture));
         cap_xcomp->egl.glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &cap_xcomp->texture_size.x);
         cap_xcomp->egl.glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &cap_xcomp->texture_size.y);
         cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, 0);
@@ -315,37 +359,18 @@ static void gsr_capture_xcomposite_cuda_tick(gsr_capture *cap, AVCodecContext *v
         cap_xcomp->texture_size.x = min_int(video_codec_context->width, max_int(2, cap_xcomp->texture_size.x & ~1));
         cap_xcomp->texture_size.y = min_int(video_codec_context->height, max_int(2, cap_xcomp->texture_size.y & ~1));
 
-        cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, cap_xcomp->target_texture_id);
-        cap_xcomp->egl.glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, cap_xcomp->texture_size.x, cap_xcomp->texture_size.y, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
-        cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, 0);
-
-        CUcontext old_ctx;
-        CUresult res = cap_xcomp->cuda.cuCtxPushCurrent_v2(cap_xcomp->cuda.cu_ctx);
-
-        cap_xcomp->cuda.cuGraphicsUnmapResources(1, &cap_xcomp->cuda_graphics_resource, 0);
-        cap_xcomp->cuda.cuGraphicsUnregisterResource(cap_xcomp->cuda_graphics_resource);
-        res = cap_xcomp->cuda.cuGraphicsGLRegisterImage(&cap_xcomp->cuda_graphics_resource, cap_xcomp->target_texture_id, GL_TEXTURE_2D, CU_GRAPHICS_REGISTER_FLAGS_READ_ONLY);
-        if (res != CUDA_SUCCESS) {
-            const char *err_str = "unknown";
-            cap_xcomp->cuda.cuGetErrorString(res, &err_str);
-            fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_tick: cuGraphicsGLRegisterImage failed, error %s, texture id: %u\n", err_str, cap_xcomp->target_texture_id);
-            cap_xcomp->should_stop = true;
-            cap_xcomp->stop_is_error = true;
-            res = cap_xcomp->cuda.cuCtxPopCurrent_v2(&old_ctx);
-            return;
+        if(!cap_xcomp->params.follow_focused) {
+            cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, cap_xcomp->target_texture_id);
+            cap_xcomp->egl.glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, cap_xcomp->texture_size.x, cap_xcomp->texture_size.y, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
+            cap_xcomp->egl.glBindTexture(GL_TEXTURE_2D, 0);
         }
 
-        res = cap_xcomp->cuda.cuGraphicsResourceSetMapFlags(cap_xcomp->cuda_graphics_resource, CU_GRAPHICS_MAP_RESOURCE_FLAGS_READ_ONLY);
-        res = cap_xcomp->cuda.cuGraphicsMapResources(1, &cap_xcomp->cuda_graphics_resource, 0);
-        res = cap_xcomp->cuda.cuGraphicsSubResourceGetMappedArray(&cap_xcomp->mapped_array, cap_xcomp->cuda_graphics_resource, 0, 0);
-
         av_frame_free(frame);
         *frame = av_frame_alloc();
         if(!frame) {
             fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_tick: failed to allocate frame\n");
             cap_xcomp->should_stop = true;
             cap_xcomp->stop_is_error = true;
-            res = cap_xcomp->cuda.cuCtxPopCurrent_v2(&old_ctx);
             return;
         }
         (*frame)->format = video_codec_context->pix_fmt;
@@ -357,14 +382,12 @@ static void gsr_capture_xcomposite_cuda_tick(gsr_capture *cap, AVCodecContext *v
             fprintf(stderr, "gsr error: gsr_capture_xcomposite_cuda_tick: av_hwframe_get_buffer failed\n");
             cap_xcomp->should_stop = true;
             cap_xcomp->stop_is_error = true;
-            res = cap_xcomp->cuda.cuCtxPopCurrent_v2(&old_ctx);
             return;
         }
 
-        // Make it completely black to clear unused parts
-        // TODO: cuMemsetD32?
-        res = cap_xcomp->cuda.cuMemsetD8_v2((CUdeviceptr)(*frame)->data[0], 0, (*frame)->width * (*frame)->height * 4);
-        res = cap_xcomp->cuda.cuCtxPopCurrent_v2(&old_ctx);
+        // Clear texture with black background because the source texture (window_texture_get_opengl_texture_id(&cap_xcomp->window_texture))
+        // might be smaller than cap_xcomp->target_texture_id
+        cap_xcomp->egl.glClearTexImage(cap_xcomp->target_texture_id, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
     }
 }
 
@@ -384,25 +407,25 @@ static bool gsr_capture_xcomposite_cuda_should_stop(gsr_capture *cap, bool *err)
 static int gsr_capture_xcomposite_cuda_capture(gsr_capture *cap, AVFrame *frame) {
     gsr_capture_xcomposite_cuda *cap_xcomp = cap->priv;
 
-    // TODO: Use a framebuffer instead. glCopyImageSubData requires opengl 4.2
     vec2i source_pos = { 0, 0 };
     vec2i source_size = cap_xcomp->texture_size;
 
-    // Requires opengl 4.2... TODO: Replace with earlier opengl if opengl < 4.2.
-    cap_xcomp->egl.glCopyImageSubData(
-        window_texture_get_opengl_texture_id(&cap_xcomp->window_texture), GL_TEXTURE_2D, 0, source_pos.x, source_pos.y, 0,
-        cap_xcomp->target_texture_id, GL_TEXTURE_2D, 0, 0, 0, 0,
-        source_size.x, source_size.y, 1);
-    unsigned int err = cap_xcomp->egl.glGetError();
-    if(err != 0) {
-        static bool error_shown = false;
-        if(!error_shown) {
-            error_shown = true;
-            fprintf(stderr, "Error: glCopyImageSubData failed, gl error: %d\n", err);
+    if(cap_xcomp->window_texture.texture_id != 0) {
+        /* TODO: Remove this copy, which is only possible by using nvenc directly and encoding window_pixmap.target_texture_id */
+        cap_xcomp->egl.glCopyImageSubData(
+            window_texture_get_opengl_texture_id(&cap_xcomp->window_texture), GL_TEXTURE_2D, 0, source_pos.x, source_pos.y, 0,
+            cap_xcomp->target_texture_id, GL_TEXTURE_2D, 0, 0, 0, 0,
+            source_size.x, source_size.y, 1);
+        unsigned int err = cap_xcomp->egl.glGetError();
+        if(err != 0) {
+            static bool error_shown = false;
+            if(!error_shown) {
+                error_shown = true;
+                fprintf(stderr, "Error: glCopyImageSubData failed, gl error: %d\n", err);
+            }
         }
     }
     cap_xcomp->egl.eglSwapBuffers(cap_xcomp->egl.egl_display, cap_xcomp->egl.egl_surface);
-    // TODO: Remove this copy, which is only possible by using nvenc directly and encoding window_pixmap.target_texture_id
 
     frame->linesize[0] = frame->width * 4;
 
@@ -426,8 +449,8 @@ static int gsr_capture_xcomposite_cuda_capture(gsr_capture *cap, AVFrame *frame)
 }
 
 static void gsr_capture_xcomposite_cuda_destroy(gsr_capture *cap, AVCodecContext *video_codec_context) {
-    gsr_capture_xcomposite_cuda_stop(cap, video_codec_context);
     if(cap->priv) {
+        gsr_capture_xcomposite_cuda_stop(cap, video_codec_context);
         free(cap->priv);
         cap->priv = NULL;
     }