GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavdevice/xcbgrab.c Lines: 0 433 0.0 %
Date: 2021-01-20 23:14:43 Branches: 0 168 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
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 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * 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
 *
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 * You should have received a copy of the GNU Lesser General Public
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 * 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
    int x, y;
64
    int width, height;
65
    int frame_size;
66
    int bpp;
67
68
    int draw_mouse;
69
    int follow_mouse;
70
    int show_region;
71
    int region_border;
72
    int centered;
73
    int select_region;
74
75
    const char *framerate;
76
77
    int has_shm;
78
} XCBGrabContext;
79
80
#define FOLLOW_CENTER -1
81
82
#define OFFSET(x) offsetof(XCBGrabContext, x)
83
#define D AV_OPT_FLAG_DECODING_PARAM
84
static const AVOption options[] = {
85
    { "x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
86
    { "y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
87
    { "grab_x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
88
    { "grab_y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
89
    { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL }, 0, 0, D },
90
    { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc" }, 0, 0, D },
91
    { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, D },
92
    { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
93
      OFFSET(follow_mouse), AV_OPT_TYPE_INT, { .i64 = 0 },  FOLLOW_CENTER, INT_MAX, D, "follow_mouse" },
94
    { "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, "follow_mouse" },
95
    { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, D },
96
    { "region_border", "Set the region border thickness.", OFFSET(region_border), AV_OPT_TYPE_INT, { .i64 = 3 }, 1, 128, D },
97
    { "select_region", "Select the grabbing region graphically using the pointer.", OFFSET(select_region), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, D },
98
    { NULL },
99
};
100
101
static const AVClass xcbgrab_class = {
102
    .class_name = "xcbgrab indev",
103
    .item_name  = av_default_item_name,
104
    .option     = options,
105
    .version    = LIBAVUTIL_VERSION_INT,
106
    .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
107
};
108
109
static int xcbgrab_reposition(AVFormatContext *s,
110
                              xcb_query_pointer_reply_t *p,
111
                              xcb_get_geometry_reply_t *geo)
112
{
113
    XCBGrabContext *c = s->priv_data;
114
    int x = c->x, y = c->y;
115
    int w = c->width, h = c->height, f = c->follow_mouse;
116
    int p_x, p_y;
117
118
    if (!p || !geo)
119
        return AVERROR(EIO);
120
121
    p_x = p->win_x;
122
    p_y = p->win_y;
123
124
    if (f == FOLLOW_CENTER) {
125
        x = p_x - w / 2;
126
        y = p_y - h / 2;
127
    } else {
128
        int left   = x + f;
129
        int right  = x + w - f;
130
        int top    = y + f;
131
        int bottom = y + h - f;
132
        if (p_x > right) {
133
            x += p_x - right;
134
        } else if (p_x < left) {
135
            x -= left - p_x;
136
        }
137
        if (p_y > bottom) {
138
            y += p_y - bottom;
139
        } else if (p_y < top) {
140
            y -= top - p_y;
141
        }
142
    }
143
144
    c->x = FFMIN(FFMAX(0, x), geo->width  - w);
145
    c->y = FFMIN(FFMAX(0, y), geo->height - h);
146
147
    return 0;
148
}
149
150
static void xcbgrab_image_reply_free(void *opaque, uint8_t *data)
151
{
152
    free(opaque);
153
}
154
155
static int xcbgrab_frame(AVFormatContext *s, AVPacket *pkt)
156
{
157
    XCBGrabContext *c = s->priv_data;
158
    xcb_get_image_cookie_t iq;
159
    xcb_get_image_reply_t *img;
160
    xcb_drawable_t drawable = c->screen->root;
