FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavdevice/xcbgrab.c
Date: 2024-02-29 09:57:37
Exec Total Coverage
Lines: 0 464 0.0%
Functions: 0 21 0.0%
Branches: 0 188 0.0%

Line Branch Exec Source
1 /*
2 * XCB input grabber
3 * Copyright (C) 2014 Luca Barbato <lu_zero@gentoo.org>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "config.h"
23
24 #include <stdlib.h>
25 #include <string.h>
26 #include <xcb/xcb.h>
27
28 #if CONFIG_LIBXCB_XFIXES
29 #include <xcb/xfixes.h>
30 #endif
31
32 #if CONFIG_LIBXCB_SHM
33 #include <sys/shm.h>
34 #include <xcb/shm.h>
35 #endif
36
37 #if CONFIG_LIBXCB_SHAPE
38 #include <xcb/shape.h>
39 #endif
40
41 #include "libavutil/internal.h"
42 #include "libavutil/mathematics.h"
43 #include "libavutil/opt.h"
44 #include "libavutil/parseutils.h"
45 #include "libavutil/time.h"
46
47 #include "libavformat/avformat.h"
48 #include "libavformat/internal.h"
49
50 typedef struct XCBGrabContext {
51 const AVClass *class;
52
53 xcb_connection_t *conn;
54 xcb_screen_t *screen;
55 xcb_window_t window;
56 #if CONFIG_LIBXCB_SHM
57 AVBufferPool *shm_pool;
58 #endif
59 int64_t time_frame;
60 AVRational time_base;
61 int64_t frame_duration;
62
63 xcb_window_t window_id;
64 int x, y;
65 int width, height;
66 int frame_size;
67 int bpp;
68
69 int draw_mouse;
70 int follow_mouse;
71 int show_region;
72 int region_border;
73 int centered;
74 int select_region;
75
76 const char *framerate;
77
78 int has_shm;
79 } XCBGrabContext;
80
81 #define FOLLOW_CENTER -1
82
83 #define OFFSET(x) offsetof(XCBGrabContext, x)
84 #define D AV_OPT_FLAG_DECODING_PARAM
85 static const AVOption options[] = {
86 { "window_id", "Window to capture.", OFFSET(window_id), AV_OPT_TYPE_INT, { .i64 = XCB_NONE }, 0, UINT32_MAX, D },
87 { "x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
88 { "y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
89 { "grab_x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
90 { "grab_y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
91 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL }, 0, 0, D },
92 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc" }, 0, 0, D },
93 { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, D },
94 { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
95 OFFSET(follow_mouse), AV_OPT_TYPE_INT, { .i64 = 0 }, FOLLOW_CENTER, INT_MAX, D, .unit = "follow_mouse" },
96 { "centered", "Keep the mouse pointer at the center of grabbing region when following.", 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, INT_MIN, INT_MAX, D, .unit = "follow_mouse" },
97 { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, D },
98 { "region_border", "Set the region border thickness.", OFFSET(region_border), AV_OPT_TYPE_INT, { .i64 = 3 }, 1, 128, D },
99 { "select_region", "Select the grabbing region graphically using the pointer.", OFFSET(select_region), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, D },
100 { NULL },
101 };
102
103 static const AVClass xcbgrab_class = {
104 .class_name = "xcbgrab indev",
105 .item_name = av_default_item_name,
106 .option = options,
107 .version = LIBAVUTIL_VERSION_INT,
