FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavdevice/xcbgrab.c
Date: 2024-07-17 14:05:47
Exec Total Coverage
Lines: 0 466 0.0%
Functions: 0 21 0.0%
Branches: 0 192 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/mem.h"
44 #include "libavutil/opt.h"
45 #include "libavutil/parseutils.h"
46 #include "libavutil/time.h"
47
48 #include "libavformat/avformat.h"
49 #include "libavformat/demux.h"
50 #include "libavformat/internal.h"
51
52 typedef struct XCBGrabContext {
53 const AVClass *class;
54
55 xcb_connection_t *conn;
56 xcb_screen_t *screen;
57 xcb_window_t window;
58 #if CONFIG_LIBXCB_SHM
59 AVBufferPool *shm_pool;
60 #endif
61 int64_t time_frame;
62 AVRational time_base;
63 int64_t frame_duration;
64
65 xcb_window_t window_id;
66 int x, y;
67 int width, height;
68 int frame_size;
69 int bpp;
70
71 int draw_mouse;
72 int follow_mouse;
73 int show_region;
74 int region_border;
75 int centered;
76 int select_region;
77
78 const char *framerate;
79
80 int has_shm;
81 } XCBGrabContext;
82
83 #define FOLLOW_CENTER -1
84
85 #define OFFSET(x) offsetof(XCBGrabContext, x)
86 #define D AV_OPT_FLAG_DECODING_PARAM
87 static const AVOption options[] = {
88 { "window_id", "Window to capture.", OFFSET(window_id), AV_OPT_TYPE_INT, { .i64 = XCB_NONE }, 0, UINT32_MAX, D },
89 { "x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
90 { "y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
91 { "grab_x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
92 { "grab_y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
93 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL }, 0, 0, D },
94 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc" }, 0, 0, D },
95 { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, D },
96 { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
97 OFFSET(follow_mouse), AV_OPT_TYPE_INT, { .i64 = 0 }, FOLLOW_CENTER, INT_MAX, D, .unit = "follow_mouse" },
98 { "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" },
99 { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, D },
100 { "region_border", "Set the region border thickness.", OFFSET(region_border), AV_OPT_TYPE_INT, { .i64 = 3 }, 1, 128, D },
101 { "select_region", "Select the grabbing region graphically using the pointer.", OFFSET(select_region), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, D },
102 { NULL },
103 };
104
105 static const AVClass xcbgrab_class = {
106 .class_name = "xcbgrab indev",
107 .item_name = av_default_item_name,
108 .option = options,
109 .version = LIBAVUTIL_VERSION_INT,
110 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
111 };
112
113 static int xcbgrab_reposition(AVFormatContext *s,
114 xcb_query_pointer_reply_t *p,
115 xcb_get_geometry_reply_t *geo)
116 {
117 XCBGrabContext *c = s->priv_data;
118 int x = c->x, y = c->y;
119 int w = c->width, h = c->height, f = c->follow_mouse;
120 int p_x, p_y;
121
122 if (!p || !geo)
123 return AVERROR(EIO);
124
125 p_x = p->win_x;
126 p_y = p->win_y;
127
128 if (f == FOLLOW_CENTER) {
129 x = p_x - w / 2;
130 y = p_y - h / 2;
