aboutsummaryrefslogtreecommitdiffstats
path: root/libavdevice/x11grab.c
blob: a9fdce4271a83b6329c7a768952524c8ba22043d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
/*
 * X11 video grab interface
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg integration:
 * Copyright (C) 2006 Clemens Fruhwirth <clemens@endorphin.org>
 *                    Edouard Gomez <ed.gomez@free.fr>
 *
 * This file contains code from grab.c:
 * Copyright (c) 2000-2001 Fabrice Bellard
 *
 * This file contains code from the xvidcap project:
 * Copyright (C) 1997-1998 Rasca, Berlin
 *               2003-2004 Karl H. Beckers, Frankfurt
 *
 * FFmpeg is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file libavdevice/x11grab.c
 * X11 frame device demuxer by Clemens Fruhwirth <clemens@endorphin.org>
 * and Edouard Gomez <ed.gomez@free.fr>.
 */

#include "config.h"
#include "libavformat/avformat.h"
#include <time.h>
#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xlibint.h>
#include <X11/Xproto.h>
#include <X11/Xutil.h>
#include <sys/shm.h>
#include <X11/extensions/XShm.h>

/**
 * X11 Device Demuxer context
 */
struct x11_grab
{
    int frame_size;          /**< Size in bytes of a grabbed frame */
    AVRational time_base;    /**< Time base */
    int64_t time_frame;      /**< Current time */

    int height;              /**< Height of the grab frame */
    int width;               /**< Width of the grab frame */
    int x_off;               /**< Horizontal top-left corner coordinate */
    int y_off;               /**< Vertical top-left corner coordinate */

    Display *dpy;            /**< X11 display from which x11grab grabs frames */
    XImage *image;           /**< X11 image holding the grab */
    int use_shm;             /**< !0 when using XShm extension */
    XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
    int mouse_warning_shown;
};

/**
 * Initializes the x11 grab device demuxer (public device demuxer API).
 *
 * @param s1 Context from avformat core
 * @param ap Parameters from avformat core
 * @return <ul>
 *          <li>AVERROR(ENOMEM) no memory left</li>
 *          <li>AVERROR(EIO) other failure case</li>
 *          <li>0 success</li>
 *         </ul>
 */
static int
x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
{
    struct x11_grab *x11grab = s1->priv_data;
    Display *dpy;
    AVStream *st = NULL;
    int input_pixfmt;
    XImage *image;
    int x_off = 0;
    int y_off = 0;
    int use_shm;
    char *param, *offset;

    param = av_strdup(s1->filename);
    offset = strchr(param, '+');
    if (offset) {
        sscanf(offset, "%d,%d", &x_off, &y_off);
        *offset= 0;
    }

    av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d height: %d\n", s1->filename, param, x_off, y_off, ap->width, ap->height);

    dpy = XOpenDisplay(param);
    if(!dpy) {
        av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
        return AVERROR(EIO);
    }

    if (!ap || ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
        av_log(s1, AV_LOG_ERROR, "AVParameters don't have video size and/or rate. Use -s and -r.\n");
        return AVERROR(EIO);
    }

    st = av_new_stream(s1, 0);
    if (!st) {
        return AVERROR(ENOMEM);
    }
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */

    use_shm = XShmQueryExtension(dpy);
    av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");

    if(use_shm) {
        int scr = XDefaultScreen(dpy);
        image = XShmCreateImage(dpy,
                                DefaultVisual(dpy, scr),
                                DefaultDepth(dpy, scr),
                                ZPixmap,
                                NULL,
                                &x11grab->shminfo,
                                ap->width, ap->height);
        x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
                                        image->bytes_per_line * image->height,
                                        IPC_CREAT|0777);
        if (x11grab->shminfo.shmid == -1) {
            av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
            return AVERROR(ENOMEM);
        }
        x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
        x11grab->shminfo.readOnly = False;

