vc1.c

来自「linux下的MPEG1」· C语言 代码 · 共 1,909 行 · 第 1/5 页

    {
        v->res_sm = get_bits(gb, 2); //reserved
        if (v->res_sm)
        {
            av_log(avctx, AV_LOG_ERROR,
                   "Reserved RES_SM=%i is forbidden\n", v->res_sm);
            return -1;
        }
    }

    // (fps-2)/4 (->30)
    v->frmrtq_postproc = get_bits(gb, 3); //common
    // (bitrate-32kbps)/64kbps
    v->bitrtq_postproc = get_bits(gb, 5); //common
    v->s.loop_filter = get_bits(gb, 1); //common
    if(v->s.loop_filter == 1 && v->profile == PROFILE_SIMPLE)
    {
        av_log(avctx, AV_LOG_ERROR,
               "LOOPFILTER shell not be enabled in simple profile\n");
    }

    v->res_x8 = get_bits(gb, 1); //reserved
    if (v->res_x8)
    {
        av_log(avctx, AV_LOG_ERROR,
               "1 for reserved RES_X8 is forbidden\n");
        //return -1;
    }
    v->multires = get_bits(gb, 1);
    v->res_fasttx = get_bits(gb, 1);
    if (!v->res_fasttx)
    {
        av_log(avctx, AV_LOG_ERROR,
               "0 for reserved RES_FASTTX is forbidden\n");
        //return -1;
    }

    v->fastuvmc =  get_bits(gb, 1); //common
    if (!v->profile && !v->fastuvmc)
    {
        av_log(avctx, AV_LOG_ERROR,
               "FASTUVMC unavailable in Simple Profile\n");
        return -1;
    }
    v->extended_mv =  get_bits(gb, 1); //common
    if (!v->profile && v->extended_mv)
    {
        av_log(avctx, AV_LOG_ERROR,
               "Extended MVs unavailable in Simple Profile\n");
        return -1;
    }
    v->dquant =  get_bits(gb, 2); //common
    v->vstransform =  get_bits(gb, 1); //common

    v->res_transtab = get_bits(gb, 1);
    if (v->res_transtab)
    {
        av_log(avctx, AV_LOG_ERROR,
               "1 for reserved RES_TRANSTAB is forbidden\n");
        return -1;
    }

    v->overlap = get_bits(gb, 1); //common

    v->s.resync_marker = get_bits(gb, 1);
    v->rangered = get_bits(gb, 1);
    if (v->rangered && v->profile == PROFILE_SIMPLE)
    {
        av_log(avctx, AV_LOG_INFO,
               "RANGERED should be set to 0 in simple profile\n");
    }

    v->s.max_b_frames = avctx->max_b_frames = get_bits(gb, 3); //common
    v->quantizer_mode = get_bits(gb, 2); //common

    v->finterpflag = get_bits(gb, 1); //common
    v->res_rtm_flag = get_bits(gb, 1); //reserved
    if (!v->res_rtm_flag)
    {
//            av_log(avctx, AV_LOG_ERROR,
//                   "0 for reserved RES_RTM_FLAG is forbidden\n");
        av_log(avctx, AV_LOG_ERROR,
               "Old WMV3 version detected, only I-frames will be decoded\n");
        //return -1;
    }
    av_log(avctx, AV_LOG_DEBUG,
               "Profile %i:\nfrmrtq_postproc=%i, bitrtq_postproc=%i\n"
               "LoopFilter=%i, MultiRes=%i, FastUVMC=%i, Extended MV=%i\n"
               "Rangered=%i, VSTransform=%i, Overlap=%i, SyncMarker=%i\n"
               "DQuant=%i, Quantizer mode=%i, Max B frames=%i\n",
               v->profile, v->frmrtq_postproc, v->bitrtq_postproc,
               v->s.loop_filter, v->multires, v->fastuvmc, v->extended_mv,
               v->rangered, v->vstransform, v->overlap, v->s.resync_marker,
               v->dquant, v->quantizer_mode, avctx->max_b_frames
               );
    return 0;
}

static int decode_sequence_header_adv(VC1Context *v, GetBitContext *gb)
{
    v->res_rtm_flag = 1;
    v->level = get_bits(gb, 3);
    if(v->level >= 5)
    {
        av_log(v->s.avctx, AV_LOG_ERROR, "Reserved LEVEL %i\n",v->level);
    }
    v->chromaformat = get_bits(gb, 2);
    if (v->chromaformat != 1)
    {
        av_log(v->s.avctx, AV_LOG_ERROR,
               "Only 4:2:0 chroma format supported\n");
        return -1;
    }

