app/main.cpp

   1 #define GST_USE_UNSTABLE_API
   2 #define HAVE_MEMFD_CREATE
   3
   4 #include <string>
   5 #include <iostream>
   6 #include <cstring>
   7 #include <cstdio>
   8 #include <cstdlib>
   9
  10 #include <signal.h>
  11 #include <wayland-client.h>
  12 #include <sys/mman.h>
  13 #include <unistd.h>
  14 #include <fcntl.h>
  15 #include <assert.h>
  16
  17 #include "utils.h"
  18 #include "xdg-shell-client-protocol.h"
  19
  20 #include <gst/gst.h>
  21
  22 #include <gst/video/videooverlay.h>
  23 #include <gst/wayland/wayland.h>
  24
  25 #if !GST_CHECK_VERSION(1, 22, 0)
  26 #define gst_is_wl_display_handle_need_context_message gst_is_wayland_display_handle_need_context_message
  27 #define gst_wl_display_handle_context_new gst_wayland_display_handle_context_new
  28 #endif
  29
  30 #ifndef APP_DATA_PATH
  31 #define APP_DATA_PATH /usr/share/applications/data
  32 #endif
  33
  34 // these only applies if the window is a dialog/pop-up one
  35 // by default the compositor make the window maximized
  36 #define WINDOW_WIDTH_SIZE       640
  37 #define WINDOW_HEIGHT_SIZE      720
  38
  39 #define WINDOW_WIDTH_POS_X      640
  40 #define WINDOW_WIDTH_POS_Y      180
  41
  42 #define MAX_BUFFER_ALLOC        2
  43
  44 // C++ requires a cast and we in wayland we do the cast implictly
  45 #define WL_ARRAY_FOR_EACH(pos, array, type) \
  46         for (pos = (type)(array)->data; \
  47              (const char *) pos < ((const char *) (array)->data + (array)->size); \
  48              (pos)++)
  49
  50 struct display {
  51         struct wl_display *wl_display;
  52         struct wl_registry *wl_registry;
  53         struct wl_compositor *wl_compositor;
  54         struct wl_output *wl_output;
  55         struct wl_shm *shm;
  56
  57         struct {
  58                 int width;
  59                 int height;
  60         } output_data;
  61
  62         struct xdg_wm_base *wm_base;
  63         int has_xrgb;
  64 };
  65
  66 struct buffer {
  67         struct wl_buffer *buffer;
  68         void *shm_data;
  69         int busy;
  70         int width, height;
  71         size_t size;    /* width * 4 * height */
  72         struct wl_list buffer_link; /** window::buffer_list */
  73 };
  74
  75 struct window {
  76         struct display *display;
  77
  78         int x, y;
  79         int width, height;
  80         int init_width;
  81         int init_height;
  82
  83         struct wl_surface *surface;
  84
  85         struct xdg_surface *xdg_surface;
  86         struct xdg_toplevel *xdg_toplevel;
  87         bool wait_for_configure;
  88
  89         int fullscreen, maximized;
  90
  91         struct wl_list buffer_list;
  92         struct wl_callback *callback;
  93         bool needs_update_buffer;
  94 };
  95
  96
  97 struct receiver_data {
  98         struct window *window;
  99
 100         GstElement *pipeline;
 101         GstVideoOverlay *overlay;
 102 };
 103
 104 static int running = 1;
 105 static bool gst_pipeline_failed = FALSE;
 106 static bool fallback_gst_pipeline_tried = FALSE;
 107
 108 static void
 109 redraw(void *data, struct wl_callback *callback, uint32_t time);
 110
 111 static struct buffer *
 112 alloc_buffer(struct window *window, int width, int height)
 113 {
 114         struct buffer *buffer = static_cast<struct buffer *>(calloc(1, sizeof(*buffer)));
 115
 116         buffer->width = width;
 117         buffer->height = height;
 118         wl_list_insert(&window->buffer_list, &buffer->buffer_link);
 119
 120         return buffer;
 121 }
 122
 123 static void
 124 destroy_buffer(struct buffer *buffer)
 125 {
 126         if (buffer->buffer)
 127                 wl_buffer_destroy(buffer->buffer);
 128
 129         munmap(buffer->shm_data, buffer->size);
 130         wl_list_remove(&buffer->buffer_link);
 131         free(buffer);
 132 }
 133
 134 static struct buffer *
 135 pick_free_buffer(struct window *window)
 136 {
 137         struct buffer *b;
 138         struct buffer *buffer = NULL;
 139
 140         wl_list_for_each(b, &window->buffer_list, buffer_link) {
 141                 if (!b->busy) {
 142                         buffer = b;
 143                         break;
 144                 }
 145         }
 146
