Init camera-gstreamermarlin_12.90.1marlin_12.90.0marlin/12.90.1marlin/12.90.0lamprey_11.92.0lamprey_11.91.0lamprey/11.92.0lamprey/11.91.0koi_11.0.4koi_11.0.3koi/11.0.4koi/11.0.3jellyfish_10.0.3jellyfish/10.0.312.90.112.90.011.92.011.91.011.0.411.0.310.0.3

Bug-AGL: SPEC-3629

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: Ib1a221f03dfac3114bbd3477dc488dd90c86ba35

5 files changed, 1170 insertions, 0 deletions

diff --git a/app/CMakeLists.txt b/app/CMakeLists.txt
new file mode 100644
index 0000000..02322d4
--- /dev/null
+++ b/app/CMakeLists.txt
@@ -0,0 +1,124 @@
+###########################################################################
+# Copyright 2018 Konsulko Group
+# Copyright 2020 Collabora, Ltd.
+#
+# Author: Scott Murray <scott.murray@konsulko.com>
+# Author: Marius Vlad <marius.vlad@collabora.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+###########################################################################
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(PkgConfig REQUIRED)
+find_program(WAYLAND_SCANNER_EXECUTABLE NAMES wayland-scanner)
+
+PROJECT_TARGET_ADD(camera-gstreamer)
+
+add_custom_command(
+	OUTPUT  agl-shell-desktop-client-protocol.h
+	COMMAND ${WAYLAND_SCANNER_EXECUTABLE} client-header
+	< ${CMAKE_SOURCE_DIR}/app/protocol/agl-shell-desktop.xml
+	> ${CMAKE_SOURCE_DIR}/app/agl-shell-desktop-client-protocol.h
+	DEPENDS ${CMAKE_SOURCE_DIR}/app/protocol/agl-shell-desktop.xml
+)
+
+
+add_custom_command(
+	OUTPUT  ${CMAKE_BINARY_DIR}/app/agl-shell-desktop-client-protocol.h
+	COMMAND ${WAYLAND_SCANNER_EXECUTABLE} client-header
+	< ${CMAKE_SOURCE_DIR}/app/protocol/agl-shell-desktop.xml
+	> ${CMAKE_SOURCE_DIR}/app/agl-shell-desktop-client-protocol.h
+	DEPENDS ${CMAKE_SOURCE_DIR}/app/protocol/agl-shell-desktop.xml
+)
+
+add_custom_command(
+	OUTPUT  agl-shell-desktop-protocol.c
+	COMMAND ${WAYLAND_SCANNER_EXECUTABLE} code
+	< ${CMAKE_SOURCE_DIR}/app/protocol/agl-shell-desktop.xml
+	> ${CMAKE_BINARY_DIR}/app/agl-shell-desktop-protocol.c
+	DEPENDS ${CMAKE_SOURCE_DIR}/app/protocol/agl-shell-desktop.xml
+)
+
+
+pkg_check_modules(GSTREAMER REQUIRED gstreamer-1.0)
+pkg_check_modules(GSTREAMER_PLUGINS_BASE REQUIRED gstreamer-plugins-base-1.0)
+pkg_check_modules(GSTREAMER_VIDEO REQUIRED gstreamer-video-1.0)
+pkg_check_modules(GSTREAMER_PLUGINS_BAD REQUIRED gstreamer-plugins-bad-1.0)
+
+pkg_check_modules(WAYLAND_CLIENT REQUIRED wayland-client)
+pkg_check_modules(WAYLAND_PROTOCOLS REQUIRED wayland-protocols>=1.18)
+pkg_get_variable(WAYLAND_PROTOCOLS_BASE wayland-protocols pkgdatadir)
+
+add_custom_command(
+	OUTPUT  xdg-shell-client-protocol.h
+	COMMAND ${WAYLAND_SCANNER_EXECUTABLE} client-header
+	< ${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml
+	> ${CMAKE_SOURCE_DIR}/app/xdg-shell-client-protocol.h
+	DEPENDS ${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml
+)
+
+
+add_custom_command(
+	OUTPUT  ${CMAKE_BINARY_DIR}/app/xdg-shell-client-protocol.h
+	COMMAND ${WAYLAND_SCANNER_EXECUTABLE} client-header
+	< ${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml
+	> ${CMAKE_SOURCE_DIR}/app/xdg-shell-client-protocol.h
+	DEPENDS ${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml
+)
+
+add_custom_command(
+	OUTPUT  xdg-shell-protocol.c
+	COMMAND ${WAYLAND_SCANNER_EXECUTABLE} code
+	< ${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml
+	> ${CMAKE_BINARY_DIR}/app/xdg-shell-protocol.c
+	DEPENDS ${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml
+)
+
+add_executable(${TARGET_NAME}
+	main.cpp
+	utils.h
+	utils.cpp
+	agl-shell-desktop-protocol.c
+	agl-shell-desktop-client-protocol.h
+	xdg-shell-protocol.c
+	xdg-shell-client-protocol.h
+	${RESOURCES}
+)
+
+include_directories(
+	"${GSTREAMER_INCLUDE_DIRS}"
+	"${GSTREAMER_PLUGINS_BASE_INCLUDE_DIRS}"
+	"${GSTREAMER_PLUGINS_BAD_INCLUDE_DIRS}"
+	"${GSTREAMER_VIDEO_INCLUDE_DIRS}"
+)
+
+set_target_properties(${TARGET_NAME} PROPERTIES
+	LABELS "EXECUTABLE"
+	PREFIX ""
+	COMPILE_FLAGS "${EXTRAS_CFLAGS} -DFOR_AFB_BINDING"
+	LINK_FLAGS "${BINDINGS_LINK_FLAG}"
+	LINK_LIBRARIES "${EXTRAS_LIBRARIES}"
