1/*
2 * X11 video grab interface
3 *
4 * This file is part of Libav.
5 *
6 * Libav 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 * Libav 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 * Libav 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 Libav; 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
34 * X11 frame device demuxer
35 * @author Clemens Fruhwirth <clemens@endorphin.org>
36 * @author Edouard Gomez <ed.gomez@free.fr>
37 */
38
39#include "config.h"
40#include "libavformat/avformat.h"
41#include "libavformat/internal.h"
42#include "libavutil/log.h"
43#include "libavutil/opt.h"
44#include "libavutil/parseutils.h"
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/shm.h>
52#include <X11/extensions/shape.h>
53#include <X11/extensions/XShm.h>
54#include <X11/extensions/Xfixes.h>
55
56/**
57 * X11 Device Demuxer context
58 */
59struct x11_grab
60{
61    const AVClass *class;    /**< Class for private options. */
62    int frame_size;          /**< Size in bytes of a grabbed frame */
63    AVRational time_base;    /**< Time base */
64    int64_t time_frame;      /**< Current time */
65
66    char *video_size;        /**< String describing video size, set by a private option. */
67    int height;              /**< Height of the grab frame */
68    int width;               /**< Width of the grab frame */
69    int x_off;               /**< Horizontal top-left corner coordinate */
70    int y_off;               /**< Vertical top-left corner coordinate */
71
72    Display *dpy;            /**< X11 display from which x11grab grabs frames */
73    XImage *image;           /**< X11 image holding the grab */
74    int use_shm;             /**< !0 when using XShm extension */
75    XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
76    int  draw_mouse;         /**< Set by a private option. */
77    int  follow_mouse;       /**< Set by a private option. */
78    int  show_region;        /**< set by a private option. */
79    char *framerate;         /**< Set by a private option. */
80
81    Window region_win;       /**< This is used by show_region option. */
82};
83
84#define REGION_WIN_BORDER 3
85/**
86 * Draw grabbing region window
87 *
88 * @param s x11_grab context
89 */
90static void
91x11grab_draw_region_win(struct x11_grab *s)
92{
93    Display *dpy = s->dpy;
94    int screen;
95    Window win = s->region_win;
96    GC gc;
97
98    screen = DefaultScreen(dpy);
99    gc = XCreateGC(dpy, win, 0, 0);
100    XSetForeground(dpy, gc, WhitePixel(dpy, screen));
101    XSetBackground(dpy, gc, BlackPixel(dpy, screen));
102    XSetLineAttributes(dpy, gc, REGION_WIN_BORDER, LineDoubleDash, 0, 0);
103    XDrawRectangle(dpy, win, gc,
104                   1, 1,
105                   (s->width  + REGION_WIN_BORDER * 2) - 1 * 2 - 1,
106                   (s->height + REGION_WIN_BORDER * 2) - 1 * 2 - 1);
107    XFreeGC(dpy, gc);
108}
109
110/**
111 * Initialize grabbing region window
112 *
113 * @param s x11_grab context
114 */
115static void
116x11grab_region_win_init(struct x11_grab *s)
117{
118    Display *dpy = s->dpy;
119    int screen;
120    XSetWindowAttributes attribs;
121    XRectangle rect;
122
123    screen = DefaultScreen(dpy);
124    attribs.override_redirect = True;
125    s->region_win = XCreateWindow(dpy, RootWindow(dpy, screen),
126                                  s->x_off  - REGION_WIN_BORDER,
127                                  s->y_off  - REGION_WIN_BORDER,
128                                  s->width  + REGION_WIN_BORDER * 2,
129                                  s->height + REGION_WIN_BORDER * 2,
130                                  0, CopyFromParent,
131                                  InputOutput, CopyFromParent,
132                                  CWOverrideRedirect, &attribs);
133    rect.x = 0;
134    rect.y = 0;
135    rect.width  = s->width;
136    rect.height = s->height;
137    XShapeCombineRectangles(dpy, s->region_win,
138                            ShapeBounding, REGION_WIN_BORDER, REGION_WIN_BORDER,
139                            &rect, 1, ShapeSubtract, 0);
140    XMapWindow(dpy, s->region_win);
141    XSelectInput(dpy, s->region_win, ExposureMask | StructureNotifyMask);
142    x11grab_draw_region_win(s);
143}
144
145/**
146 * Initialize the x11 grab device demuxer (public device demuxer API).
