x11grab: Small near-cosmetic refactorings

Signed-off-by: Diego Biurrun <diego@biurrun.de>

libavdevice/x11grab.c

@@ -95,11 +95,9 @@ static void x11grab_draw_region_win(struct x11grab *s)
 {
     Display *dpy = s->dpy;
     Window win   = s->region_win;
-    int screen;
-    GC gc;
+    int screen = DefaultScreen(dpy);
+    GC gc = XCreateGC(dpy, win, 0, 0);
 
-    screen = DefaultScreen(dpy);
-    gc     = XCreateGC(dpy, win, 0, 0);
     XSetForeground(dpy, gc, WhitePixel(dpy, screen));
     XSetBackground(dpy, gc, BlackPixel(dpy, screen));
     XSetLineAttributes(dpy, gc, REGION_WIN_BORDER, LineDoubleDash, 0, 0);
@@ -117,12 +115,10 @@ static void x11grab_draw_region_win(struct x11grab *s)
 static void x11grab_region_win_init(struct x11grab *s)
 {
     Display *dpy = s->dpy;
-    int screen;
-    XSetWindowAttributes attribs;
     XRectangle rect;
+    XSetWindowAttributes attribs = { .override_redirect = True };
+    int screen = DefaultScreen(dpy);
 
-    screen = DefaultScreen(dpy);
-    attribs.override_redirect = True;
     s->region_win = XCreateWindow(dpy, RootWindow(dpy, screen),
                                   s->x_off  - REGION_WIN_BORDER,
                                   s->y_off  - REGION_WIN_BORDER,
@@ -160,12 +156,8 @@ static int x11grab_read_header(AVFormatContext *s1)
     AVStream *st = NULL;
     enum AVPixelFormat input_pixfmt;
     XImage *image;
-    int x_off = 0;
-    int y_off = 0;
-    int screen;
-    int use_shm;
+    int x_off = 0, y_off = 0, ret = 0, screen, use_shm;
     char *param, *offset;
-    int ret = 0;
     AVRational framerate;
 
     param = av_strdup(s1->filename);
@@ -179,12 +171,15 @@ static int x11grab_read_header(AVFormatContext *s1)
         *offset = 0;
     }
 
-    if ((ret = av_parse_video_size(&x11grab->width, &x11grab->height,
-                                   x11grab->video_size)) < 0) {
+    ret = av_parse_video_size(&x11grab->width, &x11grab->height,
+                              x11grab->video_size);
+    if (ret < 0) {
         av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
         goto out;
     }
-    if ((ret = av_parse_video_rate(&framerate, x11grab->framerate)) < 0) {
+
+    ret = av_parse_video_rate(&framerate, x11grab->framerate);
+    if (ret < 0) {
         av_log(s1, AV_LOG_ERROR, "Could not parse framerate: %s.\n",
                x11grab->framerate);
         goto out;
@@ -531,10 +526,10 @@ static int x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
 
     if (s->show_region) {
         if (s->region_win) {
-            XEvent evt;
-            // clean up the events, and do the initinal draw or redraw.
-            for (evt.type = NoEventMask;
-                 XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask, &evt);)
+            XEvent evt = { .type = NoEventMask };
+            // Clean up the events, and do the initial draw or redraw.
+            while (XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask,
+                                   &evt))
                 ;
             if (evt.type)
                 x11grab_draw_region_win(s);