+	OUTPUT_NAME "${TARGET_NAME}"
+)
+
+target_link_libraries(${TARGET_NAME}
+	${GSTREAMER_LIBRARIES}
+	"${GSTREAMER_PLUGINS_BASE_LIBRARIES}"
+	"${GSTREAMER_PLUGINS_BAD_LIBRARIES}"
+	"${GSTREAMER_VIDEO_LIBRARIES}"
+	${WAYLAND_CLIENT_LIBRARIES}
+	-lgstwayland-1.0
+)
diff --git a/app/main.cpp b/app/main.cpp
new file mode 100644
index 0000000..8634bbc
--- /dev/null
+++ b/app/main.cpp
@@ -0,0 +1,739 @@
+#define GST_USE_UNSTABLE_API
+#define HAVE_MEMFD_CREATE
+
+#include <string>
+#include <iostream>
+#include <cstring>
+#include <cstdio>
+#include <cstdlib>
+
+#include <signal.h>
+#include <wayland-client.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <assert.h>
+
+#include "xdg-shell-client-protocol.h"
+#include "agl-shell-desktop-client-protocol.h"
+#include "utils.h"
+
+#include <gst/gst.h>
+
+#include <gst/video/videooverlay.h>
+#include <gst/wayland/wayland.h>
+
+#define DEFAULT_VIDEO_DEVICE	"/dev/video0"
+
+// these only applies if the window is a dialog/pop-up one
+// by default the compositor make the window maximized
+#define WINDOW_WIDTH_SIZE	640
+#define WINDOW_HEIGHT_SIZE	720
+
+#define WINDOW_WIDTH_POS_X	640
+#define WINDOW_WIDTH_POS_Y	180
+
+// C++ requires a cast and we in wayland we do the cast implictly
+#define WL_ARRAY_FOR_EACH(pos, array, type) \
+	for (pos = (type)(array)->data; \
+	     (const char *) pos < ((const char *) (array)->data + (array)->size); \
+	     (pos)++)
+
+struct display {
+	struct wl_display *wl_display;
+	struct wl_registry *wl_registry;
+	struct wl_compositor *wl_compositor;
+	struct wl_output *wl_output;
+	struct wl_shm *shm;
+
+	struct {
+		int width;
+		int height;
+	} output_data;
+
+	struct xdg_wm_base *wm_base;
+	struct agl_shell_desktop *agl_shell_desktop;
+
+	int has_xrgb;
+};
+
+struct buffer {
+	struct wl_buffer *buffer;
+	void *shm_data;
+	int busy;
+};
+
+struct window {
+	struct display *display;
+
+	int x, y;
+	int width, height;
+
+	struct wl_surface *surface;
+
+	struct xdg_surface *xdg_surface;
+	struct xdg_toplevel *xdg_toplevel;
+	bool wait_for_configure;
+
+	int fullscreen, maximized;
+
+	struct buffer buffers[2];
+	struct wl_callback *callback;
+};
+
+
+struct receiver_data {
+	struct window *window;
+
+	GstElement *pipeline;
+	GstWaylandVideo *wl_video;
+	GstVideoOverlay *overlay;
+};
+
+static int running = 1;
+
+static void
+redraw(void *data, struct wl_callback *callback, uint32_t time);
+
+static void
+paint_pixels(void *image, int padding, int width, int height, uint32_t time)
+{
+	memset(image, 0x00, width * height * 4);
+}
+
+static void
+buffer_release(void *data, struct wl_buffer *buffer)
+{
+	struct buffer *mybuf = static_cast<struct buffer *>(data);
+	mybuf->busy = 0;
+}
+
+static const struct wl_buffer_listener buffer_listener = {
+	buffer_release
+};
+
+
+static int
+create_shm_buffer(struct display *display, struct buffer *buffer,
+		  int width, int height, uint32_t format)
+{
+	struct wl_shm_pool *pool;
+	int fd, size, stride;
+	void *data;
+
+	stride = width * 4;
+	size = stride * height;
+
+	fd = os_create_anonymous_file(size);
+	if (fd < 0) {
+		fprintf(stderr, "creating a buffer file for %d B failed: %s\n",
+				size, strerror(errno));
+		return -1;
+	}
+
+	data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	if (data == MAP_FAILED) {
+		fprintf(stderr, "mmap failed: %s\n", strerror(errno));
+		close(fd);
+		return -1;
+	}
+
+	pool = wl_shm_create_pool(display->shm, fd, size);
+	buffer->buffer = wl_shm_pool_create_buffer(pool, 0, width,
+						   height, stride, format);
+	wl_buffer_add_listener(buffer->buffer, &buffer_listener, buffer);
+	wl_shm_pool_destroy(pool);
+	close(fd);
+
+	buffer->shm_data = data;
+	fprintf(stdout, "Created shm buffer with width %d, height %d\n", width, height);
+	return 0;
+}
+
+static struct buffer *
+get_next_buffer(struct window *window)
+{
+	struct buffer *buffer = NULL;
+	int ret = 0;
+
+	/* we need to create new buffers for the resized value so discard
+	 * the 'old' one and force creation of the buffer with the newer
+	 * dimensions */
+	if (window->wait_for_configure && window->maximized) {