108 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
109 };
110
111 static int xcbgrab_reposition(AVFormatContext *s,
112 xcb_query_pointer_reply_t *p,
113 xcb_get_geometry_reply_t *geo)
114 {
115 XCBGrabContext *c = s->priv_data;
116 int x = c->x, y = c->y;
117 int w = c->width, h = c->height, f = c->follow_mouse;
118 int p_x, p_y;
119
120 if (!p || !geo)
121 return AVERROR(EIO);
122
123 p_x = p->win_x;
124 p_y = p->win_y;
125
126 if (f == FOLLOW_CENTER) {
127 x = p_x - w / 2;
128 y = p_y - h / 2;
129 } else {
130 int left = x + f;
131 int right = x + w - f;
132 int top = y + f;
133 int bottom = y + h - f;
134 if (p_x > right) {
135 x += p_x - right;
136 } else if (p_x < left) {
137 x -= left - p_x;
138 }
139 if (p_y > bottom) {
140 y += p_y - bottom;
141 } else if (p_y < top) {
142 y -= top - p_y;
143 }
144 }
145
146 c->x = FFMIN(FFMAX(0, x), geo->width - w);
147 c->y = FFMIN(FFMAX(0, y), geo->height - h);
148
149 return 0;
150 }
151
152 static void xcbgrab_image_reply_free(void *opaque, uint8_t *data)
153 {
154 free(opaque);
155 }
156
157 static int xcbgrab_frame(AVFormatContext *s, AVPacket *pkt)
158 {
159 XCBGrabContext *c = s->priv_data;
160 xcb_get_image_cookie_t iq;
161 xcb_get_image_reply_t *img;
162 xcb_drawable_t drawable = c->window_id;
163 xcb_generic_error_t *e = NULL;
164 uint8_t *data;
165 int length;
166
167 iq = xcb_get_image(c->conn, XCB_IMAGE_FORMAT_Z_PIXMAP, drawable,
168 c->x, c->y, c->width, c->height, ~0);
169
170 img = xcb_get_image_reply(c->conn, iq, &e);
171
172 if (e) {
173 av_log(s, AV_LOG_ERROR,
174 "Cannot get the image data "
175 "event_error: response_type:%u error_code:%u "
176 "sequence:%u resource_id:%u minor_code:%u major_code:%u.\n",
177 e->response_type, e->error_code,
178 e->sequence, e->resource_id, e->minor_code, e->major_code);
179 free(e);
180 return AVERROR(EACCES);
181 }
182
183 if (!img)
184 return AVERROR(EAGAIN);
185
186 data = xcb_get_image_data(img);
187 length = xcb_get_image_data_length(img);
188
189 pkt->buf = av_buffer_create(data, length, xcbgrab_image_reply_free, img, 0);
190 if (!pkt->buf) {
191 free(img);
192 return AVERROR(ENOMEM);
193 }
194
195 pkt->data = data;
196 pkt->size = length;
197
198 return 0;
199 }
200
201 static int64_t wait_frame(AVFormatContext *s, AVPacket *pkt)
202 {
203 XCBGrabContext *c = s->priv_data;
204 int64_t curtime, delay;
205
206 c->time_frame += c->frame_duration;
207
208 for (;;) {
209 curtime = av_gettime_relative();
210 delay = c->time_frame - curtime;
211 if (delay <= 0)
212 break;
213 av_usleep(delay);
214 }
215
216 return curtime;
217 }
218
219 #if CONFIG_LIBXCB_SHM
220 static int check_shm(xcb_connection_t *conn)
221 {
222 xcb_shm_query_version_cookie_t cookie = xcb_shm_query_version(conn);
223 xcb_shm_query_version_reply_t *reply;
224
225 reply = xcb_shm_query_version_reply(conn, cookie, NULL);
226 if (reply) {
227 free(reply);
228 return 1;
229 }
230
231 return 0;
232 }
233
234 static void free_shm_buffer(void *opaque, uint8_t *data)
235 {
236 shmdt(data);
237 }
238
239 static AVBufferRef *allocate_shm_buffer(void *opaque, size_t size)
240 {