147 *
148 * @param s1 Context from avformat core
149 * @param ap Parameters from avformat core
150 * @return <ul>
151 *          <li>AVERROR(ENOMEM) no memory left</li>
152 *          <li>AVERROR(EIO) other failure case</li>
153 *          <li>0 success</li>
154 *         </ul>
155 */
156static int
157x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
158{
159    struct x11_grab *x11grab = s1->priv_data;
160    Display *dpy;
161    AVStream *st = NULL;
162    enum PixelFormat input_pixfmt;
163    XImage *image;
164    int x_off = 0;
165    int y_off = 0;
166    int screen;
167    int use_shm;
168    char *param, *offset;
169    int ret = 0;
170    AVRational framerate;
171
172    param = av_strdup(s1->filename);
173    offset = strchr(param, '+');
174    if (offset) {
175        sscanf(offset, "%d,%d", &x_off, &y_off);
176        x11grab->draw_mouse = !strstr(offset, "nomouse");
177        *offset= 0;
178    }
179
180    if ((ret = av_parse_video_size(&x11grab->width, &x11grab->height, x11grab->video_size)) < 0) {
181        av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
182        goto out;
183    }
184    if ((ret = av_parse_video_rate(&framerate, x11grab->framerate)) < 0) {
185        av_log(s1, AV_LOG_ERROR, "Could not parse framerate: %s.\n", x11grab->framerate);
186        goto out;
187    }
188    av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
189           s1->filename, param, x_off, y_off, x11grab->width, x11grab->height);
190
191    dpy = XOpenDisplay(param);
192    if(!dpy) {
193        av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
194        ret = AVERROR(EIO);
195        goto out;
196    }
197
198    st = avformat_new_stream(s1, NULL);
199    if (!st) {
200        ret = AVERROR(ENOMEM);
201        goto out;
202    }
203    avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
204
205    screen = DefaultScreen(dpy);
206
207    if (x11grab->follow_mouse) {
208        int screen_w, screen_h;
209        Window w;
210
211        screen_w = DisplayWidth(dpy, screen);
212        screen_h = DisplayHeight(dpy, screen);
213        XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off, &ret, &ret, &ret);
214        x_off -= x11grab->width / 2;
215        y_off -= x11grab->height / 2;
216        x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width);
217        y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height);
218        av_log(s1, AV_LOG_INFO, "followmouse is enabled, resetting grabbing region to x: %d y: %d\n", x_off, y_off);
219    }
220
221    use_shm = XShmQueryExtension(dpy);
222    av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");
223
224    if(use_shm) {
225        int scr = XDefaultScreen(dpy);
226        image = XShmCreateImage(dpy,
227                                DefaultVisual(dpy, scr),
228                                DefaultDepth(dpy, scr),
229                                ZPixmap,
230                                NULL,
231                                &x11grab->shminfo,
232                                x11grab->width, x11grab->height);
233        x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
234                                        image->bytes_per_line * image->height,
235                                        IPC_CREAT|0777);
236        if (x11grab->shminfo.shmid == -1) {
237            av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
238            ret = AVERROR(ENOMEM);
239            goto out;
240        }
241        x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
242        x11grab->shminfo.readOnly = False;
243
244        if (!XShmAttach(dpy, &x11grab->shminfo)) {
245            av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
246            /* needs some better error subroutine :) */
247            ret = AVERROR(EIO);
248            goto out;
249        }
250    } else {
251        image = XGetImage(dpy, RootWindow(dpy, screen),
252                          x_off,y_off,
253                          x11grab->width, x11grab->height,
254                          AllPlanes, ZPixmap);
255    }
256
257    switch (image->bits_per_pixel) {
258    case 8:
259        av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
260        input_pixfmt = PIX_FMT_PAL8;
261        break;
262    case 16:
263        if (       image->red_mask   == 0xf800 &&
264                   image->green_mask == 0x07e0 &&
265                   image->blue_mask  == 0x001f ) {
266            av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
267            input_pixfmt = PIX_FMT_RGB565;
268        } else if (image->red_mask   == 0x7c00 &&
269                   image->green_mask == 0x03e0 &&
