GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavdevice/xcbgrab.c Lines: 0 459 0.0 %
Date: 2021-04-15 16:04:23 Branches: 0 188 0.0 %

Line Branch Exec Source
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/*
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 * XCB input grabber
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 * Copyright (C) 2014 Luca Barbato <lu_zero@gentoo.org>
4
 *
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 * This file is part of FFmpeg.
6
 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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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
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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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
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 * 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
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#if CONFIG_LIBXCB_SHAPE
38
#include <xcb/shape.h>
39
#endif
40
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#include "libavutil/internal.h"
42
#include "libavutil/mathematics.h"
43
#include "libavutil/opt.h"
44
#include "libavutil/parseutils.h"
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#include "libavutil/time.h"
46
47
#include "libavformat/avformat.h"
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#include "libavformat/internal.h"
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50
typedef struct XCBGrabContext {
51
    const AVClass *class;
52
53
    xcb_connection_t *conn;
54
    xcb_screen_t *screen;
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    xcb_window_t window;
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#if CONFIG_LIBXCB_SHM
57
    AVBufferPool *shm_pool;
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#endif
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    int64_t time_frame;
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    AVRational time_base;
61
    int64_t frame_duration;
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63
    xcb_window_t window_id;
64
    int x, y;
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    int width, height;
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    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;
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76
    const char *framerate;
77
78
    int has_shm;
79
} XCBGrabContext;
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#define FOLLOW_CENTER -1
82
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#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 },
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    { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
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      OFFSET(follow_mouse), AV_OPT_TYPE_INT, { .i64 = 0 },  FOLLOW_CENTER, INT_MAX, D, "follow_mouse" },
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    { "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" },
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    { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, D },
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    { "region_border", "Set the region border thickness.", OFFSET(region_border), AV_OPT_TYPE_INT, { .i64 = 3 }, 1, 128, D },
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    { "select_region", "Select the grabbing region graphically using the pointer.", OFFSET(select_region), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, D },
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    { NULL },
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};
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103
static const AVClass xcbgrab_class = {
104
    .class_name = "xcbgrab indev",
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    .item_name  = av_default_item_name,
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    .option     = options,
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    .version    = LIBAVUTIL_VERSION_INT,
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    .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
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};
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static int xcbgrab_reposition(AVFormatContext *s,
112
                              xcb_query_pointer_reply_t *p,
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                              xcb_get_geometry_reply_t *geo)
114
{
115
    XCBGrabContext *c = s->priv_data;
116
    int x = c->x, y = c->y;
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    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
    }
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146
    c->x = FFMIN(FFMAX(0, x), geo->width  - w);
147
    c->y = FFMIN(FFMAX(0, y), geo->height - h);
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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);
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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 "
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               "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
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    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
}
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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, buffer_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)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
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
};