2 * X11 video grab interface
4 * This file is part of Libav.
7 * Copyright (C) 2006 Clemens Fruhwirth <clemens@endorphin.org>
8 * Edouard Gomez <ed.gomez@free.fr>
10 * This file contains code from grab.c:
11 * Copyright (c) 2000-2001 Fabrice Bellard
13 * This file contains code from the xvidcap project:
14 * Copyright (C) 1997-1998 Rasca, Berlin
15 * 2003-2004 Karl H. Beckers, Frankfurt
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.
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.
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
34 * X11 frame device demuxer by Clemens Fruhwirth <clemens@endorphin.org>
35 * and Edouard Gomez <ed.gomez@free.fr>.
39 #include "libavformat/avformat.h"
40 #include "libavutil/log.h"
41 #include "libavutil/opt.h"
42 #include "libavutil/parseutils.h"
46 #include <X11/Xlibint.h>
47 #include <X11/Xproto.h>
48 #include <X11/Xutil.h>
50 #include <X11/extensions/XShm.h>
51 #include <X11/extensions/Xfixes.h>
54 * X11 Device Demuxer context
58 const AVClass *class; /**< Class for private options. */
59 int frame_size; /**< Size in bytes of a grabbed frame */
60 AVRational time_base; /**< Time base */
61 int64_t time_frame; /**< Current time */
63 char *video_size; /**< String describing video size, set by a private option. */
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 */
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 */
77 * Initialize the x11 grab device demuxer (public device demuxer API).
79 * @param s1 Context from avformat core
80 * @param ap Parameters from avformat core
82 * <li>AVERROR(ENOMEM) no memory left</li>
83 * <li>AVERROR(EIO) other failure case</li>
88 x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
90 struct x11_grab *x11grab = s1->priv_data;
93 enum PixelFormat input_pixfmt;
101 param = av_strdup(s1->filename);
102 offset = strchr(param, '+');
104 sscanf(offset, "%d,%d", &x_off, &y_off);
105 x11grab->nomouse= strstr(offset, "nomouse");
109 if ((ret = av_parse_video_size(&x11grab->width, &x11grab->height, x11grab->video_size)) < 0) {
110 av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
113 #if FF_API_FORMAT_PARAMETERS
115 x11grab->width = ap->width;
117 x11grab->height = ap->height;
119 av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
120 s1->filename, param, x_off, y_off, x11grab->width, x11grab->height);
122 dpy = XOpenDisplay(param);
124 av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
129 if (ap->time_base.den <= 0) {
130 av_log(s1, AV_LOG_ERROR, "AVParameters don't have video size and/or rate. Use -s and -r.\n");
131 ret = AVERROR(EINVAL);
135 st = av_new_stream(s1, 0);
137 ret = AVERROR(ENOMEM);
140 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
142 use_shm = XShmQueryExtension(dpy);
143 av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");
146 int scr = XDefaultScreen(dpy);
147 image = XShmCreateImage(dpy,
148 DefaultVisual(dpy, scr),
149 DefaultDepth(dpy, scr),
153 x11grab->width, x11grab->height);
154 x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
155 image->bytes_per_line * image->height,
157 if (x11grab->shminfo.shmid == -1) {
158 av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
159 ret = AVERROR(ENOMEM);
162 x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
163 x11grab->shminfo.readOnly = False;
165 if (!XShmAttach(dpy, &x11grab->shminfo)) {
166 av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
167 /* needs some better error subroutine :) */
172 image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
174 x11grab->width, x11grab->height,
178 switch (image->bits_per_pixel) {
180 av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
181 input_pixfmt = PIX_FMT_PAL8;
184 if ( image->red_mask == 0xf800 &&
185 image->green_mask == 0x07e0 &&
186 image->blue_mask == 0x001f ) {
187 av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
188 input_pixfmt = PIX_FMT_RGB565;
189 } else if (image->red_mask == 0x7c00 &&
190 image->green_mask == 0x03e0 &&
191 image->blue_mask == 0x001f ) {
192 av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
193 input_pixfmt = PIX_FMT_RGB555;
195 av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
196 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);
202 if ( image->red_mask == 0xff0000 &&
203 image->green_mask == 0x00ff00 &&
204 image->blue_mask == 0x0000ff ) {
205 input_pixfmt = PIX_FMT_BGR24;
206 } else if ( image->red_mask == 0x0000ff &&
207 image->green_mask == 0x00ff00 &&
208 image->blue_mask == 0xff0000 ) {
209 input_pixfmt = PIX_FMT_RGB24;
211 av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
212 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);
219 GetColorInfo (image, &c_info);
220 if ( c_info.alpha_mask == 0xff000000 && image->green_mask == 0x0000ff00) {
221 /* byte order is relevant here, not endianness
222 * endianness is handled by avcodec, but atm no such thing
223 * as having ABGR, instead of ARGB in a word. Since we
224 * need this for Solaris/SPARC, but need to do the conversion
225 * for every frame we do it outside of this loop, cf. below
226 * this matches both ARGB32 and ABGR32 */
227 input_pixfmt = PIX_FMT_ARGB32;
229 av_log(s1, AV_LOG_ERROR,"image depth %i not supported ... aborting\n", image->bits_per_pixel);
233 input_pixfmt = PIX_FMT_RGB32;
236 av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
237 ret = AVERROR(EINVAL);
241 x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel/8;
243 x11grab->time_base = ap->time_base;
244 x11grab->time_frame = av_gettime() / av_q2d(ap->time_base);
245 x11grab->x_off = x_off;
246 x11grab->y_off = y_off;
247 x11grab->image = image;
248 x11grab->use_shm = use_shm;
250 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
251 st->codec->codec_id = CODEC_ID_RAWVIDEO;
252 st->codec->width = x11grab->width;
253 st->codec->height = x11grab->height;
254 st->codec->pix_fmt = input_pixfmt;
255 st->codec->time_base = ap->time_base;
256 st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(ap->time_base) * 8;
259 av_freep(&x11grab->video_size);
264 * Paint a mouse pointer in an X11 image.