        if (!XShmAttach(dpy, &x11grab->shminfo)) {
            av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
            /* needs some better error subroutine :) */
            return AVERROR(EIO);
        }
    } else {
        image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
                          x_off,y_off,
                          ap->width,ap->height,
                          AllPlanes, ZPixmap);
    }

    switch (image->bits_per_pixel) {
    case 8:
        av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
        input_pixfmt = PIX_FMT_PAL8;
        break;
    case 16:
        if (       image->red_mask   == 0xf800 &&
                   image->green_mask == 0x07e0 &&
                   image->blue_mask  == 0x001f ) {
            av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
            input_pixfmt = PIX_FMT_RGB565;
        } else if (image->red_mask   == 0x7c00 &&
                   image->green_mask == 0x03e0 &&
                   image->blue_mask  == 0x001f ) {
            av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
            input_pixfmt = PIX_FMT_RGB555;
        } else {
            av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
            av_log(s1, AV_LOG_ERROR, "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n", image->red_mask, image->green_mask, image->blue_mask);
            return AVERROR(EIO);
        }
        break;
    case 24:
        if (        image->red_mask   == 0xff0000 &&
                    image->green_mask == 0x00ff00 &&
                    image->blue_mask  == 0x0000ff ) {
            input_pixfmt = PIX_FMT_BGR24;
        } else if ( image->red_mask   == 0x0000ff &&
                    image->green_mask == 0x00ff00 &&
                    image->blue_mask  == 0xff0000 ) {
            input_pixfmt = PIX_FMT_RGB24;
        } else {
            av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
            av_log(s1, AV_LOG_ERROR, "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n", image->red_mask, image->green_mask, image->blue_mask);
            return AVERROR(EIO);
        }
        break;
    case 32:
#if 0
        GetColorInfo (image, &c_info);
        if ( c_info.alpha_mask == 0xff000000 && image->green_mask == 0x0000ff00) {
            /* byte order is relevant here, not endianness
             * endianness is handled by avcodec, but atm no such thing
             * as having ABGR, instead of ARGB in a word. Since we
             * need this for Solaris/SPARC, but need to do the conversion
             * for every frame we do it outside of this loop, cf. below
             * this matches both ARGB32 and ABGR32 */
            input_pixfmt = PIX_FMT_ARGB32;
        }  else {
            av_log(s1, AV_LOG_ERROR,"image depth %i not supported ... aborting\n", image->bits_per_pixel);
            return AVERROR(EIO);
        }
#endif
        input_pixfmt = PIX_FMT_RGB32;
        break;
    default:
        av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
        return -1;
    }

    x11grab->frame_size = ap->width * ap->height * image->bits_per_pixel/8;
    x11grab->dpy = dpy;
    x11grab->width = ap->width;
    x11grab->height = ap->height;
    x11grab->time_base  = ap->time_base;
    x11grab->time_frame = av_gettime() / av_q2d(ap->time_base);
    x11grab->x_off = x_off;
    x11grab->y_off = y_off;
    x11grab->image = image;
    x11grab->use_shm = use_shm;
    x11grab->mouse_warning_shown = 0;

    st->codec->codec_type = CODEC_TYPE_VIDEO;
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
    st->codec->width = ap->width;
    st->codec->height = ap->height;
    st->codec->pix_fmt = input_pixfmt;
    st->codec->time_base = ap->time_base;
    st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(ap->time_base) * 8;

    return 0;
}

/**
 * Get pointer coordinates from X11.
 *
 * @param x Integer where horizontal coordinate will be returned
 * @param y Integer where vertical coordinate will be returned
 * @param dpy X11 display from where pointer coordinates are retrieved
 * @param s1 Context used for logging errors if necessary
 */
static void
get_pointer_coordinates(int *x, int *y, Display *dpy, AVFormatContext *s1)
{
    Window mrootwindow, childwindow;
    int dummy;

    mrootwindow = DefaultRootWindow(dpy);

    if (XQueryPointer(dpy, mrootwindow, &mrootwindow, &childwindow,
                      x, y, &dummy, &dummy, (unsigned int*)&dummy)) {
    } else {
        struct x11_grab *s = s1->priv_data;
        if (!s->mouse_warning_shown) {
            av_log(s1, AV_LOG_INFO, "couldn't find mouse pointer\n");
            s->mouse_warning_shown = 1;
        }
        *x = -1;
        *y = -1;
    }
}

