Mirror video output when calling linphone_core_preview_ogl_render().

coreapi/linphonecore.c

@@ -5559,8 +5559,11 @@ void linphone_core_preview_ogl_render(const LinphoneCore *lc) {
 	LinphoneCall *call = linphone_core_get_current_call(lc);
 	VideoStream *stream = call ? call->videostream : lc->previewstream;
 
-	if (stream && stream->output2 && ms_filter_get_id(stream->output2) == MS_OGL_ID)
+	if (stream && stream->output2 && ms_filter_get_id(stream->output2) == MS_OGL_ID) {
+		int mirroring = TRUE;
+		ms_filter_call_method(stream->output2, MS_VIDEO_DISPLAY_ENABLE_MIRRORING, &mirroring);
 		ms_filter_call_method(stream->output2, MS_OGL_RENDER, NULL);
+	}
 
 	#endif
 }