    // (fps-2)/4 (->30)
    v->frmrtq_postproc = get_bits(gb, 3); //common
    // (bitrate-32kbps)/64kbps
    v->bitrtq_postproc = get_bits(gb, 5); //common
    v->postprocflag = get_bits(gb, 1); //common

    v->s.avctx->coded_width = (get_bits(gb, 12) + 1) << 1;
    v->s.avctx->coded_height = (get_bits(gb, 12) + 1) << 1;
    v->broadcast = get_bits1(gb);
    v->interlace = get_bits1(gb);
    if(v->interlace){
        av_log(v->s.avctx, AV_LOG_ERROR, "Interlaced mode not supported (yet)\n");
        return -1;
    }
    v->tfcntrflag = get_bits1(gb);
    v->finterpflag = get_bits1(gb);
    get_bits1(gb); // reserved

    av_log(v->s.avctx, AV_LOG_DEBUG,
               "Advanced Profile level %i:\nfrmrtq_postproc=%i, bitrtq_postproc=%i\n"
               "LoopFilter=%i, ChromaFormat=%i, Pulldown=%i, Interlace: %i\n"
               "TFCTRflag=%i, FINTERPflag=%i\n",
               v->level, v->frmrtq_postproc, v->bitrtq_postproc,
               v->s.loop_filter, v->chromaformat, v->broadcast, v->interlace,
               v->tfcntrflag, v->finterpflag
               );

    v->psf = get_bits1(gb);
    if(v->psf) { //PsF, 6.1.13
        av_log(v->s.avctx, AV_LOG_ERROR, "Progressive Segmented Frame mode: not supported (yet)\n");
        return -1;
    }
    if(get_bits1(gb)) { //Display Info - decoding is not affected by it
        int w, h, ar = 0;
        av_log(v->s.avctx, AV_LOG_INFO, "Display extended info:\n");
        w = get_bits(gb, 14) + 1;
        h = get_bits(gb, 14) + 1;
        av_log(v->s.avctx, AV_LOG_INFO, "Display dimensions: %ix%i\n", w, h);
        if(get_bits1(gb))
            ar = get_bits(gb, 4);
        if(ar && ar < 14){
            v->s.avctx->sample_aspect_ratio = vc1_pixel_aspect[ar];
        }else if(ar == 15){
            w = get_bits(gb, 8);
            h = get_bits(gb, 8);
            v->s.avctx->sample_aspect_ratio = (AVRational){w, h};
        }

        if(get_bits1(gb)){ //framerate stuff
            if(get_bits1(gb)) {
                get_bits(gb, 16);
            } else {
                get_bits(gb, 8);
                get_bits(gb, 4);
            }
        }

        if(get_bits1(gb)){
            v->color_prim = get_bits(gb, 8);
            v->transfer_char = get_bits(gb, 8);
            v->matrix_coef = get_bits(gb, 8);
        }
    }

    v->hrd_param_flag = get_bits1(gb);
    if(v->hrd_param_flag) {
        int i;
        v->hrd_num_leaky_buckets = get_bits(gb, 5);
        get_bits(gb, 4); //bitrate exponent
        get_bits(gb, 4); //buffer size exponent
        for(i = 0; i < v->hrd_num_leaky_buckets; i++) {
            get_bits(gb, 16); //hrd_rate[n]
            get_bits(gb, 16); //hrd_buffer[n]
        }
    }
    return 0;
}

static int decode_entry_point(AVCodecContext *avctx, GetBitContext *gb)
{
    VC1Context *v = avctx->priv_data;
    int i, blink, refdist;

    av_log(avctx, AV_LOG_DEBUG, "Entry point: %08X\n", show_bits_long(gb, 32));
    blink = get_bits1(gb); // broken link
    avctx->max_b_frames = 1 - get_bits1(gb); // 'closed entry' also signalize possible B-frames
    v->panscanflag = get_bits1(gb);
    refdist = get_bits1(gb); // refdist flag
    v->s.loop_filter = get_bits1(gb);
    v->fastuvmc = get_bits1(gb);
    v->extended_mv = get_bits1(gb);
    v->dquant = get_bits(gb, 2);
    v->vstransform = get_bits1(gb);
    v->overlap = get_bits1(gb);
    v->quantizer_mode = get_bits(gb, 2);

