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 <unistd.h>
  41 #include <fcntl.h>
  42 #include <sys/ioctl.h>
  43 #include <sys/time.h>
  44 #define _LINUX_TIME_H 1
  45 #include <time.h>
  46 #include <X11/X.h>
  47 #include <X11/Xlib.h>
  48 #include <X11/Xlibint.h>
  49 #include <X11/Xproto.h>
  50 #include <X11/Xutil.h>
  51 #include <sys/ipc.h>
  52 #include <sys/shm.h>
  53 #include <X11/extensions/XShm.h>
  54
  55 /**
  56  * X11 Device Demuxer context
  57  */
  58 struct x11_grab
  59 {
  60     int frame_size;          /**< Size in bytes of a grabbed frame */
  61     AVRational time_base;    /**< Time base */
  62     int64_t time_frame;      /**< Current time */
  63
  64     int height;              /**< Height of the grab frame */
  65     int width;               /**< Width of the grab frame */
  66     int x_off;               /**< Horizontal top-left corner coordinate */
  67     int y_off;               /**< Vertical top-left corner coordinate */
  68
  69     Display *dpy;            /**< X11 display from which x11grab grabs frames */
  70     XImage *image;           /**< X11 image holding the grab */
  71     int use_shm;             /**< !0 when using XShm extension */
  72     XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
  73     int mouse_warning_shown;
  74 };
  75
  76 /**
  77  * Initializes the x11 grab device demuxer (public device demuxer API).
  78  *
  79  * @param s1 Context from avformat core
  80  * @param ap Parameters from avformat core
  81  * @return <ul>
  82  *          <li>AVERROR(ENOMEM) no memory left</li>
  83  *          <li>AVERROR(EIO) other failure case</li>
  84  *          <li>0 success</li>
  85  *         </ul>
  86  */
  87 static int
  88 x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
  89 {
  90     struct x11_grab *x11grab = s1->priv_data;
  91     Display *dpy;
  92     AVStream *st = NULL;
  93     int input_pixfmt;
  94     XImage *image;
  95     int x_off = 0;
  96     int y_off = 0;
  97     int use_shm;
  98     char *param, *offset;
  99
 100     param = av_strdup(s1->filename);
 101     offset = strchr(param, '+');
 102     if (offset) {
 103         sscanf(offset, "%d,%d", &x_off, &y_off);
 104         *offset= 0;
 105     }
 106
 107     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);
 108
 109     dpy = XOpenDisplay(param);
 110     if(!dpy) {
 111         av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
 112         return AVERROR(EIO);
 113     }
 114
 115     if (!ap || ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
 116         av_log(s1, AV_LOG_ERROR, "AVParameters don't have video size and/or rate. Use -s and -r.\n");
 117         return AVERROR(EIO);
 118     }
 119
 120     st = av_new_stream(s1, 0);
 121     if (!st) {
 122         return AVERROR(ENOMEM);
 123     }
 124     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 125
 126     use_shm = XShmQueryExtension(dpy);
 127     av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");
 128
 129     if(use_shm) {
 130         int scr = XDefaultScreen(dpy);
 131         image = XShmCreateImage(dpy,
 132                                 DefaultVisual(dpy, scr),
 133                                 DefaultDepth(dpy, scr),
 134                                 ZPixmap,
 135                                 NULL,
 136                                 &x11grab->shminfo,
 137                                 ap->width, ap->height);
 138         x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
 139                                         image->bytes_per_line * image->height,
 140                                         IPC_CREAT|0777);
 141         if (x11grab->shminfo.shmid == -1) {
 142             av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
 143             return AVERROR(ENOMEM);
 144         }
 145         x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
 146         x11grab->shminfo.readOnly = False;
 147
 148         if (!XShmAttach(dpy, &x11grab->shminfo)) {
 149             av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
 150             /* needs some better error subroutine :) */
 151             return AVERROR(EIO);
 152         }
 153     } else {
 154         image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
 155                           x_off,y_off,
 156                           ap->width,ap->height,
 157                           AllPlanes, ZPixmap);
 158     }
 159
 160     switch (image->bits_per_pixel) {
 161     case 8:
 162         av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
 163         input_pixfmt = PIX_FMT_PAL8;