131 } else {
132 int left = x + f;
133 int right = x + w - f;
134 int top = y + f;
135 int bottom = y + h - f;
136 if (p_x > right) {
137 x += p_x - right;
138 } else if (p_x < left) {
139 x -= left - p_x;
140 }
141 if (p_y > bottom) {
142 y += p_y - bottom;
143 } else if (p_y < top) {
144 y -= top - p_y;
145 }
146 }
147
148 c->x = FFMIN(FFMAX(0, x), geo->width - w);
149 c->y = FFMIN(FFMAX(0, y), geo->height - h);
150
151 return 0;
152 }
153
154 static void xcbgrab_image_reply_free(void *opaque, uint8_t *data)
155 {
156 free(opaque);
157 }
158
159 static int xcbgrab_frame(AVFormatContext *s, AVPacket *pkt)
160 {
161 XCBGrabContext *c = s->priv_data;
162 xcb_get_image_cookie_t iq;
163 xcb_get_image_reply_t *img;
164 xcb_drawable_t drawable = c->window_id;
165 xcb_generic_error_t *e = NULL;
166 uint8_t *data;
167 int length;
168
169 iq = xcb_get_image(c->conn, XCB_IMAGE_FORMAT_Z_PIXMAP, drawable,
170 c->x, c->y, c->width, c->height, ~0);
171
172 img = xcb_get_image_reply(c->conn, iq, &e);
173
174 if (e) {
175 av_log(s, AV_LOG_ERROR,
176 "Cannot get the image data "
177 "event_error: response_type:%u error_code:%u "
178 "sequence:%u resource_id:%u minor_code:%u major_code:%u.\n",
179 e->response_type, e->error_code,
180 e->sequence, e->resource_id, e->minor_code, e->major_code);
181 free(e);
182 return AVERROR(EACCES);
183 }
184
185 if (!img)
186 return AVERROR(EAGAIN);
187
188 data = xcb_get_image_data(img);
189 length = xcb_get_image_data_length(img);
190
191 pkt->buf = av_buffer_create(data, length, xcbgrab_image_reply_free, img, 0);
192 if (!pkt->buf) {
193 free(img);
194 return AVERROR(ENOMEM);
195 }
196
197 pkt->data = data;
198 pkt->size = length;
199
200 return 0;
201 }
202
203 static int64_t wait_frame(AVFormatContext *s, AVPacket *pkt)
204 {
205 XCBGrabContext *c = s->priv_data;
206 int64_t curtime, delay;
207
208 c->time_frame += c->frame_duration;
209
210 for (;;) {
211 curtime = av_gettime_relative();
212 delay = c->time_frame - curtime;
213 if (delay <= 0)
214 break;
215 av_usleep(delay);
216 }
217
218 return curtime;
219 }
220
221 #if CONFIG_LIBXCB_SHM
222 static int check_shm(xcb_connection_t *conn)
223 {
224 xcb_shm_query_version_cookie_t cookie = xcb_shm_query_version(conn);
225 xcb_shm_query_version_reply_t *reply;
226
227 reply = xcb_shm_query_version_reply(conn, cookie, NULL);
228 if (reply) {
229 free(reply);
230 return 1;
231 }
232
233 return 0;
234 }
235
236 static void free_shm_buffer(void *opaque, uint8_t *data)
237 {
238 shmdt(data);
239 }
240
241 static AVBufferRef *allocate_shm_buffer(void *opaque, size_t size)
242 {
243 xcb_connection_t *conn = opaque;
244 xcb_shm_seg_t segment;
245 AVBufferRef *ref;
246 uint8_t *data;
247 int id;
248
249 id = shmget(IPC_PRIVATE, size, IPC_CREAT | 0777);
250 if (id == -1)
251 return NULL;
252
253 segment = xcb_generate_id(conn);
254 xcb_shm_attach(conn, segment, id, 0);
255 data = shmat(id, NULL, 0);
256 shmctl(id, IPC_RMID, 0);
257 if ((intptr_t)data == -1 || !data)
258 return NULL;
259
260 ref = av_buffer_create(data, size, free_shm_buffer, (void *)(ptrdiff_t)segment, 0);
