vc1.c

mediastreamer2是开源的网络传输媒体流的库

        v->pquantizer = 0;
    v->pqindex = pqindex;
    if (pqindex < 9) v->halfpq = get_bits1(gb);
    else v->halfpq = 0;
    if (v->quantizer_mode == QUANT_FRAME_EXPLICIT)
        v->pquantizer = get_bits1(gb);
    v->dquantfrm = 0;
    if (v->extended_mv == 1) v->mvrange = get_unary(gb, 0, 3);
    v->k_x = v->mvrange + 9 + (v->mvrange >> 1); //k_x can be 9 10 12 13
    v->k_y = v->mvrange + 8; //k_y can be 8 9 10 11
    v->range_x = 1 << (v->k_x - 1);
    v->range_y = 1 << (v->k_y - 1);
    if (v->profile == PROFILE_ADVANCED)
    {
        if (v->postprocflag) v->postproc = get_bits1(gb);
    }
    else
        if (v->multires && v->s.pict_type != B_TYPE) v->respic = get_bits(gb, 2);

    if(v->res_x8 && (v->s.pict_type == I_TYPE || v->s.pict_type == BI_TYPE)){
        v->x8_type = get_bits1(gb);
    }else v->x8_type = 0;
//av_log(v->s.avctx, AV_LOG_INFO, "%c Frame: QP=[%i]%i (+%i/2) %i\n",
//        (v->s.pict_type == P_TYPE) ? 'P' : ((v->s.pict_type == I_TYPE) ? 'I' : 'B'), pqindex, v->pq, v->halfpq, v->rangeredfrm);

    if(v->s.pict_type == I_TYPE || v->s.pict_type == P_TYPE) v->use_ic = 0;

    switch(v->s.pict_type) {
    case P_TYPE:
        if (v->pq < 5) v->tt_index = 0;
        else if(v->pq < 13) v->tt_index = 1;
        else v->tt_index = 2;

        lowquant = (v->pq > 12) ? 0 : 1;
        v->mv_mode = ff_vc1_mv_pmode_table[lowquant][get_unary(gb, 1, 4)];
        if (v->mv_mode == MV_PMODE_INTENSITY_COMP)
        {
            int scale, shift, i;
            v->mv_mode2 = ff_vc1_mv_pmode_table2[lowquant][get_unary(gb, 1, 3)];
            v->lumscale = get_bits(gb, 6);
            v->lumshift = get_bits(gb, 6);
            v->use_ic = 1;
            /* fill lookup tables for intensity compensation */
            if(!v->lumscale) {
                scale = -64;
                shift = (255 - v->lumshift * 2) << 6;
                if(v->lumshift > 31)
                    shift += 128 << 6;
            } else {
                scale = v->lumscale + 32;
                if(v->lumshift > 31)
                    shift = (v->lumshift - 64) << 6;
                else
                    shift = v->lumshift << 6;
            }
            for(i = 0; i < 256; i++) {
                v->luty[i] = av_clip_uint8((scale * i + shift + 32) >> 6);
                v->lutuv[i] = av_clip_uint8((scale * (i - 128) + 128*64 + 32) >> 6);
            }
        }
        if(v->mv_mode == MV_PMODE_1MV_HPEL || v->mv_mode == MV_PMODE_1MV_HPEL_BILIN)
            v->s.quarter_sample = 0;
        else if(v->mv_mode == MV_PMODE_INTENSITY_COMP) {
            if(v->mv_mode2 == MV_PMODE_1MV_HPEL || v->mv_mode2 == MV_PMODE_1MV_HPEL_BILIN)
                v->s.quarter_sample = 0;
            else
                v->s.quarter_sample = 1;
        } else
            v->s.quarter_sample = 1;
        v->s.mspel = !(v->mv_mode == MV_PMODE_1MV_HPEL_BILIN || (v->mv_mode == MV_PMODE_INTENSITY_COMP && v->mv_mode2 == MV_PMODE_1MV_HPEL_BILIN));

