/* * XCB input grabber * Copyright (C) 2014 Luca Barbato <lu_zero@gentoo.org> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "config.h" #include <stdlib.h> #include <xcb/xcb.h> #if CONFIG_LIBXCB_XFIXES #include <xcb/xfixes.h> #endif #if CONFIG_LIBXCB_SHM #include <sys/shm.h> #include <xcb/shm.h> #endif #if CONFIG_LIBXCB_SHAPE #include <xcb/shape.h> #endif #include "libavutil/internal.h" #include "libavutil/mathematics.h" #include "libavutil/opt.h" #include "libavutil/parseutils.h" #include "libavutil/time.h" #include "libavformat/avformat.h" #include "libavformat/internal.h" typedef struct XCBGrabContext { const AVClass *class; xcb_connection_t *conn; xcb_screen_t *screen; xcb_window_t window; #if CONFIG_LIBXCB_SHM xcb_shm_seg_t segment; #endif int64_t time_frame; AVRational time_base; int x, y; int width, height; int frame_size; int bpp; int draw_mouse; int follow_mouse; int show_region; int region_border; int centered; const char *video_size; const char *framerate; int has_shm; } XCBGrabContext; #define FOLLOW_CENTER -1 #define OFFSET(x) offsetof(XCBGrabContext, x) #define D AV_OPT_FLAG_DECODING_PARAM static const AVOption options[] = { { "x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D }, { "y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D }, { "grab_x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D }, { "grab_y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D }, { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = "vga" }, 0, 0, D }, { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc" }, 0, 0, D }, { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, D }, { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.", OFFSET(follow_mouse), AV_OPT_TYPE_INT, { .i64 = 0 }, FOLLOW_CENTER, INT_MAX, D, "follow_mouse" }, { "centered", "Keep the mouse pointer at the center of grabbing region when following.", 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, INT_MIN, INT_MAX, D, "follow_mouse" }, { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, D }, { "region_border", "Set the region border thickness.", OFFSET(region_border), AV_OPT_TYPE_INT, { .i64 = 3 }, 1, 128, D }, { NULL }, }; static const AVClass xcbgrab_class = { .class_name = "xcbgrab indev", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT, }; static int xcbgrab_reposition(AVFormatContext *s, xcb_query_pointer_reply_t *p, xcb_get_geometry_reply_t *geo) { XCBGrabContext *c = s->priv_data; int x = c->x, y = c->y; int w = c->width, h = c->height, f = c->follow_mouse; int p_x, p_y; if (!p || !geo) return AVERROR(EIO); p_x = p->win_x; p_y = p->win_y; if (f == FOLLOW_CENTER) { x = p_x - w / 2; y = p_y - h / 2; } else { int left = x + f; int right = x + w - f; int top = y + f; int bottom = y + h + f; if (p_x > right) { x += p_x - right; } else if (p_x < left) { x -= left - p_x; } if (p_y > bottom) { y += p_y - bottom; } else if (p_y < top) { y -= top - p_y; } } c->x = FFMIN(FFMAX(0, x), geo->width - w); c->y = FFMIN(FFMAX(0, y), geo->height - h); return 0; } static int xcbgrab_frame(AVFormatContext *s, AVPacket *pkt) { XCBGrabContext *c = s->priv_data; xcb_get_image_cookie_t iq; xcb_get_image_reply_t *img; xcb_drawable_t drawable = c->screen->root; xcb_generic_error_t *e = NULL; uint8_t *data; int length, ret; iq = xcb_get_image(c->conn, XCB_IMAGE_FORMAT_Z_PIXMAP, drawable, c->x, c->y, c->width, c->height, ~0); img = xcb_get_image_reply(c->conn, iq, &e); if (e) { av_log(s, AV_LOG_ERROR, "Cannot get the image data " "event_error: response_type:%u error_code:%u " "sequence:%u resource_id:%u minor_code:%u major_code:%u.