261 if (!ref)
262 shmdt(data);
263
264 return ref;
265 }
266
267 static int xcbgrab_frame_shm(AVFormatContext *s, AVPacket *pkt)
268 {
269 XCBGrabContext *c = s->priv_data;
270 xcb_shm_get_image_cookie_t iq;
271 xcb_shm_get_image_reply_t *img;
272 xcb_drawable_t drawable = c->window_id;
273 xcb_generic_error_t *e = NULL;
274 AVBufferRef *buf;
275 xcb_shm_seg_t segment;
276
277 buf = av_buffer_pool_get(c->shm_pool);
278 if (!buf) {
279 av_log(s, AV_LOG_ERROR, "Could not get shared memory buffer.\n");
280 return AVERROR(ENOMEM);
281 }
282 segment = (xcb_shm_seg_t)(uintptr_t)av_buffer_pool_buffer_get_opaque(buf);
283
284 iq = xcb_shm_get_image(c->conn, drawable,
285 c->x, c->y, c->width, c->height, ~0,
286 XCB_IMAGE_FORMAT_Z_PIXMAP, segment, 0);
287 img = xcb_shm_get_image_reply(c->conn, iq, &e);
288
289 xcb_flush(c->conn);
290
291 if (e) {
292 av_log(s, AV_LOG_ERROR,
293 "Cannot get the image data "
294 "event_error: response_type:%u error_code:%u "
295 "sequence:%u resource_id:%u minor_code:%u major_code:%u.\n",
296 e->response_type, e->error_code,
297 e->sequence, e->resource_id, e->minor_code, e->major_code);
298
299 free(e);
300 av_buffer_unref(&buf);
301 return AVERROR(EACCES);
302 }
303
304 free(img);
305
306 pkt->buf = buf;
307 pkt->data = buf->data;
308 pkt->size = c->frame_size;
309
310 return 0;
311 }
312 #endif /* CONFIG_LIBXCB_SHM */
313
314 #if CONFIG_LIBXCB_XFIXES
315 static int check_xfixes(xcb_connection_t *conn)
316 {
317 xcb_xfixes_query_version_cookie_t cookie;
318 xcb_xfixes_query_version_reply_t *reply;
319
320 cookie = xcb_xfixes_query_version(conn, XCB_XFIXES_MAJOR_VERSION,
321 XCB_XFIXES_MINOR_VERSION);
322 reply = xcb_xfixes_query_version_reply(conn, cookie, NULL);
323
324 if (reply) {
325 free(reply);
326 return 1;
327 }
328 return 0;
329 }
330
331 #define BLEND(target, source, alpha) \
332 (target) + ((source) * (255 - (alpha)) + 255 / 2) / 255
333
334 static void xcbgrab_draw_mouse(AVFormatContext *s, AVPacket *pkt,
335 xcb_query_pointer_reply_t *p,
336 xcb_get_geometry_reply_t *geo,
337 int win_x, int win_y)
338 {
339 XCBGrabContext *gr = s->priv_data;
340 uint32_t *cursor;
341 uint8_t *image = pkt->data;
342 int stride = gr->bpp / 8;
343 xcb_xfixes_get_cursor_image_cookie_t cc;
344 xcb_xfixes_get_cursor_image_reply_t *ci;
345 int cx, cy, x, y, w, h, c_off, i_off;
346
347 cc = xcb_xfixes_get_cursor_image(gr->conn);
348 ci = xcb_xfixes_get_cursor_image_reply(gr->conn, cc, NULL);
349 if (!ci)
350 return;
351
352 cursor = xcb_xfixes_get_cursor_image_cursor_image(ci);
353 if (!cursor)
354 return;
355
356 cx = ci->x - ci->xhot;
357 cy = ci->y - ci->yhot;
358
359 x = FFMAX(cx, win_x + gr->x);
360 y = FFMAX(cy, win_y + gr->y);
361
362 w = FFMIN(cx + ci->width, win_x + gr->x + gr->width) - x;
363 h = FFMIN(cy + ci->height, win_y + gr->y + gr->height) - y;
364
365 c_off = x - cx;
366 i_off = x - gr->x - win_x;
367
368 cursor += (y - cy) * ci->width;
369 image += (y - gr->y - win_y) * gr->width * stride;
370
371 for (y = 0; y < h; y++) {
372 cursor += c_off;