    if(v->hrd_param_flag){
        for(i = 0; i < v->hrd_num_leaky_buckets; i++) {
            get_bits(gb, 8); //hrd_full[n]
        }
    }

    if(get_bits1(gb)){
        avctx->coded_width = (get_bits(gb, 12)+1)<<1;
        avctx->coded_height = (get_bits(gb, 12)+1)<<1;
    }
    if(v->extended_mv)
        v->extended_dmv = get_bits1(gb);
    if(get_bits1(gb)) {
        av_log(avctx, AV_LOG_ERROR, "Luma scaling is not supported, expect wrong picture\n");
        skip_bits(gb, 3); // Y range, ignored for now
    }
    if(get_bits1(gb)) {
        av_log(avctx, AV_LOG_ERROR, "Chroma scaling is not supported, expect wrong picture\n");
        skip_bits(gb, 3); // UV range, ignored for now
    }

    av_log(avctx, AV_LOG_DEBUG, "Entry point info:\n"
        "BrokenLink=%i, ClosedEntry=%i, PanscanFlag=%i\n"
        "RefDist=%i, Postproc=%i, FastUVMC=%i, ExtMV=%i\n"
        "DQuant=%i, VSTransform=%i, Overlap=%i, Qmode=%i\n",
        blink, 1 - avctx->max_b_frames, v->panscanflag, refdist, v->s.loop_filter,
        v->fastuvmc, v->extended_mv, v->dquant, v->vstransform, v->overlap, v->quantizer_mode);

    return 0;
}

static int vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
{
    int pqindex, lowquant, status;

    if(v->finterpflag) v->interpfrm = get_bits(gb, 1);
    skip_bits(gb, 2); //framecnt unused
    v->rangeredfrm = 0;
    if (v->rangered) v->rangeredfrm = get_bits(gb, 1);
    v->s.pict_type = get_bits(gb, 1);
    if (v->s.avctx->max_b_frames) {
        if (!v->s.pict_type) {
            if (get_bits(gb, 1)) v->s.pict_type = I_TYPE;
            else v->s.pict_type = B_TYPE;
        } else v->s.pict_type = P_TYPE;
    } else v->s.pict_type = v->s.pict_type ? P_TYPE : I_TYPE;

    v->bi_type = 0;
    if(v->s.pict_type == B_TYPE) {
        v->bfraction = get_vlc2(gb, vc1_bfraction_vlc.table, VC1_BFRACTION_VLC_BITS, 1);
        v->bfraction = vc1_bfraction_lut[v->bfraction];
        if(v->bfraction == 0) {
            v->s.pict_type = BI_TYPE;
        }
    }
    if(v->s.pict_type == I_TYPE || v->s.pict_type == BI_TYPE)
        get_bits(gb, 7); // skip buffer fullness

    /* calculate RND */
    if(v->s.pict_type == I_TYPE || v->s.pict_type == BI_TYPE)
        v->rnd = 1;
    if(v->s.pict_type == P_TYPE)
        v->rnd ^= 1;

    /* Quantizer stuff */
    pqindex = get_bits(gb, 5);
    if (v->quantizer_mode == QUANT_FRAME_IMPLICIT)
        v->pq = pquant_table[0][pqindex];
    else
        v->pq = 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_bits(gb, 1);
    else v->halfpq = 0;
    if (v->quantizer_mode == QUANT_FRAME_EXPLICIT)
        v->pquantizer = get_bits(gb, 1);
    v->dquantfrm = 0;
    if (v->extended_mv == 1) v->mvrange = get_prefix(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_bits(gb, 1);
    }
    else
        if (v->multires && v->s.pict_type != B_TYPE) v->respic = get_bits(gb, 2);

//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 = mv_pmode_table[lowquant][get_prefix(gb, 1, 4)];
        if (v->mv_mode == MV_PMODE_INTENSITY_COMP)
        {
            int scale, shift, i;
            v->mv_mode2 = mv_pmode_table2[lowquant][get_prefix(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] = clip_uint8((scale * i + shift + 32) >> 6);
                v->lutuv[i] = 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 vc1_ tables
        v->cbpcy_vlc = &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)