rv34.c

ffmpeg移植到symbian的全部源代码

        code = get_vlc2(gb, rvlc->third_pattern[sc].table, 9, 2);
        decode_subblock(dst + 8*2+2, code, 0, gb, &rvlc->coefficient);
    }

}

/**
 * Dequantize ordinary 4x4 block.
 * @todo optimize
 */
static inline void rv34_dequant4x4(DCTELEM *block, int Qdc, int Q)
{
    int i, j;

    block[0] = (block[0] * Qdc + 8) >> 4;
    for(i = 0; i < 4; i++)
        for(j = !i; j < 4; j++)
            block[j + i*8] = (block[j + i*8] * Q + 8) >> 4;
}

/**
 * Dequantize 4x4 block of DC values for 16x16 macroblock.
 * @todo optimize
 */
static inline void rv34_dequant4x4_16x16(DCTELEM *block, int Qdc, int Q)
{
    int i;

    for(i = 0; i < 3; i++)
         block[rv34_dezigzag[i]] = (block[rv34_dezigzag[i]] * Qdc + 8) >> 4;
    for(; i < 16; i++)
         block[rv34_dezigzag[i]] = (block[rv34_dezigzag[i]] * Q + 8) >> 4;
}
/** @} */ //block functions


/**
 * @defgroup bitstream RV30/40 bitstream parsing
 * @{
 */

/**
 * Decode starting slice position.
 * @todo Maybe replace with ff_h263_decode_mba() ?
 */
int ff_rv34_get_start_offset(GetBitContext *gb, int mb_size)
{
    int i;
    for(i = 0; i < 5; i++)
        if(rv34_mb_max_sizes[i] > mb_size)
            break;
    return rv34_mb_bits_sizes[i];
}

/**
 * Select VLC set for decoding from current quantizer, modifier and frame type.
 */
static inline RV34VLC* choose_vlc_set(int quant, int mod, int type)
{
    if(mod == 2 && quant < 19) quant += 10;
    else if(mod && quant < 26) quant += 5;
    return type ? &inter_vlcs[rv34_quant_to_vlc_set[1][av_clip(quant, 0, 30)]]
                : &intra_vlcs[rv34_quant_to_vlc_set[0][av_clip(quant, 0, 30)]];
}

/**
 * Decode quantizer difference and return modified quantizer.
 */
static inline int rv34_decode_dquant(GetBitContext *gb, int quant)
{
    if(get_bits1(gb))
        return rv34_dquant_tab[get_bits1(gb)][quant];
    else
        return get_bits(gb, 5);
}

/** @} */ //bitstream functions

/**
 * @defgroup mv motion vector related code (prediction, reconstruction, motion compensation)
 * @{
 */

/** macroblock partition width in 8x8 blocks */
static const uint8_t part_sizes_w[RV34_MB_TYPES] = { 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2 };

/** macroblock partition height in 8x8 blocks */
static const uint8_t part_sizes_h[RV34_MB_TYPES] = { 2, 2, 2, 1, 2, 2, 2, 2, 1, 2, 2, 2 };

/** availability index for subblocks */
static const uint8_t avail_indexes[4] = { 5, 6, 9, 10 };

/**
 * motion vector prediction
 *
 * Motion prediction performed for the block by using median prediction of
 * motion vectors from the left, top and right top blocks but in corner cases
 * some other vectors may be used instead.
 */
static void rv34_pred_mv(RV34DecContext *r, int block_type, int subblock_no, int dmv_no)
{
    MpegEncContext *s = &r->s;
    int mv_pos = s->mb_x * 2 + s->mb_y * 2 * s->b8_stride;
    int A[2] = {0}, B[2], C[2];
    int i, j;
    int mx, my;
    int avail_index = avail_indexes[subblock_no];
    int c_off = part_sizes_w[block_type];

    mv_pos += (subblock_no & 1) + (subblock_no >> 1)*s->b8_stride;
    if(subblock_no == 3)
        c_off = -1;