+		if (!window->buffers[0].busy) {
+			wl_buffer_destroy(window->buffers[0].buffer);
+			window->buffers[0].buffer = NULL;
+			window->wait_for_configure = false;
+		}
+	}
+
+	if (!window->buffers[0].busy) {
+		buffer = &window->buffers[0];
+	} else if (!window->buffers[1].busy) {
+		buffer = &window->buffers[1];
+	} else {
+		return NULL;
+	}
+
+	if (!buffer->buffer) {
+		ret = create_shm_buffer(window->display, buffer, window->width,
+					window->height, WL_SHM_FORMAT_XRGB8888);
+
+		if (ret < 0)
+			return NULL;
+
+		/* paint the padding */
+		memset(buffer->shm_data, 0x00, window->width * window->height * 4);
+	}
+
+	return buffer;
+}
+
+
+static const struct wl_callback_listener frame_listener = {
+	redraw
+};
+
+static void
+redraw(void *data, struct wl_callback *callback, uint32_t time)
+{
+        struct window *window = static_cast<struct window *>(data);
+        struct buffer *buffer;
+
+        buffer = get_next_buffer(window);
+        if (!buffer) {
+                fprintf(stderr,
+                        !callback ? "Failed to create the first buffer.\n" :
+                        "Both buffers busy at redraw(). Server bug?\n");
+                abort();
+        }
+
+	// do the actual painting
+	paint_pixels(buffer->shm_data, 0x0, window->width, window->height, time);
+
+        wl_surface_attach(window->surface, buffer->buffer, 0, 0);
+        wl_surface_damage(window->surface, 0, 0, window->width, window->height);
+
+        if (callback)
+                wl_callback_destroy(callback);
+
+        window->callback = wl_surface_frame(window->surface);
+        wl_callback_add_listener(window->callback, &frame_listener, window);
+        wl_surface_commit(window->surface);
+
+        buffer->busy = 1;
+}
+
+static void
+shm_format(void *data, struct wl_shm *wl_shm, uint32_t format)
+{
+	struct display *d = static_cast<struct display *>(data);
+
+	if (format == WL_SHM_FORMAT_XRGB8888)
+		d->has_xrgb = true;
+}
+
+static const struct wl_shm_listener shm_listener = {
+	shm_format
+};
+
+static void
+xdg_wm_base_ping(void *data, struct xdg_wm_base *shell, uint32_t serial)
+{
+        xdg_wm_base_pong(shell, serial);
+}
+
+static const struct xdg_wm_base_listener xdg_wm_base_listener = {
+        xdg_wm_base_ping,
+};
+
+static void
+display_handle_geometry(void *data, struct wl_output *wl_output,
+			int x, int y, int physical_width, int physical_height,
+			int subpixel, const char *make, const char *model, int transform)
+{
+	(void) data;
+	(void) wl_output;
+	(void) x;
+	(void) y;
+	(void) physical_width;
+	(void) physical_height;
+	(void) subpixel;
+	(void) make;
+	(void) model;
+	(void) transform;
+}
+
+static void
+display_handle_mode(void *data, struct wl_output *wl_output, uint32_t flags,
+		    int width, int height, int refresh)
+{
+	struct display *d = static_cast<struct display *>(data);
+
+	if (wl_output == d->wl_output && (flags & WL_OUTPUT_MODE_CURRENT)) {
+		d->output_data.width = width;
+		d->output_data.height = height;
+
+		fprintf(stdout, "Found output with width %d and height %d\n",
+				d->output_data.width, d->output_data.height);
+	}
+}
+
+static void
+display_handle_scale(void *data, struct wl_output *wl_output, int scale)
+{
+	(void) data;
+	(void) wl_output;
+	(void) scale;
+}
+
+static void
+display_handle_done(void *data, struct wl_output *wl_output)
+{
+	(void) data;
+	(void) wl_output;
+}
+
+static const struct wl_output_listener output_listener = {
+	display_handle_geometry,
+	display_handle_mode,
+	display_handle_done,
+	display_handle_scale
+};
+
+static void
+application_id(void *data, struct agl_shell_desktop *agl_shell_desktop,
+		const char *app_id)
+{
+	(void) data;
+	(void) agl_shell_desktop;
+	(void) app_id;
+}
+
+static void
+application_id_state(void *data, struct agl_shell_desktop *agl_shell_desktop,
+		     const char *app_id, const char *app_data,
+		     uint32_t app_state, uint32_t app_role)
+{
+        (void) data;
+        (void) app_data;
+        (void) agl_shell_desktop;
+        (void) app_id;
+        (void) app_state;
+        (void) app_role;
+}
+