161
    xcb_generic_error_t *e = NULL;
162
    uint8_t *data;
163
    int length;
164
165
    iq  = xcb_get_image(c->conn, XCB_IMAGE_FORMAT_Z_PIXMAP, drawable,
166
                        c->x, c->y, c->width, c->height, ~0);
167
168
    img = xcb_get_image_reply(c->conn, iq, &e);
169
170
    if (e) {
171
        av_log(s, AV_LOG_ERROR,
172
               "Cannot get the image data "
173
               "event_error: response_type:%u error_code:%u "
174
               "sequence:%u resource_id:%u minor_code:%u major_code:%u.\n",
175
               e->response_type, e->error_code,
176
               e->sequence, e->resource_id, e->minor_code, e->major_code);
177
        free(e);
178
        return AVERROR(EACCES);
179
    }
180
181
    if (!img)
182
        return AVERROR(EAGAIN);
183
184
    data   = xcb_get_image_data(img);
185
    length = xcb_get_image_data_length(img);
186
187
    av_init_packet(pkt);
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();
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, int 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->screen->root;
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)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
    av_init_packet(pkt);
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
{
338
    XCBGrabContext *gr = s->priv_data;
339
    uint32_t *cursor;
340
    uint8_t *image = pkt->data;
341
    int stride     = gr->bpp / 8;
342
    xcb_xfixes_get_cursor_image_cookie_t cc;
343
    xcb_xfixes_get_cursor_image_reply_t *ci;
344
    int cx, cy, x, y, w, h, c_off, i_off;
345
346
    cc = xcb_xfixes_get_cursor_image(gr->conn);
347
    ci = xcb_xfixes_get_cursor_image_reply(gr->conn, cc, NULL);
348
    if (!ci)
349
        return;
350
351
    cursor = xcb_xfixes_get_cursor_image_cursor_image(ci);
352
    if (!cursor)
353
        return;
354
355
    cx = ci->x - ci->xhot;
356
    cy = ci->y - ci->yhot;
357
358
    x = FFMAX(cx, gr->x);
359
    y = FFMAX(cy, gr->y);
360
361
    w = FFMIN(cx + ci->width,  gr->x + gr->width)  - x;
362
    h = FFMIN(cy + ci->height, gr->y + gr->height) - y;
363
364
    c_off = x - cx;
365
    i_off = x - gr->x;
366
367
    cursor += (y - cy) * ci->width;
368
    image  += (y - gr->y) * gr->width * stride;
369
370
    for (y = 0; y < h; y++) {
371
        cursor += c_off;
372
        image  += i_off * stride;
373
        for (x = 0; x < w; x++, cursor++, image += stride) {
374
            int r, g, b, a;
375
376
            r =  *cursor        & 0xff;
377
            g = (*cursor >>  8) & 0xff;
378
            b = (*cursor >> 16) & 0xff;
379
            a = (*cursor >> 24) & 0xff;
380
381
            if (!a)
382
                continue;
383
384
            if (a == 255) {
385
                image[0] = r;
386
                image[1] = g;
387
                image[2] = b;
388
            } else {
389
                image[0] = BLEND(r, image[0], a);
390
                image[1] = BLEND(g, image[1], a);
391
                image[2] = BLEND(b, image[2], a);
392
            }
393
394
        }
395
        cursor +=  ci->width - w - c_off;
396
        image  += (gr->width - w - i_off) * stride;
397
    }
398
399
    free(ci);
400
}
401
#endif /* CONFIG_LIBXCB_XFIXES */
402
403
static void xcbgrab_update_region(AVFormatContext *s)
404
{
405
    XCBGrabContext *c     = s->priv_data;
406
    const uint32_t args[] = { c->x - c->region_border,
407
                              c->y - c->region_border };
408
409
    xcb_configure_window(c->conn,
410
                         c->window,
411
                         XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y,
412
                         args);
413
}
414
415
static int xcbgrab_read_packet(AVFormatContext *s, AVPacket *pkt)
416
{
417
    XCBGrabContext *c = s->priv_data;
418
    xcb_query_pointer_cookie_t pc;
419
    xcb_get_geometry_cookie_t gc;
420
    xcb_query_pointer_reply_t *p  = NULL;
421
    xcb_get_geometry_reply_t *geo = NULL;