241 xcb_connection_t *conn = opaque;
242 xcb_shm_seg_t segment;
243 AVBufferRef *ref;
244 uint8_t *data;
245 int id;
246
247 id = shmget(IPC_PRIVATE, size, IPC_CREAT | 0777);
248 if (id == -1)
249 return NULL;
250
251 segment = xcb_generate_id(conn);
252 xcb_shm_attach(conn, segment, id, 0);
253 data = shmat(id, NULL, 0);
254 shmctl(id, IPC_RMID, 0);
255 if ((intptr_t)data == -1 || !data)
256 return NULL;
257
258 ref = av_buffer_create(data, size, free_shm_buffer, (void *)(ptrdiff_t)segment, 0);
259 if (!ref)
260 shmdt(data);
261
262 return ref;
263 }
264
265 static int xcbgrab_frame_shm(AVFormatContext *s, AVPacket *pkt)
266 {
267 XCBGrabContext *c = s->priv_data;
268 xcb_shm_get_image_cookie_t iq;
269 xcb_shm_get_image_reply_t *img;
270 xcb_drawable_t drawable = c->window_id;
271 xcb_generic_error_t *e = NULL;
272 AVBufferRef *buf;
273 xcb_shm_seg_t segment;
274
275 buf = av_buffer_pool_get(c->shm_pool);
276 if (!buf) {
277 av_log(s, AV_LOG_ERROR, "Could not get shared memory buffer.\n");
278 return AVERROR(ENOMEM);
279 }
280 segment = (xcb_shm_seg_t)(uintptr_t)av_buffer_pool_buffer_get_opaque(buf);
281
282 iq = xcb_shm_get_image(c->conn, drawable,
283 c->x, c->y, c->width, c->height, ~0,
284 XCB_IMAGE_FORMAT_Z_PIXMAP, segment, 0);
285 img = xcb_shm_get_image_reply(c->conn, iq, &e);
286
287 xcb_flush(c->conn);
288
289 if (e) {
290 av_log(s, AV_LOG_ERROR,
291 "Cannot get the image data "
292 "event_error: response_type:%u error_code:%u "
293 "sequence:%u resource_id:%u minor_code:%u major_code:%u.\n",
294 e->response_type, e->error_code,
295 e->sequence, e->resource_id, e->minor_code, e->major_code);
296
297 free(e);
298 av_buffer_unref(&buf);
299 return AVERROR(EACCES);
300 }
301
302 free(img);
303
304 pkt->buf = buf;
305 pkt->data = buf->data;
306 pkt->size = c->frame_size;
307
308 return 0;
309 }
310 #endif /* CONFIG_LIBXCB_SHM */
311
312 #if CONFIG_LIBXCB_XFIXES
313 static int check_xfixes(xcb_connection_t *conn)
314 {
315 xcb_xfixes_query_version_cookie_t cookie;
316 xcb_xfixes_query_version_reply_t *reply;
317
318 cookie = xcb_xfixes_query_version(conn, XCB_XFIXES_MAJOR_VERSION,
319 XCB_XFIXES_MINOR_VERSION);
320 reply = xcb_xfixes_query_version_reply(conn, cookie, NULL);
321
322 if (reply) {
323 free(reply);
324 return 1;
325 }
326 return 0;
327 }
328
329 #define BLEND(target, source, alpha) \
330 (target) + ((source) * (255 - (alpha)) + 255 / 2) / 255
331
332 static void xcbgrab_draw_mouse(AVFormatContext *s, AVPacket *pkt,
333 xcb_query_pointer_reply_t *p,
334 xcb_get_geometry_reply_t *geo,
335 int win_x, int win_y)
336 {
337 XCBGrabContext *gr = s->priv_data;
338 uint32_t *cursor;
339 uint8_t *image = pkt->data;
340 int stride = gr->bpp / 8;
341 xcb_xfixes_get_cursor_image_cookie_t cc;
342 xcb_xfixes_get_cursor_image_reply_t *ci;
343 int cx, cy, x, y, w, h, c_off, i_off;
344
345 cc = xcb_xfixes_get_cursor_image(gr->conn);
346 ci = xcb_xfixes_get_cursor_image_reply(gr->conn, cc, NULL);
347 if (!ci)
348 return;
349
350 cursor = xcb_xfixes_get_cursor_image_cursor_image(ci);
351 if (!cursor)
352 return;
353
354 cx = ci->x - ci->xhot;
355 cy = ci->y - ci->yhot;