+static const struct agl_shell_desktop_listener agl_shell_desktop_listener = {
+        application_id,
+        application_id_state,
+};
+
+static void
+registry_handle_global(void *data, struct wl_registry *registry, uint32_t id,
+		       const char *interface, uint32_t version)
+{
+	struct display *d = static_cast<struct display *>(data);
+
+	if (strcmp(interface, "wl_compositor") == 0) {
+		d->wl_compositor =
+			static_cast<struct wl_compositor *>(wl_registry_bind(registry, id,
+						    &wl_compositor_interface, 1));
+	} else if (strcmp(interface, "xdg_wm_base") == 0) {
+		d->wm_base = static_cast<struct xdg_wm_base *>(wl_registry_bind(registry,
+				id, &xdg_wm_base_interface, 1));
+		xdg_wm_base_add_listener(d->wm_base, &xdg_wm_base_listener, d);
+	} else if (strcmp(interface, "wl_shm") == 0) {
+		d->shm = static_cast<struct wl_shm *>(wl_registry_bind(registry,
+				id, &wl_shm_interface, 1));
+		wl_shm_add_listener(d->shm, &shm_listener, d);
+	} else if (strcmp(interface, "agl_shell_desktop") == 0) {
+		d->agl_shell_desktop = static_cast<struct agl_shell_desktop *>(wl_registry_bind(registry, id,
+						        &agl_shell_desktop_interface, 1));
+		/* as an example, show how to register for events from the compositor */
+		agl_shell_desktop_add_listener(d->agl_shell_desktop,
+					       &agl_shell_desktop_listener, d);
+	} else if (strcmp(interface, "wl_output") == 0) {
+		d->wl_output = static_cast<struct wl_output *>(wl_registry_bind(registry, id,
+					     &wl_output_interface, 1));
+		wl_output_add_listener(d->wl_output, &output_listener, d);
+	}
+}
+
+static void
+registry_handle_global_remove(void *data, struct wl_registry *reg, uint32_t id)
+{
+	(void) data;
+	(void) reg;
+	(void) id;
+}
+
+static const struct wl_registry_listener registry_listener = {
+	registry_handle_global,
+	registry_handle_global_remove,
+};
+
+
+static void
+error_cb(GstBus *bus, GstMessage *msg, gpointer user_data)
+{
+	struct receiver_data *d =
+		static_cast<struct receiver_data *>(user_data);
+
+	gchar *debug = NULL;
+	GError *err = NULL;
+
+	gst_message_parse_error(msg, &err, &debug);
+
+	g_print("Error: %s\n", err->message);
+	g_error_free(err);
+
+	if (debug) {
+		g_print("Debug details: %s\n", debug);
+		g_free(debug);
+	}
+
+	gst_element_set_state(d->pipeline, GST_STATE_NULL);
+}
+
+static GstBusSyncReply
+bus_sync_handler(GstBus *bus, GstMessage *message, gpointer user_data)
+{
+	struct receiver_data *d =
+		static_cast<struct receiver_data *>(user_data);
+
+	if (gst_is_wayland_display_handle_need_context_message(message)) {
+		GstContext *context;
+		struct wl_display *display_handle = d->window->display->wl_display;
+
+		context = gst_wayland_display_handle_context_new(display_handle);
+		d->wl_video = GST_WAYLAND_VIDEO(GST_MESSAGE_SRC(message));
+		gst_element_set_context(GST_ELEMENT(GST_MESSAGE_SRC(message)), context);
+
+		goto drop;
+	} else if (gst_is_video_overlay_prepare_window_handle_message(message)) {
+		struct wl_surface *window_handle = d->window->surface;
+
+		/* GST_MESSAGE_SRC(message) will be the overlay object that we
+		 * have to use. This may be waylandsink, but it may also be
+		 * playbin. In the latter case, we must make sure to use
+		 * playbin instead of waylandsink, because playbin resets the
+		 * window handle and render_rectangle after restarting playback
+		 * and the actual window size is lost */
+		d->overlay = GST_VIDEO_OVERLAY(GST_MESSAGE_SRC(message));
+
+		g_print("setting window handle and size (%d x %d) w %d, h %d\n",
+				d->window->x, d->window->y,
+				d->window->width, d->window->height);
+
+		gst_video_overlay_set_window_handle(d->overlay, (guintptr) window_handle);
+		gst_video_overlay_set_render_rectangle(d->overlay,
+						       d->window->x, d->window->y,
+						       d->window->width, d->window->height);
+
+		goto drop;
+	}
+
+	return GST_BUS_PASS;
+
+drop:
+	gst_message_unref(message);
+	return GST_BUS_DROP;
+}
+
+static void
+handle_xdg_surface_configure(void *data, struct xdg_surface *surface, uint32_t serial)
+{
+	struct window *window = static_cast<struct window *>(data);