373 image += i_off * stride;
374 for (x = 0; x < w; x++, cursor++, image += stride) {
375 int r, g, b, a;
376
377 r = *cursor & 0xff;
378 g = (*cursor >> 8) & 0xff;
379 b = (*cursor >> 16) & 0xff;
380 a = (*cursor >> 24) & 0xff;
381
382 if (!a)
383 continue;
384
385 if (a == 255) {
386 image[0] = r;
387 image[1] = g;
388 image[2] = b;
389 } else {
390 image[0] = BLEND(r, image[0], a);
391 image[1] = BLEND(g, image[1], a);
392 image[2] = BLEND(b, image[2], a);
393 }
394
395 }
396 cursor += ci->width - w - c_off;
397 image += (gr->width - w - i_off) * stride;
398 }
399
400 free(ci);
401 }
402 #endif /* CONFIG_LIBXCB_XFIXES */
403
404 static void xcbgrab_update_region(AVFormatContext *s, int win_x, int win_y)
405 {
406 XCBGrabContext *c = s->priv_data;
407 const uint32_t args[] = { win_x + c->x - c->region_border,
408 win_y + c->y - c->region_border };
409
410 xcb_configure_window(c->conn,
411 c->window,
412 XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y,
413 args);
414 }
415
416 static int xcbgrab_read_packet(AVFormatContext *s, AVPacket *pkt)
417 {
418 XCBGrabContext *c = s->priv_data;
419 xcb_query_pointer_cookie_t pc;
420 xcb_get_geometry_cookie_t gc;
421 xcb_translate_coordinates_cookie_t tc;
422 xcb_query_pointer_reply_t *p = NULL;
423 xcb_get_geometry_reply_t *geo = NULL;
424 xcb_translate_coordinates_reply_t *translate = NULL;
425 int ret = 0;
426 int64_t pts;
427 int win_x = 0, win_y = 0;
428
429 wait_frame(s, pkt);
430 pts = av_gettime();
431
432 if (c->follow_mouse || c->draw_mouse) {
433 pc = xcb_query_pointer(c->conn, c->window_id);
434 gc = xcb_get_geometry(c->conn, c->window_id);
435 p = xcb_query_pointer_reply(c->conn, pc, NULL);
436 if (!p) {
437 av_log(s, AV_LOG_ERROR, "Failed to query xcb pointer\n");
438 return AVERROR_EXTERNAL;
439 }
440 geo = xcb_get_geometry_reply(c->conn, gc, NULL);
441 if (!geo) {
442 av_log(s, AV_LOG_ERROR, "Failed to get xcb geometry\n");
443 free(p);
444 return AVERROR_EXTERNAL;
445 }
446 }
447 if (c->window_id != c->screen->root) {
448 tc = xcb_translate_coordinates(c->conn, c->window_id, c->screen->root, 0, 0);
449 translate = xcb_translate_coordinates_reply(c->conn, tc, NULL);
450 if (!translate) {
451 free(p);
452 free(geo);
453 av_log(s, AV_LOG_ERROR, "Failed to translate xcb geometry\n");
454 return AVERROR_EXTERNAL;
455 }
456 win_x = translate->dst_x;
457 win_y = translate->dst_y;
458 free(translate);
459 }
460
461 if (c->follow_mouse && p->same_screen)
462 xcbgrab_reposition(s, p, geo);
463
464 if (c->show_region)
465 xcbgrab_update_region(s, win_x, win_y);
466
467 #if CONFIG_LIBXCB_SHM
468 if (c->has_shm && xcbgrab_frame_shm(s, pkt) < 0) {
469 av_log(s, AV_LOG_WARNING, "Continuing without shared memory.\n");
470 c->has_shm = 0;
471 }
472 #endif
473 if (!c->has_shm)
474 ret = xcbgrab_frame(s, pkt);
475 pkt->dts = pkt->pts = pts;
476 pkt->duration = c->frame_duration;
477
478 #if CONFIG_LIBXCB_XFIXES
479 if (ret >= 0 && c->draw_mouse && p->same_screen)
480 xcbgrab_draw_mouse(s, pkt, p, geo, win_x, win_y);
481 #endif
482
483 free(p);