 147         return buffer;
 148 }
 149
 150 static void
 151 prune_old_released_buffers(struct window *window)
 152 {
 153         struct buffer *b, *b_next;
 154
 155         wl_list_for_each_safe(b, b_next,
 156                               &window->buffer_list, buffer_link) {
 157                 if (!b->busy && (b->width != window->width ||
 158                                  b->height != window->height))
 159                         destroy_buffer(b);
 160         }
 161 }
 162
 163 static void
 164 paint_pixels(void *image, int padding, int width, int height, uint32_t time)
 165 {
 166         memset(image, 0x00, width * height * 4);
 167 }
 168
 169 static void
 170 buffer_release(void *data, struct wl_buffer *buffer)
 171 {
 172         struct buffer *mybuf = static_cast<struct buffer *>(data);
 173         mybuf->busy = 0;
 174 }
 175
 176 static const struct wl_buffer_listener buffer_listener = {
 177         buffer_release
 178 };
 179
 180
 181 static int
 182 create_shm_buffer(struct display *display, struct buffer *buffer,
 183                   int width, int height, uint32_t format)
 184 {
 185         struct wl_shm_pool *pool;
 186         int fd, size, stride;
 187         void *data;
 188
 189         stride = width * 4;
 190         size = stride * height;
 191
 192         fd = os_create_anonymous_file(size);
 193         if (fd < 0) {
 194                 fprintf(stderr, "creating a buffer file for %d B failed: %s\n",
 195                                 size, strerror(errno));
 196                 return -1;
 197         }
 198
 199         data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 200         if (data == MAP_FAILED) {
 201                 fprintf(stderr, "mmap failed: %s\n", strerror(errno));
 202                 close(fd);
 203                 return -1;
 204         }
 205
 206         pool = wl_shm_create_pool(display->shm, fd, size);
 207         buffer->buffer = wl_shm_pool_create_buffer(pool, 0, width,
 208                                                    height, stride, format);
 209         wl_buffer_add_listener(buffer->buffer, &buffer_listener, buffer);
 210         wl_shm_pool_destroy(pool);
 211         close(fd);
 212
 213         buffer->shm_data = data;
 214         buffer->size = size;
 215         buffer->width = width;
 216         buffer->height = height;
 217
 218         fprintf(stdout, "Created shm buffer with width %d, height %d\n", width, height);
 219         return 0;
 220 }
 221
 222 static struct buffer *
 223 get_next_buffer(struct window *window)
 224 {
 225         struct buffer *buffer = NULL;
 226         int ret = 0;
 227
 228         if (window->needs_update_buffer) {
 229                 int i;
 230
 231                 for (i = 0; i < MAX_BUFFER_ALLOC; i++)
 232                         alloc_buffer(window, window->width, window->height);
 233
 234                 window->needs_update_buffer = false;
 235         }
 236
 237         buffer = pick_free_buffer(window);
 238         if (!buffer)
 239                 return NULL;
 240
 241
 242         if (!buffer->buffer) {
 243                 ret = create_shm_buffer(window->display, buffer, window->width,
 244                                         window->height, WL_SHM_FORMAT_XRGB8888);
 245
 246                 if (ret < 0)
 247                         return NULL;
 248
 249                 /* paint the padding */
 250                 memset(buffer->shm_data, 0x00, window->width * window->height * 4);
 251         }
 252
 253         return buffer;
 254 }
 255
 256
 257 static const struct wl_callback_listener frame_listener = {
 258         redraw
 259 };
 260
 261 static void
 262 redraw(void *data, struct wl_callback *callback, uint32_t time)
 263 {
 264         struct window *window = static_cast<struct window *>(data);
 265         struct buffer *buffer;
 266
 267         prune_old_released_buffers(window);
 268
 269         buffer = get_next_buffer(window);
 270         if (!buffer) {
 271                 fprintf(stderr,
 272                                 !callback ? "Failed to create the first buffer.\n" :
 273                                 "Both buffers busy at redraw(). Server bug?\n");
 274                 abort();
 275         }
 276
