int avcodec_close(AVCodecContext *avctx)
{
    entangled_thread_counter++;
    if(entangled_thread_counter != 1){
        av_log(avctx, AV_LOG_ERROR, "insufficient thread locking around avcodec_open/close()\n");
        entangled_thread_counter--;
        return -1;
    }

    if (HAVE_THREADS && avctx->thread_opaque)
        avcodec_thread_free(avctx);
    if (avctx->codec->close)
        avctx->codec->close(avctx);
    avcodec_default_free_buffers(avctx);
    av_freep(&avctx->priv_data);
    avctx->codec = NULL;
    entangled_thread_counter--;
    return 0;
}