        if ((v->mv_mode == MV_PMODE_INTENSITY_COMP &&
                 v->mv_mode2 == MV_PMODE_MIXED_MV)
                || v->mv_mode == MV_PMODE_MIXED_MV)
        {
            status = bitplane_decoding(v->mv_type_mb_plane, &v->mv_type_is_raw, v);
            if (status < 0) return -1;
            av_log(v->s.avctx, AV_LOG_DEBUG, "MB MV Type plane encoding: "
                   "Imode: %i, Invert: %i\n", status>>1, status&1);
        } else {
            v->mv_type_is_raw = 0;
            memset(v->mv_type_mb_plane, 0, v->s.mb_stride * v->s.mb_height);
        }
        status = bitplane_decoding(v->s.mbskip_table, &v->skip_is_raw, v);
        if (status < 0) return -1;
        av_log(v->s.avctx, AV_LOG_DEBUG, "MB Skip plane encoding: "
               "Imode: %i, Invert: %i\n", status>>1, status&1);

        /* Hopefully this is correct for P frames */
        v->s.mv_table_index = get_bits(gb, 2); //but using ff_vc1_ tables
        v->cbpcy_vlc = &ff_vc1_cbpcy_p_vlc[get_bits(gb, 2)];

        if (v->dquant)
        {
            av_log(v->s.avctx, AV_LOG_DEBUG, "VOP DQuant info\n");
            vop_dquant_decoding(v);
        }

        v->ttfrm = 0; //FIXME Is that so ?
        if (v->vstransform)
        {
            v->ttmbf = get_bits1(gb);
            if (v->ttmbf)
            {
                v->ttfrm = ff_vc1_ttfrm_to_tt[get_bits(gb, 2)];
            }
        } else {
            v->ttmbf = 1;
            v->ttfrm = TT_8X8;
        }
        break;
    case B_TYPE:
        if (v->pq < 5) v->tt_index = 0;
        else if(v->pq < 13) v->tt_index = 1;
        else v->tt_index = 2;

        lowquant = (v->pq > 12) ? 0 : 1;
        v->mv_mode = get_bits1(gb) ? MV_PMODE_1MV : MV_PMODE_1MV_HPEL_BILIN;
        v->s.quarter_sample = (v->mv_mode == MV_PMODE_1MV);
        v->s.mspel = v->s.quarter_sample;

        status = bitplane_decoding(v->direct_mb_plane, &v->dmb_is_raw, v);
        if (status < 0) return -1;
        av_log(v->s.avctx, AV_LOG_DEBUG, "MB Direct Type plane encoding: "
               "Imode: %i, Invert: %i\n", status>>1, status&1);
        status = bitplane_decoding(v->s.mbskip_table, &v->skip_is_raw, v);
        if (status < 0) return -1;
        av_log(v->s.avctx, AV_LOG_DEBUG, "MB Skip plane encoding: "
               "Imode: %i, Invert: %i\n", status>>1, status&1);

        v->s.mv_table_index = get_bits(gb, 2);
        v->cbpcy_vlc = &ff_vc1_cbpcy_p_vlc[get_bits(gb, 2)];

        if (v->dquant)
        {
            av_log(v->s.avctx, AV_LOG_DEBUG, "VOP DQuant info\n");
            vop_dquant_decoding(v);
        }

        v->ttfrm = 0;
        if (v->vstransform)
        {
            v->ttmbf = get_bits1(gb);
            if (v->ttmbf)
            {
                v->ttfrm = ff_vc1_ttfrm_to_tt[get_bits(gb, 2)];
            }
        } else {
            v->ttmbf = 1;
            v->ttfrm = TT_8X8;
        }
        break;
    }

    if(!v->x8_type)
    {
        /* AC Syntax */
        v->c_ac_table_index = decode012(gb);
        if (v->s.pict_type == I_TYPE || v->s.pict_type == BI_TYPE)
        {
            v->y_ac_table_index = decode012(gb);
        }
        /* DC Syntax */
        v->s.dc_table_index = get_bits1(gb);
    }

    if(v->s.pict_type == BI_TYPE) {
        v->s.pict_type = B_TYPE;
        v->bi_type = 1;
    }
    return 0;
}

