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 */
74 char *framerate; /**< Set by a private option. */
78 * Initialize the x11 grab device demuxer (public device demuxer API).
80 * @param s1 Context from avformat core
81 * @param ap Parameters from avformat core
83 * <li>AVERROR(ENOMEM) no memory left</li>
84 * <li>AVERROR(EIO) other failure case</li>
89 x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
91 struct x11_grab *x11grab = s1->priv_data;
94 enum PixelFormat input_pixfmt;
101 AVRational framerate;
103 param = av_strdup(s1->filename);
104 offset = strchr(param, '+');
106 sscanf(offset, "%d,%d", &x_off, &y_off);
107 x11grab->nomouse= strstr(offset, "nomouse");
111 if ((ret = av_parse_video_size(&x11grab->width, &x11grab->height, x11grab->video_size)) < 0) {
112 av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
115 if ((ret = av_parse_video_rate(&framerate, x11grab->framerate)) < 0) {
116 av_log(s1, AV_LOG_ERROR, "Could not parse framerate: %s.\n", x11grab->framerate);
119 #if FF_API_FORMAT_PARAMETERS
121 x11grab->width = ap->width;
123 x11grab->height = ap->height;
124 if (ap->time_base.num)
125 framerate = (AVRational){ap->time_base.den, ap->time_base.num};
127 av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
128 s1->filename, param, x_off, y_off, x11grab->width, x11grab->height);
130 dpy = XOpenDisplay(param);
132 av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
137 st = av_new_stream(s1, 0);
139 ret = AVERROR(ENOMEM);
142 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
144 use_shm = XShmQueryExtension(dpy);
145 av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");
148 int scr = XDefaultScreen(dpy);
149 image = XShmCreateImage(dpy,
150 DefaultVisual(dpy, scr),
151 DefaultDepth(dpy, scr),
155 x11grab->width, x11grab->height);
156 x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
157 image->bytes_per_line * image->height,
159 if (x11grab->shminfo.shmid == -1) {
160 av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
161 ret = AVERROR(ENOMEM);
164 x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
165 x11grab->shminfo.readOnly = False;
167 if (!XShmAttach(dpy, &x11grab->shminfo)) {
168 av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
169 /* needs some better error subroutine :) */
174 image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
176 x11grab->width, x11grab->height,
180 switch (image->bits_per_pixel) {
182 av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
183 input_pixfmt = PIX_FMT_PAL8;
186 if ( image->red_mask == 0xf800 &&
187 image->green_mask == 0x07e0 &&
188 image->blue_mask == 0x001f ) {
189 av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
190 input_pixfmt = PIX_FMT_RGB565;
191 } else if (image->red_mask == 0x7c00 &&
192 image->green_mask == 0x03e0 &&
193 image->blue_mask == 0x001f ) {
194 av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
195 input_pixfmt = PIX_FMT_RGB555;
197 av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
198 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);
204 if ( image->red_mask == 0xff0000 &&
205 image->green_mask == 0x00ff00 &&
206 image->blue_mask == 0x0000ff ) {
207 input_pixfmt = PIX_FMT_BGR24;
208 } else if ( image->red_mask == 0x0000ff &&
209 image->green_mask == 0x00ff00 &&
210 image->blue_mask == 0xff0000 ) {
211 input_pixfmt = PIX_FMT_RGB24;
213 av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
214 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);
221 GetColorInfo (image, &c_info);
222 if ( c_info.alpha_mask == 0xff000000 && image->green_mask == 0x0000ff00) {
223 /* byte order is relevant here, not endianness
224 * endianness is handled by avcodec, but atm no such thing
225 * as having ABGR, instead of ARGB in a word. Since we
226 * need this for Solaris/SPARC, but need to do the conversion
227 * for every frame we do it outside of this loop, cf. below
228 * this matches both ARGB32 and ABGR32 */
229 input_pixfmt = PIX_FMT_ARGB32;
231 av_log(s1, AV_LOG_ERROR,"image depth %i not supported ... aborting\n", image->bits_per_pixel);
235 input_pixfmt = PIX_FMT_RGB32;
238 av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
239 ret = AVERROR(EINVAL);
243 x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel/8;
245 x11grab->time_base = (AVRational){framerate.den, framerate.num};
246 x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base);
247 x11grab->x_off = x_off;
248 x11grab->y_off = y_off;
249 x11grab->image = image;
250 x11grab->use_shm = use_shm;
252 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
253 st->codec->codec_id = CODEC_ID_RAWVIDEO;
254 st->codec->width = x11grab->width;
255 st->codec->height = x11grab->height;
256 st->codec->pix_fmt = input_pixfmt;
257 st->codec->time_base = x11grab->time_base;
258 st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(x11grab->time_base) * 8;
265 * Paint a mouse pointer in an X11 image.