 164         break;
 165     case 16:
 166         if (       image->red_mask   == 0xf800 &&
 167                    image->green_mask == 0x07e0 &&
 168                    image->blue_mask  == 0x001f ) {
 169             av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
 170             input_pixfmt = PIX_FMT_RGB565;
 171         } else if (image->red_mask   == 0x7c00 &&
 172                    image->green_mask == 0x03e0 &&
 173                    image->blue_mask  == 0x001f ) {
 174             av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
 175             input_pixfmt = PIX_FMT_RGB555;
 176         } else {
 177             av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
 178             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);
 179             return AVERROR(EIO);
 180         }
 181         break;
 182     case 24:
 183         if (        image->red_mask   == 0xff0000 &&
 184                     image->green_mask == 0x00ff00 &&
 185                     image->blue_mask  == 0x0000ff ) {
 186             input_pixfmt = PIX_FMT_BGR24;
 187         } else if ( image->red_mask   == 0x0000ff &&
 188                     image->green_mask == 0x00ff00 &&
 189                     image->blue_mask  == 0xff0000 ) {
 190             input_pixfmt = PIX_FMT_RGB24;
 191         } else {
 192             av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
 193             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);
 194             return AVERROR(EIO);
 195         }
 196         break;
 197     case 32:
 198 #if 0
 199         GetColorInfo (image, &c_info);
 200         if ( c_info.alpha_mask == 0xff000000 && image->green_mask == 0x0000ff00) {
 201             /* byte order is relevant here, not endianness
 202              * endianness is handled by avcodec, but atm no such thing
 203              * as having ABGR, instead of ARGB in a word. Since we
 204              * need this for Solaris/SPARC, but need to do the conversion
 205              * for every frame we do it outside of this loop, cf. below
 206              * this matches both ARGB32 and ABGR32 */
 207             input_pixfmt = PIX_FMT_ARGB32;
 208         }  else {
 209             av_log(s1, AV_LOG_ERROR,"image depth %i not supported ... aborting\n", image->bits_per_pixel);
 210             return AVERROR(EIO);
 211         }
 212 #endif
 213         input_pixfmt = PIX_FMT_RGB32;
 214         break;
 215     default:
 216         av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
 217         return -1;
 218     }
 219
 220     x11grab->frame_size = ap->width * ap->height * image->bits_per_pixel/8;
 221     x11grab->dpy = dpy;
 222     x11grab->width = ap->width;
 223     x11grab->height = ap->height;
 224     x11grab->time_base  = ap->time_base;
 225     x11grab->time_frame = av_gettime() / av_q2d(ap->time_base);
 226     x11grab->x_off = x_off;
 227     x11grab->y_off = y_off;
 228     x11grab->image = image;
 229     x11grab->use_shm = use_shm;
 230     x11grab->mouse_warning_shown = 0;
 231
 232     st->codec->codec_type = CODEC_TYPE_VIDEO;
 233     st->codec->codec_id = CODEC_ID_RAWVIDEO;
 234     st->codec->width = ap->width;
 235     st->codec->height = ap->height;
 236     st->codec->pix_fmt = input_pixfmt;
 237     st->codec->time_base = ap->time_base;
 238     st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(ap->time_base) * 8;
 239
 240     return 0;
 241 }
 242
 243 /**
 244  * Get pointer coordinates from X11.
 245  *
 246  * @param x Integer where horizontal coordinate will be returned
 247  * @param y Integer where vertical coordinate will be returned
 248  * @param dpy X11 display from where pointer coordinates are retrieved
 249  * @param s1 Context used for logging errors if necessary
 250  */
 251 static void
 252 get_pointer_coordinates(int *x, int *y, Display *dpy, AVFormatContext *s1)
 253 {
 254     Window mrootwindow, childwindow;
 255     int dummy;
 256
 257     mrootwindow = DefaultRootWindow(dpy);
 258
 259     if (XQueryPointer(dpy, mrootwindow, &mrootwindow, &childwindow,
 260                       x, y, &dummy, &dummy, (unsigned int*)&dummy)) {
 261     } else {
 262         struct x11_grab *s = s1->priv_data;
 263         if (!s->mouse_warning_shown) {
 264             av_log(s1, AV_LOG_INFO, "couldn't find mouse pointer\n");
 265             s->mouse_warning_shown = 1;
 266         }
 267         *x = -1;
 268         *y = -1;
 269     }
 270 }
 271
 272 /**
 273  * Mouse painting helper function that applies an 'and' and 'or' mask pair to
 274  * '*dst' pixel. It actually draws a mouse pointer pixel to grabbed frame.
