ffplay: warn that -s is no longer working, suggest alternative

Also remove now unused variables.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

doc/ffplay.texi

@@ -38,8 +38,8 @@ Force displayed width.
 @item -y @var{height}
 Force displayed height.
 @item -s @var{size}
-Set frame size (WxH or abbreviation), needed for videos which don't
-contain a header with the frame size like raw YUV.
+This option has been removed. Use private format options for specifying the
+input video size.
 @item -an
 Disable audio.
 @item -vn

ffplay.c

@@ -226,8 +226,6 @@ static int fs_screen_width;
 static int fs_screen_height;
 static int screen_width = 0;
 static int screen_height = 0;
-static int frame_width = 0;
-static int frame_height = 0;
 static enum PixelFormat frame_pix_fmt = PIX_FMT_NONE;
 static int audio_disable;
 static int video_disable;
@@ -2823,15 +2821,9 @@ static void event_loop(void)
 
 static int opt_frame_size(const char *opt, const char *arg)
 {
-    if (av_parse_video_size(&frame_width, &frame_height, arg) < 0) {
-        fprintf(stderr, "Incorrect frame size\n");
-        return AVERROR(EINVAL);
-    }
-    if ((frame_width % 2) != 0 || (frame_height % 2) != 0) {
-        fprintf(stderr, "Frame size must be a multiple of 2\n");
-        return AVERROR(EINVAL);
-    }
-    return 0;
+    av_log(NULL, AV_LOG_ERROR,
+           "Option '%s' has been removed, use private format options instead\n", opt);
+    return AVERROR(EINVAL);
 }
 
 static int opt_width(const char *opt, const char *arg)