356
357 x = FFMAX(cx, win_x + gr->x);
358 y = FFMAX(cy, win_y + gr->y);
359
360 w = FFMIN(cx + ci->width, win_x + gr->x + gr->width) - x;
361 h = FFMIN(cy + ci->height, win_y + gr->y + gr->height) - y;
362
363 c_off = x - cx;
364 i_off = x - gr->x - win_x;
365
366 cursor += (y - cy) * ci->width;
367 image += (y - gr->y - win_y) * gr->width * stride;
368
369 for (y = 0; y < h; y++) {
370 cursor += c_off;
371 image += i_off * stride;
372 for (x = 0; x < w; x++, cursor++, image += stride) {
373 int r, g, b, a;
374
375 r = *cursor & 0xff;
376 g = (*cursor >> 8) & 0xff;
377 b = (*cursor >> 16) & 0xff;
378 a = (*cursor >> 24) & 0xff;
379
380 if (!a)
381 continue;
382
383 if (a == 255) {
384 image[0] = r;
385 image[1] = g;
386 image[2] = b;
387 } else {
388 image[0] = BLEND(r, image[0], a);
389 image[1] = BLEND(g, image[1], a);
390 image[2] = BLEND(b, image[2], a);
391 }
392
393 }
394 cursor += ci->width - w - c_off;
395 image += (gr->width - w - i_off) * stride;
396 }
397
398 free(ci);
399 }
400 #endif /* CONFIG_LIBXCB_XFIXES */
401
402 static void xcbgrab_update_region(AVFormatContext *s, int win_x, int win_y)
403 {
404 XCBGrabContext *c = s->priv_data;
405 const uint32_t args[] = { win_x + c->x - c->region_border,
406 win_y + c->y - c->region_border };
407
408 xcb_configure_window(c->conn,
409 c->window,
410 XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y,
411 args);
412 }
413
414 static int xcbgrab_read_packet(AVFormatContext *s, AVPacket *pkt)
415 {
416 XCBGrabContext *c = s->priv_data;
417 xcb_query_pointer_cookie_t pc;
418 xcb_get_geometry_cookie_t gc;
419 xcb_translate_coordinates_cookie_t tc;
420 xcb_query_pointer_reply_t *p = NULL;
421 xcb_get_geometry_reply_t *geo = NULL;
422 xcb_translate_coordinates_reply_t *translate = NULL;
423 int ret = 0;
424 int64_t pts;
425 int win_x = 0, win_y = 0;
426
427 wait_frame(s, pkt);
428 pts = av_gettime();
429
430 if (c->follow_mouse || c->draw_mouse) {
431 pc = xcb_query_pointer(c->conn, c->window_id);
432 gc = xcb_get_geometry(c->conn, c->window_id);
433 p = xcb_query_pointer_reply(c->conn, pc, NULL);
434 if (!p) {
435 av_log(s, AV_LOG_ERROR, "Failed to query xcb pointer\n");
436 return AVERROR_EXTERNAL;
437 }
438 geo = xcb_get_geometry_reply(c->conn, gc, NULL);
439 if (!geo) {
440 av_log(s, AV_LOG_ERROR, "Failed to get xcb geometry\n");
441 free(p);
442 return AVERROR_EXTERNAL;
443 }
444 }
445 if (c->window_id != c->screen->root) {
446 tc = xcb_translate_coordinates(c->conn, c->window_id, c->screen->root, 0, 0);
447 translate = xcb_translate_coordinates_reply(c->conn, tc, NULL);
448 if (!translate) {
449 free(p);
450 free(geo);
451 av_log(s, AV_LOG_ERROR, "Failed to translate xcb geometry\n");
452 return AVERROR_EXTERNAL;
453 }
454 win_x = translate->dst_x;
455 win_y = translate->dst_y;
456 free(translate);
457 }
458
459 if (c->follow_mouse && p->same_screen)
460 xcbgrab_reposition(s, p, geo);
461
462 if (c->show_region)
463 xcbgrab_update_region(s, win_x, win_y);
464
465 #if CONFIG_LIBXCB_SHM
466 if (c->has_shm && xcbgrab_frame_shm(s, pkt) < 0) {
467 av_log(s, AV_LOG_WARNING, "Continuing without shared memory.\n");