484 free(geo);
485
486 return ret;
487 }
488
489 static av_cold int xcbgrab_read_close(AVFormatContext *s)
490 {
491 XCBGrabContext *ctx = s->priv_data;
492
493 #if CONFIG_LIBXCB_SHM
494 av_buffer_pool_uninit(&ctx->shm_pool);
495 #endif
496
497 xcb_disconnect(ctx->conn);
498
499 return 0;
500 }
501
502 static xcb_screen_t *get_screen(const xcb_setup_t *setup, int screen_num)
503 {
504 xcb_screen_iterator_t it = xcb_setup_roots_iterator(setup);
505 xcb_screen_t *screen = NULL;
506
507 for (; it.rem > 0; xcb_screen_next (&it)) {
508 if (!screen_num) {
509 screen = it.data;
510 break;
511 }
512
513 screen_num--;
514 }
515
516 return screen;
517 }
518
519 static int pixfmt_from_pixmap_format(AVFormatContext *s, int depth,
520 int *pix_fmt, int *bpp)
521 {
522 XCBGrabContext *c = s->priv_data;
523 const xcb_setup_t *setup = xcb_get_setup(c->conn);
524 const xcb_format_t *fmt = xcb_setup_pixmap_formats(setup);
525 int length = xcb_setup_pixmap_formats_length(setup);
526
527 *pix_fmt = 0;
528
529 while (length--) {
530 if (fmt->depth == depth) {
531 switch (depth) {
532 case 32:
533 if (fmt->bits_per_pixel == 32)
534 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
535 AV_PIX_FMT_BGR0 : AV_PIX_FMT_0RGB;
536 break;
537 case 24:
538 if (fmt->bits_per_pixel == 32)
539 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
540 AV_PIX_FMT_BGR0 : AV_PIX_FMT_0RGB;
541 else if (fmt->bits_per_pixel == 24)
542 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
543 AV_PIX_FMT_BGR24 : AV_PIX_FMT_RGB24;
544 break;
545 case 16:
546 if (fmt->bits_per_pixel == 16)
547 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
548 AV_PIX_FMT_RGB565LE : AV_PIX_FMT_RGB565BE;
549 break;
550 case 15:
551 if (fmt->bits_per_pixel == 16)
552 *pix_fmt = setup->image_byte_order == XCB_IMAGE_ORDER_LSB_FIRST ?
553 AV_PIX_FMT_RGB555LE : AV_PIX_FMT_RGB555BE;
554 break;
555 case 8:
556 if (fmt->bits_per_pixel == 8)
557 *pix_fmt = AV_PIX_FMT_RGB8;
558 break;
559 }
560 }
561
562 if (*pix_fmt) {
563 *bpp = fmt->bits_per_pixel;
564 return 0;
565 }
566
567 fmt++;
568 }
569 avpriv_report_missing_feature(s, "Mapping this pixmap format");
570
571 return AVERROR_PATCHWELCOME;
572 }
573
574 static int create_stream(AVFormatContext *s)
575 {
576 XCBGrabContext *c = s->priv_data;
577 AVStream *st = avformat_new_stream(s, NULL);
578 xcb_get_geometry_cookie_t gc;
579 xcb_get_geometry_reply_t *geo;
580 int64_t frame_size_bits;
581 int ret;
582
583 if (!st)
584 return AVERROR(ENOMEM);
585
586 ret = av_parse_video_rate(&st->avg_frame_rate, c->framerate);
587 if (ret < 0)
588 return ret;
589
590 avpriv_set_pts_info(st, 64, 1, 1000000);
591
592 gc = xcb_get_geometry(c->conn, c->window_id);
593 geo = xcb_get_geometry_reply(c->conn, gc, NULL);
594 if (!geo) {
595 av_log(s, AV_LOG_ERROR, "Can't find window '0x%x', aborting.\n", c->window_id);
596 return AVERROR_EXTERNAL;
597 }
598
599 if (!c->width || !c->height) {
600 c->width = geo->width;
601 c->height = geo->height;
602 }
603
604 if (c->x + c->width > geo->width ||
605 c->y + c->height > geo->height) {
