mpeg12.c

从FFMPEG转换而来的H264解码程序,VC下编译..

                 vlc_dc_lum_code, 2, 2, 1);
        init_vlc(&dc_chroma_vlc,  DC_VLC_BITS, 12,
                 vlc_dc_chroma_bits, 1, 1,
                 vlc_dc_chroma_code, 2, 2, 1);
        init_vlc(&mv_vlc, MV_VLC_BITS, 17,
                 &mbMotionVectorTable[0][1], 2, 1,
                 &mbMotionVectorTable[0][0], 2, 1, 1);
        init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 36,
                 &mbAddrIncrTable[0][1], 2, 1,
                 &mbAddrIncrTable[0][0], 2, 1, 1);
        init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
                 &mbPatTable[0][1], 2, 1,
                 &mbPatTable[0][0], 2, 1, 1);

        init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
                 &table_mb_ptype[0][1], 2, 1,
                 &table_mb_ptype[0][0], 2, 1, 1);
        init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
                 &table_mb_btype[0][1], 2, 1,
                 &table_mb_btype[0][0], 2, 1, 1);
        init_rl(&rl_mpeg1, static_rl_table_store[0]);
        init_rl(&rl_mpeg2, static_rl_table_store[1]);

        init_2d_vlc_rl(&rl_mpeg1, 1);
        init_2d_vlc_rl(&rl_mpeg2, 1);
    }
}

static inline int get_dmv(MpegEncContext *s)
{
    if(get_bits1(&s->gb))
        return 1 - (get_bits1(&s->gb) << 1);
    else
        return 0;
}

static inline int get_qscale(MpegEncContext *s)
{
    int qscale = get_bits(&s->gb, 5);
    if (s->q_scale_type) {
        return non_linear_qscale[qscale];
    } else {
        return qscale << 1;
    }
}

/* motion type (for mpeg2) */
#define MT_FIELD 1
#define MT_FRAME 2
#define MT_16X8  2
#define MT_DMV   3

static int mpeg_decode_mb(MpegEncContext *s,
                          DCTELEM block[12][64])
{
    int i, j, k, cbp, val, mb_type, motion_type;
    const int mb_block_count = 4 + (1<< s->chroma_format);

    dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);

    assert(s->mb_skipped==0);

    if (s->mb_skip_run-- != 0) {
        if(s->pict_type == I_TYPE){
            av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
            return -1;
        }

        /* skip mb */
        s->mb_intra = 0;
        for(i=0;i<12;i++)
            s->block_last_index[i] = -1;
        if(s->picture_structure == PICT_FRAME)
            s->mv_type = MV_TYPE_16X16;
        else
            s->mv_type = MV_TYPE_FIELD;
        if (s->pict_type == P_TYPE) {
            /* if P type, zero motion vector is implied */
            s->mv_dir = MV_DIR_FORWARD;
            s->mv[0][0][0] = s->mv[0][0][1] = 0;
            s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
            s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
            s->field_select[0][0]= s->picture_structure - 1;
            s->mb_skipped = 1;
            s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
        } else {
            int mb_type;

            if(s->mb_x)
                mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
            else
                mb_type= s->current_picture.mb_type[ s->mb_width + (s->mb_y-1)*s->mb_stride - 1]; // FIXME not sure if this is allowed in mpeg at all,
            if(IS_INTRA(mb_type))
                return -1;

            /* if B type, reuse previous vectors and directions */
            s->mv[0][0][0] = s->last_mv[0][0][0];
            s->mv[0][0][1] = s->last_mv[0][0][1];
            s->mv[1][0][0] = s->last_mv[1][0][0];
            s->mv[1][0][1] = s->last_mv[1][0][1];

            s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
                mb_type | MB_TYPE_SKIP;
//            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));

            if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
                s->mb_skipped = 1;
        }

        return 0;
    }

    switch(s->pict_type) {
    default:
    case I_TYPE:
        if (get_bits1(&s->gb) == 0) {
            if (get_bits1(&s->gb) == 0){
                av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
                return -1;
            }
            mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
        } else {
            mb_type = MB_TYPE_INTRA;
        }
        break;
    case P_TYPE:
        mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
        if (mb_type < 0){
            av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
            return -1;
        }
        mb_type = ptype2mb_type[ mb_type ];
        break;
    case B_TYPE:
        mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
        if (mb_type < 0){
            av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
            return -1;
        }
        mb_type = btype2mb_type[ mb_type ];
        break;
    }
    dprintf(s->avctx, "mb_type=%x\n", mb_type);
//    motion_type = 0; /* avoid warning */
    if (IS_INTRA(mb_type)) {
        s->dsp.clear_blocks(s->block[0]);

        if(!s->chroma_y_shift){
            s->dsp.clear_blocks(s->block[6]);
        }

        /* compute dct type */
        if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
            !s->frame_pred_frame_dct) {
            s->interlaced_dct = get_bits1(&s->gb);
        }

        if (IS_QUANT(mb_type))
            s->qscale = get_qscale(s);

        if (s->concealment_motion_vectors) {
            /* just parse them */
            if (s->picture_structure != PICT_FRAME)
                skip_bits1(&s->gb); /* field select */

            s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
                mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
            s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
                mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);

            skip_bits1(&s->gb); /* marker */
        }else
            memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
        s->mb_intra = 1;
#ifdef HAVE_XVMC
        //one 1 we memcpy blocks in xvmcvideo
        if(s->avctx->xvmc_acceleration > 1){
            XVMC_pack_pblocks(s,-1);//inter are always full blocks
            if(s->swap_uv){
                exchange_uv(s);
            }
        }
#endif

        if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
            if(s->flags2 & CODEC_FLAG2_FAST){
                for(i=0;i<6;i++) {
                    mpeg2_fast_decode_block_intra(s, s->pblocks[i], i);
                }
            }else{
                for(i=0;i<mb_block_count;i++) {
                    if (mpeg2_decode_block_intra(s, s->pblocks[i], i) < 0)
                        return -1;
                }
            }
        } else {
            for(i=0;i<6;i++) {
                if (mpeg1_decode_block_intra(s, s->pblocks[i], i) < 0)
                    return -1;
            }
        }
    } else {
        if (mb_type & MB_TYPE_ZERO_MV){
            assert(mb_type & MB_TYPE_CBP);