 277         // do the actual painting
 278         paint_pixels(buffer->shm_data, 0x0, window->width, window->height, time);
 279
 280         wl_surface_attach(window->surface, buffer->buffer, 0, 0);
 281         wl_surface_damage(window->surface, 0, 0, window->width, window->height);
 282
 283         if (callback)
 284                 wl_callback_destroy(callback);
 285
 286         window->callback = wl_surface_frame(window->surface);
 287         wl_callback_add_listener(window->callback, &frame_listener, window);
 288         wl_surface_commit(window->surface);
 289
 290         buffer->busy = 1;
 291 }
 292
 293 static void
 294 shm_format(void *data, struct wl_shm *wl_shm, uint32_t format)
 295 {
 296         struct display *d = static_cast<struct display *>(data);
 297
 298         if (format == WL_SHM_FORMAT_XRGB8888)
 299                 d->has_xrgb = true;
 300 }
 301
 302 static const struct wl_shm_listener shm_listener = {
 303         shm_format
 304 };
 305
 306 static void
 307 xdg_wm_base_ping(void *data, struct xdg_wm_base *shell, uint32_t serial)
 308 {
 309         xdg_wm_base_pong(shell, serial);
 310 }
 311
 312 static const struct xdg_wm_base_listener xdg_wm_base_listener = {
 313         xdg_wm_base_ping,
 314 };
 315
 316 static void
 317 display_handle_geometry(void *data, struct wl_output *wl_output,
 318                         int x, int y, int physical_width, int physical_height,
 319                         int subpixel, const char *make, const char *model, int transform)
 320 {
 321         (void) data;
 322         (void) wl_output;
 323         (void) x;
 324         (void) y;
 325         (void) physical_width;
 326         (void) physical_height;
 327         (void) subpixel;
 328         (void) make;
 329         (void) model;
 330         (void) transform;
 331 }
 332
 333 static void
 334 display_handle_mode(void *data, struct wl_output *wl_output, uint32_t flags,
 335                     int width, int height, int refresh)
 336 {
 337         struct display *d = static_cast<struct display *>(data);
 338
 339         if (wl_output == d->wl_output && (flags & WL_OUTPUT_MODE_CURRENT)) {
 340                 d->output_data.width = width;
 341                 d->output_data.height = height;
 342
 343                 fprintf(stdout, "Found output with width %d and height %d\n",
 344                                 d->output_data.width, d->output_data.height);
 345         }
 346 }
 347
 348 static void
 349 display_handle_scale(void *data, struct wl_output *wl_output, int scale)
 350 {
 351         (void) data;
 352         (void) wl_output;
 353         (void) scale;
 354 }
 355
 356 static void
 357 display_handle_done(void *data, struct wl_output *wl_output)
 358 {
 359         (void) data;
 360         (void) wl_output;
 361 }
 362
 363 static const struct wl_output_listener output_listener = {
 364         display_handle_geometry,
 365         display_handle_mode,
 366         display_handle_done,
 367         display_handle_scale
 368 };
 369
 370
 371 static void
 372 registry_handle_global(void *data, struct wl_registry *registry, uint32_t id,
 373                        const char *interface, uint32_t version)
 374 {
 375         struct display *d = static_cast<struct display *>(data);
 376
 377         if (strcmp(interface, "wl_compositor") == 0) {
 378                 d->wl_compositor =
 379                         static_cast<struct wl_compositor *>(wl_registry_bind(registry, id,
 380                                                     &wl_compositor_interface, 1));
 381         } else if (strcmp(interface, "xdg_wm_base") == 0) {
 382                 d->wm_base = static_cast<struct xdg_wm_base *>(wl_registry_bind(registry,
 383                                 id, &xdg_wm_base_interface, 1));
 384                 xdg_wm_base_add_listener(d->wm_base, &xdg_wm_base_listener, d);
 385         } else if (strcmp(interface, "wl_shm") == 0) {
 386                 d->shm = static_cast<struct wl_shm *>(wl_registry_bind(registry,
 387                                 id, &wl_shm_interface, 1));
 388                 wl_shm_add_listener(d->shm, &shm_listener, d);
 389         } else if (strcmp(interface, "wl_output") == 0) {
 390                 d->wl_output = static_cast<struct wl_output *>(wl_registry_bind(registry, id,