422
    int ret = 0;
423
    int64_t pts;
424
425
    pts = wait_frame(s, pkt);
426
427
    if (c->follow_mouse || c->draw_mouse) {
428
        pc  = xcb_query_pointer(c->conn, c->screen->root);
429
        gc  = xcb_get_geometry(c->conn, c->screen->root);
430
        p   = xcb_query_pointer_reply(c->conn, pc, NULL);
431
        if (!p) {
432
            av_log(s, AV_LOG_ERROR, "Failed to query xcb pointer\n");
433
            return AVERROR_EXTERNAL;
434
        }
435
        geo = xcb_get_geometry_reply(c->conn, gc, NULL);
436
        if (!geo) {
437
            av_log(s, AV_LOG_ERROR, "Failed to get xcb geometry\n");
438
            free(p);
439
            return AVERROR_EXTERNAL;
440
        }
441
    }
442
443
    if (c->follow_mouse && p->same_screen)
444
        xcbgrab_reposition(s, p, geo);
445
446
    if (c->show_region)
447
        xcbgrab_update_region(s);
448
449
#if CONFIG_LIBXCB_SHM
450
    if (c->has_shm && xcbgrab_frame_shm(s, pkt) < 0) {
451
        av_log(s, AV_LOG_WARNING, "Continuing without shared memory.\n");
452
        c->has_shm = 0;
453
    }
454
#endif
455
    if (!c->has_shm)
456
        ret = xcbgrab_frame(s, pkt);
457
    pkt->dts = pkt->pts = pts;
458
    pkt->duration = c->frame_duration;
459
460
#if CONFIG_LIBXCB_XFIXES
461
    if (ret >= 0 && c->draw_mouse && p->same_screen)
462
        xcbgrab_draw_mouse(s, pkt, p, geo);
463
#endif
464
465
    free(p);
466
    free(geo);
467
468
    return ret;
469
}
470
471
static av_cold int xcbgrab_read_close(AVFormatContext *s)
472
{
473
    XCBGrabContext *ctx = s->priv_data;
474
475
#if CONFIG_LIBXCB_SHM
476
    av_buffer_pool_uninit(&ctx->shm_pool);
477
#endif
478
479
    xcb_disconnect(ctx->conn);
480
481
    return 0;
482
}
483
484
static xcb_screen_t *get_screen(const xcb_setup_t *setup, int screen_num)
485
{
486
    xcb_screen_iterator_t it = xcb_setup_roots_iterator(setup);
487
    xcb_screen_t *screen     = NULL;
488
489
    for (; it.rem > 0; xcb_screen_next (&it)) {
490
        if (!screen_num) {
491
            screen = it.data;
492
            break;
493
        }
494
495
        screen_num--;
496
    }
497
498
    return screen;
499
}
500
501
static int pixfmt_from_pixmap_format(AVFormatContext *s, int depth,
502
                                     int *pix_fmt, int *bpp)
503
{
504
    XCBGrabContext *c        = s->priv_data;
505
    const xcb_setup_t *setup = xcb_get_setup(c->conn);
506
    const xcb_format_t *fmt  = xcb_setup_pixmap_formats(setup);
507
    int length               = xcb_setup_pixmap_formats_length(setup);
508
509
    *pix_fmt = 0;
510
511
    while (length--) {
512
        if (fmt->depth == depth) {
513
            switch (depth) {
514
            case 32:
515
                if (fmt->bits_per_pixel == 32)
516
                    *pix_fmt = AV_PIX_FMT_0RGB;
517
                break;
518
            case 24:
519
                if (fmt->bits_per_pixel == 32)
520
                    *pix_fmt = AV_PIX_FMT_0RGB32;
521
                else if (fmt->bits_per_pixel == 24)
522
                    *pix_fmt = AV_PIX_FMT_RGB24;
523
                break;
524
            case 16:
525
                if (fmt->bits_per_pixel == 16)
526
                    *pix_fmt = AV_PIX_FMT_RGB565;
527
                break;
528
            case 15:
529
                if (fmt->bits_per_pixel == 16)
530
                    *pix_fmt = AV_PIX_FMT_RGB555;
531
                break;
532
            case 8:
533
                if (fmt->bits_per_pixel == 8)
534
                    *pix_fmt = AV_PIX_FMT_RGB8;
535
                break;
536
            }
537
        }
538
539
        if (*pix_fmt) {
540
            *bpp        = fmt->bits_per_pixel;
541
            return 0;
542
        }
543
544
        fmt++;
545
    }
546
    avpriv_report_missing_feature(s, "Mapping this pixmap format");
547
548
    return AVERROR_PATCHWELCOME;
549
}
550
551
static int create_stream(AVFormatContext *s)
