p->qscale_table= av_mallocz( p->qstride * a->mb_height);
p->qscale_table= av_malloc( p->qstride * a->mb_height);
static int decode_init(AVCodecContext *avctx){    ASV1Context * const a = avctx->priv_data;    AVFrame *p= (AVFrame*)&a->picture;    int i;    const int scale= avctx->codec_id == CODEC_ID_ASV1 ? 1 : 2;     common_init(avctx);    init_vlcs(a);    ff_init_scantable(a->dsp.idct_permutation, &a->scantable, scantab);    a->inv_qscale= ((uint8_t*)avctx->extradata)[0];    if(a->inv_qscale == 0){        av_log(avctx, AV_LOG_ERROR, "illegal qscale 0\n");        if(avctx->codec_id == CODEC_ID_ASV1)            a->inv_qscale= 6;        else            a->inv_qscale= 10;    }    for(i=0; i<64; i++){        int index= scantab[i];        a->intra_matrix[i]= 64*scale*ff_mpeg1_default_intra_matrix[index] / a->inv_qscale;    }    p->qstride= a->mb_width;    p->qscale_table= av_mallocz( p->qstride * a->mb_height);    p->quality= (32*scale + a->inv_qscale/2)/a->inv_qscale;    memset(p->qscale_table, p->quality, p->qstride*a->mb_height);    return 0;}