267 * @param image image to paint the mouse pointer to
268 * @param s context used to retrieve original grabbing rectangle
272 paint_mouse_pointer(XImage *image, struct x11_grab *s)
274 int x_off = s->x_off;
275 int y_off = s->y_off;
276 int width = s->width;
277 int height = s->height;
278 Display *dpy = s->dpy;
279 XFixesCursorImage *xcim;
282 int to_line, to_column;
283 int pixstride = image->bits_per_pixel >> 3;
284 /* Warning: in its insanity, xlib provides unsigned image data through a
285 * char* pointer, so we have to make it uint8_t to make things not break.
286 * Anyone who performs further investigation of the xlib API likely risks
287 * permanent brain damage. */
288 uint8_t *pix = image->data;
290 /* Code doesn't currently support 16-bit or PAL8 */
291 if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
294 xcim = XFixesGetCursorImage(dpy);
296 x = xcim->x - xcim->xhot;
297 y = xcim->y - xcim->yhot;
299 to_line = FFMIN((y + xcim->height), (height + y_off));
300 to_column = FFMIN((x + xcim->width), (width + x_off));
302 for (line = FFMAX(y, y_off); line < to_line; line++) {
303 for (column = FFMAX(x, x_off); column < to_column; column++) {
304 int xcim_addr = (line - y) * xcim->width + column - x;
305 int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
306 int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0);
307 int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8);
308 int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
309 int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
312 pix[image_addr+0] = r;
313 pix[image_addr+1] = g;
314 pix[image_addr+2] = b;
316 /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
317 pix[image_addr+0] = r + (pix[image_addr+0]*(255-a) + 255/2) / 255;
318 pix[image_addr+1] = g + (pix[image_addr+1]*(255-a) + 255/2) / 255;
319 pix[image_addr+2] = b + (pix[image_addr+2]*(255-a) + 255/2) / 255;
330 * Read new data in the image structure.
332 * @param dpy X11 display to grab from
334 * @param image Image where the grab will be put
335 * @param x Top-Left grabbing rectangle horizontal coordinate
336 * @param y Top-Left grabbing rectangle vertical coordinate
337 * @return 0 if error, !0 if successful
340 xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
351 GetReq(GetImage, req);
353 /* First set up the standard stuff in the request */
357 req->width = image->width;
358 req->height = image->height;
359 req->planeMask = (unsigned int)AllPlanes;
360 req->format = ZPixmap;
362 if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
368 nbytes = (long)rep.length << 2;
369 _XReadPad(dpy, image->data, nbytes);
377 * Grab a frame from x11 (public device demuxer API).
379 * @param s1 Context from avformat core
380 * @param pkt Packet holding the brabbed frame
381 * @return frame size in bytes
384 x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
386 struct x11_grab *s = s1->priv_data;
387 Display *dpy = s->dpy;
388 XImage *image = s->image;
389 int x_off = s->x_off;
390 int y_off = s->y_off;
392 int64_t curtime, delay;
395 /* Calculate the time of the next frame */
396 s->time_frame += INT64_C(1000000);
398 /* wait based on the frame rate */
400 curtime = av_gettime();
401 delay = s->time_frame * av_q2d(s->time_base) - curtime;
403 if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
404 s->time_frame += INT64_C(1000000);
408 ts.tv_sec = delay / 1000000;
409 ts.tv_nsec = (delay % 1000000) * 1000;
410 nanosleep(&ts, NULL);
414 pkt->data = image->data;
415 pkt->size = s->frame_size;
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);
432 return s->frame_size;
436 * Close x11 frame grabber (public device demuxer API).
438 * @param s1 Context from avformat core
439 * @return 0 success, !0 failure
442 x11grab_read_close(AVFormatContext *s1)
444 struct x11_grab *x11grab = s1->priv_data;
446 /* Detach cleanly from shared mem */
447 if (x11grab->use_shm) {
448 XShmDetach(x11grab->dpy, &x11grab->shminfo);
449 shmdt(x11grab->shminfo.shmaddr);
450 shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
453 /* Destroy X11 image */
454 if (x11grab->image) {
455 XDestroyImage(x11grab->image);
456 x11grab->image = NULL;
459 /* Free X11 display */
460 XCloseDisplay(x11grab->dpy);
464 #define OFFSET(x) offsetof(struct x11_grab, x)
465 #define DEC AV_OPT_FLAG_DECODING_PARAM
466 static const AVOption options[] = {
467 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), FF_OPT_TYPE_STRING, {.str = "vga"}, 0, 0, DEC },
468 { "framerate", "", OFFSET(framerate), FF_OPT_TYPE_STRING, {.str = "ntsc"}, 0, 0, DEC },
472 static const AVClass x11_class = {
473 .class_name = "X11grab indev",
474 .item_name = av_default_item_name,
476 .version = LIBAVUTIL_VERSION_INT,
479 /** x11 grabber device demuxer declaration */
480 AVInputFormat ff_x11_grab_device_demuxer =
483 NULL_IF_CONFIG_SMALL("X11grab"),
484 sizeof(struct x11_grab),
489 .flags = AVFMT_NOFILE,
490 .priv_class = &x11_class,