+
+	xdg_surface_ack_configure(surface, serial);
+
+	if (window->wait_for_configure) {
+		redraw(window, NULL, 0);
+	}
+}
+
+static const struct xdg_surface_listener xdg_surface_listener = {
+	handle_xdg_surface_configure,
+};
+
+static void
+handle_xdg_toplevel_configure(void *data, struct xdg_toplevel *xdg_toplevel,
+			      int32_t width, int32_t height,
+			      struct wl_array *states)
+{
+	struct window *window = static_cast<struct window *>(data);
+	uint32_t *p;
+
+	window->fullscreen = 0;
+	window->maximized = 0;
+
+	// use our own macro as C++ can't typecast from (void *) directly
+	WL_ARRAY_FOR_EACH(p, states, uint32_t *) {
+		uint32_t state = *p; 
+		switch (state) {
+		case XDG_TOPLEVEL_STATE_FULLSCREEN:
+			window->fullscreen = 1;
+			break;
+		case XDG_TOPLEVEL_STATE_MAXIMIZED:
+			window->maximized = 1;
+			break;
+		}
+	}
+
+	if (width > 0 && height > 0) {
+		if (!window->fullscreen && !window->maximized) {
+			window->width = width;
+			window->height = height;
+		}
+		window->width = width;
+		window->height = height;
+	} else if (!window->fullscreen && !window->maximized) {
+		if (width == 0)
+			window->width = WINDOW_WIDTH_SIZE;
+		else
+			window->width = width;
+
+		if (height == 0)
+			window->height = WINDOW_HEIGHT_SIZE;
+		else
+			window->height = height;
+	}
+
+	/* if we've been resized set wait_for_configure to adjust the fb size 
+	 * in the frame callback handler, which will also clear this up */
+	if ((window->width > 0 && window->width != WINDOW_WIDTH_SIZE) &&
+	    (window->height > 0 && window->height != WINDOW_HEIGHT_SIZE)) {
+		window->wait_for_configure = true;
+	}
+}
+
+static void
+handle_xdg_toplevel_close(void *data, struct xdg_toplevel *xdg_toplevel)
+{
+	running = 0;
+}
+
+static const struct xdg_toplevel_listener xdg_toplevel_listener = {
+	handle_xdg_toplevel_configure,
+	handle_xdg_toplevel_close,
+};
+
+static struct window *
+create_window(struct display *display, int width, int height, const char *app_id)
+{
+	struct window *window;
+
+	assert(display->wm_base != NULL);
+
+	window = static_cast<struct window *>(calloc(1, sizeof(*window)));
+	if (!window)
+		return NULL;
+
+	window->callback = NULL;
+	window->display = display;
+	window->width = width;
+	window->height = height;
+	window->surface = wl_compositor_create_surface(display->wl_compositor);
+
+	if (display->wm_base) {
+		window->xdg_surface =
+			xdg_wm_base_get_xdg_surface(display->wm_base, window->surface);
+		assert(window->xdg_surface);
+
+		xdg_surface_add_listener(window->xdg_surface,
+					 &xdg_surface_listener, window);
+		window->xdg_toplevel = xdg_surface_get_toplevel(window->xdg_surface);
+		assert(window->xdg_toplevel);
+
+		xdg_toplevel_add_listener(window->xdg_toplevel,
+					  &xdg_toplevel_listener, window);
+
+		xdg_toplevel_set_app_id(window->xdg_toplevel, app_id);
+
+		wl_surface_commit(window->surface);
+		window->wait_for_configure = true;
+	}
+
+	return window;
+}
+
+
+static void
+destroy_window(struct window *window)
+{
+	if (window->callback)
+		wl_callback_destroy(window->callback);
+
+	if (window->buffers[0].buffer)
+		wl_buffer_destroy(window->buffers[0].buffer);
+	if (window->buffers[1].buffer)
+		wl_buffer_destroy(window->buffers[1].buffer);
+
+	if (window->xdg_toplevel)
+		xdg_toplevel_destroy(window->xdg_toplevel);
+
+	if (window->xdg_surface)
+		xdg_surface_destroy(window->xdg_surface);
+
+	wl_surface_destroy(window->surface);
+	free(window);
+}
+
+static void
+signal_int(int sig, siginfo_t *si, void *_unused)
+{
+	running = 0;
+}
+
+static struct display *
+create_display(int argc, char *argv[])
+{
+	struct display *display;
+
+	display = static_cast<struct display *>(calloc(1, sizeof(*display)));
+	if (display == NULL) {
+		fprintf(stderr, "out of memory\n");
+		exit(1);
+	}
+	display->wl_display = wl_display_connect(NULL);
+	assert(display->wl_display);
+
+	display->has_xrgb = false;
+	display->wl_registry = wl_display_get_registry(display->wl_display);
+
+	wl_registry_add_listener(display->wl_registry, &registry_listener, display);