552
{
553
    XCBGrabContext *c = s->priv_data;
554
    AVStream *st      = avformat_new_stream(s, NULL);
555
    xcb_get_geometry_cookie_t gc;
556
    xcb_get_geometry_reply_t *geo;
557
    int64_t frame_size_bits;
558
    int ret;
559
560
    if (!st)
561
        return AVERROR(ENOMEM);
562
563
    ret = av_parse_video_rate(&st->avg_frame_rate, c->framerate);
564
    if (ret < 0)
565
        return ret;
566
567
    avpriv_set_pts_info(st, 64, 1, 1000000);
568
569
    gc  = xcb_get_geometry(c->conn, c->screen->root);
570
    geo = xcb_get_geometry_reply(c->conn, gc, NULL);
571
    if (!geo)
572
        return AVERROR_EXTERNAL;
573
574
    if (!c->width || !c->height) {
575
        c->width = geo->width;
576
        c->height = geo->height;
577
    }
578
579
    if (c->x + c->width > geo->width ||
580
        c->y + c->height > geo->height) {
581
        av_log(s, AV_LOG_ERROR,
582
               "Capture area %dx%d at position %d.%d "
583
               "outside the screen size %dx%d\n",
584
               c->width, c->height,
585
               c->x, c->y,
586
               geo->width, geo->height);
587
        free(geo);
588
        return AVERROR(EINVAL);
589
    }
590
591
    c->time_base  = (AVRational){ st->avg_frame_rate.den,
592
                                  st->avg_frame_rate.num };
593
    c->frame_duration = av_rescale_q(1, c->time_base, AV_TIME_BASE_Q);
594
    c->time_frame = av_gettime();
595
596
    ret = pixfmt_from_pixmap_format(s, geo->depth, &st->codecpar->format, &c->bpp);
597
    free(geo);
598
    if (ret < 0)
599
        return ret;
600
601
    frame_size_bits = (int64_t)c->width * c->height * c->bpp;
602
    if (frame_size_bits / 8 + AV_INPUT_BUFFER_PADDING_SIZE > INT_MAX) {
603
        av_log(s, AV_LOG_ERROR, "Captured area is too large\n");
604
        return AVERROR_PATCHWELCOME;
605
    }
606
    c->frame_size = frame_size_bits / 8;
607
608
#if CONFIG_LIBXCB_SHM
609
    c->shm_pool = av_buffer_pool_init2(c->frame_size + AV_INPUT_BUFFER_PADDING_SIZE,
610
                                           c->conn, allocate_shm_buffer, NULL);
611
    if (!c->shm_pool)
612
        return AVERROR(ENOMEM);
613
#endif
614
615
    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
616
    st->codecpar->codec_id   = AV_CODEC_ID_RAWVIDEO;
617
    st->codecpar->width      = c->width;
618
    st->codecpar->height     = c->height;
619
    st->codecpar->bit_rate   = av_rescale(frame_size_bits, st->avg_frame_rate.num, st->avg_frame_rate.den);
620
621
    return ret;
622
}
623
624
static void draw_rectangle(AVFormatContext *s)
625
{
626
    XCBGrabContext *c = s->priv_data;
627
    xcb_gcontext_t gc = xcb_generate_id(c->conn);
628
    uint32_t mask     = XCB_GC_FOREGROUND |
629
                        XCB_GC_BACKGROUND |
630
                        XCB_GC_LINE_WIDTH |
631
                        XCB_GC_LINE_STYLE |
632
                        XCB_GC_FILL_STYLE;
633
    uint32_t values[] = { c->screen->black_pixel,
634
                          c->screen->white_pixel,
635
                          c->region_border,
636
                          XCB_LINE_STYLE_DOUBLE_DASH,
637
                          XCB_FILL_STYLE_SOLID };
638
    xcb_rectangle_t r = { 1, 1,
639
                          c->width  + c->region_border * 2 - 3,
640
                          c->height + c->region_border * 2 - 3 };
641
642
    xcb_create_gc(c->conn, gc, c->window, mask, values);
643
644
    xcb_poly_rectangle(c->conn, c->window, gc, 1, &r);
645
}
646
647
static void setup_window(AVFormatContext *s)
648
{
649
    XCBGrabContext *c = s->priv_data;
650
    uint32_t mask     = XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK;
651
    uint32_t values[] = { 1,
652
                          XCB_EVENT_MASK_EXPOSURE |
653
                          XCB_EVENT_MASK_STRUCTURE_NOTIFY };
654
    av_unused xcb_rectangle_t rect = { 0, 0, c->width, c->height };
655
656
    c->window = xcb_generate_id(c->conn);