606 av_log(s, AV_LOG_ERROR,
607 "Capture area %dx%d at position %d.%d "
608 "outside the screen size %dx%d\n",
609 c->width, c->height,
610 c->x, c->y,
611 geo->width, geo->height);
612 free(geo);
613 return AVERROR(EINVAL);
614 }
615
616 c->time_base = (AVRational){ st->avg_frame_rate.den,
617 st->avg_frame_rate.num };
618 c->frame_duration = av_rescale_q(1, c->time_base, AV_TIME_BASE_Q);
619 c->time_frame = av_gettime_relative();
620
621 ret = pixfmt_from_pixmap_format(s, geo->depth, &st->codecpar->format, &c->bpp);
622 free(geo);
623 if (ret < 0)
624 return ret;
625
626 frame_size_bits = (int64_t)c->width * c->height * c->bpp;
627 if (frame_size_bits / 8 + AV_INPUT_BUFFER_PADDING_SIZE > INT_MAX) {
628 av_log(s, AV_LOG_ERROR, "Captured area is too large\n");
629 return AVERROR_PATCHWELCOME;
630 }
631 c->frame_size = frame_size_bits / 8;
632
633 #if CONFIG_LIBXCB_SHM
634 c->shm_pool = av_buffer_pool_init2(c->frame_size + AV_INPUT_BUFFER_PADDING_SIZE,
635 c->conn, allocate_shm_buffer, NULL);
636 if (!c->shm_pool)
637 return AVERROR(ENOMEM);
638 #endif
639
640 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
641 st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
642 st->codecpar->width = c->width;
643 st->codecpar->height = c->height;
644 st->codecpar->bit_rate = av_rescale(frame_size_bits, st->avg_frame_rate.num, st->avg_frame_rate.den);
645
646 return ret;
647 }
648
649 static void draw_rectangle(AVFormatContext *s)
650 {
651 XCBGrabContext *c = s->priv_data;
652 xcb_gcontext_t gc = xcb_generate_id(c->conn);
653 uint32_t mask = XCB_GC_FOREGROUND |
654 XCB_GC_BACKGROUND |
655 XCB_GC_LINE_WIDTH |
656 XCB_GC_LINE_STYLE |
657 XCB_GC_FILL_STYLE;
658 uint32_t values[] = { c->screen->black_pixel,
659 c->screen->white_pixel,
660 c->region_border,
661 XCB_LINE_STYLE_DOUBLE_DASH,
662 XCB_FILL_STYLE_SOLID };
663 xcb_rectangle_t r = { 1, 1,
664 c->width + c->region_border * 2 - 3,
665 c->height + c->region_border * 2 - 3 };
666
667 xcb_create_gc(c->conn, gc, c->window, mask, values);
668
669 xcb_poly_rectangle(c->conn, c->window, gc, 1, &r);
670 }
671
672 static void setup_window(AVFormatContext *s)
673 {
674 XCBGrabContext *c = s->priv_data;
675 uint32_t mask = XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK;
676 uint32_t values[] = { 1,
677 XCB_EVENT_MASK_EXPOSURE |
678 XCB_EVENT_MASK_STRUCTURE_NOTIFY };
679 av_unused xcb_rectangle_t rect = { 0, 0, c->width, c->height };
680
681 c->window = xcb_generate_id(c->conn);
682
683 xcb_create_window(c->conn, XCB_COPY_FROM_PARENT,
684 c->window,
685 c->screen->root,
686 c->x - c->region_border,
687 c->y - c->region_border,
688 c->width + c->region_border * 2,
689 c->height + c->region_border * 2,
690 0,
691 XCB_WINDOW_CLASS_INPUT_OUTPUT,
692 XCB_COPY_FROM_PARENT,
693 mask, values);
694
695 #if CONFIG_LIBXCB_SHAPE
696 xcb_shape_rectangles(c->conn, XCB_SHAPE_SO_SUBTRACT,
697 XCB_SHAPE_SK_BOUNDING, XCB_CLIP_ORDERING_UNSORTED,
698 c->window,
699 c->region_border, c->region_border,
700 1, &rect);
701 #endif
702
703 xcb_map_window(c->conn, c->window);
704