 391                                              &wl_output_interface, 1));
 392                 wl_output_add_listener(d->wl_output, &output_listener, d);
 393         }
 394 }
 395
 396 static void
 397 registry_handle_global_remove(void *data, struct wl_registry *reg, uint32_t id)
 398 {
 399         (void) data;
 400         (void) reg;
 401         (void) id;
 402 }
 403
 404 static const struct wl_registry_listener registry_listener = {
 405         registry_handle_global,
 406         registry_handle_global_remove,
 407 };
 408
 409
 410 static void
 411 error_cb(GstBus *bus, GstMessage *msg, gpointer user_data)
 412 {
 413         struct receiver_data *d =
 414                 static_cast<struct receiver_data *>(user_data);
 415
 416         gchar *debug = NULL;
 417         GError *err = NULL;
 418
 419         gst_message_parse_error(msg, &err, &debug);
 420
 421         g_print("Error: %s\n", err->message);
 422         g_error_free(err);
 423
 424         if (debug) {
 425                 g_print("Debug details: %s\n", debug);
 426                 g_free(debug);
 427         }
 428
 429         gst_element_set_state(d->pipeline, GST_STATE_NULL);
 430 }
 431
 432 static GstBusSyncReply
 433 bus_sync_handler(GstBus *bus, GstMessage *message, gpointer user_data)
 434 {
 435         struct receiver_data *d =
 436                 static_cast<struct receiver_data *>(user_data);
 437
 438         if (gst_is_wl_display_handle_need_context_message(message)) {
 439                 GstContext *context;
 440                 struct wl_display *display_handle = d->window->display->wl_display;
 441
 442                 context = gst_wl_display_handle_context_new(display_handle);
 443                 gst_element_set_context(GST_ELEMENT(GST_MESSAGE_SRC(message)), context);
 444
 445                 goto drop;
 446         } else if (gst_is_video_overlay_prepare_window_handle_message(message)) {
 447                 struct wl_surface *window_handle = d->window->surface;
 448
 449                 /* GST_MESSAGE_SRC(message) will be the overlay object that we
 450                  * have to use. This may be waylandsink, but it may also be
 451                  * playbin. In the latter case, we must make sure to use
 452                  * playbin instead of waylandsink, because playbin resets the
 453                  * window handle and render_rectangle after restarting playback
 454                  * and the actual window size is lost */
 455                 d->overlay = GST_VIDEO_OVERLAY(GST_MESSAGE_SRC(message));
 456
 457                 g_print("setting window handle and size (%d x %d) w %d, h %d\n",
 458                                 d->window->x, d->window->y,
 459                                 d->window->width, d->window->height);
 460
 461                 gst_video_overlay_set_window_handle(d->overlay, (guintptr) window_handle);
 462                 gst_video_overlay_set_render_rectangle(d->overlay,
 463                                                        d->window->x, d->window->y,
 464                                                        d->window->width, d->window->height);
 465
 466                 goto drop;
 467         }
 468         else if (GST_MESSAGE_TYPE(message) == GST_MESSAGE_ERROR) {
 469                 GError* err = NULL;
 470                 gchar* dbg_info = NULL;
 471
 472                 gst_message_parse_error(message, &err, &dbg_info);
 473                 g_printerr("ERROR from element %s: %s code %d\n",
 474                         GST_OBJECT_NAME(message->src), err->message, err->code);
 475                 g_printerr("Debugging info: %s\n", (dbg_info) ? dbg_info : "none");
 476                 gst_pipeline_failed = TRUE;
 477                 g_error_free(err);
 478                 g_free(dbg_info);
 479                 goto drop;
 480         }
 481
 482         return GST_BUS_PASS;
 483
 484 drop:
 485         gst_message_unref(message);
 486         return GST_BUS_DROP;
 487 }
 488
 489 static void
 490 handle_xdg_surface_configure(void *data, struct xdg_surface *surface, uint32_t serial)
 491 {
 492         struct window *window = static_cast<struct window *>(data);
 493
 494         xdg_surface_ack_configure(surface, serial);