 275  *
 276  * @param dst Destination pixel
 277  * @param and Part of the mask that must be applied using a bitwise 'and'
 278  *            operator
 279  * @param or  Part of the mask that must be applied using a bitwise 'or'
 280  *            operator
 281  * @param bits_per_pixel Bits per pixel used in the grabbed image
 282  */
 283 static void inline
 284 apply_masks(uint8_t *dst, int and, int or, int bits_per_pixel)
 285 {
 286     switch (bits_per_pixel) {
 287     case 32:
 288         *(uint32_t*)dst = (*(uint32_t*)dst & and) | or;
 289         break;
 290     case 16:
 291         *(uint16_t*)dst = (*(uint16_t*)dst & and) | or;
 292         break;
 293     case 8:
 294         *dst = !!or;
 295         break;
 296     }
 297 }
 298
 299 /**
 300  * Paints a mouse pointer in an X11 image.
 301  *
 302  * @param image image to paint the mouse pointer to
 303  * @param s context used to retrieve original grabbing rectangle
 304  *          coordinates
 305  * @param x Mouse pointer coordinate
 306  * @param y Mouse pointer coordinate
 307  */
 308 static void
 309 paint_mouse_pointer(XImage *image, struct x11_grab *s, int x, int y)
 310 {
 311     /* 16x20x1bpp bitmap for the black channel of the mouse pointer */
 312     static const uint16_t const mousePointerBlack[] =
 313         {
 314             0x0000, 0x0003, 0x0005, 0x0009, 0x0011,
 315             0x0021, 0x0041, 0x0081, 0x0101, 0x0201,
 316             0x03c1, 0x0049, 0x0095, 0x0093, 0x0120,
 317             0x0120, 0x0240, 0x0240, 0x0380, 0x0000
 318         };
 319
 320     /* 16x20x1bpp bitmap for the white channel of the mouse pointer */
 321     static const uint16_t const mousePointerWhite[] =
 322         {
 323             0x0000, 0x0000, 0x0002, 0x0006, 0x000e,
 324             0x001e, 0x003e, 0x007e, 0x00fe, 0x01fe,
 325             0x003e, 0x0036, 0x0062, 0x0060, 0x00c0,
 326             0x00c0, 0x0180, 0x0180, 0x0000, 0x0000
 327         };
 328
 329     int x_off = s->x_off;
 330     int y_off = s->y_off;
 331     int width = s->width;
 332     int height = s->height;
 333
 334     if (   x - x_off >= 0 && x < width + x_off
 335         && y - y_off >= 0 && y < height + y_off) {
 336         uint8_t *im_data = (uint8_t*)image->data;
 337         int bytes_per_pixel;
 338         int line;
 339         int masks;
 340
 341         /* Select correct masks and pixel size */
 342         if (image->bits_per_pixel == 8) {
 343             masks = 1;
 344         } else {
 345             masks = (image->red_mask|image->green_mask|image->blue_mask);
 346         }
 347         bytes_per_pixel = image->bits_per_pixel>>3;
 348
 349         /* Shift to right line */
 350         im_data += image->bytes_per_line * (y - y_off);
 351         /* Shift to right pixel in the line */
 352         im_data += bytes_per_pixel * (x - x_off);
 353
 354         /* Draw the cursor - proper loop */
 355         for (line = 0; line < FFMIN(20, (y_off + height) - y); line++) {
 356             uint8_t *cursor = im_data;
 357             int column;
 358             uint16_t bm_b;
 359             uint16_t bm_w;
 360
 361             bm_b = mousePointerBlack[line];
 362             bm_w = mousePointerWhite[line];
 363
 364             for (column = 0; column < FFMIN(16, (x_off + width) - x); column++) {
 365                 apply_masks(cursor, ~(masks*(bm_b&1)), masks*(bm_w&1),
 366                             image->bits_per_pixel);
 367                 cursor += bytes_per_pixel;
 368                 bm_b >>= 1;
 369                 bm_w >>= 1;
 370             }
 371             im_data += image->bytes_per_line;
 372         }
 373     }
 374 }
 375
 376
 377 /**
 378  * Reads new data in the image structure.