static int vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
{
    int pqindex, lowquant;
    int status;

    v->p_frame_skipped = 0;

    if(v->interlace){
        v->fcm = decode012(gb);
        if(v->fcm) return -1; // interlaced frames/fields are not implemented
    }
    switch(get_unary(gb, 0, 4)) {
    case 0:
        v->s.pict_type = P_TYPE;
        break;
    case 1:
        v->s.pict_type = B_TYPE;
        break;
    case 2:
        v->s.pict_type = I_TYPE;
        break;
    case 3:
        v->s.pict_type = BI_TYPE;
        break;
    case 4:
        v->s.pict_type = P_TYPE; // skipped pic
        v->p_frame_skipped = 1;
        return 0;
    }
    if(v->tfcntrflag)
        skip_bits(gb, 8);
    if(v->broadcast) {
        if(!v->interlace || v->psf) {
            v->rptfrm = get_bits(gb, 2);
        } else {
            v->tff = get_bits1(gb);
            v->rptfrm = get_bits1(gb);
        }
    }
    if(v->panscanflag) {
        //...
    }
    v->rnd = get_bits1(gb);
    if(v->interlace)
        v->uvsamp = get_bits1(gb);
    if(v->finterpflag) v->interpfrm = get_bits1(gb);
    if(v->s.pict_type == B_TYPE) {
        v->bfraction = get_vlc2(gb, ff_vc1_bfraction_vlc.table, VC1_BFRACTION_VLC_BITS, 1);
        v->bfraction = ff_vc1_bfraction_lut[v->bfraction];
        if(v->bfraction == 0) {
            v->s.pict_type = BI_TYPE; /* XXX: should not happen here */
        }
    }
    pqindex = get_bits(gb, 5);
    if(!pqindex) return -1;
    v->pqindex = pqindex;
    if (v->quantizer_mode == QUANT_FRAME_IMPLICIT)
        v->pq = ff_vc1_pquant_table[0][pqindex];
    else
        v->pq = ff_vc1_pquant_table[1][pqindex];

    v->pquantizer = 1;
    if (v->quantizer_mode == QUANT_FRAME_IMPLICIT)
        v->pquantizer = pqindex < 9;
    if (v->quantizer_mode == QUANT_NON_UNIFORM)
        v->pquantizer = 0;
    v->pqindex = pqindex;
    if (pqindex < 9) v->halfpq = get_bits1(gb);
    else v->halfpq = 0;
    if (v->quantizer_mode == QUANT_FRAME_EXPLICIT)
        v->pquantizer = get_bits1(gb);

    if(v->s.pict_type == I_TYPE || v->s.pict_type == P_TYPE) v->use_ic = 0;

    switch(v->s.pict_type) {
    case I_TYPE:
    case BI_TYPE:
        status = bitplane_decoding(v->acpred_plane, &v->acpred_is_raw, v);
        if (status < 0) return -1;
        av_log(v->s.avctx, AV_LOG_DEBUG, "ACPRED plane encoding: "
                "Imode: %i, Invert: %i\n", status>>1, status&1);
        v->condover = CONDOVER_NONE;
        if(v->overlap && v->pq <= 8) {
            v->condover = decode012(gb);
            if(v->condover == CONDOVER_SELECT) {
                status = bitplane_decoding(v->over_flags_plane, &v->overflg_is_raw, v);
                if (status < 0) return -1;
                av_log(v->s.avctx, AV_LOG_DEBUG, "CONDOVER plane encoding: "
                        "Imode: %i, Invert: %i\n", status>>1, status&1);
            }
        }
        break;
    case P_TYPE:
        if(v->postprocflag)
            v->postproc = get_bits1(gb);
        if (v->extended_mv) v->mvrange = get_unary(gb, 0, 3);
        else v->mvrange = 0;
        v->k_x = v->mvrange + 9 + (v->mvrange >> 1); //k_x can be 9 10 12 13
        v->k_y = v->mvrange + 8; //k_y can be 8 9 10 11
        v->range_x = 1 << (v->k_x - 1);
        v->range_y = 1 << (v->k_y - 1);