 495
 496         if (window->wait_for_configure) {
 497                 redraw(window, NULL, 0);
 498                 window->wait_for_configure = false;
 499         }
 500 }
 501
 502 static const struct xdg_surface_listener xdg_surface_listener = {
 503         handle_xdg_surface_configure,
 504 };
 505
 506 static void
 507 handle_xdg_toplevel_configure(void *data, struct xdg_toplevel *xdg_toplevel,
 508                               int32_t width, int32_t height,
 509                               struct wl_array *states)
 510 {
 511         struct window *window = static_cast<struct window *>(data);
 512         uint32_t *p;
 513
 514         window->fullscreen = 0;
 515         window->maximized = 0;
 516
 517         // use our own macro as C++ can't typecast from (void *) directly
 518         WL_ARRAY_FOR_EACH(p, states, uint32_t *) {
 519                 uint32_t state = *p;
 520                 switch (state) {
 521                 case XDG_TOPLEVEL_STATE_FULLSCREEN:
 522                         window->fullscreen = 1;
 523                         break;
 524                 case XDG_TOPLEVEL_STATE_MAXIMIZED:
 525                         window->maximized = 1;
 526                         break;
 527                 }
 528         }
 529
 530         if (width > 0 && height > 0) {
 531                 if (!window->fullscreen && !window->maximized) {
 532                         window->init_width = width;
 533                         window->init_height = height;
 534                 }
 535                 window->width = width;
 536                 window->height = height;
 537         } else if (!window->fullscreen && !window->maximized) {
 538                 window->width = window->init_width;
 539                 window->height = window->init_height;
 540         }
 541
 542         window->needs_update_buffer = true;
 543
 544 }
 545
 546 static void
 547 handle_xdg_toplevel_close(void *data, struct xdg_toplevel *xdg_toplevel)
 548 {
 549         running = 0;
 550 }
 551
 552 static const struct xdg_toplevel_listener xdg_toplevel_listener = {
 553         handle_xdg_toplevel_configure,
 554         handle_xdg_toplevel_close,
 555 };
 556
 557 static struct window *
 558 create_window(struct display *display, int width, int height, const char *app_id)
 559 {
 560         struct window *window;
 561         int i;
 562
 563         assert(display->wm_base != NULL);
 564
 565         window = static_cast<struct window *>(calloc(1, sizeof(*window)));
 566         if (!window)
 567                 return NULL;
 568
 569         wl_list_init(&window->buffer_list);
 570         window->callback = NULL;
 571         window->display = display;
 572         window->width = width;
 573         window->height = height;
 574         window->surface = wl_compositor_create_surface(display->wl_compositor);
 575
 576         if (display->wm_base) {
 577                 window->xdg_surface =
 578                         xdg_wm_base_get_xdg_surface(display->wm_base, window->surface);
 579                 assert(window->xdg_surface);
 580
 581                 xdg_surface_add_listener(window->xdg_surface,
 582                                          &xdg_surface_listener, window);
 583                 window->xdg_toplevel = xdg_surface_get_toplevel(window->xdg_surface);
 584                 assert(window->xdg_toplevel);
 585
 586                 xdg_toplevel_add_listener(window->xdg_toplevel,
 587                                           &xdg_toplevel_listener, window);
 588
 589                 xdg_toplevel_set_app_id(window->xdg_toplevel, app_id);
 590
 591                 wl_surface_commit(window->surface);
 592                 window->wait_for_configure = true;
 593         }
 594
 595         for (i = 0; i < MAX_BUFFER_ALLOC; i++)
 596                 alloc_buffer(window, window->width, window->height);
 597
 598         return window;
 599 }
 600
 601
 602 static void
 603 destroy_window(struct window *window)
 604 {
 605         struct buffer *buffer, *buffer_next;
 606
 607         if (window->callback)
 608                 wl_callback_destroy(window->callback);
 609
 610         wl_list_for_each_safe(buffer, buffer_next,
 611                               &window->buffer_list, buffer_link)
