Hi,
Example commands:
./ffmpeg -f x11grab -s cif -r 25 -i ':0.0;followmouse' /tmp/out.mpg
./ffmpeg -f x11grab -s cif -r 25 -i ':0.0;followmouse=100' /tmp/out.mpg
In first command, the grabbing region moves as mouse moves, mouse
pointer will be kept at center unless close to screen edges. The
second command, the region only moves when mouse pointer reaches
within 100 pixels to the edges of current grabbing region.
There will be a second patch to be posted right after this, which
renders a rectangle box to indicate current grabbing region.
(Aside: I have tried to submit a similar patch to FFmpeg-devel, but
after a week with no response, so I decided to continue making the
indication box and forgot the patch submission. Yesterday, I saw the
forwarded notice to FFmpeg-devel about the upcoming (or ongoing
already) major changes on libav. That's my first time heard of libav,
then I checked the logs of x11grabc, it seems the recent changes were
made from libav. So, I think I should try here instead of bumping my
post there.)
Sincerely yours,
Yu-Jie Lin
From 9d3505ae4a00f6576048f4058aaeaff902ee0157 Mon Sep 17 00:00:00 2001
From: Yu-Jie Lin <[email protected]>
Date: Sat, 30 Jul 2011 18:46:36 +0800
Subject: [PATCH 1/2] x11grab: add followmouse option.
Two modes of followmouse are added: a) appending ";followmouse" to input
file name will move grabbing region to where mouse pointer at center;
b) appending ";followmouse=PIXELES" will only move when pointer reaches
with in PIXELES to the edge of grabbing region.
Signed-off-by: Yu-Jie Lin <[email protected]>
---
doc/ffmpeg.texi | 16 +++++++++++
doc/indevs.texi | 14 ++++++++++
libavdevice/x11grab.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++---
3 files changed, 95 insertions(+), 4 deletions(-)
diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 4dca5d8..9b3728b 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -903,6 +903,22 @@ ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
variable. 10 is the x-offset and 20 the y-offset for the grabbing.
+@example
+ffmpeg -f x11grab -s cif -r 25 -i ':0.0;followmouse' /tmp/out.mpg
+@end example
+
+0.0 is display.screen number of your X11 server, same as the DISPLAY environment
+variable. Grabbing region follows the mouse pointer, which stays at center of
+grabbing region.
+
+@example
+ffmpeg -f x11grab -s cif -r 25 -i ':0.0;followmouse=100' /tmp/out.mpg
+@end example
+
+0.0 is display.screen number of your X11 server, same as the DISPLAY environment
+variable. Grabbing region follows the mouse pointer, but only when mouse
+pointer reaches within 100 pixels to the edge of grabbing region.
+
@section Video and Audio file format conversion
Any supported file format and protocol can serve as input to ffmpeg:
diff --git a/doc/indevs.texi b/doc/indevs.texi
index c5e04b0..3876807 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -227,6 +227,7 @@ This device allows to capture a region of an X11 display.
The filename passed as input has the syntax:
@example
[@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
+[;followmouse[=@var{follow_mouse}]]
@end example
@var{hostname}:@var{display_number}.@var{screen_number} specifies the
@@ -251,4 +252,17 @@ ffmpeg -f x11grab -r 25 -s cif -i :0.0 out.mpg
ffmpeg -f x11grab -25 -s cif -i :0.0+10,20 out.mpg
@end example
+If "followmouse" is specified, then the grabbing region follows the mouse
+pointer and keeps pointer at center of region; and if @var{follow_mouse} is also
+specified, then grabbing region only moves when mouse pointer reaches within
+@var{follow_mouse} pixels to the edge of region.