705 draw_rectangle(s);
706 }
707
708 #define CROSSHAIR_CURSOR 34
709
710 static xcb_rectangle_t rectangle_from_corners(xcb_point_t *corner_a,
711 xcb_point_t *corner_b)
712 {
713 xcb_rectangle_t rectangle;
714 rectangle.x = FFMIN(corner_a->x, corner_b->x);
715 rectangle.y = FFMIN(corner_a->y, corner_b->y);
716 rectangle.width = FFABS(corner_a->x - corner_b->x);
717 rectangle.height = FFABS(corner_a->y - corner_b->y);
718 return rectangle;
719 }
720
721 static int select_region(AVFormatContext *s)
722 {
723 XCBGrabContext *c = s->priv_data;
724 xcb_connection_t *conn = c->conn;
725 xcb_screen_t *screen = c->screen;
726
727 int ret = 0, done = 0, was_pressed = 0;
728 xcb_cursor_t cursor;
729 xcb_font_t cursor_font;
730 xcb_point_t press_position;
731 xcb_generic_event_t *event;
732 xcb_rectangle_t rectangle = { 0 };
733 xcb_grab_pointer_reply_t *reply;
734 xcb_grab_pointer_cookie_t cookie;
735
736 xcb_window_t root_window = screen->root;
737 xcb_gcontext_t gc = xcb_generate_id(conn);
738 uint32_t mask = XCB_GC_FUNCTION | XCB_GC_SUBWINDOW_MODE;
739 uint32_t values[] = { XCB_GX_INVERT, XCB_SUBWINDOW_MODE_INCLUDE_INFERIORS };
740 xcb_create_gc(conn, gc, root_window, mask, values);
741
742 cursor_font = xcb_generate_id(conn);
743 xcb_open_font(conn, cursor_font, strlen("cursor"), "cursor");
744 cursor = xcb_generate_id(conn);
745 xcb_create_glyph_cursor(conn, cursor, cursor_font, cursor_font,
746 CROSSHAIR_CURSOR, CROSSHAIR_CURSOR + 1, 0, 0, 0,
747 0xFFFF, 0xFFFF, 0xFFFF);
748 cookie = xcb_grab_pointer(conn, 0, root_window,
749 XCB_EVENT_MASK_BUTTON_PRESS |
750 XCB_EVENT_MASK_BUTTON_RELEASE |
751 XCB_EVENT_MASK_BUTTON_MOTION,
752 XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC,
753 root_window, cursor, XCB_CURRENT_TIME);
754 reply = xcb_grab_pointer_reply(conn, cookie, NULL);
755 if (!reply || reply->status != XCB_GRAB_STATUS_SUCCESS) {
756 av_log(s, AV_LOG_ERROR,
757 "Failed to select region. Could not grab pointer.\n");
758 ret = AVERROR(EIO);
759 free(reply);
760 goto fail;
761 }
762 free(reply);
763
764 xcb_grab_server(conn);
765
766 while (!done && (event = xcb_wait_for_event(conn))) {
767 switch (event->response_type & ~0x80) {
768 case XCB_BUTTON_PRESS: {
769 xcb_button_press_event_t *press = (xcb_button_press_event_t *)event;
770 press_position = (xcb_point_t){ press->event_x, press->event_y };
771 rectangle.x = press_position.x;
772 rectangle.y = press_position.y;
773 xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
774 was_pressed = 1;
775 break;
776 }
777 case XCB_MOTION_NOTIFY: {
778 if (was_pressed) {
779 xcb_motion_notify_event_t *motion =
780 (xcb_motion_notify_event_t *)event;
781 xcb_point_t cursor_position = { motion->event_x, motion->event_y };
782 xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
783 rectangle = rectangle_from_corners(&press_position, &cursor_position);
784 xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
785 }
786 break;
787 }
788 case XCB_BUTTON_RELEASE: {
789 xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
790 done = 1;
791 break;
