Merge "vpxenc: send usage to stderr"

vpxenc.c

@@ -1180,22 +1180,22 @@ static void usage_exit() {
           exec_name);
 
   fprintf(stderr, "\nOptions:\n");
-  arg_show_usage(stdout, main_args);
+  arg_show_usage(stderr, main_args);
   fprintf(stderr, "\nEncoder Global Options:\n");
-  arg_show_usage(stdout, global_args);
+  arg_show_usage(stderr, global_args);
   fprintf(stderr, "\nRate Control Options:\n");
-  arg_show_usage(stdout, rc_args);
+  arg_show_usage(stderr, rc_args);
   fprintf(stderr, "\nTwopass Rate Control Options:\n");
-  arg_show_usage(stdout, rc_twopass_args);
+  arg_show_usage(stderr, rc_twopass_args);
   fprintf(stderr, "\nKeyframe Placement Options:\n");
-  arg_show_usage(stdout, kf_args);
+  arg_show_usage(stderr, kf_args);
 #if CONFIG_VP8_ENCODER
   fprintf(stderr, "\nVP8 Specific Options:\n");
-  arg_show_usage(stdout, vp8_args);
+  arg_show_usage(stderr, vp8_args);
 #endif
 #if CONFIG_VP9_ENCODER
   fprintf(stderr, "\nVP9 Specific Options:\n");
-  arg_show_usage(stdout, vp9_args);
+  arg_show_usage(stderr, vp9_args);
 #endif
   fprintf(stderr, "\nStream timebase (--timebase):\n"
           "  The desired precision of timestamps in the output, expressed\n"