+	wl_display_roundtrip(display->wl_display);
+
+	if (display->shm == NULL) {
+		fprintf(stderr, "No wl_shm global\n");
+		return NULL;
+	}
+
+	if (display->agl_shell_desktop == NULL) {
+		fprintf(stderr, "No agl_shell extension present\n");
+		return NULL;
+	}
+
+	wl_display_roundtrip(display->wl_display);
+
+	if (!display->has_xrgb) {
+		fprintf(stderr, "WL_SHM_FORMAT_XRGB32 not available\n");
+		return NULL;
+	}
+
+	return display;
+}
+
+static void
+destroy_display(struct display *display)
+{
+	if (display->shm)
+		wl_shm_destroy(display->shm);
+
+	if (display->wm_base)
+		xdg_wm_base_destroy(display->wm_base);
+
+	if (display->agl_shell_desktop)
+		agl_shell_desktop_destroy(display->agl_shell_desktop);
+
+	if (display->wl_compositor)
+		wl_compositor_destroy(display->wl_compositor);
+
+	wl_registry_destroy(display->wl_registry);
+	wl_display_flush(display->wl_display);
+	wl_display_disconnect(display->wl_display);
+	free(display);
+}
+
+int main(int argc, char *argv[])
+{
+	int ret = 0;
+	struct sigaction sa;
+	struct receiver_data receiver_data = {};
+	struct display *display;
+	struct window *window;
+	char pipeline_str[1024];
+	GError *error = NULL;
+	const char *app_id = "camera-gstreamer";
+
+	sa.sa_sigaction = signal_int;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_RESETHAND | SA_SIGINFO;
+	sigaction(SIGINT, &sa, NULL);
+
+	int gargc = 2;
+	char **gargv = static_cast<char **>(calloc(2, sizeof(char *)));
+
+	gargv[0] = strdup(argv[0]);
+	gargv[1] = strdup("--gst-debug-level=2");
+
+	memset(pipeline_str, 0, sizeof(pipeline_str));
+	snprintf(pipeline_str, sizeof(pipeline_str), "v4l2src device=%s ! video/x-raw,width=%d,height=%d ! waylandsink", 
+		DEFAULT_VIDEO_DEVICE, WINDOW_WIDTH_SIZE, WINDOW_HEIGHT_SIZE);
+	gst_init(&gargc, &gargv);
+
+	fprintf(stdout, "Using pipeline: %s\n", pipeline_str);
+
+	GstElement *pipeline = gst_parse_launch(pipeline_str, &error);
+	if (error || !pipeline) {
+		fprintf(stderr, "gstreamer pipeline construction failed!\n");
+		free(argv);
+		return EXIT_FAILURE;
+	}
+
+	receiver_data.pipeline = pipeline;
+
+	display = create_display(argc, argv);
+	if (!display)
+		return -1;
+
+	// if you'd want to place the video in a pop-up/dialog type of window:
+	// agl_shell_desktop_set_app_property(display->agl_shell_desktop, app_id, 
+	//				   AGL_SHELL_DESKTOP_APP_ROLE_POPUP,
+	//				   WINDOW_WIDTH_POS_X, WINDOW_WIDTH_POS_Y,
+	//				   0, 0, WINDOW_WIDTH_SIZE, WINDOW_HEIGHT_SIZE,
+	//				   display->wl_output);
+
+	// we use the role to set a correspondence between the top level
+	// surface and our application, with the previous call letting the
+	// compositor know that we're one and the same
+	window = create_window(display, WINDOW_WIDTH_SIZE, WINDOW_HEIGHT_SIZE, app_id); 
+
+	if (!window) {
+		free(argv);
+		return EXIT_FAILURE;
+	}
+
+	window->display = display;
+	receiver_data.window = window;
+
+	/* Initialise damage to full surface, so the padding gets painted */
+	wl_surface_damage(window->surface, 0, 0,
+			  window->width, window->height);
+
+	if (!window->wait_for_configure) {
+		redraw(window, NULL, 0);
+	}
+
+	GstBus *bus = gst_element_get_bus(pipeline);
+	gst_bus_add_signal_watch(bus);
+
+	g_signal_connect(bus, "message::error", G_CALLBACK(error_cb), &receiver_data);
+	gst_bus_set_sync_handler(bus, bus_sync_handler, &receiver_data, NULL);
+	gst_object_unref(bus);
+
+	gst_element_set_state(pipeline, GST_STATE_PLAYING);
+	fprintf(stdout, "gstreamer pipeline running\n");
+
+	// run the application
+	while (running && ret != -1)
+		ret = wl_display_dispatch(display->wl_display);
+
+	destroy_window(window);
+	destroy_display(display);
+	free(argv);
+
+	gst_element_set_state(pipeline, GST_STATE_NULL);
+	gst_object_unref(pipeline);
+	return ret;
+}
diff --git a/app/protocol/agl-shell-desktop.xml b/app/protocol/agl-shell-desktop.xml
new file mode 100644
index 0000000..e8ae153
--- /dev/null
+++ b/app/protocol/agl-shell-desktop.xml
@@ -0,0 +1,142 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="agl_shell_desktop">
+  <copyright>
+    Copyright © 2020 Collabora, Ltd.