792 }
793 default:
794 break;
795 }
796 xcb_flush(conn);
797 free(event);
798 }
799 c->width = rectangle.width;
800 c->height = rectangle.height;
801 if (c->width && c->height) {
802 c->x = rectangle.x;
803 c->y = rectangle.y;
804 } else {
805 c->x = 0;
806 c->y = 0;
807 }
808 xcb_ungrab_server(conn);
809 xcb_ungrab_pointer(conn, XCB_CURRENT_TIME);
810 xcb_flush(conn);
811
812 fail:
813 xcb_free_cursor(conn, cursor);
814 xcb_close_font(conn, cursor_font);
815 xcb_free_gc(conn, gc);
816 return ret;
817 }
818
819 static av_cold int xcbgrab_read_header(AVFormatContext *s)
820 {
821 XCBGrabContext *c = s->priv_data;
822 int screen_num, ret;
823 const xcb_setup_t *setup;
824 char *display_name = av_strdup(s->url);
825
826 if (!display_name)
827 return AVERROR(ENOMEM);
828
829 if (!sscanf(s->url, "%[^+]+%d,%d", display_name, &c->x, &c->y)) {
830 *display_name = 0;
831 if(sscanf(s->url, "+%d,%d", &c->x, &c->y) != 2) {
832 if (*s->url)
833 av_log(s, AV_LOG_WARNING, "Ambigous URL: %s\n", s->url);
834 }
835 }
836
837 c->conn = xcb_connect(display_name[0] ? display_name : NULL, &screen_num);
838 av_freep(&display_name);
839
840 if ((ret = xcb_connection_has_error(c->conn))) {
841 av_log(s, AV_LOG_ERROR, "Cannot open display %s, error %d.\n",
842 s->url[0] ? s->url : "default", ret);
843 return AVERROR(EIO);
844 }
845
846 setup = xcb_get_setup(c->conn);
847
848 c->screen = get_screen(setup, screen_num);
849 if (!c->screen) {
850 av_log(s, AV_LOG_ERROR, "The screen %d does not exist.\n",
851 screen_num);
852 xcbgrab_read_close(s);
853 return AVERROR(EIO);
854 }
855
856 if (c->window_id == XCB_NONE)
857 c->window_id = c->screen->root;
858 else {
859 if (c->select_region) {
860 av_log(s, AV_LOG_WARNING, "select_region ignored with window_id.\n");
861 c->select_region = 0;
862 }
863 if (c->follow_mouse) {
864 av_log(s, AV_LOG_WARNING, "follow_mouse ignored with window_id.\n");
865 c->follow_mouse = 0;
866 }
867 }
868
869 if (c->select_region) {
870 ret = select_region(s);
871 if (ret < 0) {
872 xcbgrab_read_close(s);
873 return ret;
874 }
875 }
876
877 ret = create_stream(s);
878
879 if (ret < 0) {
880 xcbgrab_read_close(s);
881 return ret;
882 }
883
884 #if CONFIG_LIBXCB_SHM
885 c->has_shm = check_shm(c->conn);
886 #endif
887
888 #if CONFIG_LIBXCB_XFIXES
889 if (c->draw_mouse) {
890 if (!(c->draw_mouse = check_xfixes(c->conn))) {
891 av_log(s, AV_LOG_WARNING,
892 "XFixes not available, cannot draw the mouse.\n");
893 }
894 if (c->bpp < 24) {
895 avpriv_report_missing_feature(s, "%d bits per pixel screen",
896 c->bpp);
897 c->draw_mouse = 0;
898 }
899 }
900 #endif
901
902 if (c->show_region)
903 setup_window(s);
904
905 return 0;
906 }
907
908 const FFInputFormat ff_xcbgrab_demuxer = {
909 .p.name = "x11grab",
910 .p.long_name = NULL_IF_CONFIG_SMALL("X11 screen capture, using XCB"),
911 .p.flags = AVFMT_NOFILE,
912 .p.priv_class = &xcbgrab_class,
913 .priv_data_size = sizeof(XCBGrabContext),
914 .read_header = xcbgrab_read_header,
915 .read_packet = xcbgrab_read_packet,
916 .read_close = xcbgrab_read_close,
917 };
918