266 * @param image image to paint the mouse pointer to
267 * @param s context used to retrieve original grabbing rectangle
271 paint_mouse_pointer(XImage *image, struct x11_grab *s)
273 int x_off = s->x_off;
274 int y_off = s->y_off;
275 int width = s->width;
276 int height = s->height;
277 Display *dpy = s->dpy;
278 XFixesCursorImage *xcim;
281 int to_line, to_column;
282 int pixstride = image->bits_per_pixel >> 3;
283 /* Warning: in its insanity, xlib provides unsigned image data through a
284 * char* pointer, so we have to make it uint8_t to make things not break.
285 * Anyone who performs further investigation of the xlib API likely risks
286 * permanent brain damage. */
287 uint8_t *pix = image->data;
289 /* Code doesn't currently support 16-bit or PAL8 */
290 if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
293 xcim = XFixesGetCursorImage(dpy);
295 x = xcim->x - xcim->xhot;
296 y = xcim->y - xcim->yhot;
298 to_line = FFMIN((y + xcim->height), (height + y_off));
299 to_column = FFMIN((x + xcim->width), (width + x_off));
301 for (line = FFMAX(y, y_off); line < to_line; line++) {
302 for (column = FFMAX(x, x_off); column < to_column; column++) {
303 int xcim_addr = (line - y) * xcim->width + column - x;
304 int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
305 int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0);
306 int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8);
307 int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
308 int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
311 pix[image_addr+0] = r;
312 pix[image_addr+1] = g;
313 pix[image_addr+2] = b;
315 /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
316 pix[image_addr+0] = r + (pix[image_addr+0]*(255-a) + 255/2) / 255;
317 pix[image_addr+1] = g + (pix[image_addr+1]*(255-a) + 255/2) / 255;
318 pix[image_addr+2] = b + (pix[image_addr+2]*(255-a) + 255/2) / 255;
329 * Read new data in the image structure.
331 * @param dpy X11 display to grab from
333 * @param image Image where the grab will be put
334 * @param x Top-Left grabbing rectangle horizontal coordinate
335 * @param y Top-Left grabbing rectangle vertical coordinate
336 * @return 0 if error, !0 if successful
339 xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
350 GetReq(GetImage, req);
352 /* First set up the standard stuff in the request */
356 req->width = image->width;
357 req->height = image->height;
358 req->planeMask = (unsigned int)AllPlanes;
359 req->format = ZPixmap;
361 if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
367 nbytes = (long)rep.length << 2;
368 _XReadPad(dpy, image->data, nbytes);
376 * Grab a frame from x11 (public device demuxer API).
378 * @param s1 Context from avformat core
379 * @param pkt Packet holding the brabbed frame
380 * @return frame size in bytes
383 x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
385 struct x11_grab *s = s1->priv_data;
386 Display *dpy = s->dpy;
387 XImage *image = s->image;
388 int x_off = s->x_off;
389 int y_off = s->y_off;
391 int64_t curtime, delay;
394 /* Calculate the time of the next frame */
395 s->time_frame += INT64_C(1000000);
397 /* wait based on the frame rate */
399 curtime = av_gettime();
400 delay = s->time_frame * av_q2d(s->time_base) - curtime;
402 if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
403 s->time_frame += INT64_C(1000000);
407 ts.tv_sec = delay / 1000000;
408 ts.tv_nsec = (delay % 1000000) * 1000;
409 nanosleep(&ts, NULL);
412 if (av_new_packet(pkt, s->frame_size) < 0) {
419 if (!XShmGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off, AllPlanes)) {
420 av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
423 if (!xget_zpixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {
424 av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
429 paint_mouse_pointer(image, s);
433 /* XXX: avoid memcpy */
434 memcpy(pkt->data, image->data, s->frame_size);
435 return s->frame_size;
439 * Close x11 frame grabber (public device demuxer API).
441 * @param s1 Context from avformat core
442 * @return 0 success, !0 failure
445 x11grab_read_close(AVFormatContext *s1)
447 struct x11_grab *x11grab = s1->priv_data;
449 /* Detach cleanly from shared mem */
450 if (x11grab->use_shm) {
451 XShmDetach(x11grab->dpy, &x11grab->shminfo);
452 shmdt(x11grab->shminfo.shmaddr);
453 shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
456 /* Destroy X11 image */
457 if (x11grab->image) {
458 XDestroyImage(x11grab->image);
459 x11grab->image = NULL;
462 /* Free X11 display */
463 XCloseDisplay(x11grab->dpy);
467 #define OFFSET(x) offsetof(struct x11_grab, x)
468 #define DEC AV_OPT_FLAG_DECODING_PARAM
469 static const AVOption options[] = {
470 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), FF_OPT_TYPE_STRING, {.str = "vga"}, 0, 0, DEC },
474 static const AVClass x11_class = {
475 .class_name = "X11grab indev",
476 .item_name = av_default_item_name,
478 .version = LIBAVUTIL_VERSION_INT,
481 /** x11 grabber device demuxer declaration */
482 AVInputFormat ff_x11_grab_device_demuxer =
485 NULL_IF_CONFIG_SMALL("X11grab"),
486 sizeof(struct x11_grab),
491 .flags = AVFMT_NOFILE,
492 .priv_class = &x11_class,