657
658
    xcb_create_window(c->conn, XCB_COPY_FROM_PARENT,
659
                      c->window,
660
                      c->screen->root,
661
                      c->x - c->region_border,
662
                      c->y - c->region_border,
663
                      c->width + c->region_border * 2,
664
                      c->height + c->region_border * 2,
665
                      0,
666
                      XCB_WINDOW_CLASS_INPUT_OUTPUT,
667
                      XCB_COPY_FROM_PARENT,
668
                      mask, values);
669
670
#if CONFIG_LIBXCB_SHAPE
671
    xcb_shape_rectangles(c->conn, XCB_SHAPE_SO_SUBTRACT,
672
                         XCB_SHAPE_SK_BOUNDING, XCB_CLIP_ORDERING_UNSORTED,
673
                         c->window,
674
                         c->region_border, c->region_border,
675
                         1, &rect);
676
#endif
677
678
    xcb_map_window(c->conn, c->window);
679
680
    draw_rectangle(s);
681
}
682
683
#define CROSSHAIR_CURSOR 34
684
685
static xcb_rectangle_t rectangle_from_corners(xcb_point_t *corner_a,
686
                                              xcb_point_t *corner_b)
687
{
688
    xcb_rectangle_t rectangle;
689
    rectangle.x = FFMIN(corner_a->x, corner_b->x);
690
    rectangle.y = FFMIN(corner_a->y, corner_b->y);
691
    rectangle.width = FFABS(corner_a->x - corner_b->x);
692
    rectangle.height = FFABS(corner_a->y - corner_b->y);
693
    return rectangle;
694
}
695
696
static int select_region(AVFormatContext *s)
697
{
698
    XCBGrabContext *c = s->priv_data;
699
    xcb_connection_t *conn = c->conn;
700
    xcb_screen_t *screen = c->screen;
701
702
    int ret = 0, done = 0, was_pressed = 0;
703
    xcb_cursor_t cursor;
704
    xcb_font_t cursor_font;
705
    xcb_point_t press_position;
706
    xcb_generic_event_t *event;
707
    xcb_rectangle_t rectangle = { 0 };
708
    xcb_grab_pointer_reply_t *reply;
709
    xcb_grab_pointer_cookie_t cookie;
710
711
    xcb_window_t root_window = screen->root;
712
    xcb_gcontext_t gc = xcb_generate_id(conn);
713
    uint32_t mask = XCB_GC_FUNCTION | XCB_GC_SUBWINDOW_MODE;
714
    uint32_t values[] = { XCB_GX_INVERT, XCB_SUBWINDOW_MODE_INCLUDE_INFERIORS };
715
    xcb_create_gc(conn, gc, root_window, mask, values);
716
717
    cursor_font = xcb_generate_id(conn);
718
    xcb_open_font(conn, cursor_font, strlen("cursor"), "cursor");
719
    cursor = xcb_generate_id(conn);
720
    xcb_create_glyph_cursor(conn, cursor, cursor_font, cursor_font,
721
                            CROSSHAIR_CURSOR, CROSSHAIR_CURSOR + 1, 0, 0, 0,
722
                            0xFFFF, 0xFFFF, 0xFFFF);
723
    cookie = xcb_grab_pointer(conn, 0, root_window,
724
                              XCB_EVENT_MASK_BUTTON_PRESS |
725
                              XCB_EVENT_MASK_BUTTON_RELEASE |
726
                              XCB_EVENT_MASK_BUTTON_MOTION,
727
                              XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC,
728
                              root_window, cursor, XCB_CURRENT_TIME);
729
    reply = xcb_grab_pointer_reply(conn, cookie, NULL);
730
    if (!reply || reply->status != XCB_GRAB_STATUS_SUCCESS) {
731
        av_log(s, AV_LOG_ERROR,
732
               "Failed to select region. Could not grab pointer.\n");
733
        ret = AVERROR(EIO);
734
        free(reply);
735
        goto fail;
736
    }
737
    free(reply);
738
739
    xcb_grab_server(conn);
740
741
    while (!done && (event = xcb_wait_for_event(conn))) {
742
        switch (event->response_type & ~0x80) {
743
        case XCB_BUTTON_PRESS: {
744
            xcb_button_press_event_t *press = (xcb_button_press_event_t *)event;
745
            press_position = (xcb_point_t){ press->event_x, press->event_y };
746
            rectangle.x = press_position.x;
747
            rectangle.y = press_position.y;
748
            xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
749
            was_pressed = 1;
750
