[FFmpeg-cvslog] avdevice/xcbgrab: Add option for grabbing a window
sgerwk
git at videolan.org
Mon Mar 15 00:27:36 EET 2021
ffmpeg | branch: master | sgerwk <sgerwk at aol.com> | Wed Feb 10 17:36:00 2021 +0100| [07de796b5d1f4db239bd986f553760b868a908f0] | committer: Andriy Gelman
avdevice/xcbgrab: Add option for grabbing a window
The option allows to select a specific window instead of the whole
screen.
Reviewed-by: Andriy Gelman <andriy.gelman at gmail.com>
Signed-off-by: Andriy Gelman <andriy.gelman at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=07de796b5d1f4db239bd986f553760b868a908f0
---
doc/indevs.texi | 15 ++++++++++-
libavdevice/xcbgrab.c | 70 ++++++++++++++++++++++++++++++++++++++-------------
2 files changed, 66 insertions(+), 19 deletions(-)
diff --git a/doc/indevs.texi b/doc/indevs.texi
index 3924d03908..b377924c2f 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -1564,8 +1564,21 @@ With @var{follow_mouse}:
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
@end example
+ at item window_id
+Grab this window, instead of the whole screen. Default value is 0, which maps to
+the whole screen (root window).
+
+The id of a window can be found using the @command{xwininfo} program, possibly with options -tree and
+-root.
+
+If the window is later enlarged, the new area is not recorded. Video ends when
+the window is closed, unmapped (i.e., iconified) or shrunk beyond the video
+size (which defaults to the initial window size).
+
+This option disables options @option{follow_mouse} and @option{select_region}.
+
@item video_size
-Set the video frame size. Default is the full desktop.
+Set the video frame size. Default is the full desktop or window.
@item grab_x
@item grab_y
diff --git a/libavdevice/xcbgrab.c b/libavdevice/xcbgrab.c
index f9ea5a56b2..71f0902f8e 100644
--- a/libavdevice/xcbgrab.c
+++ b/libavdevice/xcbgrab.c
@@ -60,6 +60,7 @@ typedef struct XCBGrabContext {
AVRational time_base;
int64_t frame_duration;
+ xcb_window_t window_id;
int x, y;
int width, height;
int frame_size;
@@ -82,6 +83,7 @@ typedef struct XCBGrabContext {
#define OFFSET(x) offsetof(XCBGrabContext, x)
#define D AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
+ { "window_id", "Window to capture.", OFFSET(window_id), AV_OPT_TYPE_INT, { .i64 = XCB_NONE }, 0, UINT32_MAX, D },
{ "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 },
@@ -157,7 +159,7 @@ 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_drawable_t drawable = c->window_id;
xcb_generic_error_t *e = NULL;
uint8_t *data;
int length;
@@ -267,7 +269,7 @@ 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;
+ xcb_drawable_t drawable = c->window_id;
xcb_generic_error_t *e = NULL;
AVBufferRef *buf;
xcb_shm_seg_t segment;
@@ -333,7 +335,8 @@ static int check_xfixes(xcb_connection_t *conn)
static void xcbgrab_draw_mouse(AVFormatContext *s, AVPacket *pkt,
xcb_query_pointer_reply_t *p,
- xcb_get_geometry_reply_t *geo)
+ xcb_get_geometry_reply_t *geo,
+ int win_x, int win_y)
{
XCBGrabContext *gr = s->priv_data;
uint32_t *cursor;
@@ -355,17 +358,17 @@ static void xcbgrab_draw_mouse(AVFormatContext *s, AVPacket *pkt,
cx = ci->x - ci->xhot;
cy = ci->y - ci->yhot;
- x = FFMAX(cx, gr->x);
- y = FFMAX(cy, gr->y);
+ x = FFMAX(cx, win_x + gr->x);
+ y = FFMAX(cy, win_y + gr->y);
- w = FFMIN(cx + ci->width, gr->x + gr->width) - x;
- h = FFMIN(cy + ci->height, gr->y + gr->height) - y;
+ w = FFMIN(cx + ci->width, win_x + gr->x + gr->width) - x;
