FS-8240 #resolve [local_stream a/v gets out of sync when running in the background]

src/mod/formats/mod_local_stream/mod_local_stream.c

@@ -279,6 +279,8 @@ static void *SWITCH_THREAD_FUNC read_stream_thread(switch_thread_t *thread, void
 				flush_video_queue(source->video_q);
 			}
 
+			switch_buffer_zero(audio_buffer);
+			
 			if (switch_core_timer_init(&timer, source->timer_name, source->interval, (int)source->samples, temp_pool) != SWITCH_STATUS_SUCCESS) {
 				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Can't start timer.\n");
 				switch_dir_close(source->dir_handle);