/**
 * Mouse painting helper function that applies an 'and' and 'or' mask pair to
 * '*dst' pixel. It actually draws a mouse pointer pixel to grabbed frame.
 *
 * @param dst Destination pixel
 * @param and Part of the mask that must be applied using a bitwise 'and'
 *            operator
 * @param or  Part of the mask that must be applied using a bitwise 'or'
 *            operator
 * @param bits_per_pixel Bits per pixel used in the grabbed image
 */
static void inline
apply_masks(uint8_t *dst, int and, int or, int bits_per_pixel)
{
    switch (bits_per_pixel) {
    case 32:
        *(uint32_t*)dst = (*(uint32_t*)dst & and) | or;
        break;
    case 16:
        *(uint16_t*)dst = (*(uint16_t*)dst & and) | or;
        break;
    case 8:
        *dst = !!or;
        break;
    }
}

/**
 * Paints a mouse pointer in an X11 image.
 *
 * @param image image to paint the mouse pointer to
 * @param s context used to retrieve original grabbing rectangle
 *          coordinates
 * @param x Mouse pointer coordinate
 * @param y Mouse pointer coordinate
 */
static void
paint_mouse_pointer(XImage *image, struct x11_grab *s, int x, int y)
{
    /* 16x20x1bpp bitmap for the black channel of the mouse pointer */
    static const uint16_t const mousePointerBlack[] =
        {
            0x0000, 0x0003, 0x0005, 0x0009, 0x0011,
            0x0021, 0x0041, 0x0081, 0x0101, 0x0201,
            0x03c1, 0x0049, 0x0095, 0x0093, 0x0120,
            0x0120, 0x0240, 0x0240, 0x0380, 0x0000
        };

    /* 16x20x1bpp bitmap for the white channel of the mouse pointer */
    static const uint16_t const mousePointerWhite[] =
        {
            0x0000, 0x0000, 0x0002, 0x0006, 0x000e,
            0x001e, 0x003e, 0x007e, 0x00fe, 0x01fe,
            0x003e, 0x0036, 0x0062, 0x0060, 0x00c0,
            0x00c0, 0x0180, 0x0180, 0x0000, 0x0000
        };

    int x_off = s->x_off;
    int y_off = s->y_off;
    int width = s->width;
    int height = s->height;

    if (   x - x_off >= 0 && x < width + x_off
        && y - y_off >= 0 && y < height + y_off) {
        uint8_t *im_data = (uint8_t*)image->data;
        int bytes_per_pixel;
        int line;
        int masks;

        /* Select correct masks and pixel size */
        if (image->bits_per_pixel == 8) {
            masks = 1;
        } else {
            masks = (image->red_mask|image->green_mask|image->blue_mask);
        }
        bytes_per_pixel = image->bits_per_pixel>>3;

        /* Shift to right line */
        im_data += image->bytes_per_line * (y - y_off);
        /* Shift to right pixel in the line */
        im_data += bytes_per_pixel * (x - x_off);

        /* Draw the cursor - proper loop */
        for (line = 0; line < FFMIN(20, (y_off + height) - y); line++) {
            uint8_t *cursor = im_data;
            int column;
            uint16_t bm_b;
            uint16_t bm_w;

            bm_b = mousePointerBlack[line];
            bm_w = mousePointerWhite[line];

            for (column = 0; column < FFMIN(16, (x_off + width) - x); column++) {
                apply_masks(cursor, ~(masks*(bm_b&1)), masks*(bm_w&1),
                            image->bits_per_pixel);
                cursor += bytes_per_pixel;
                bm_b >>= 1;
                bm_w >>= 1;
            }
            im_data += image->bytes_per_line;
        }
    }
}