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice (including the next
+    paragraph) shall be included in all copies or substantial portions of the
+    Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+  </copyright>
+  <interface name="agl_shell_desktop" version="1">
+    <description summary="Private extension to allow applications activate other apps">
+      This extension can be used by regular application to instruct to compositor
+      to activate or switch to other running (regular) applications. The client
+      is responsbile for filtering their own app_id when receiving application id.
+
+      The compositor will allow clients to bind to this interface only if the
+      policy engine allows it.
+    </description>
+
+    <enum name="app_role">
+      <entry name="popup" value="0"/>
+      <entry name="fullscreen" value="1"/>
+      <entry name="split_vertical" value="2"/>
+      <entry name="split_horizontal" value="3"/>
+      <entry name="remote" value="4"/>
+    </enum>
+
+    <enum name="app_state">
+      <entry name="activated" value="0"/>
+      <entry name="deactivated" value="1"/>
+    </enum>
+
+    <event name="application">
+      <description summary="advertise application id">
+        The compositor may choose to advertise one or more application ids which
+        can be used to activate/switch to.
+
+        When this global is bound, the compositor will send all application ids
+        available for activation, but may send additional application id at any
+        time (when they've been mapped in the compositor).
+      </description>
+      <arg name="app_id" type="string"/>
+    </event>
+
+    <request name="activate_app">
+      <description summary="make client current window">
+        Ask the compositor to make a toplevel to become the current/focused
+        window for window management purposes.
+
+        See xdg_toplevel.set_app_id from the xdg-shell protocol for a
+        description of app_id.
+      </description>
+      <arg name="app_id" type="string"/>
+      <arg name="app_data" type="string" allow-null="true"/>
+      <arg name="output" type="object" interface="wl_output"/>
+    </request>
+
+    <request name="set_app_property">
+      <description summary="set properties for a client identified by app_id">
+        Ask the compositor to make a top-level window obey the 'app_role' enum
+        and, depending on that role, to use some of the arguments as initial
+        values to take into account.
+
+        Note that x, y, bx, by, width and height would only make sense for the
+        pop-up role, with the output argument being applicable to all the roles.
+        The width and height values define the maximum area which the
+        top-level window should be placed into. Note this doesn't correspond to
+        top-level surface size, but to a bounding box which will be used to
+        clip the surface to, in case the surface area extends that of this
+        bounding box. Both of these values need to be larger than 0 (zero) to be
+        taken into account by the compositor. Any negative values for the width
+        and height will be discarded.
+
+        The x and y values will serve as the (initial) position values.
+        The bx and by values are the top-left x and y value of the bounding box.
+        Any clipping happening to the bounding box will not affect the surface
+        size or the position of the underlying surface backing the top-level
+        window. The bx and by values, like the positional values, could be
+        both set to zero, or even negative values. The compositor will pass
+        those on without any further validation.
+
+        The initial position values and the bounding rectangle will still be
+        in effect on a subsequent activation request of the 'app_id', assuming
+        it was previously de-activated at some point in time.
+
+        See xdg_toplevel.set_app_id from the xdg-shell protocol for a
+        description of app_id.
+      </description>
+      <arg name="app_id" type="string"/>
+      <arg name="role" type="uint" enum="app_role"/>
+      <arg name="x" type="int"/>
+      <arg name="y" type="int"/>
+      <arg name="bx" type="int"/>
+      <arg name="by" type="int"/>
+      <arg name="width" type="int"/>
+      <arg name="height" type="int"/>
+      <arg name="output" type="object" interface="wl_output"/>
+    </request>
+
+    <request name="deactivate_app">
+      <description summary="de-activate/hide window identified by app_id">
+        Ask the compositor to hide the toplevel window for window
+        management purposes. Depending on the window role, this request
+        will either display the previously active window (or the background
+        in case there's no previously activate surface) or temporarly (or
+        until a 'activate_app' is called upon) hide the surface. All
+        the surfaces are identifiable by using the app_id, and no actions are
+        taken in case the app_id is not/was not present.
+
+        See xdg_toplevel.set_app_id from the xdg-shell protocol for a
+        description of app_id.
+      </description>
+      <arg name="app_id" type="string"/>
+    </request>
+
+    <event name="state_app">
+      <description summary="event sent when application has suffered state modification">
+        Notifies application(s) when other application have suffered state modifications.