+ h = FFMIN(cy + ci->height, win_y + gr->y + gr->height) - y;
c_off = x - cx;
- i_off = x - gr->x;
+ i_off = x - gr->x - win_x;
cursor += (y - cy) * ci->width;
- image += (y - gr->y) * gr->width * stride;
+ image += (y - gr->y - win_y) * gr->width * stride;
for (y = 0; y < h; y++) {
cursor += c_off;
@@ -400,11 +403,11 @@ static void xcbgrab_draw_mouse(AVFormatContext *s, AVPacket *pkt,
}
#endif /* CONFIG_LIBXCB_XFIXES */
-static void xcbgrab_update_region(AVFormatContext *s)
+static void xcbgrab_update_region(AVFormatContext *s, int win_x, int win_y)
{
XCBGrabContext *c = s->priv_data;
- const uint32_t args[] = { c->x - c->region_border,
- c->y - c->region_border };
+ const uint32_t args[] = { win_x + c->x - c->region_border,
+ win_y + c->y - c->region_border };
xcb_configure_window(c->conn,
c->window,
@@ -417,17 +420,20 @@ 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_translate_coordinates_cookie_t tc;
xcb_query_pointer_reply_t *p = NULL;
xcb_get_geometry_reply_t *geo = NULL;
+ xcb_translate_coordinates_reply_t *translate = NULL;
int ret = 0;
int64_t pts;
+ int win_x = 0, win_y = 0;
wait_frame(s, pkt);
pts = av_gettime();
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);
+ pc = xcb_query_pointer(c->conn, c->window_id);
+ gc = xcb_get_geometry(c->conn, c->window_id);
p = xcb_query_pointer_reply(c->conn, pc, NULL);
if (!p) {
av_log(s, AV_LOG_ERROR, "Failed to query xcb pointer\n");
@@ -440,12 +446,25 @@ static int xcbgrab_read_packet(AVFormatContext *s, AVPacket *pkt)
return AVERROR_EXTERNAL;
}
}
+ if (c->window_id != c->screen->root) {
+ tc = xcb_translate_coordinates(c->conn, c->window_id, c->screen->root, 0, 0);
+ translate = xcb_translate_coordinates_reply(c->conn, tc, NULL);
+ if (!translate) {
+ free(p);
+ free(geo);
+ av_log(s, AV_LOG_ERROR, "Failed to translate xcb geometry\n");
+ return AVERROR_EXTERNAL;
+ }
+ win_x = translate->dst_x;
+ win_y = translate->dst_y;
+ free(translate);
+ }
if (c->follow_mouse && p->same_screen)
xcbgrab_reposition(s, p, geo);
if (c->show_region)
- xcbgrab_update_region(s);
+ xcbgrab_update_region(s, win_x, win_y);
#if CONFIG_LIBXCB_SHM
if (c->has_shm && xcbgrab_frame_shm(s, pkt) < 0) {
@@ -460,7 +479,7 @@ static int xcbgrab_read_packet(AVFormatContext *s, AVPacket *pkt)
#if CONFIG_LIBXCB_XFIXES
if (ret >= 0 && c->draw_mouse && p->same_screen)
- xcbgrab_draw_mouse(s, pkt, p, geo);
+ xcbgrab_draw_mouse(s, pkt, p, geo, win_x, win_y);
#endif
free(p);
@@ -572,10 +591,12 @@ static int create_stream(AVFormatContext *s)
avpriv_set_pts_info(st, 64, 1, 1000000);
- gc = xcb_get_geometry(c->conn, c->screen->root);
+ gc = xcb_get_geometry(c->conn, c->window_id);
geo = xcb_get_geometry_reply(c->conn, gc, NULL);
- if (!geo)
+ if (!geo) {
+ av_log(s, AV_LOG_ERROR, "Can't find window '0x%x', aborting.\n", c->window_id);
return AVERROR_EXTERNAL;
+ }
if (!c->width || !c->height) {
c->width = geo->width;
@@ -831,6 +852,19 @@ static av_cold int xcbgrab_read_header(AVFormatContext *s)
return AVERROR(EIO);
}
+ if (c->window_id == XCB_NONE)
+ c->window_id = c->screen->root;
+ else {
+ if (c->select_region) {
+ av_log(s, AV_LOG_WARNING, "select_region ignored with window_id.\n");
+ c->select_region = 0;
+ }
+ if (c->follow_mouse) {
+ av_log(s, AV_LOG_WARNING, "follow_mouse ignored with window_id.\n");
+ c->follow_mouse = 0;
+ }
+ }
+
if (c->select_region) {
ret = select_region(s);
if (ret < 0) {
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