libavdevice/x11grab.c

   1 /*
   2  * X11 video grab interface
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg integration:
   7  * Copyright (C) 2006 Clemens Fruhwirth <clemens@endorphin.org>
   8  *                    Edouard Gomez <ed.gomez@free.fr>
   9  *
  10  * This file contains code from grab.c:
  11  * Copyright (c) 2000-2001 Fabrice Bellard
  12  *
  13  * This file contains code from the xvidcap project:
  14  * Copyright (C) 1997-1998 Rasca, Berlin
  15  *               2003-2004 Karl H. Beckers, Frankfurt
  16  *
  17  * FFmpeg is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 2 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * FFmpeg is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with FFmpeg; if not, write to the Free Software
  29  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  30  */
  31
  32 /**
  33  * @file libavdevice/x11grab.c
  34  * X11 frame device demuxer by Clemens Fruhwirth <clemens@endorphin.org>
  35  * and Edouard Gomez <ed.gomez@free.fr>.
  36  */
  37
  38 #include "config.h"
  39 #include "libavformat/avformat.h"
  40 #include <time.h>
  41 #include <X11/X.h>
  42 #include <X11/Xlib.h>
  43 #include <X11/Xlibint.h>
  44 #include <X11/Xproto.h>
  45 #include <X11/Xutil.h>
  46 #include <sys/shm.h>
  47 #include <X11/extensions/XShm.h>
  48
  49 /**
  50  * X11 Device Demuxer context
  51  */
  52 struct x11_grab
  53 {
  54     int frame_size;          /**< Size in bytes of a grabbed frame */
  55     AVRational time_base;    /**< Time base */
  56     int64_t time_frame;      /**< Current time */
  57
  58     int height;              /**< Height of the grab frame */
  59     int width;               /**< Width of the grab frame */
  60     int x_off;               /**< Horizontal top-left corner coordinate */
  61     int y_off;               /**< Vertical top-left corner coordinate */
  62
  63     Display *dpy;            /**< X11 display from which x11grab grabs frames */
  64     XImage *image;           /**< X11 image holding the grab */
  65     int use_shm;             /**< !0 when using XShm extension */
  66     XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
  67     int mouse_warning_shown;
  68 };
  69
  70 /**
  71  * Initializes the x11 grab device demuxer (public device demuxer API).
  72  *
  73  * @param s1 Context from avformat core
  74  * @param ap Parameters from avformat core
  75  * @return <ul>
  76  *          <li>AVERROR(ENOMEM) no memory left</li>
  77  *          <li>AVERROR(EIO) other failure case</li>
  78  *          <li>0 success</li>
  79  *         </ul>
  80  */
  81 static int
  82 x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
  83 {
  84     struct x11_grab *x11grab = s1->priv_data;
  85     Display *dpy;
  86     AVStream *st = NULL;
  87     int input_pixfmt;
  88     XImage *image;
  89     int x_off = 0;
  90     int y_off = 0;
  91     int use_shm;
  92     char *param, *offset;
  93
  94     param = av_strdup(s1->filename);
  95     offset = strchr(param, '+');
  96     if (offset) {
  97         sscanf(offset, "%d,%d", &x_off, &y_off);
  98         *offset= 0;
  99     }
 100
 101     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);
 102
 103     dpy = XOpenDisplay(param);
 104     if(!dpy) {
 105         av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
 106         return AVERROR(EIO);
 107     }
 108
 109     if (!ap || ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
 110         av_log(s1, AV_LOG_ERROR, "AVParameters don't have video size and/or rate. Use -s and -r.\n");
 111         return AVERROR(EIO);
 112     }
 113
 114     st = av_new_stream(s1, 0);
 115     if (!st) {
 116         return AVERROR(ENOMEM);
 117     }
 118     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 119
 120     use_shm = XShmQueryExtension(dpy);
 121     av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");
 122
 123     if(use_shm) {
 124         int scr = XDefaultScreen(dpy);
 125         image = XShmCreateImage(dpy,
 126                                 DefaultVisual(dpy, scr),
 127                                 DefaultDepth(dpy, scr),
 128                                 ZPixmap,
 129                                 NULL,
 130                                 &x11grab->shminfo,
 131                                 ap->width, ap->height);
 132         x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
 133                                         image->bytes_per_line * image->height,
 134                                         IPC_CREAT|0777);
 135         if (x11grab->shminfo.shmid == -1) {
 136             av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
 137             return AVERROR(ENOMEM);
 138         }
 139         x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
 140         x11grab->shminfo.readOnly = False;
 141
 142         if (!XShmAttach(dpy, &x11grab->shminfo)) {
 143             av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
 144             /* needs some better error subroutine :) */
 145             return AVERROR(EIO);