\n", e->response_type, e->error_code, e->sequence, e->resource_id, e->minor_code, e->major_code); return AVERROR(EACCES); } if (!img) return AVERROR(EAGAIN); data = xcb_get_image_data(img); length = xcb_get_image_data_length(img); ret = av_new_packet(pkt, length); if (!ret) memcpy(pkt->data, data, length); free(img); return ret; } static void wait_frame(AVFormatContext *s, AVPacket *pkt) { XCBGrabContext *c = s->priv_data; int64_t curtime, delay; int64_t frame_time = av_rescale_q(1, c->time_base, AV_TIME_BASE_Q); c->time_frame += frame_time; for (;;) { curtime = av_gettime(); delay = c->time_frame - curtime; if (delay <= 0) break; av_usleep(delay); } pkt->pts = curtime; } #if CONFIG_LIBXCB_SHM static int check_shm(xcb_connection_t *conn) { xcb_shm_query_version_cookie_t cookie = xcb_shm_query_version(conn); xcb_shm_query_version_reply_t *reply; reply = xcb_shm_query_version_reply(conn, cookie, NULL); if (reply) { free(reply); return 1; } return 0; } static void dealloc_shm(void *unused, uint8_t *data) { shmdt(data); } static int xcbgrab_frame_shm(AVFormatContext *s, AVPacket *pkt) { XCBGrabContext *c = s->priv_data; xcb_shm_get_image_cookie_t iq; xcb_shm_get_image_reply_t *img; xcb_drawable_t drawable = c->screen->root; uint8_t *data; int size = c->frame_size + AV_INPUT_BUFFER_PADDING_SIZE; int id = shmget(IPC_PRIVATE, size, IPC_CREAT | 0777); xcb_generic_error_t *e = NULL; if (id == -1) { char errbuf[1024]; int err = AVERROR(errno); av_strerror(err, errbuf, sizeof(errbuf)); av_log(s, AV_LOG_ERROR, "Cannot get %d bytes of shared memory: %s.\n", size, errbuf); return err; } xcb_shm_attach(c->conn, c->segment, id, 0); iq = xcb_shm_get_image(c->conn, drawable, c->x, c->y, c->width, c->height, ~0, XCB_IMAGE_FORMAT_Z_PIXMAP, c->segment, 0); xcb_shm_detach(c->conn, c->segment); img = xcb_shm_get_image_reply(c->conn, iq, &e); xcb_flush(c->conn); if (e) { av_log(s, AV_LOG_ERROR, "Cannot get the image data " "event_error: response_type:%u error_code:%u " "sequence:%u resource_id:%u minor_code:%u major_code:%u.\n", e->response_type, e->error_code, e->sequence, e->resource_id, e->minor_code, e->major_code); shmctl(id, IPC_RMID, 0); return AVERROR(EACCES); } free(img); data = shmat(id, NULL, 0); shmctl(id, IPC_RMID, 0); if ((intptr_t)data == -1) return AVERROR(errno); pkt->buf = av_buffer_create(data, size, dealloc_shm, NULL, 0); if (!pkt->buf) { shmdt(data); return AVERROR(ENOMEM); } pkt->data = pkt->buf->data; pkt->size = c->frame_size; return 0; } #endif /* CONFIG_LIBXCB_SHM */ #if CONFIG_LIBXCB_XFIXES static int check_xfixes(xcb_connection_t *conn) { xcb_xfixes_query_version_cookie_t cookie; xcb_xfixes_query_version_reply_t *reply; cookie = xcb_xfixes_query_version(conn, XCB_XFIXES_MAJOR_VERSION, XCB_XFIXES_MINOR_VERSION); reply = xcb_xfixes_query_version_reply(conn, cookie, NULL); if (reply) { free(reply); return 1; } return 0; } #define BLEND(target, source, alpha) \ (target) + ((source) * (255 - (alpha)) + 255 / 2) / 255 static void xcbgrab_draw_mouse(AVFormatContext *s, AVPacket *pkt, xcb_query_pointer_reply_t *p, xcb_get_geometry_reply_t *geo) { XCBGrabContext *gr = s->priv_data; uint32_t *cursor; uint8_t *image = pkt->data; int stride = gr->bpp / 8; xcb_xfixes_get_cursor_image_cookie_t cc; xcb_xfixes_get_cursor_image_reply_t *ci; int cx, cy, x, y, w, h, c_off, i_off; cc = xcb_xfixes_get_cursor_image(gr->conn); ci = xcb_xfixes_get_cursor_image_reply(gr->conn, cc, NULL); if (!ci) return; cursor = xcb_xfixes_get_cursor_image_cursor_image(ci); if (!cursor) return; cx = ci->x - ci->xhot; cy = ci->y - ci->yhot; x = FFMAX(cx, gr->x); y = FFMAX(cy, gr->y); w = FFMIN(cx + ci->width, gr->x + gr->width) - x; h = FFMIN(cy + ci->height, gr->y + gr->height) - y; c_off = x - cx; i_off = x - gr->x; cursor += (y - cy) * ci->width; image += (y - gr->y) * gr->width * stride; for (y = 0; y < h; y++) { cursor += c_off; image += i_off * stride; for (x = 0; x < w; x++, cursor++, image += stride) { int r, g, b, a; r = *cursor & 0xff; g = (*cursor >> 8) & 0xff; b = (*cursor >> 16) & 0xff; a = (*cursor >> 24) & 0xff; if (!a) continue; if (a == 255) { image[0] = r; image[1] = g; image[2] = b; } else { image[0] = BLEND(r, image[0], a); image[1] = BLEND(g, image[1], a); image[2] = BLEND(b, image[2], a); } } cursor += ci->width - w - c_off; image += (gr->width - w - i_off) * stride; } free(ci); } #endif /* CONFIG_LIBXCB_XFIXES */ static void xcbgrab_update_region(AVFormatContext *s) { XCBGrabContext *c = s->priv_data; const uint32_t args[] = { c->x - c->region_border, c->y - c->region_border }; xcb_configure_window(c->conn, c->window, XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y, args); } static int xcbgrab_read_packet(AVFormatContext *s, AVPacket *pkt) { XCBGrabContext *c = s->priv_data; xcb_query_pointer_cookie_t pc; xcb_get_geometry_cookie_t gc; xcb_query_pointer_reply_t *p = NULL; xcb_get_geometry_reply_t *geo = NULL; int ret = 0; wait_frame(s, pkt); if (c->follow_mouse || c->draw_mouse) { pc = xcb_query_pointer(c->conn, c->screen->root); gc = xcb_get_geometry(c->conn, c->screen->root); p = xcb_query_pointer_reply(c->conn, pc, NULL); geo = xcb_get_geometry_reply(c->conn, gc, NULL); } if (c->follow_mouse && p->same_screen) xcbgrab_reposition(s, p, geo); if (c->show_region) xcbgrab_update_region(s); #if CONFIG_LIBXCB_SHM if (c->has_shm && xcbgrab_frame_shm(s, pkt) < 0) c->has_shm = 0; #endif if (!c->has_shm) ret = xcbgrab_frame(s, pkt); #if CONFIG_LIBXCB_XFIXES if (ret >= 0 && c->draw_mouse && p->same_screen) xcbgrab_draw_mouse(s, pkt, p, geo); #endif free(p); free(geo); return ret; } static av_cold int xcbgrab_read_close(AVFormatContext *s) { XCBGrabContext *ctx = s->priv_data; xcb_disconnect(ctx->conn); return 0; } static xcb_screen_t *get_screen(const xcb_setup_t *setup, int screen_num) { xcb_screen_iterator_t it = xcb_setup_roots_iterator(setup); xcb_screen_t *screen = NULL; for (; it.rem > 0; xcb_screen_next (&it)) { if (!screen_num) { screen = it.data; break; } screen_num--; } return screen; } static int pixfmt_from_pixmap_format(AVFormatContext *s, int depth, int *pix_fmt) { XCBGrabContext *c = s->priv_data; const xcb_setup_t *setup = xcb_get_setup(c->conn); const xcb_format_t *fmt = xcb_setup_pixmap_formats(setup); int length = xcb_setup_pixmap_formats_length(setup); *pix_fmt = 0; while (length--) { if (fmt->depth == depth) { switch (depth) { case 32: if (fmt->bits_per_pixel == 32) *pix_fmt = AV_PIX_FMT_0RGB; break; case 24: if (fmt->bits_per_pixel == 32) *pix_fmt = AV_PIX_FMT_0RGB32; else if (fmt->bits_per_pixel == 24) *pix_fmt = AV_PIX_FMT_RGB24; break; case 16: if (fmt->bits_per_pixel == 16) *pix_fmt = AV_PIX_FMT_RGB565; break; case 15: if (fmt->bits_per_pixel == 16) *pix_fmt = AV_PIX_FMT_RGB555; break; case 8: if (fmt->bits_per_pixel == 8) *pix_fmt = AV_PIX_FMT_RGB8; break; } } if (*pix_fmt) { c->bpp = fmt->bits_per_pixel; c->frame_size = c->width * c->height * fmt->bits_per_pixel / 8; return 0; } fmt++; } av_log(s, AV_LOG_ERROR, "Pixmap format not mappable.\n"); return AVERROR_PATCHWELCOME; } static int create_stream(AVFormatContext *s) { XCBGrabContext *c = s->priv_data; AVStream *st = avformat_new_stream(s, NULL); xcb_get_geometry_cookie_t gc; xcb_get_geometry_reply_t *geo; int ret; if (!st) return AVERROR(ENOMEM); ret = av_parse_video_size(&c->width, &c->height, c->video_size); if (ret < 0) return ret; ret = av_parse_video_rate(&st->avg_frame_rate, c->framerate); if (ret < 0) return ret; avpriv_set_pts_info(st, 64, 1, 1000000); gc = xcb_get_geometry(c->conn, c->screen->root); geo = xcb_get_geometry_reply(c->conn, gc, NULL); if (c->x + c->width > geo->width || c->y + c->height > geo->height) { av_log(s, AV_LOG_ERROR, "Capture area %dx%d at position %d.