 612                 destroy_buffer(buffer);
 613
 614         if (window->xdg_toplevel)
 615                 xdg_toplevel_destroy(window->xdg_toplevel);
 616
 617         if (window->xdg_surface)
 618                 xdg_surface_destroy(window->xdg_surface);
 619
 620         wl_surface_destroy(window->surface);
 621         free(window);
 622 }
 623
 624 static void
 625 signal_int(int sig, siginfo_t *si, void *_unused)
 626 {
 627         running = 0;
 628 }
 629
 630 static struct display *
 631 create_display(int argc, char *argv[])
 632 {
 633         struct display *display;
 634
 635         display = static_cast<struct display *>(calloc(1, sizeof(*display)));
 636         if (display == NULL) {
 637                 fprintf(stderr, "out of memory\n");
 638                 exit(1);
 639         }
 640         display->wl_display = wl_display_connect(NULL);
 641         assert(display->wl_display);
 642
 643         display->has_xrgb = false;
 644         display->wl_registry = wl_display_get_registry(display->wl_display);
 645
 646         wl_registry_add_listener(display->wl_registry, &registry_listener, display);
 647         wl_display_roundtrip(display->wl_display);
 648
 649         if (display->shm == NULL) {
 650                 fprintf(stderr, "No wl_shm global\n");
 651                 return NULL;
 652         }
 653
 654         wl_display_roundtrip(display->wl_display);
 655
 656         if (!display->has_xrgb) {
 657                 fprintf(stderr, "WL_SHM_FORMAT_XRGB32 not available\n");
 658                 return NULL;
 659         }
 660
 661         return display;
 662 }
 663
 664 static void
 665 destroy_display(struct display *display)
 666 {
 667         if (display->shm)
 668                 wl_shm_destroy(display->shm);
 669
 670         if (display->wm_base)
 671                 xdg_wm_base_destroy(display->wm_base);
 672
 673         if (display->wl_compositor)
 674                 wl_compositor_destroy(display->wl_compositor);
 675
 676         wl_registry_destroy(display->wl_registry);
 677         wl_display_flush(display->wl_display);
 678         wl_display_disconnect(display->wl_display);
 679         free(display);
 680 }
 681
 682 // stringify the un-quoted string to quoted C string
 683 #define xstr(a) str(a)
 684 #define str(a) #a
 685
 686 GstElement* create_pipeline(int* argc, char** argv[])
 687 {
 688         GError *error = NULL;
 689         const char *camera_device = NULL;
 690         const char *width_str = NULL;
 691         const char *height_str = NULL;
 692         int width;
 693         int height;
 694
 695         // pipewire is default.
 696         char *v4l2_path = getenv("ENABLE_V4L2_PATH");
 697         bool v4l2 = false;
 698
 699         char pipeline_str[1024];
 700
 701         camera_device = getenv("DEFAULT_V4L2_DEVICE");
 702         if (!camera_device)
 703                 camera_device = get_first_camera_device();
 704
 705         width_str = getenv("DEFAULT_DEVICE_WIDTH");
 706         if (!width_str)
 707                 width = WINDOW_WIDTH_SIZE;
 708         else
 709                 width = atoi(width_str);
 710
 711         height_str = getenv("DEFAULT_DEVICE_HEIGHT");
 712         if (!height_str)
 713                 height = WINDOW_HEIGHT_SIZE;
 714         else
 715                 height = atoi(height_str);
 716
 717         if (v4l2_path == NULL)
 718                 v4l2 = false;
 719         else if (g_str_equal(v4l2_path, "yes") || g_str_equal(v4l2_path, "true"))
 720                 v4l2 = true;
 721
 722         memset(pipeline_str, 0, sizeof(pipeline_str));
 723
 724         if (v4l2)
 725                 snprintf(pipeline_str, sizeof(pipeline_str), "v4l2src device=%s ! video/x-raw,width=%d,height=%d ! waylandsink",
 726                         camera_device, width, height);
 727         else if (gst_pipeline_failed == TRUE) {
 728                 snprintf(pipeline_str, sizeof(pipeline_str), "filesrc location=%s/still-image.jpg ! decodebin ! videoconvert ! imagefreeze ! waylandsink fullscreen=true",
 729                         xstr(APP_DATA_PATH));
 730                 fallback_gst_pipeline_tried = TRUE;
 731         }
 732         else {