 146         }
 147     } else {
 148         image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
 149                           x_off,y_off,
 150                           ap->width,ap->height,
 151                           AllPlanes, ZPixmap);
 152     }
 153
 154     switch (image->bits_per_pixel) {
 155     case 8:
 156         av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
 157         input_pixfmt = PIX_FMT_PAL8;
 158         break;
 159     case 16:
 160         if (       image->red_mask   == 0xf800 &&
 161                    image->green_mask == 0x07e0 &&
 162                    image->blue_mask  == 0x001f ) {
 163             av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
 164             input_pixfmt = PIX_FMT_RGB565;
 165         } else if (image->red_mask   == 0x7c00 &&
 166                    image->green_mask == 0x03e0 &&
 167                    image->blue_mask  == 0x001f ) {
 168             av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
 169             input_pixfmt = PIX_FMT_RGB555;
 170         } else {
 171             av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
 172             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);
 173             return AVERROR(EIO);
 174         }
 175         break;
 176     case 24:
 177         if (        image->red_mask   == 0xff0000 &&
 178                     image->green_mask == 0x00ff00 &&
 179                     image->blue_mask  == 0x0000ff ) {
 180             input_pixfmt = PIX_FMT_BGR24;
 181         } else if ( image->red_mask   == 0x0000ff &&
 182                     image->green_mask == 0x00ff00 &&
 183                     image->blue_mask  == 0xff0000 ) {
 184             input_pixfmt = PIX_FMT_RGB24;
 185         } else {
 186             av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
 187             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);
 188             return AVERROR(EIO);
 189         }
 190         break;
 191     case 32:
 192 #if 0
 193         GetColorInfo (image, &c_info);
 194         if ( c_info.alpha_mask == 0xff000000 && image->green_mask == 0x0000ff00) {
 195             /* byte order is relevant here, not endianness
 196              * endianness is handled by avcodec, but atm no such thing
 197              * as having ABGR, instead of ARGB in a word. Since we
 198              * need this for Solaris/SPARC, but need to do the conversion
 199              * for every frame we do it outside of this loop, cf. below
 200              * this matches both ARGB32 and ABGR32 */
 201             input_pixfmt = PIX_FMT_ARGB32;
 202         }  else {
 203             av_log(s1, AV_LOG_ERROR,"image depth %i not supported ... aborting\n", image->bits_per_pixel);
 204             return AVERROR(EIO);
 205         }
 206 #endif
 207         input_pixfmt = PIX_FMT_RGB32;
 208         break;
 209     default:
 210         av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
 211         return -1;
 212     }
 213
 214     x11grab->frame_size = ap->width * ap->height * image->bits_per_pixel/8;
 215     x11grab->dpy = dpy;
 216     x11grab->width = ap->width;
 217     x11grab->height = ap->height;
 218     x11grab->time_base  = ap->time_base;
 219     x11grab->time_frame = av_gettime() / av_q2d(ap->time_base);
 220     x11grab->x_off = x_off;
 221     x11grab->y_off = y_off;
 222     x11grab->image = image;
 223     x11grab->use_shm = use_shm;
 224     x11grab->mouse_warning_shown = 0;
 225
 226     st->codec->codec_type = CODEC_TYPE_VIDEO;
 227     st->codec->codec_id = CODEC_ID_RAWVIDEO;
 228     st->codec->width = ap->width;
 229     st->codec->height = ap->height;
 230     st->codec->pix_fmt = input_pixfmt;
 231     st->codec->time_base = ap->time_base;
 232     st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(ap->time_base) * 8;
 233
 234     return 0;
 235 }
 236
 237 /**
 238  * Get pointer coordinates from X11.
 239  *
 240  * @param x Integer where horizontal coordinate will be returned
 241  * @param y Integer where vertical coordinate will be returned
 242  * @param dpy X11 display from where pointer coordinates are retrieved
 243  * @param s1 Context used for logging errors if necessary
 244  */
 245 static void
 246 get_pointer_coordinates(int *x, int *y, Display *dpy, AVFormatContext *s1)
 247 {
 248     Window mrootwindow, childwindow;
 249     int dummy;
 250
 251     mrootwindow = DefaultRootWindow(dpy);
 252
 253     if (XQueryPointer(dpy, mrootwindow, &mrootwindow, &childwindow,
 254                       x, y, &dummy, &dummy, (unsigned int*)&dummy)) {
 255     } else {
 256         struct x11_grab *s = s1->priv_data;
 257         if (!s->mouse_warning_shown) {
 258             av_log(s1, AV_LOG_INFO, "couldn't find mouse pointer\n");
 259             s->mouse_warning_shown = 1;
 260         }
 261         *x = -1;
 262         *y = -1;
 263     }
 264 }
 265
 266 /**
 267  * Mouse painting helper function that applies an 'and' and 'or' mask pair to
 268  * '*dst' pixel. It actually draws a mouse pointer pixel to grabbed frame.