468 c->has_shm = 0;
469 }
470 #endif
471 if (!c->has_shm)
472 ret = xcbgrab_frame(s, pkt);
473 pkt->dts = pkt->pts = pts;
474 pkt->duration = c->frame_duration;
475
476 #if CONFIG_LIBXCB_XFIXES
477 if (ret >= 0 && c->draw_mouse && p->same_screen)
478 xcbgrab_draw_mouse(s, pkt, p, geo, win_x, win_y);
479 #endif
480
481 free(p);
482 free(geo);
483
484 return ret;
485 }
486
487 static av_cold int xcbgrab_read_close(AVFormatContext *s)
488 {
489 XCBGrabContext *ctx = s->priv_data;
490
491 #if CONFIG_LIBXCB_SHM
492 av_buffer_pool_uninit(&ctx->shm_pool);
493 #endif
494
495 xcb_disconnect(ctx->conn);
496
497 return 0;
498 }
499
500 static xcb_screen_t *get_screen(const xcb_setup_t *setup, int screen_num)
501 {
502 xcb_screen_iterator_t it = xcb_setup_roots_iterator(setup);
503 xcb_screen_t *screen = NULL;
504
505 for (; it.rem > 0; xcb_screen_next (&it)) {
506 if (!screen_num) {
507 screen = it.data;
508 break;
509 }
510
511 screen_num--;
512 }
513
514 return screen;
515 }
516
517 static int pixfmt_from_pixmap_format(AVFormatContext *s, int depth,
518 int *pix_fmt, int *bpp)
519 {
520 XCBGrabContext *c = s->priv_data;
521 const xcb_setup_t *setup = xcb_get_setup(c->conn);
522 const xcb_format_t *fmt = xcb_setup_pixmap_formats(setup);
523 int length = xcb_setup_pixmap_formats_length(setup);
524
525 *pix_fmt = 0;
526
527 while (length--) {
528 if (fmt->depth == depth) {
529 switch (depth) {
530 case 32:
531 if (fmt->bits_per_pixel == 32)
532 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
533 AV_PIX_FMT_BGR0 : AV_PIX_FMT_0RGB;
534 break;
535 case 24:
536 if (fmt->bits_per_pixel == 32)
537 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
538 AV_PIX_FMT_BGR0 : AV_PIX_FMT_0RGB;
539 else if (fmt->bits_per_pixel == 24)
540 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
541 AV_PIX_FMT_BGR24 : AV_PIX_FMT_RGB24;
542 break;
543 case 16:
544 if (fmt->bits_per_pixel == 16)
545 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
546 AV_PIX_FMT_RGB565LE : AV_PIX_FMT_RGB565BE;
547 break;
548 case 15:
549 if (fmt->bits_per_pixel == 16)
550 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
551 AV_PIX_FMT_RGB555LE : AV_PIX_FMT_RGB555BE;
552 break;
553 case 8:
554 if (fmt->bits_per_pixel == 8)
555 *pix_fmt = AV_PIX_FMT_RGB8;
556 break;
557 }
558 }
559
560 if (*pix_fmt) {
561 *bpp = fmt->bits_per_pixel;
562 return 0;
563 }
564
565 fmt++;
566 }
567 avpriv_report_missing_feature(s, "Mapping this pixmap format");
568
569 return AVERROR_PATCHWELCOME;
570 }
571
572 static int create_stream(AVFormatContext *s)
573 {
574 XCBGrabContext *c = s->priv_data;
575 AVStream *st = avformat_new_stream(s, NULL);
576 xcb_get_geometry_cookie_t gc;
577 xcb_get_geometry_reply_t *geo;
578 int64_t frame_size_bits;
579 int ret;
580
581 if (!st)
582 return AVERROR(ENOMEM);
583
584 ret = av_parse_video_rate(&st->avg_frame_rate, c->framerate);
585 if (ret < 0)
586 return ret;
587
588 avpriv_set_pts_info(st, 64, 1, 1000000);
589
590 gc = xcb_get_geometry(c->conn, c->window_id);
591 geo = xcb_get_geometry_reply(c->conn, gc, NULL);
592 if (!geo) {
