av_freep(&s->bitstream);
static int flac_decode_close(AVCodecContext *avctx){    FLACContext *s = avctx->priv_data;    int i;        for (i = 0; i < s->channels; i++)    {        if (s->decoded[i])            av_free(s->decoded[i]);        if (s->residual[i])            av_free(s->residual[i]);    }        return 0;}