 269  *
 270  * @param dst Destination pixel
 271  * @param and Part of the mask that must be applied using a bitwise 'and'
 272  *            operator
 273  * @param or  Part of the mask that must be applied using a bitwise 'or'
 274  *            operator
 275  * @param bits_per_pixel Bits per pixel used in the grabbed image
 276  */
 277 static void inline
 278 apply_masks(uint8_t *dst, int and, int or, int bits_per_pixel)
 279 {
 280     switch (bits_per_pixel) {
 281     case 32:
 282         *(uint32_t*)dst = (*(uint32_t*)dst & and) | or;
 283         break;
 284     case 16:
 285         *(uint16_t*)dst = (*(uint16_t*)dst & and) | or;
 286         break;
 287     case 8:
 288         *dst = !!or;
 289         break;
 290     }
 291 }
 292
 293 /**
 294  * Paints a mouse pointer in an X11 image.
 295  *
 296  * @param image image to paint the mouse pointer to
 297  * @param s context used to retrieve original grabbing rectangle
 298  *          coordinates
 299  * @param x Mouse pointer coordinate
 300  * @param y Mouse pointer coordinate
 301  */
 302 static void
 303 paint_mouse_pointer(XImage *image, struct x11_grab *s, int x, int y)
 304 {
 305     /* 16x20x1bpp bitmap for the black channel of the mouse pointer */
 306     static const uint16_t const mousePointerBlack[] =
 307         {
 308             0x0000, 0x0003, 0x0005, 0x0009, 0x0011,
 309             0x0021, 0x0041, 0x0081, 0x0101, 0x0201,
 310             0x03c1, 0x0049, 0x0095, 0x0093, 0x0120,
 311             0x0120, 0x0240, 0x0240, 0x0380, 0x0000
 312         };
 313
 314     /* 16x20x1bpp bitmap for the white channel of the mouse pointer */
 315     static const uint16_t const mousePointerWhite[] =
 316         {
 317             0x0000, 0x0000, 0x0002, 0x0006, 0x000e,
 318             0x001e, 0x003e, 0x007e, 0x00fe, 0x01fe,
 319             0x003e, 0x0036, 0x0062, 0x0060, 0x00c0,
 320             0x00c0, 0x0180, 0x0180, 0x0000, 0x0000
 321         };
 322
 323     int x_off = s->x_off;
 324     int y_off = s->y_off;
 325     int width = s->width;
 326     int height = s->height;
 327
 328     if (   x - x_off >= 0 && x < width + x_off
 329         && y - y_off >= 0 && y < height + y_off) {
 330         uint8_t *im_data = (uint8_t*)image->data;
 331         int bytes_per_pixel;
 332         int line;
 333         int masks;
 334
 335         /* Select correct masks and pixel size */
 336         if (image->bits_per_pixel == 8) {
 337             masks = 1;
 338         } else {
 339             masks = (image->red_mask|image->green_mask|image->blue_mask);
 340         }
 341         bytes_per_pixel = image->bits_per_pixel>>3;
 342
 343         /* Shift to right line */
 344         im_data += image->bytes_per_line * (y - y_off);
 345         /* Shift to right pixel in the line */
 346         im_data += bytes_per_pixel * (x - x_off);
 347
 348         /* Draw the cursor - proper loop */
 349         for (line = 0; line < FFMIN(20, (y_off + height) - y); line++) {
 350             uint8_t *cursor = im_data;
 351             int column;
 352             uint16_t bm_b;
 353             uint16_t bm_w;
 354
 355             bm_b = mousePointerBlack[line];
 356             bm_w = mousePointerWhite[line];
 357
 358             for (column = 0; column < FFMIN(16, (x_off + width) - x); column++) {
 359                 apply_masks(cursor, ~(masks*(bm_b&1)), masks*(bm_w&1),
 360                             image->bits_per_pixel);
 361                 cursor += bytes_per_pixel;
 362                 bm_b >>= 1;
 363                 bm_w >>= 1;
 364             }
 365             im_data += image->bytes_per_line;
 366         }
 367     }
 368 }
 369
 370
 371 /**
 372  * Reads new data in the image structure.