593 av_log(s, AV_LOG_ERROR, "Can't find window '0x%x', aborting.\n", c->window_id);
594 return AVERROR_EXTERNAL;
595 }
596
597 if (!c->width || !c->height) {
598 c->width = geo->width;
599 c->height = geo->height;
600 }
601
602 if (c->x + c->width > geo->width ||
603 c->y + c->height > geo->height) {
604 av_log(s, AV_LOG_ERROR,
605 "Capture area %dx%d at position %d.%d "
606 "outside the screen size %dx%d\n",
607 c->width, c->height,
608 c->x, c->y,
609 geo->width, geo->height);
610 free(geo);
611 return AVERROR(EINVAL);
612 }
613
614 c->time_base = (AVRational){ st->avg_frame_rate.den,
615 st->avg_frame_rate.num };
616 c->frame_duration = av_rescale_q(1, c->time_base, AV_TIME_BASE_Q);
617 c->time_frame = av_gettime_relative();
618
619 ret = pixfmt_from_pixmap_format(s, geo->depth, &st->codecpar->format, &c->bpp);
620 free(geo);
621 if (ret < 0)
622 return ret;
623
624 frame_size_bits = (int64_t)c->width * c->height * c->bpp;
625 if (frame_size_bits / 8 + AV_INPUT_BUFFER_PADDING_SIZE > INT_MAX) {
626 av_log(s, AV_LOG_ERROR, "Captured area is too large\n");
627 return AVERROR_PATCHWELCOME;
628 }
629 c->frame_size = frame_size_bits / 8;
630
631 #if CONFIG_LIBXCB_SHM
632 c->shm_pool = av_buffer_pool_init2(c->frame_size + AV_INPUT_BUFFER_PADDING_SIZE,
633 c->conn, allocate_shm_buffer, NULL);
634 if (!c->shm_pool)
635 return AVERROR(ENOMEM);
636 #endif
637
638 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
639 st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
640 st->codecpar->width = c->width;
641 st->codecpar->height = c->height;
642 st->codecpar->bit_rate = av_rescale(frame_size_bits, st->avg_frame_rate.num, st->avg_frame_rate.den);
643
644 return ret;
645 }
646
647 static void draw_rectangle(AVFormatContext *s)
648 {
649 XCBGrabContext *c = s->priv_data;
650 xcb_gcontext_t gc = xcb_generate_id(c->conn);
651 uint32_t mask = XCB_GC_FOREGROUND |
652 XCB_GC_BACKGROUND |
653 XCB_GC_LINE_WIDTH |
654 XCB_GC_LINE_STYLE |
655 XCB_GC_FILL_STYLE;
656 uint32_t values[] = { c->screen->black_pixel,
657 c->screen->white_pixel,
658 c->region_border,
659 XCB_LINE_STYLE_DOUBLE_DASH,
660 XCB_FILL_STYLE_SOLID };
661 xcb_rectangle_t r = { 1, 1,
662 c->width + c->region_border * 2 - 3,
663 c->height + c->region_border * 2 - 3 };
664
665 xcb_create_gc(c->conn, gc, c->window, mask, values);
666
667 xcb_poly_rectangle(c->conn, c->window, gc, 1, &r);
668 }
669
670 static void setup_window(AVFormatContext *s)
671 {
672 XCBGrabContext *c = s->priv_data;
673 uint32_t mask = XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK;
674 uint32_t values[] = { 1,
675 XCB_EVENT_MASK_EXPOSURE |
676 XCB_EVENT_MASK_STRUCTURE_NOTIFY };
677 av_unused xcb_rectangle_t rect = { 0, 0, c->width, c->height };
678
679 c->window = xcb_generate_id(c->conn);
680
681 xcb_create_window(c->conn, XCB_COPY_FROM_PARENT,
682 c->window,
683 c->screen->root,
684 c->x - c->region_border,
685 c->y - c->region_border,
686 c->width + c->region_border * 2,
687 c->height + c->region_border * 2,
688 0,
689 XCB_WINDOW_CLASS_INPUT_OUTPUT,
690 XCB_COPY_FROM_PARENT,
691 mask, values);
692
693 #if CONFIG_LIBXCB_SHAPE