270                   image->blue_mask  == 0x001f ) {
271            av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
272            input_pixfmt = PIX_FMT_RGB555;
273        } else {
274            av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
275            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);
276            ret = AVERROR(EIO);
277            goto out;
278        }
279        break;
280    case 24:
281        if (        image->red_mask   == 0xff0000 &&
282                    image->green_mask == 0x00ff00 &&
283                    image->blue_mask  == 0x0000ff ) {
284            input_pixfmt = PIX_FMT_BGR24;
285        } else if ( image->red_mask   == 0x0000ff &&
286                    image->green_mask == 0x00ff00 &&
287                    image->blue_mask  == 0xff0000 ) {
288            input_pixfmt = PIX_FMT_RGB24;
289        } else {
290            av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
291            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);
292            ret = AVERROR(EIO);
293            goto out;
294        }
295        break;
296    case 32:
297        input_pixfmt = PIX_FMT_RGB32;
298        break;
299    default:
300        av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
301        ret = AVERROR(EINVAL);
302        goto out;
303    }
304
305    x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel/8;
306    x11grab->dpy = dpy;
307    x11grab->time_base  = (AVRational){framerate.den, framerate.num};
308    x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base);
309    x11grab->x_off = x_off;
310    x11grab->y_off = y_off;
311    x11grab->image = image;
312    x11grab->use_shm = use_shm;
313
314    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
315    st->codec->codec_id = CODEC_ID_RAWVIDEO;
316    st->codec->width  = x11grab->width;
317    st->codec->height = x11grab->height;
318    st->codec->pix_fmt = input_pixfmt;
319    st->codec->time_base = x11grab->time_base;
320    st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(x11grab->time_base) * 8;
321
322out:
323    return ret;
324}
325
326/**
327 * Paint a mouse pointer in an X11 image.
328 *
329 * @param image image to paint the mouse pointer to
330 * @param s context used to retrieve original grabbing rectangle
331 *          coordinates
332 */
333static void
334paint_mouse_pointer(XImage *image, struct x11_grab *s)
335{
336    int x_off = s->x_off;
337    int y_off = s->y_off;
338    int width = s->width;
339    int height = s->height;
340    Display *dpy = s->dpy;
341    XFixesCursorImage *xcim;
342    int x, y;
343    int line, column;
344    int to_line, to_column;
345    int pixstride = image->bits_per_pixel >> 3;
346    /* Warning: in its insanity, xlib provides unsigned image data through a
347     * char* pointer, so we have to make it uint8_t to make things not break.
348     * Anyone who performs further investigation of the xlib API likely risks
349     * permanent brain damage. */
350    uint8_t *pix = image->data;
351
352    /* Code doesn't currently support 16-bit or PAL8 */
353    if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
354        return;
355
356    xcim = XFixesGetCursorImage(dpy);
357
358    x = xcim->x - xcim->xhot;
359    y = xcim->y - xcim->yhot;
360
361    to_line = FFMIN((y + xcim->height), (height + y_off));
362    to_column = FFMIN((x + xcim->width), (width + x_off));
363
364    for (line = FFMAX(y, y_off); line < to_line; line++) {
365        for (column = FFMAX(x, x_off); column < to_column; column++) {
366            int  xcim_addr = (line - y) * xcim->width + column - x;
367            int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
368            int r = (uint8_t)(xcim->pixels[xcim_addr] >>  0);
369            int g = (uint8_t)(xcim->pixels[xcim_addr] >>  8);
370            int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
371            int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
372
373            if (a == 255) {
374                pix[image_addr+0] = r;
375                pix[image_addr+1] = g;
376                pix[image_addr+2] = b;
377            } else if (a) {
378                /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
379                pix[image_addr+0] = r + (pix[image_addr+0]*(255-a) + 255/2) / 255;
380                pix[image_addr+1] = g + (pix[image_addr+1]*(255-a) + 255/2) / 255;
381                pix[image_addr+2] = b + (pix[image_addr+2]*(255-a) + 255/2) / 255;
382            }
383        }
384    }
385
386    XFree(xcim);
387    xcim = NULL;
388}
389
390
391/**
392 * Read new data in the image structure.
