ts mux ActiveKeyCallback: reduce critical section

modules/mux/mpeg/ts.c

@@ -899,17 +899,26 @@ static int ActiveKeyCallback( vlc_object_t *p_this, char const *psz_cmd,
     VLC_UNUSED(psz_cmd); VLC_UNUSED(oldval); VLC_UNUSED(p_data);
     sout_mux_t      *p_mux = (sout_mux_t*)p_this;
     sout_mux_sys_t  *p_sys = p_mux->p_sys;
-    int             i_res = VLC_EBADVAR;
+    int             i_res, use_odd = -1;
 
-    vlc_mutex_lock( &p_sys->csa_lock );
-    if( !strcmp(newval.psz_string, "odd" ) || !strcmp(newval.psz_string, "first" ) || !strcmp(newval.psz_string, "1" ) )
+    if( !strcmp(newval.psz_string, "odd" ) ||
+        !strcmp(newval.psz_string, "first" ) ||
+        !strcmp(newval.psz_string, "1" ) )
     {
-        i_res = csa_UseKey( (vlc_object_t*)p_mux, p_sys->csa, 1 );
+        use_odd = 1;
     }
-    else if( !strcmp(newval.psz_string, "even" ) || !strcmp(newval.psz_string, "second" ) || !strcmp(newval.psz_string, "2" ) )
+    else if( !strcmp(newval.psz_string, "even" ) ||
+             !strcmp(newval.psz_string, "second" ) ||
+             !strcmp(newval.psz_string, "2" ) )
     {
-        i_res = csa_UseKey( (vlc_object_t*)p_mux, p_sys->csa, 0 );
+        use_odd = 0;
     }
+
+    if (use_odd < 0)
+        return VLC_EBADVAR;
+
+    vlc_mutex_lock( &p_sys->csa_lock );
+    i_res = csa_UseKey( p_this, p_sys->csa, use_odd );
     vlc_mutex_unlock( &p_sys->csa_lock );
 
     return i_res;