diff --git a/libavdevice/x11grab.c b/libavdevice/x11grab.c index 56eeea9812..4ca5434a9e 100644 --- a/libavdevice/x11grab.c +++ b/libavdevice/x11grab.c @@ -139,6 +139,35 @@ static void x11grab_region_win_init(X11GrabContext *s) x11grab_draw_region_win(s); } +static int setup_shm(AVFormatContext *s, Display *dpy, XImage **image) +{ + X11GrabContext *g = s->priv_data; + int scr = XDefaultScreen(dpy); + XImage *img = XShmCreateImage(dpy, DefaultVisual(dpy, scr), + DefaultDepth(dpy, scr), ZPixmap, NULL, + &g->shminfo, g->width, g->height); + + g->shminfo.shmid = shmget(IPC_PRIVATE, img->bytes_per_line * img->height, + IPC_CREAT | 0777); + + if (g->shminfo.shmid == -1) { + av_log(s, AV_LOG_ERROR, "Cannot get shared memory!\n"); + return AVERROR(ENOMEM); + } + + g->shminfo.shmaddr = img->data = shmat(g->shminfo.shmid, 0, 0); + g->shminfo.readOnly = False; + + if (!XShmAttach(dpy, &g->shminfo)) { + av_log(s, AV_LOG_ERROR, "Failed to attach shared memory!\n"); + /* needs some better error subroutine :) */ + return AVERROR(EIO); + } + + *image = img; + return 0; +} + /** * Initialize the x11 grab device demuxer (public device demuxer API). * @@ -225,33 +254,12 @@ static int x11grab_read_header(AVFormatContext *s1) av_log(s1, AV_LOG_INFO, "shared memory extension %sfound\n", use_shm ? "" : "not "); - if (use_shm) { - int scr = XDefaultScreen(dpy); - image = XShmCreateImage(dpy, - DefaultVisual(dpy, scr), - DefaultDepth(dpy, scr), - ZPixmap, - NULL, - &x11grab->shminfo, - x11grab->width, x11grab->height); - x11grab->shminfo.shmid = shmget(IPC_PRIVATE, - image->bytes_per_line * image->height, - IPC_CREAT | 0777); - if (x11grab->shminfo.shmid == -1) { - av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n"); - ret = AVERROR(ENOMEM); - goto out; - } - x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0); - x11grab->shminfo.readOnly = False; + if (use_shm && setup_shm(s1, dpy, &image) < 0) { + av_log(s1, AV_LOG_WARNING, "Falling back to XGetImage\n"); + use_shm = 0; + } - if (!XShmAttach(dpy, &x11grab->shminfo)) { - av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n"); - /* needs some better error subroutine :) */ - ret = AVERROR(EIO); - goto out; - } - } else { + if (!use_shm) { image = XGetImage(dpy, RootWindow(dpy, screen), x_off, y_off, x11grab->width, x11grab->height,