393 *
394 * @param dpy X11 display to grab from
395 * @param d
396 * @param image Image where the grab will be put
397 * @param x Top-Left grabbing rectangle horizontal coordinate
398 * @param y Top-Left grabbing rectangle vertical coordinate
399 * @return 0 if error, !0 if successful
400 */
401static int
402xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
403{
404    xGetImageReply rep;
405    xGetImageReq *req;
406    long nbytes;
407
408    if (!image) {
409        return 0;
410    }
411
412    LockDisplay(dpy);
413    GetReq(GetImage, req);
414
415    /* First set up the standard stuff in the request */
416    req->drawable = d;
417    req->x = x;
418    req->y = y;
419    req->width = image->width;
420    req->height = image->height;
421    req->planeMask = (unsigned int)AllPlanes;
422    req->format = ZPixmap;
423
424    if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
425        UnlockDisplay(dpy);
426        SyncHandle();
427        return 0;
428    }
429
430    nbytes = (long)rep.length << 2;
431    _XReadPad(dpy, image->data, nbytes);
432
433    UnlockDisplay(dpy);
434    SyncHandle();
435    return 1;
436}
437
438/**
439 * Grab a frame from x11 (public device demuxer API).
440 *
441 * @param s1 Context from avformat core
442 * @param pkt Packet holding the brabbed frame
443 * @return frame size in bytes
444 */
445static int
446x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
447{
448    struct x11_grab *s = s1->priv_data;
449    Display *dpy = s->dpy;
450    XImage *image = s->image;
451    int x_off = s->x_off;
452    int y_off = s->y_off;
453
454    int screen;
455    Window root;
456    int follow_mouse = s->follow_mouse;
457
458    int64_t curtime, delay;
459    struct timespec ts;
460
461    /* Calculate the time of the next frame */
462    s->time_frame += INT64_C(1000000);
463
464    /* wait based on the frame rate */
465    for(;;) {
466        curtime = av_gettime();
467        delay = s->time_frame * av_q2d(s->time_base) - curtime;
468        if (delay <= 0) {
469            if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
470                s->time_frame += INT64_C(1000000);
471            }
472            break;
473        }
474        ts.tv_sec = delay / 1000000;
475        ts.tv_nsec = (delay % 1000000) * 1000;
476        nanosleep(&ts, NULL);
477    }
478
479    av_init_packet(pkt);
480    pkt->data = image->data;
481    pkt->size = s->frame_size;
482    pkt->pts = curtime;
483
484    screen = DefaultScreen(dpy);
485    root = RootWindow(dpy, screen);
486    if (follow_mouse) {
487        int screen_w, screen_h;
488        int pointer_x, pointer_y, _;
489        Window w;
490
491        screen_w = DisplayWidth(dpy, screen);
492        screen_h = DisplayHeight(dpy, screen);
493        XQueryPointer(dpy, root, &w, &w, &pointer_x, &pointer_y, &_, &_, &_);
494        if (follow_mouse == -1) {
495            // follow the mouse, put it at center of grabbing region
496            x_off += pointer_x - s->width  / 2 - x_off;
497            y_off += pointer_y - s->height / 2 - y_off;
498        } else {
499            // follow the mouse, but only move the grabbing region when mouse
500            // reaches within certain pixels to the edge.