        if (v->pq < 5) v->tt_index = 0;
        else if(v->pq < 13) v->tt_index = 1;
        else v->tt_index = 2;

        lowquant = (v->pq > 12) ? 0 : 1;
        v->mv_mode = ff_vc1_mv_pmode_table[lowquant][get_unary(gb, 1, 4)];
        if (v->mv_mode == MV_PMODE_INTENSITY_COMP)
        {
            int scale, shift, i;
            v->mv_mode2 = ff_vc1_mv_pmode_table2[lowquant][get_unary(gb, 1, 3)];
            v->lumscale = get_bits(gb, 6);
            v->lumshift = get_bits(gb, 6);
            /* fill lookup tables for intensity compensation */
            if(!v->lumscale) {
                scale = -64;
                shift = (255 - v->lumshift * 2) << 6;
                if(v->lumshift > 31)
                    shift += 128 << 6;
            } else {
                scale = v->lumscale + 32;
                if(v->lumshift > 31)
                    shift = (v->lumshift - 64) << 6;
                else
                    shift = v->lumshift << 6;
            }
            for(i = 0; i < 256; i++) {
                v->luty[i] = av_clip_uint8((scale * i + shift + 32) >> 6);
                v->lutuv[i] = av_clip_uint8((scale * (i - 128) + 128*64 + 32) >> 6);
            }
            v->use_ic = 1;
        }
        if(v->mv_mode == MV_PMODE_1MV_HPEL || v->mv_mode == MV_PMODE_1MV_HPEL_BILIN)
            v->s.quarter_sample = 0;
        else if(v->mv_mode == MV_PMODE_INTENSITY_COMP) {
            if(v->mv_mode2 == MV_PMODE_1MV_HPEL || v->mv_mode2 == MV_PMODE_1MV_HPEL_BILIN)
                v->s.quarter_sample = 0;
            else
                v->s.quarter_sample = 1;
        } else
            v->s.quarter_sample = 1;
        v->s.mspel = !(v->mv_mode == MV_PMODE_1MV_HPEL_BILIN || (v->mv_mode == MV_PMODE_INTENSITY_COMP && v->mv_mode2 == MV_PMODE_1MV_HPEL_BILIN));

        if ((v->mv_mode == MV_PMODE_INTENSITY_COMP &&
                 v->mv_mode2 == MV_PMODE_MIXED_MV)
                || v->mv_mode == MV_PMODE_MIXED_MV)
        {
            status = bitplane_decoding(v->mv_type_mb_plane, &v->mv_type_is_raw, v);
            if (status < 0) return -1;
            av_log(v->s.avctx, AV_LOG_DEBUG, "MB MV Type plane encoding: "
                   "Imode: %i, Invert: %i\n", status>>1, status&1);
        } else {
            v->mv_type_is_raw = 0;
            memset(v->mv_type_mb_plane, 0, v->s.mb_stride * v->s.mb_height);
        }
        status = bitplane_decoding(v->s.mbskip_table, &v->skip_is_raw, v);
        if (status < 0) return -1;
        av_log(v->s.avctx, AV_LOG_DEBUG, "MB Skip plane encoding: "
               "Imode: %i, Invert: %i\n", status>>1, status&1);

        /* Hopefully this is correct for P frames */
        v->s.mv_table_index = get_bits(gb, 2); //but using ff_vc1_ tables
        v->cbpcy_vlc = &ff_vc1_cbpcy_p_vlc[get_bits(gb, 2)];
        if (v->dquant)
        {
            av_log(v->s.avctx, AV_LOG_DEBUG, "VOP DQuant info\n");
            vop_dquant_decoding(v);
        }

        v->ttfrm = 0; //FIXME Is that so ?
        if (v->vstransform)
        {
            v->ttmbf = get_bits1(gb);
            if (v->ttmbf)
            {
                v->ttfrm = ff_vc1_ttfrm_to_tt[get_bits(gb, 2)];
            }
        } else {
            v->ttmbf = 1;
            v->ttfrm = TT_8X8;
        }
        break;
    case B_TYPE:
        if(v->postprocflag)
            v->postproc = get_bits1(gb);