+      </description>
+      <arg name="app_id" type="string"/>
+      <arg name="app_data" type="string" allow-null="true"/>
+      <arg name="state" type="uint" enum="app_state"/>
+      <arg name="role" type="uint" enum="app_role"/>
+    </event>
+
+  </interface>
+</protocol>
diff --git a/app/utils.cpp b/app/utils.cpp
new file mode 100644
index 0000000..f1c3eae
--- /dev/null
+++ b/app/utils.cpp
@@ -0,0 +1,150 @@
+#include <sys/mman.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <cstdlib>
+#include <cstring>
+#include <cerrno>
+
+#include "utils.h"
+
+static int
+os_fd_set_cloexec(int fd)
+{
+	long flags;
+
+	if (fd == -1)
+		return -1;
+
+	flags = fcntl(fd, F_GETFD);
+	if (flags == -1)
+		return -1;
+
+	if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1)
+		return -1;
+
+	return 0;
+}
+
+static int
+set_cloexec_or_close(int fd)
+{
+	if (os_fd_set_cloexec(fd) != 0) {
+		close(fd);
+		return -1;
+	}
+	return fd;
+}
+
+static int
+create_tmpfile_cloexec(char *tmpname)
+{
+	int fd;
+
+#ifdef HAVE_MKOSTEMP
+	fd = mkostemp(tmpname, O_CLOEXEC);
+	if (fd >= 0)
+		unlink(tmpname);
+#else
+	fd = mkstemp(tmpname);
+	if (fd >= 0) {
+		fd = set_cloexec_or_close(fd);
+		unlink(tmpname);
+	}
+#endif
+
+	return fd;
+}
+
+/*
+ * Create a new, unique, anonymous file of the given size, and
+ * return the file descriptor for it. The file descriptor is set
+ * CLOEXEC. The file is immediately suitable for mmap()'ing
+ * the given size at offset zero.
+ *
+ * The file should not have a permanent backing store like a disk,
+ * but may have if XDG_RUNTIME_DIR is not properly implemented in OS.
+ *
+ * The file name is deleted from the file system.
+ *
+ * The file is suitable for buffer sharing between processes by
+ * transmitting the file descriptor over Unix sockets using the
+ * SCM_RIGHTS methods.
+ *
+ * If the C library implements posix_fallocate(), it is used to
+ * guarantee that disk space is available for the file at the
+ * given size. If disk space is insufficient, errno is set to ENOSPC.
+ * If posix_fallocate() is not supported, program may receive
+ * SIGBUS on accessing mmap()'ed file contents instead.
+ *
+ * If the C library implements memfd_create(), it is used to create the
+ * file purely in memory, without any backing file name on the file
+ * system, and then sealing off the possibility of shrinking it.  This
+ * can then be checked before accessing mmap()'ed file contents, to
+ * make sure SIGBUS can't happen.  It also avoids requiring
+ * XDG_RUNTIME_DIR.
+ */
+int
+os_create_anonymous_file(off_t size)
+{
+	static const char weston_template[] = "/weston-shared-XXXXXX";
+	const char *path;
+	char *name;
+	int fd;
+	int ret;
+
+#ifdef HAVE_MEMFD_CREATE
+	fd = memfd_create("weston-shared", MFD_CLOEXEC | MFD_ALLOW_SEALING);
+	if (fd >= 0) {
+		/* We can add this seal before calling posix_fallocate(), as
+		 * the file is currently zero-sized anyway.
+		 *
+		 * There is also no need to check for the return value, we
+		 * couldn't do anything with it anyway.
+		 */
+		fcntl(fd, F_ADD_SEALS, F_SEAL_SHRINK);
+	} else
+#endif
+	{
+		path = getenv("XDG_RUNTIME_DIR");
+		if (!path) {
+			errno = ENOENT;
+			return -1;
+		}
+
+		name = static_cast<char *>(malloc(strlen(path) + sizeof(weston_template)));
+		if (!name)
+			return -1;
+
+		strcpy(name, path);
+		strcat(name, weston_template);
+
+		fd = create_tmpfile_cloexec(name);
+
+		free(name);
+
+		if (fd < 0)
+			return -1;
+	}
+
+#ifdef HAVE_POSIX_FALLOCATE
+	do {
+		ret = posix_fallocate(fd, 0, size);
+	} while (ret == EINTR);
+	if (ret != 0) {
+		close(fd);
+		errno = ret;
+		return -1;
+	}
+#else
+	do {
+		ret = ftruncate(fd, size);
+	} while (ret < 0 && errno == EINTR);
+	if (ret < 0) {
+		close(fd);
+		return -1;
+	}
+#endif
+
+	return fd;
+}
diff --git a/app/utils.h b/app/utils.h
new file mode 100644
index 0000000..99b2e30
--- /dev/null
+++ b/app/utils.h
@@ -0,0 +1,15 @@
+#ifndef __UTILS_H
+#define __UTILS_H
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+int
+os_create_anonymous_file(off_t size);
+
+#ifdef  __cplusplus
+}
+#endif
+
+#endif