694 xcb_shape_rectangles(c->conn, XCB_SHAPE_SO_SUBTRACT,
695 XCB_SHAPE_SK_BOUNDING, XCB_CLIP_ORDERING_UNSORTED,
696 c->window,
697 c->region_border, c->region_border,
698 1, &rect);
699 #endif
700
701 xcb_map_window(c->conn, c->window);
702
703 draw_rectangle(s);
704 }
705
706 #define CROSSHAIR_CURSOR 34
707
708 static xcb_rectangle_t rectangle_from_corners(xcb_point_t *corner_a,
709 xcb_point_t *corner_b)
710 {
711 xcb_rectangle_t rectangle;
712 rectangle.x = FFMIN(corner_a->x, corner_b->x);
713 rectangle.y = FFMIN(corner_a->y, corner_b->y);
714 rectangle.width = FFABS(corner_a->x - corner_b->x);
715 rectangle.height = FFABS(corner_a->y - corner_b->y);
716 return rectangle;
717 }
718
719 static int select_region(AVFormatContext *s)
720 {
721 XCBGrabContext *c = s->priv_data;
722 xcb_connection_t *conn = c->conn;
723 xcb_screen_t *screen = c->screen;
724
725 int ret = 0, done = 0, was_pressed = 0;
726 xcb_cursor_t cursor;
727 xcb_font_t cursor_font;
728 xcb_point_t press_position;
729 xcb_generic_event_t *event;
730 xcb_rectangle_t rectangle = { 0 };
731 xcb_grab_pointer_reply_t *reply;
732 xcb_grab_pointer_cookie_t cookie;
733
734 xcb_window_t root_window = screen->root;
735 xcb_gcontext_t gc = xcb_generate_id(conn);
736 uint32_t mask = XCB_GC_FUNCTION | XCB_GC_SUBWINDOW_MODE;
737 uint32_t values[] = { XCB_GX_INVERT, XCB_SUBWINDOW_MODE_INCLUDE_INFERIORS };
738 xcb_create_gc(conn, gc, root_window, mask, values);
739
740 cursor_font = xcb_generate_id(conn);
741 xcb_open_font(conn, cursor_font, strlen("cursor"), "cursor");
742 cursor = xcb_generate_id(conn);
743 xcb_create_glyph_cursor(conn, cursor, cursor_font, cursor_font,
744 CROSSHAIR_CURSOR, CROSSHAIR_CURSOR + 1, 0, 0, 0,
745 0xFFFF, 0xFFFF, 0xFFFF);
746 cookie = xcb_grab_pointer(conn, 0, root_window,
747 XCB_EVENT_MASK_BUTTON_PRESS |
748 XCB_EVENT_MASK_BUTTON_RELEASE |
749 XCB_EVENT_MASK_BUTTON_MOTION,
750 XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC,
751 root_window, cursor, XCB_CURRENT_TIME);
752 reply = xcb_grab_pointer_reply(conn, cookie, NULL);
753 if (!reply || reply->status != XCB_GRAB_STATUS_SUCCESS) {
754 av_log(s, AV_LOG_ERROR,
755 "Failed to select region. Could not grab pointer.\n");
756 ret = AVERROR(EIO);
757 free(reply);
758 goto fail;
759 }
760 free(reply);
761
762 xcb_grab_server(conn);
763
764 while (!done && (event = xcb_wait_for_event(conn))) {
765 switch (event->response_type & ~0x80) {
766 case XCB_BUTTON_PRESS: {
767 xcb_button_press_event_t *press = (xcb_button_press_event_t *)event;
768 press_position = (xcb_point_t){ press->event_x, press->event_y };
769 rectangle.x = press_position.x;
770 rectangle.y = press_position.y;
771 xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
772 was_pressed = 1;
773 break;
774 }
775 case XCB_MOTION_NOTIFY: {
776 if (was_pressed) {
777 xcb_motion_notify_event_t *motion =
778 (xcb_motion_notify_event_t *)event;
779 xcb_point_t cursor_position = { motion->event_x, motion->event_y };
780 xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
781 rectangle = rectangle_from_corners(&press_position, &cursor_position);
782 xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