%d " "outside the screen size %dx%d\n", c->width, c->height, c->x, c->y, geo->width, geo->height); return AVERROR(EINVAL); } c->time_base = (AVRational){ st->avg_frame_rate.den, st->avg_frame_rate.num }; c->time_frame = av_gettime(); st->codec->codec_type = AVMEDIA_TYPE_VIDEO; st->codec->codec_id = AV_CODEC_ID_RAWVIDEO; st->codec->width = c->width; st->codec->height = c->height; st->codec->time_base = c->time_base; ret = pixfmt_from_pixmap_format(s, geo->depth, &st->codec->pix_fmt); free(geo); return ret; } static void draw_rectangle(AVFormatContext *s) { XCBGrabContext *c = s->priv_data; xcb_gcontext_t gc = xcb_generate_id(c->conn); uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_LINE_WIDTH | XCB_GC_LINE_STYLE | XCB_GC_FILL_STYLE; uint32_t values[] = { c->screen->black_pixel, c->screen->white_pixel, c->region_border, XCB_LINE_STYLE_DOUBLE_DASH, XCB_FILL_STYLE_SOLID }; xcb_rectangle_t r = { 1, 1, c->width + c->region_border * 2 - 3, c->height + c->region_border * 2 - 3 }; xcb_create_gc(c->conn, gc, c->window, mask, values); xcb_poly_rectangle(c->conn, c->window, gc, 1, &r); } static void setup_window(AVFormatContext *s) { XCBGrabContext *c = s->priv_data; uint32_t mask = XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK; uint32_t values[] = { 1, XCB_EVENT_MASK_EXPOSURE | XCB_EVENT_MASK_STRUCTURE_NOTIFY }; av_unused xcb_rectangle_t rect = { 0, 0, c->width, c->height }; c->window = xcb_generate_id(c->conn); xcb_create_window(c->conn, XCB_COPY_FROM_PARENT, c->window, c->screen->root, c->x - c->region_border, c->y - c->region_border, c->width + c->region_border * 2, c->height + c->region_border * 2, 0, XCB_WINDOW_CLASS_INPUT_OUTPUT, XCB_COPY_FROM_PARENT, mask, values); #if CONFIG_LIBXCB_SHAPE xcb_shape_rectangles(c->conn, XCB_SHAPE_SO_SUBTRACT, XCB_SHAPE_SK_BOUNDING, XCB_CLIP_ORDERING_UNSORTED, c->window, c->region_border, c->region_border, 1, &rect); #endif xcb_map_window(c->conn, c->window); draw_rectangle(s); } static av_cold int xcbgrab_read_header(AVFormatContext *s) { XCBGrabContext *c = s->priv_data; int screen_num, ret; const xcb_setup_t *setup; char *display_name = av_strdup(s->filename); if (!display_name) return AVERROR(ENOMEM); if (!sscanf(s->filename, "%[^+]+%d,%d", display_name, &c->x, &c->y)) { *display_name = 0; sscanf(s->filename, "+%d,%d", &c->x, &c->y); } c->conn = xcb_connect(display_name[0] ? display_name : NULL, &screen_num); av_freep(&display_name); if ((ret = xcb_connection_has_error(c->conn))) { av_log(s, AV_LOG_ERROR, "Cannot open display %s, error %d.\n", s->filename[0] ? s->filename : "default", ret); return AVERROR(EIO); } setup = xcb_get_setup(c->conn); c->screen = get_screen(setup, screen_num); if (!c->screen) { av_log(s, AV_LOG_ERROR, "The screen %d does not exist.\n", screen_num); xcbgrab_read_close(s); return AVERROR(EIO); } ret = create_stream(s); if (ret < 0) { xcbgrab_read_close(s); return ret; } #if CONFIG_LIBXCB_SHM if ((c->has_shm = check_shm(c->conn))) c->segment = xcb_generate_id(c->conn); #endif #if CONFIG_LIBXCB_XFIXES if (c->draw_mouse) { if (!(c->draw_mouse = check_xfixes(c->conn))) { av_log(s, AV_LOG_WARNING, "XFixes not available, cannot draw the mouse.\n"); } if (c->bpp < 24) { avpriv_report_missing_feature(s, "%d bits per pixel screen", c->bpp); c->draw_mouse = 0; } } #endif if (c->show_region) setup_window(s); return 0; } AVInputFormat ff_x11grab_xcb_demuxer = { .name = "x11grab", .long_name = NULL_IF_CONFIG_SMALL("X11 screen capture, using XCB"), .priv_data_size = sizeof(XCBGrabContext), .read_header = xcbgrab_read_header, .read_packet = xcbgrab_read_packet, .read_close = xcbgrab_read_close, .flags = AVFMT_NOFILE, .priv_class = &xcbgrab_class, };