501            if (pointer_x > x_off + s->width - follow_mouse) {
502                x_off += pointer_x - (x_off + s->width - follow_mouse);
503            } else if (pointer_x < x_off + follow_mouse)
504                x_off -= (x_off + follow_mouse) - pointer_x;
505            if (pointer_y > y_off + s->height - follow_mouse) {
506                y_off += pointer_y - (y_off + s->height - follow_mouse);
507            } else if (pointer_y < y_off + follow_mouse)
508                y_off -= (y_off + follow_mouse) - pointer_y;
509        }
510        // adjust grabbing region position if it goes out of screen.
511        s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width);
512        s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height);
513
514        if (s->show_region && s->region_win)
515            XMoveWindow(dpy, s->region_win,
516                        s->x_off - REGION_WIN_BORDER,
517                        s->y_off - REGION_WIN_BORDER);
518    }
519
520    if (s->show_region) {
521        if (s->region_win) {
522            XEvent evt;
523            // clean up the events, and do the initinal draw or redraw.
524            for (evt.type = NoEventMask; XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask, &evt); );
525            if (evt.type)
526                x11grab_draw_region_win(s);
527        } else {
528            x11grab_region_win_init(s);
529        }
530    }
531
532    if(s->use_shm) {
533        if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes)) {
534            av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
535        }
536    } else {
537        if (!xget_zpixmap(dpy, root, image, x_off, y_off)) {
538            av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
539        }
540    }
541
542    if (s->draw_mouse) {
543        paint_mouse_pointer(image, s);
544    }
545
546    return s->frame_size;
547}
548
549/**
550 * Close x11 frame grabber (public device demuxer API).
551 *
552 * @param s1 Context from avformat core
553 * @return 0 success, !0 failure
554 */
555static int
556x11grab_read_close(AVFormatContext *s1)
557{
558    struct x11_grab *x11grab = s1->priv_data;
559
560    /* Detach cleanly from shared mem */
561    if (x11grab->use_shm) {
562        XShmDetach(x11grab->dpy, &x11grab->shminfo);
563        shmdt(x11grab->shminfo.shmaddr);
564        shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
565    }
566
567    /* Destroy X11 image */
568    if (x11grab->image) {
569        XDestroyImage(x11grab->image);
570        x11grab->image = NULL;
571    }
572
573    if (x11grab->region_win) {
574        XDestroyWindow(x11grab->dpy, x11grab->region_win);
575    }
576
577    /* Free X11 display */
578    XCloseDisplay(x11grab->dpy);
579    return 0;
580}
581
582#define OFFSET(x) offsetof(struct x11_grab, x)
583#define DEC AV_OPT_FLAG_DECODING_PARAM
584static const AVOption options[] = {
585    { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = "vga"}, 0, 0, DEC },
586    { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc"}, 0, 0, DEC },
587    { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { 1 }, 0, 1, DEC },
588    { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
589      OFFSET(follow_mouse), AV_OPT_TYPE_INT, { 0 }, -1, INT_MAX, DEC, "follow_mouse" },
590    { "centered", "Keep the mouse pointer at the center of grabbing region when following.", 0, AV_OPT_TYPE_CONST, { -1 }, INT_MIN, INT_MAX, DEC, "follow_mouse" },
591    { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { 0 }, 0, 1, DEC },
592    { NULL },
593};
594
595static const AVClass x11_class = {
596    .class_name = "X11grab indev",
597    .item_name  = av_default_item_name,
598    .option     = options,
599    .version    = LIBAVUTIL_VERSION_INT,
600};
601
602/** x11 grabber device demuxer declaration */
603AVInputFormat ff_x11_grab_device_demuxer = {
604    .name           = "x11grab",
605    .long_name      = NULL_IF_CONFIG_SMALL("X11grab"),
606    .priv_data_size = sizeof(struct x11_grab),
607    .read_header    = x11grab_read_header,
608    .read_packet    = x11grab_read_packet,
609    .read_close     = x11grab_read_close,
610    .flags          = AVFMT_NOFILE,
611    .priv_class     = &x11_class,
612};
613