 379  *
 380  * @param dpy X11 display to grab from
 381  * @param d
 382  * @param image Image where the grab will be put
 383  * @param x Top-Left grabbing rectangle horizontal coordinate
 384  * @param y Top-Left grabbing rectangle vertical coordinate
 385  * @return 0 if error, !0 if successful
 386  */
 387 static int
 388 xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
 389 {
 390     xGetImageReply rep;
 391     xGetImageReq *req;
 392     long nbytes;
 393
 394     if (!image) {
 395         return 0;
 396     }
 397
 398     LockDisplay(dpy);
 399     GetReq(GetImage, req);
 400
 401     /* First set up the standard stuff in the request */
 402     req->drawable = d;
 403     req->x = x;
 404     req->y = y;
 405     req->width = image->width;
 406     req->height = image->height;
 407     req->planeMask = (unsigned int)AllPlanes;
 408     req->format = ZPixmap;
 409
 410     if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
 411         UnlockDisplay(dpy);
 412         SyncHandle();
 413         return 0;
 414     }
 415
 416     nbytes = (long)rep.length << 2;
 417     _XReadPad(dpy, image->data, nbytes);
 418
 419     UnlockDisplay(dpy);
 420     SyncHandle();
 421     return 1;
 422 }
 423
 424 /**
 425  * Grabs a frame from x11 (public device demuxer API).
 426  *
 427  * @param s1 Context from avformat core
 428  * @param pkt Packet holding the brabbed frame
 429  * @return frame size in bytes
 430  */
 431 static int
 432 x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
 433 {
 434     struct x11_grab *s = s1->priv_data;
 435     Display *dpy = s->dpy;
 436     XImage *image = s->image;
 437     int x_off = s->x_off;
 438     int y_off = s->y_off;
 439
 440     int64_t curtime, delay;
 441     struct timespec ts;
 442
 443     /* Calculate the time of the next frame */
 444     s->time_frame += INT64_C(1000000);
 445
 446     /* wait based on the frame rate */
 447     for(;;) {
 448         curtime = av_gettime();
 449         delay = s->time_frame * av_q2d(s->time_base) - curtime;
 450         if (delay <= 0) {
 451             if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
 452                 s->time_frame += INT64_C(1000000);
 453             }
 454             break;
 455         }
 456         ts.tv_sec = delay / 1000000;
 457         ts.tv_nsec = (delay % 1000000) * 1000;
 458         nanosleep(&ts, NULL);
 459     }
 460
 461     if (av_new_packet(pkt, s->frame_size) < 0) {
 462         return AVERROR(EIO);
 463     }
 464
 465     pkt->pts = curtime;
 466
 467     if(s->use_shm) {
 468         if (!XShmGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off, AllPlanes)) {
 469             av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
 470         }
 471     } else {
 472         if (!xget_zpixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {
 473             av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
 474         }
 475     }
 476
 477     {
 478         int pointer_x, pointer_y;
 479         get_pointer_coordinates(&pointer_x, &pointer_y, dpy, s1);
 480         paint_mouse_pointer(image, s, pointer_x, pointer_y);
 481     }
 482
 483
 484     /* XXX: avoid memcpy */
 485     memcpy(pkt->data, image->data, s->frame_size);
 486     return s->frame_size;
 487 }
 488
 489 /**
 490  * Closes x11 frame grabber (public device demuxer API).
 491  *
 492  * @param s1 Context from avformat core
 493  * @return 0 success, !0 failure
 494  */
 495 static int
 496 x11grab_read_close(AVFormatContext *s1)
 497 {
 498     struct x11_grab *x11grab = s1->priv_data;
 499
 500     /* Detach cleanly from shared mem */
 501     if (x11grab->use_shm) {
 502         XShmDetach(x11grab->dpy, &x11grab->shminfo);
 503         shmdt(x11grab->shminfo.shmaddr);
 504         shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
 505     }
 506
 507     /* Destroy X11 image */
 508     if (x11grab->image) {
 509         XDestroyImage(x11grab->image);
 510         x11grab->image = NULL;
 511     }
 512
 513     /* Free X11 display */
 514     XCloseDisplay(x11grab->dpy);
 515     return 0;
 516 }
 517
 518 /** x11 grabber device demuxer declaration */
 519 AVInputFormat x11_grab_device_demuxer =
 520 {
 521     "x11grab",
 522     NULL_IF_CONFIG_SMALL("X11grab"),
 523     sizeof(struct x11_grab),
 524     NULL,
 525     x11grab_read_header,
 526     x11grab_read_packet,
 527     x11grab_read_close,
 528     .flags = AVFMT_NOFILE,
 529 };