/**
 * Reads new data in the image structure.
 *
 * @param dpy X11 display to grab from
 * @param d
 * @param image Image where the grab will be put
 * @param x Top-Left grabbing rectangle horizontal coordinate
 * @param y Top-Left grabbing rectangle vertical coordinate
 * @return 0 if error, !0 if successful
 */
static int
xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
{
    xGetImageReply rep;
    xGetImageReq *req;
    long nbytes;

    if (!image) {
        return 0;
    }

    LockDisplay(dpy);
    GetReq(GetImage, req);

    /* First set up the standard stuff in the request */
    req->drawable = d;
    req->x = x;
    req->y = y;
    req->width = image->width;
    req->height = image->height;
    req->planeMask = (unsigned int)AllPlanes;
    req->format = ZPixmap;

    if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
        UnlockDisplay(dpy);
        SyncHandle();
        return 0;
    }

    nbytes = (long)rep.length << 2;
    _XReadPad(dpy, image->data, nbytes);

    UnlockDisplay(dpy);
    SyncHandle();
    return 1;
}

/**
 * Grabs a frame from x11 (public device demuxer API).
 *
 * @param s1 Context from avformat core
 * @param pkt Packet holding the brabbed frame
 * @return frame size in bytes
 */
static int
x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
{
    struct x11_grab *s = s1->priv_data;
    Display *dpy = s->dpy;
    XImage *image = s->image;
    int x_off = s->x_off;
    int y_off = s->y_off;

    int64_t curtime, delay;
    struct timespec ts;

    /* Calculate the time of the next frame */
    s->time_frame += INT64_C(1000000);

    /* wait based on the frame rate */
    for(;;) {
        curtime = av_gettime();
        delay = s->time_frame * av_q2d(s->time_base) - curtime;
        if (delay <= 0) {
            if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
                s->time_frame += INT64_C(1000000);
            }
            break;
        }
        ts.tv_sec = delay / 1000000;
        ts.tv_nsec = (delay % 1000000) * 1000;
        nanosleep(&ts, NULL);
    }

    if (av_new_packet(pkt, s->frame_size) < 0) {
        return AVERROR(EIO);
    }

    pkt->pts = curtime;

    if(s->use_shm) {
        if (!XShmGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off, AllPlanes)) {
            av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
        }
    } else {
        if (!xget_zpixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {
            av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
        }
    }

    {
        int pointer_x, pointer_y;
        get_pointer_coordinates(&pointer_x, &pointer_y, dpy, s1);
        paint_mouse_pointer(image, s, pointer_x, pointer_y);
    }


    /* XXX: avoid memcpy */
    memcpy(pkt->data, image->data, s->frame_size);
    return s->frame_size;
}

/**
 * Closes x11 frame grabber (public device demuxer API).
 *
 * @param s1 Context from avformat core
 * @return 0 success, !0 failure
 */
static int
x11grab_read_close(AVFormatContext *s1)
{
    struct x11_grab *x11grab = s1->priv_data;

    /* Detach cleanly from shared mem */
    if (x11grab->use_shm) {
        XShmDetach(x11grab->dpy, &x11grab->shminfo);
        shmdt(x11grab->shminfo.shmaddr);
        shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
    }

    /* Destroy X11 image */
    if (x11grab->image) {
        XDestroyImage(x11grab->image);
        x11grab->image = NULL;
    }

    /* Free X11 display */
    XCloseDisplay(x11grab->dpy);
    return 0;
}

/** x11 grabber device demuxer declaration */
AVInputFormat x11_grab_device_demuxer =
{
    "x11grab",
    NULL_IF_CONFIG_SMALL("X11grab"),
    sizeof(struct x11_grab),
    NULL,
    x11grab_read_header,
    x11grab_read_packet,
    x11grab_read_close,
    .flags = AVFMT_NOFILE,
};