+
+For example:
+@example
+ffmpeg -f x11grab -r 25 -s cif -i ':0.0;followmouse' out.mpg
+
+# Moving grabbing region only when mouse reaches within 100 pixels to edge
+ffmpeg -f x11grab -r 25 -s cif -i ':0.0;followmouse=100' out.mpg
+@end example
+
@c man end INPUT DEVICES
diff --git a/libavdevice/x11grab.c b/libavdevice/x11grab.c
index 80507ab..c04c198 100644
--- a/libavdevice/x11grab.c
+++ b/libavdevice/x11grab.c
@@ -71,6 +71,7 @@ struct x11_grab
int use_shm; /**< !0 when using XShm extension */
XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
int draw_mouse; /**< Set by a private option. */
+ int follow_mouse; /**< Set by a private option. */
char *framerate; /**< Set by a private option. */
};
@@ -95,6 +96,9 @@ x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
XImage *image;
int x_off = 0;
int y_off = 0;
+ int screen;
+ int screen_w, screen_h;
+ Window w;
int use_shm;
char *param, *offset;
int ret = 0;
@@ -105,8 +109,15 @@ x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
if (offset) {
sscanf(offset, "%d,%d", &x_off, &y_off);
x11grab->draw_mouse = !strstr(offset, "nomouse");
- *offset= 0;
}
+ x11grab->follow_mouse = 0;
+ if (offset = strstr(param, ";followmouse")) {
+ x11grab->follow_mouse = -1;
+ sscanf(offset, ";followmouse=%d", &x11grab->follow_mouse);
+ }
+ /* trim dpyname to only [hostname]:<display_number>.<screen_number> */
+ if (offset = strpbrk(param, "+;"))
+ *offset = 0;
if ((ret = av_parse_video_size(&x11grab->width, &x11grab->height, x11grab->video_size)) < 0) {
av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
@@ -141,6 +152,19 @@ x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
}
av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
+ screen = DefaultScreen(dpy);
+ screen_w = DisplayWidth(dpy, screen);
+ screen_h = DisplayHeight(dpy, screen);
+
+ if (x11grab->follow_mouse) {
+ XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off, &ret, &ret, &ret);
+ x_off -= x11grab->width >> 1;
+ y_off -= x11grab->height >> 1;
+ x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width);
+ y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height);
+ av_log(s1, AV_LOG_INFO, "followmouse is enabled, resetting grabbing region to x: %d y: %d\n", x_off, y_off);
+ }
+
use_shm = XShmQueryExtension(dpy);
av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");
@@ -171,7 +195,7 @@ x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
goto out;
}
} else {
- image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
+ image = XGetImage(dpy, RootWindow(dpy, screen),
x_off,y_off,
x11grab->width, x11grab->height,
AllPlanes, ZPixmap);
@@ -374,6 +398,13 @@ x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
int x_off = s->x_off;
int y_off = s->y_off;
+ int screen;
+ Window root, w;
+ int screen_w;
+ int screen_h;
+ int x, y, _;
+ int follow_mouse = s->follow_mouse;
+
int64_t curtime, delay;
struct timespec ts;
@@ -400,12 +431,41 @@ x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
pkt->size = s->frame_size;
pkt->pts = curtime;
+ screen = DefaultScreen(dpy);
+ root = RootWindow(dpy, screen);
+ if (follow_mouse) {
+ screen_w = DisplayWidth(dpy, screen);
+ screen_h = DisplayHeight(dpy, screen);
+ XQueryPointer(dpy, root, &w, &w, &x, &y, &_, &_, &_);
+ if (follow_mouse == -1) {
+ // follow the mouse, put it at center of grabbing region
+ if ((x_off <= screen_w - s->width && x_off >= 0) && x - s->width >> 1 != s->x_off)
+ x_off += copysign(abs(x - s->width >> 1 - s->x_off), x - s->width >> 1 - s->x_off);
+ if ((y_off <= screen_h - s->height && y_off >= 0) && y - s->height >> 1 != s->y_off)
+ y_off += copysign(abs(y - s->height >> 1 - s->y_off), y - s->height >> 1 - s->y_off);
+ } else {
+ // follow the mouse, but only move the grabbing region when mouse
+ // reaches within certain pixels to the edge.
+ if (x_off < screen_w - s->width && x > x_off + s->width - follow_mouse) {
+ x_off += x - x_off - s->width + follow_mouse;
+ } else if (x_off > 0 && x < x_off + follow_mouse)
+ x_off -= x_off + follow_mouse - x;
+ if (y_off < screen_h - s->height && y > y_off + s->height - follow_mouse) {
+ y_off += y - y_off - s->height + follow_mouse;
+ } else if (y_off > 0 && y < y_off + follow_mouse)
+ y_off -= y_off + follow_mouse - y;
+ }
+ // adjust grabbing region position if it goes out of screen.
+ s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width);
+ s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height);
+ }
+
if(s->use_shm) {
- if (!XShmGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off, AllPlanes)) {
+ if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes)) {
av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
}
} else {
- if (!xget_zpixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {
+ if (!xget_zpixmap(dpy, root, image, x_off, y_off)) {
av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
}
}
@@ -452,6 +512,7 @@ static const AVOption options[] = {
{ "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), FF_OPT_TYPE_STRING, {.str = "vga"}, 0, 0, DEC },
{ "framerate", "", OFFSET(framerate), FF_OPT_TYPE_STRING, {.str = "ntsc"}, 0, 0, DEC },
{ "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), FF_OPT_TYPE_INT, { 1 }, 0, 1, DEC },
+ { "follow_mouse", "Follow the mouse pointer.", OFFSET(follow_mouse), FF_OPT_TYPE_INT, { 0 }, -1, INT_MAX, DEC },
{ NULL },
};
--
1.7.3.4
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