avcodec_default_free_buffers(avctx);
static int decode_end(AVCodecContext *avctx){    FourXContext * const f = avctx->priv_data;    int i;    av_freep(&f->bitstream_buffer);    f->bitstream_buffer_size=0;    for(i=0; i<CFRAME_BUFFER_COUNT; i++){        av_freep(&f->cfrm[i].data);        f->cfrm[i].allocated_size= 0;    }    free_vlc(&f->pre_vlc);        avcodec_default_free_buffers(avctx);    return 0;}