 373  *
 374  * @param dpy X11 display to grab from
 375  * @param d
 376  * @param image Image where the grab will be put
 377  * @param x Top-Left grabbing rectangle horizontal coordinate
 378  * @param y Top-Left grabbing rectangle vertical coordinate
 379  * @return 0 if error, !0 if successful
 380  */
 381 static int
 382 xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
 383 {
 384     xGetImageReply rep;
 385     xGetImageReq *req;
 386     long nbytes;
 387
 388     if (!image) {
 389         return 0;
 390     }
 391
 392     LockDisplay(dpy);
 393     GetReq(GetImage, req);
 394
 395     /* First set up the standard stuff in the request */
 396     req->drawable = d;
 397     req->x = x;
 398     req->y = y;
 399     req->width = image->width;
 400     req->height = image->height;
 401     req->planeMask = (unsigned int)AllPlanes;
 402     req->format = ZPixmap;
 403
 404     if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
 405         UnlockDisplay(dpy);
 406         SyncHandle();
 407         return 0;
 408     }
 409
 410     nbytes = (long)rep.length << 2;
 411     _XReadPad(dpy, image->data, nbytes);
 412
 413     UnlockDisplay(dpy);
 414     SyncHandle();
 415     return 1;
 416 }
 417
 418 /**
 419  * Grabs a frame from x11 (public device demuxer API).
 420  *
 421  * @param s1 Context from avformat core
 422  * @param pkt Packet holding the brabbed frame
 423  * @return frame size in bytes
 424  */
 425 static int
 426 x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
 427 {
 428     struct x11_grab *s = s1->priv_data;
 429     Display *dpy = s->dpy;
 430     XImage *image = s->image;
 431     int x_off = s->x_off;
 432     int y_off = s->y_off;
 433
 434     int64_t curtime, delay;
 435     struct timespec ts;
 436
 437     /* Calculate the time of the next frame */
 438     s->time_frame += INT64_C(1000000);
 439
 440     /* wait based on the frame rate */
 441     for(;;) {
 442         curtime = av_gettime();
 443         delay = s->time_frame * av_q2d(s->time_base) - curtime;
 444         if (delay <= 0) {
 445             if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
 446                 s->time_frame += INT64_C(1000000);
 447             }
 448             break;
 449         }
 450         ts.tv_sec = delay / 1000000;
 451         ts.tv_nsec = (delay % 1000000) * 1000;
 452         nanosleep(&ts, NULL);
 453     }
 454
 455     if (av_new_packet(pkt, s->frame_size) < 0) {
 456         return AVERROR(EIO);
 457     }
 458
 459     pkt->pts = curtime;
 460
 461     if(s->use_shm) {
 462         if (!XShmGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off, AllPlanes)) {
 463             av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
 464         }
 465     } else {
 466         if (!xget_zpixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {
 467             av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
 468         }
 469     }
 470
 471     {
 472         int pointer_x, pointer_y;
 473         get_pointer_coordinates(&pointer_x, &pointer_y, dpy, s1);
 474         paint_mouse_pointer(image, s, pointer_x, pointer_y);
 475     }
 476
 477
 478     /* XXX: avoid memcpy */
 479     memcpy(pkt->data, image->data, s->frame_size);
 480     return s->frame_size;
 481 }
 482
 483 /**
 484  * Closes x11 frame grabber (public device demuxer API).
 485  *
 486  * @param s1 Context from avformat core
 487  * @return 0 success, !0 failure
 488  */
 489 static int
 490 x11grab_read_close(AVFormatContext *s1)
 491 {
 492     struct x11_grab *x11grab = s1->priv_data;
 493
 494     /* Detach cleanly from shared mem */
 495     if (x11grab->use_shm) {
 496         XShmDetach(x11grab->dpy, &x11grab->shminfo);
 497         shmdt(x11grab->shminfo.shmaddr);
 498         shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
 499     }
 500
 501     /* Destroy X11 image */
 502     if (x11grab->image) {
 503         XDestroyImage(x11grab->image);
 504         x11grab->image = NULL;
 505     }
 506
 507     /* Free X11 display */
 508     XCloseDisplay(x11grab->dpy);
 509     return 0;
 510 }
 511
 512 /** x11 grabber device demuxer declaration */
 513 AVInputFormat x11_grab_device_demuxer =
 514 {
 515     "x11grab",
 516     NULL_IF_CONFIG_SMALL("X11grab"),
 517     sizeof(struct x11_grab),
 518     NULL,
 519     x11grab_read_header,
 520     x11grab_read_packet,
 521     x11grab_read_close,
 522     .flags = AVFMT_NOFILE,
 523 };