 733                 snprintf(pipeline_str, sizeof(pipeline_str), "pipewiresrc ! video/x-raw,width=%d,height=%d ! waylandsink", width,
 734                         height);
 735         }
 736
 737         fprintf(stdout, "Using pipeline: %s\n", pipeline_str);
 738
 739         GstElement *pipeline = gst_parse_launch(pipeline_str, &error);
 740
 741         if (error || !pipeline) {
 742                 fprintf(stderr, "gstreamer pipeline construction failed!\n");
 743                 free(argv);
 744                 return NULL;
 745         }
 746
 747         return pipeline;
 748 }
 749
 750 int main(int argc, char* argv[])
 751 {
 752         int ret = 0;
 753         struct sigaction sa;
 754         struct receiver_data receiver_data = {};
 755         struct display* display;
 756         struct window* window;
 757         const char* app_id = "camera-gstreamer";
 758
 759         sa.sa_sigaction = signal_int;
 760         sigemptyset(&sa.sa_mask);
 761         sa.sa_flags = SA_RESETHAND | SA_SIGINFO;
 762         sigaction(SIGINT, &sa, NULL);
 763
 764         int gargc = 2;
 765         char** gargv = static_cast<char**>(calloc(2, sizeof(char*)));
 766
 767         gargv[0] = strdup(argv[0]);
 768         gargv[1] = strdup("--gst-debug-level=2");
 769
 770         setbuf(stdout, NULL);
 771
 772         gst_init(&gargc, &gargv);
 773
 774         receiver_data.pipeline = create_pipeline(&gargc, &gargv);
 775
 776         if (!receiver_data.pipeline)
 777                 return EXIT_FAILURE;
 778
 779         display = create_display(argc, argv);
 780         if (!display)
 781                 return -1;
 782
 783         // we use the role to set a correspondence between the top level
 784         // surface and our application, with the previous call letting the
 785         // compositor know that we're one and the same
 786         window = create_window(display, WINDOW_WIDTH_SIZE, WINDOW_HEIGHT_SIZE, app_id);
 787
 788         if (!window) {
 789                 free(gargv);
 790                 return EXIT_FAILURE;
 791         }
 792
 793         window->display = display;
 794         receiver_data.window = window;
 795
 796         /* Initialise damage to full surface, so the padding gets painted */
 797         wl_surface_damage(window->surface, 0, 0,
 798                           window->width, window->height);
 799
 800         if (!window->wait_for_configure) {
 801                 redraw(window, NULL, 0);
 802         }
 803
 804         GstBus *bus = gst_element_get_bus(receiver_data.pipeline);
 805         gst_bus_add_signal_watch(bus);
 806
 807         g_signal_connect(bus, "message::error", G_CALLBACK(error_cb), &receiver_data);
 808         gst_bus_set_sync_handler(bus, bus_sync_handler, &receiver_data, NULL);
 809         gst_object_unref(bus);
 810
 811         gst_element_set_state(receiver_data.pipeline, GST_STATE_PLAYING);
 812         fprintf(stdout, "gstreamer pipeline running\n");
 813
 814         // run the application
 815         while (running && ret != -1) {
 816                 ret = wl_display_dispatch(display->wl_display);
 817                 if (gst_pipeline_failed && fallback_gst_pipeline_tried == FALSE) {
 818                         gst_element_set_state(receiver_data.pipeline, GST_STATE_NULL);
 819                         gst_object_unref(receiver_data.pipeline);
 820                         /* retry with fallback pipeline */
 821                         receiver_data.pipeline = create_pipeline(&gargc, &gargv);
 822                         GstBus *bus = gst_element_get_bus(receiver_data.pipeline);
 823                         gst_bus_add_signal_watch(bus);
 824                         g_signal_connect(bus, "message::error", G_CALLBACK(error_cb), &receiver_data);
 825                         gst_bus_set_sync_handler(bus, bus_sync_handler, &receiver_data, NULL);
 826                         gst_object_unref(bus);
 827                         gst_element_set_state(receiver_data.pipeline, GST_STATE_PLAYING);
 828                 }
 829         }
 830         gst_element_set_state(receiver_data.pipeline, GST_STATE_NULL);
 831         gst_object_unref(receiver_data.pipeline);
 832
 833         destroy_window(window);
 834         destroy_display(display);
 835         free(gargv);
 836
 837         return ret;
 838 }