    if(r->avail_cache[avail_index - 1]){
        A[0] = s->current_picture_ptr->motion_val[0][mv_pos-1][0];
        A[1] = s->current_picture_ptr->motion_val[0][mv_pos-1][1];
    }
    if(r->avail_cache[avail_index - 4]){
        B[0] = s->current_picture_ptr->motion_val[0][mv_pos-s->b8_stride][0];
        B[1] = s->current_picture_ptr->motion_val[0][mv_pos-s->b8_stride][1];
    }else{
        B[0] = A[0];
        B[1] = A[1];
    }
    if(!r->avail_cache[avail_index - 4 + c_off]){
        if(r->avail_cache[avail_index - 4] && (r->avail_cache[avail_index - 1] || r->rv30)){
            C[0] = s->current_picture_ptr->motion_val[0][mv_pos-s->b8_stride-1][0];
            C[1] = s->current_picture_ptr->motion_val[0][mv_pos-s->b8_stride-1][1];
        }else{
            C[0] = A[0];
            C[1] = A[1];
        }
    }else{
        C[0] = s->current_picture_ptr->motion_val[0][mv_pos-s->b8_stride+c_off][0];
        C[1] = s->current_picture_ptr->motion_val[0][mv_pos-s->b8_stride+c_off][1];
    }
    mx = mid_pred(A[0], B[0], C[0]);
    my = mid_pred(A[1], B[1], C[1]);
    mx += r->dmv[dmv_no][0];
    my += r->dmv[dmv_no][1];
    for(j = 0; j < part_sizes_h[block_type]; j++){
        for(i = 0; i < part_sizes_w[block_type]; i++){
            s->current_picture_ptr->motion_val[0][mv_pos + i + j*s->b8_stride][0] = mx;
            s->current_picture_ptr->motion_val[0][mv_pos + i + j*s->b8_stride][1] = my;
        }
    }
}

#define GET_PTS_DIFF(a, b) ((a - b + 8192) & 0x1FFF)

/**
 * Calculate motion vector component that should be added for direct blocks.
 */
static int calc_add_mv(RV34DecContext *r, int dir, int val)
{
    int refdist = GET_PTS_DIFF(r->next_pts, r->last_pts);
    int dist = dir ? GET_PTS_DIFF(r->next_pts, r->cur_pts) : GET_PTS_DIFF(r->cur_pts, r->last_pts);

    if(!refdist) return 0;
    if(!dir)
        return (val * dist + refdist - 1) / refdist;
    else
        return -(val * dist / refdist);
}

/**
 * Predict motion vector for B-frame macroblock.
 */
static inline void rv34_pred_b_vector(int A[2], int B[2], int C[2],
                                      int A_avail, int B_avail, int C_avail,
                                      int *mx, int *my)
{
    if(A_avail + B_avail + C_avail != 3){
        *mx = A[0] + B[0] + C[0];
        *my = A[1] + B[1] + C[1];
        if(A_avail + B_avail + C_avail == 2){
            *mx /= 2;
            *my /= 2;
        }
    }else{
        *mx = mid_pred(A[0], B[0], C[0]);
        *my = mid_pred(A[1], B[1], C[1]);
    }
}

/**
 * motion vector prediction for B-frames
 */
static void rv34_pred_mv_b(RV34DecContext *r, int block_type, int dir)
{
    MpegEncContext *s = &r->s;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int mv_pos = s->mb_x * 2 + s->mb_y * 2 * s->b8_stride;
    int A[2], B[2], C[2];
    int has_A = 0, has_B = 0, has_C = 0;
    int mx, my;
    int i, j;
    Picture *cur_pic = s->current_picture_ptr;
    const int mask = dir ? MB_TYPE_L1 : MB_TYPE_L0;
    int type = cur_pic->mb_type[mb_pos];