783 }
784 break;
785 }
786 case XCB_BUTTON_RELEASE: {
787 xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
788 done = 1;
789 break;
790 }
791 default:
792 break;
793 }
794 xcb_flush(conn);
795 free(event);
796 }
797 c->width = rectangle.width;
798 c->height = rectangle.height;
799 if (c->width && c->height) {
800 c->x = rectangle.x;
801 c->y = rectangle.y;
802 } else {
803 c->x = 0;
804 c->y = 0;
805 }
806 xcb_ungrab_server(conn);
807 xcb_ungrab_pointer(conn, XCB_CURRENT_TIME);
808 xcb_flush(conn);
809
810 fail:
811 xcb_free_cursor(conn, cursor);
812 xcb_close_font(conn, cursor_font);
813 xcb_free_gc(conn, gc);
814 return ret;
815 }
816
817 static av_cold int xcbgrab_read_header(AVFormatContext *s)
818 {
819 XCBGrabContext *c = s->priv_data;
820 int screen_num, ret;
821 const xcb_setup_t *setup;
822 char *display_name = av_strdup(s->url);
823
824 if (!display_name)
825 return AVERROR(ENOMEM);
826
827 if (!sscanf(s->url, "%[^+]+%d,%d", display_name, &c->x, &c->y)) {
828 *display_name = 0;
829 sscanf(s->url, "+%d,%d", &c->x, &c->y);
830 }
831
832 c->conn = xcb_connect(display_name[0] ? display_name : NULL, &screen_num);
833 av_freep(&display_name);
834
835 if ((ret = xcb_connection_has_error(c->conn))) {
836 av_log(s, AV_LOG_ERROR, "Cannot open display %s, error %d.\n",
837 s->url[0] ? s->url : "default", ret);
838 return AVERROR(EIO);
839 }
840
841 setup = xcb_get_setup(c->conn);
842
843 c->screen = get_screen(setup, screen_num);
844 if (!c->screen) {
845 av_log(s, AV_LOG_ERROR, "The screen %d does not exist.\n",
846 screen_num);
847 xcbgrab_read_close(s);
848 return AVERROR(EIO);
849 }
850
851 if (c->window_id == XCB_NONE)
852 c->window_id = c->screen->root;
853 else {
854 if (c->select_region) {
855 av_log(s, AV_LOG_WARNING, "select_region ignored with window_id.\n");
856 c->select_region = 0;
857 }
858 if (c->follow_mouse) {
859 av_log(s, AV_LOG_WARNING, "follow_mouse ignored with window_id.\n");
860 c->follow_mouse = 0;
861 }
862 }
863
864 if (c->select_region) {
865 ret = select_region(s);
866 if (ret < 0) {
867 xcbgrab_read_close(s);
868 return ret;
869 }
870 }
871
872 ret = create_stream(s);
873
874 if (ret < 0) {
875 xcbgrab_read_close(s);
876 return ret;
877 }
878
879 #if CONFIG_LIBXCB_SHM
880 c->has_shm = check_shm(c->conn);
881 #endif
882
883 #if CONFIG_LIBXCB_XFIXES
884 if (c->draw_mouse) {
885 if (!(c->draw_mouse = check_xfixes(c->conn))) {
886 av_log(s, AV_LOG_WARNING,
887 "XFixes not available, cannot draw the mouse.\n");
888 }
889 if (c->bpp < 24) {
890 avpriv_report_missing_feature(s, "%d bits per pixel screen",
891 c->bpp);
892 c->draw_mouse = 0;
893 }
894 }
895 #endif
896
897 if (c->show_region)
898 setup_window(s);
899
900 return 0;
901 }
902
903 const AVInputFormat ff_xcbgrab_demuxer = {
904 .name = "x11grab",
905 .long_name = NULL_IF_CONFIG_SMALL("X11 screen capture, using XCB"),
906 .priv_data_size = sizeof(XCBGrabContext),
907 .read_header = xcbgrab_read_header,
908 .read_packet = xcbgrab_read_packet,
909 .read_close = xcbgrab_read_close,
910 .flags = AVFMT_NOFILE,
911 .priv_class = &xcbgrab_class,
912 };
913