+int av_thread_message_queue_nb_elems(AVThreadMessageQueue *mq)
+{
+#if HAVE_THREADS
+ int ret;
+ pthread_mutex_lock(&mq->lock);
+ ret = av_fifo_size(mq->fifo);
+ pthread_mutex_unlock(&mq->lock);
+ return ret / mq->elsize;
+#else
+ return AVERROR(ENOSYS);
+#endif
+}
+