            /* compute dct type */
            if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
                !s->frame_pred_frame_dct) {
                s->interlaced_dct = get_bits1(&s->gb);
            }

            if (IS_QUANT(mb_type))
                s->qscale = get_qscale(s);

            s->mv_dir = MV_DIR_FORWARD;
            if(s->picture_structure == PICT_FRAME)
                s->mv_type = MV_TYPE_16X16;
            else{
                s->mv_type = MV_TYPE_FIELD;
                mb_type |= MB_TYPE_INTERLACED;
                s->field_select[0][0]= s->picture_structure - 1;
            }
            s->last_mv[0][0][0] = 0;
            s->last_mv[0][0][1] = 0;
            s->last_mv[0][1][0] = 0;
            s->last_mv[0][1][1] = 0;
            s->mv[0][0][0] = 0;
            s->mv[0][0][1] = 0;
        }else{
            assert(mb_type & MB_TYPE_L0L1);
//FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
            /* get additional motion vector type */
            if (s->frame_pred_frame_dct)
                motion_type = MT_FRAME;
            else{
                motion_type = get_bits(&s->gb, 2);
            }

            /* compute dct type */
            if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
                !s->frame_pred_frame_dct && HAS_CBP(mb_type)) {
                s->interlaced_dct = get_bits1(&s->gb);
            }

            if (IS_QUANT(mb_type))
                s->qscale = get_qscale(s);

            /* motion vectors */
            s->mv_dir = 0;
            for(i=0;i<2;i++) {
                if (USES_LIST(mb_type, i)) {
                    s->mv_dir |= (MV_DIR_FORWARD >> i);
                    dprintf(s->avctx, "motion_type=%d\n", motion_type);
                    switch(motion_type) {
                    case MT_FRAME: /* or MT_16X8 */
                        if (s->picture_structure == PICT_FRAME) {
                            /* MT_FRAME */
                            mb_type |= MB_TYPE_16x16;
                            s->mv_type = MV_TYPE_16X16;
                            s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
                                mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
                            s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
                                mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
                            /* full_pel: only for mpeg1 */
                            if (s->full_pel[i]){
                                s->mv[i][0][0] <<= 1;
                                s->mv[i][0][1] <<= 1;
                            }
                        } else {
                            /* MT_16X8 */
                            mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
                            s->mv_type = MV_TYPE_16X8;
                            for(j=0;j<2;j++) {
                                s->field_select[i][j] = get_bits1(&s->gb);
                                for(k=0;k<2;k++) {
                                    val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
                                                             s->last_mv[i][j][k]);
                                    s->last_mv[i][j][k] = val;
                                    s->mv[i][j][k] = val;
                                }
                            }
                        }
                        break;
                    case MT_FIELD:
                        s->mv_type = MV_TYPE_FIELD;
                        if (s->picture_structure == PICT_FRAME) {
                            mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
                            for(j=0;j<2;j++) {
                                s->field_select[i][j] = get_bits1(&s->gb);
                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
                                                         s->last_mv[i][j][0]);
                                s->last_mv[i][j][0] = val;
                                s->mv[i][j][0] = val;
                                dprintf(s->avctx, "fmx=%d\n", val);
                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
                                                         s->last_mv[i][j][1] >> 1);
                                s->last_mv[i][j][1] = val << 1;
                                s->mv[i][j][1] = val;
                                dprintf(s->avctx, "fmy=%d\n", val);
                            }
                        } else {
                            mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
                            s->field_select[i][0] = get_bits1(&s->gb);
                            for(k=0;k<2;k++) {
                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
                                                         s->last_mv[i][0][k]);
                                s->last_mv[i][0][k] = val;
                                s->last_mv[i][1][k] = val;
                                s->mv[i][0][k] = val;
                            }
                        }
                        break;
                    case MT_DMV:
                        {
                            int dmx, dmy, mx, my, m;

                            mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
                                                    s->last_mv[i][0][0]);
                            s->last_mv[i][0][0] = mx;
                            s->last_mv[i][1][0] = mx;
                            dmx = get_dmv(s);
                            my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
                                                    s->last_mv[i][0][1] >> 1);
                            dmy = get_dmv(s);
                            s->mv_type = MV_TYPE_DMV;


                            s->last_mv[i][0][1] = my<<1;
                            s->last_mv[i][1][1] = my<<1;

                            s->mv[i][0][0] = mx;
                            s->mv[i][0][1] = my;
                            s->mv[i][1][0] = mx;//not used
                            s->mv[i][1][1] = my;//not used

                            if (s->picture_structure == PICT_FRAME) {
                                mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;

                                //m = 1 + 2 * s->top_field_first;
                                m = s->top_field_first ? 1 : 3;

                                /* top -> top pred */
                                s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
                                s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
                                m = 4 - m;
                                s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
                                s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
                            } else {
                                mb_type |= MB_TYPE_16x16;