quant_matrix = s->non_intra_matrix;
quant_matrix = s->inter_matrix;
static void dct_unquantize_mpeg1_c(MpegEncContext *s,                                    DCTELEM *block, int n, int qscale){    int i, level, nCoeffs;    const UINT16 *quant_matrix;    if(s->alternate_scan) nCoeffs= 64;    else nCoeffs= s->block_last_index[n]+1;        if (s->mb_intra) {        if (n < 4)             block[0] = block[0] * s->y_dc_scale;        else            block[0] = block[0] * s->c_dc_scale;        /* XXX: only mpeg1 */        quant_matrix = s->intra_matrix;        for(i=1;i<nCoeffs;i++) {            int j= zigzag_direct[i];            level = block[j];            if (level) {                if (level < 0) {                    level = -level;                    level = (int)(level * qscale * quant_matrix[j]) >> 3;                    level = (level - 1) | 1;                    level = -level;                } else {                    level = (int)(level * qscale * quant_matrix[j]) >> 3;                    level = (level - 1) | 1;                }#ifdef PARANOID                if (level < -2048 || level > 2047)                    fprintf(stderr, "unquant error %d %d\n", i, level);#endif                block[j] = level;            }        }    } else {        i = 0;        quant_matrix = s->non_intra_matrix;        for(;i<nCoeffs;i++) {            int j= zigzag_direct[i];            level = block[j];            if (level) {                if (level < 0) {                    level = -level;                    level = (((level << 1) + 1) * qscale *                             ((int) (quant_matrix[j]))) >> 4;                    level = (level - 1) | 1;                    level = -level;                } else {                    level = (((level << 1) + 1) * qscale *                             ((int) (quant_matrix[j]))) >> 4;                    level = (level - 1) | 1;                }#ifdef PARANOID                if (level < -2048 || level > 2047)                    fprintf(stderr, "unquant error %d %d\n", i, level);#endif                block[j] = level;            }        }    }}