            break;
751
        }
752
        case XCB_MOTION_NOTIFY: {
753
            if (was_pressed) {
754
                xcb_motion_notify_event_t *motion =
755
                    (xcb_motion_notify_event_t *)event;
756
                xcb_point_t cursor_position = { motion->event_x, motion->event_y };
757
                xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
758
                rectangle = rectangle_from_corners(&press_position, &cursor_position);
759
                xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
760
            }
761
            break;
762
        }
763
        case XCB_BUTTON_RELEASE: {
764
            xcb_poly_rectangle(conn, root_window, gc, 1, &rectangle);
765
            done = 1;
766
            break;
767
        }
768
        default:
769
            break;
770
        }
771
        xcb_flush(conn);
772
        free(event);
773
    }
774
    c->width  = rectangle.width;
775
    c->height = rectangle.height;
776
    if (c->width && c->height) {
777
        c->x = rectangle.x;
778
        c->y = rectangle.y;
779
    } else {
780
        c->x = 0;
781
        c->y = 0;
782
    }
783
    xcb_ungrab_server(conn);
784
    xcb_ungrab_pointer(conn, XCB_CURRENT_TIME);
785
    xcb_flush(conn);
786
787
fail:
788
    xcb_free_cursor(conn, cursor);
789
    xcb_close_font(conn, cursor_font);
790
    xcb_free_gc(conn, gc);
791
    return ret;
792
}
793
794
static av_cold int xcbgrab_read_header(AVFormatContext *s)
795
{
796
    XCBGrabContext *c = s->priv_data;
797
    int screen_num, ret;
798
    const xcb_setup_t *setup;
799
    char *display_name = av_strdup(s->url);
800
801
    if (!display_name)
802
        return AVERROR(ENOMEM);
803
804
    if (!sscanf(s->url, "%[^+]+%d,%d", display_name, &c->x, &c->y)) {
805
        *display_name = 0;
806
        sscanf(s->url, "+%d,%d", &c->x, &c->y);
807
    }
808
809
    c->conn = xcb_connect(display_name[0] ? display_name : NULL, &screen_num);
810
    av_freep(&display_name);
811
812
    if ((ret = xcb_connection_has_error(c->conn))) {
813
        av_log(s, AV_LOG_ERROR, "Cannot open display %s, error %d.\n",
814
               s->url[0] ? s->url : "default", ret);
815
        return AVERROR(EIO);
816
    }
817
818
    setup = xcb_get_setup(c->conn);
819
820
    c->screen = get_screen(setup, screen_num);
821
    if (!c->screen) {
822
        av_log(s, AV_LOG_ERROR, "The screen %d does not exist.\n",
823
               screen_num);
824
        xcbgrab_read_close(s);
825
        return AVERROR(EIO);
826
    }
827
828
    if (c->select_region) {
829
        ret = select_region(s);
830
        if (ret < 0) {
831
            xcbgrab_read_close(s);
832
            return ret;
833
        }
834
    }
835
836
    ret = create_stream(s);
837
838
    if (ret < 0) {
839
        xcbgrab_read_close(s);
840
        return ret;
841
    }
842
843
#if CONFIG_LIBXCB_SHM
844
    c->has_shm = check_shm(c->conn);
845
#endif
846
847
#if CONFIG_LIBXCB_XFIXES
848
    if (c->draw_mouse) {
849
        if (!(c->draw_mouse = check_xfixes(c->conn))) {
850
            av_log(s, AV_LOG_WARNING,
851
                   "XFixes not available, cannot draw the mouse.\n");
852
        }
853
        if (c->bpp < 24) {
854
            avpriv_report_missing_feature(s, "%d bits per pixel screen",
855
                                          c->bpp);
856
            c->draw_mouse = 0;
857
        }
858
    }
859
#endif
860
861
    if (c->show_region)
862
        setup_window(s);
863
864
    return 0;
865
}
866
867
AVInputFormat ff_xcbgrab_demuxer = {
868
    .name           = "x11grab",
869
    .long_name      = NULL_IF_CONFIG_SMALL("X11 screen capture, using XCB"),
870
    .priv_data_size = sizeof(XCBGrabContext),
871
    .read_header    = xcbgrab_read_header,
872
    .read_packet    = xcbgrab_read_packet,
873
    .read_close     = xcbgrab_read_close,
874
    .flags          = AVFMT_NOFILE,
875
    .priv_class     = &xcbgrab_class,
876
};