ffplay: add options to specify window position

Signed-off-by: Marton Balint <cus@passwd.hu>

doc/ffplay.texi

@@ -74,6 +74,10 @@ as 100.
 Force format.
 @item -window_title @var{title}
 Set window title (default is the input filename).
+@item -left @var{title}
+Set the x position for the left of the window (default is a centered window).
+@item -top @var{title}
+Set the y position for the top of the window (default is a centered window).
 @item -loop @var{number}
 Loops movie playback <number> times. 0 means forever.
 @item -showmode @var{mode}

fftools/ffplay.c

@@ -314,6 +314,8 @@ static int default_width  = 640;
 static int default_height = 480;
 static int screen_width  = 0;
 static int screen_height = 0;
+static int screen_left = SDL_WINDOWPOS_CENTERED;
+static int screen_top = SDL_WINDOWPOS_CENTERED;
 static int audio_disable;
 static int video_disable;
 static int subtitle_disable;
@@ -1346,7 +1348,7 @@ static int video_open(VideoState *is)
     SDL_SetWindowTitle(window, window_title);
 
     SDL_SetWindowSize(window, w, h);
-    SDL_SetWindowPosition(window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
+    SDL_SetWindowPosition(window, screen_left, screen_top);
     if (is_full_screen)
         SDL_SetWindowFullscreen(window, SDL_WINDOW_FULLSCREEN_DESKTOP);
     SDL_ShowWindow(window);
@@ -3602,6 +3604,8 @@ static const OptionDef options[] = {
     { "framedrop", OPT_BOOL | OPT_EXPERT, { &framedrop }, "drop frames when cpu is too slow", "" },
     { "infbuf", OPT_BOOL | OPT_EXPERT, { &infinite_buffer }, "don't limit the input buffer size (useful with realtime streams)", "" },
     { "window_title", OPT_STRING | HAS_ARG, { &window_title }, "set window title", "window title" },
+    { "left", OPT_INT | HAS_ARG | OPT_EXPERT, { &screen_left }, "set the x position for the left of the window", "x pos" },
+    { "top", OPT_INT | HAS_ARG | OPT_EXPERT, { &screen_top }, "set the y position for the top of the window", "y pos" },
 #if CONFIG_AVFILTER
     { "vf", OPT_EXPERT | HAS_ARG, { .func_arg = opt_add_vfilter }, "set video filters", "filter_graph" },
     { "af", OPT_STRING | HAS_ARG, { &afilters }, "set audio filters", "filter_graph" },