    memset(A, 0, sizeof(A));
    memset(B, 0, sizeof(B));
    memset(C, 0, sizeof(C));
    if((r->avail_cache[5-1] & type) & mask){
        A[0] = cur_pic->motion_val[dir][mv_pos - 1][0];
        A[1] = cur_pic->motion_val[dir][mv_pos - 1][1];
        has_A = 1;
    }
    if((r->avail_cache[5-4] & type) & mask){
        B[0] = cur_pic->motion_val[dir][mv_pos - s->b8_stride][0];
        B[1] = cur_pic->motion_val[dir][mv_pos - s->b8_stride][1];
        has_B = 1;
    }
    if((r->avail_cache[5-2] & type) & mask){
        C[0] = cur_pic->motion_val[dir][mv_pos - s->b8_stride + 2][0];
        C[1] = cur_pic->motion_val[dir][mv_pos - s->b8_stride + 2][1];
        has_C = 1;
    }else if((s->mb_x+1) == s->mb_width && (r->avail_cache[5-5] & type) & mask){
        C[0] = cur_pic->motion_val[dir][mv_pos - s->b8_stride - 1][0];
        C[1] = cur_pic->motion_val[dir][mv_pos - s->b8_stride - 1][1];
        has_C = 1;
    }

    rv34_pred_b_vector(A, B, C, has_A, has_B, has_C, &mx, &my);

    mx += r->dmv[dir][0];
    my += r->dmv[dir][1];

    for(j = 0; j < 2; j++){
        for(i = 0; i < 2; i++){
            cur_pic->motion_val[dir][mv_pos + i + j*s->b8_stride][0] = mx;
            cur_pic->motion_val[dir][mv_pos + i + j*s->b8_stride][1] = my;
        }
    }
    if(block_type == RV34_MB_B_BACKWARD || block_type == RV34_MB_B_FORWARD)
        fill_rectangle(cur_pic->motion_val[!dir][mv_pos], 2, 2, s->b8_stride, 0, 4);
}

static const int chroma_coeffs[3] = { 8, 5, 3 };

/**
 * generic motion compensation function
 *
 * @param r decoder context
 * @param block_type type of the current block
 * @param xoff horizontal offset from the start of the current block
 * @param yoff vertical offset from the start of the current block
 * @param mv_off offset to the motion vector information
 * @param width width of the current partition in 8x8 blocks
 * @param height height of the current partition in 8x8 blocks
 */
static inline void rv34_mc(RV34DecContext *r, const int block_type,
                          const int xoff, const int yoff, int mv_off,
                          const int width, const int height, int dir,
                          const int thirdpel,
                          qpel_mc_func (*qpel_mc)[16],
                          h264_chroma_mc_func (*chroma_mc))
{
    MpegEncContext *s = &r->s;
    uint8_t *Y, *U, *V, *srcY, *srcU, *srcV;
    int dxy, mx, my, lx, ly, uvmx, uvmy, src_x, src_y, uvsrc_x, uvsrc_y;
    int mv_pos = s->mb_x * 2 + s->mb_y * 2 * s->b8_stride + mv_off;
    int is16x16 = 1;

    if(thirdpel){
        mx = (s->current_picture_ptr->motion_val[dir][mv_pos][0] + (3 << 24)) / 3 - (1 << 24);
        my = (s->current_picture_ptr->motion_val[dir][mv_pos][1] + (3 << 24)) / 3 - (1 << 24);
        lx = (s->current_picture_ptr->motion_val[dir][mv_pos][0] + (3 << 24)) % 3;
        ly = (s->current_picture_ptr->motion_val[dir][mv_pos][1] + (3 << 24)) % 3;
        uvmx = chroma_coeffs[(3*(mx&1) + lx) >> 1];
        uvmy = chroma_coeffs[(3*(my&1) + ly) >> 1];
    }else{
        mx = s->current_picture_ptr->motion_val[dir][mv_pos][0] >> 2;
        my = s->current_picture_ptr->motion_val[dir][mv_pos][1] >> 2;
        lx = s->current_picture_ptr->motion_val[dir][mv_pos][0] & 3;
        ly = s->current_picture_ptr->motion_val[dir][mv_pos][1] & 3;
        uvmx = mx & 6;
        uvmy = my & 6;
    }
    dxy = ly*4 + lx;
    srcY = dir ? s->next_picture_ptr->data[0] : s->last_picture_ptr->data[0];
    srcU = dir ? s->next_picture_ptr->data[1] : s->last_picture_ptr->data[1];
    srcV = dir ? s->next_picture_ptr->data[2] : s->last_picture_ptr->data[2];
    src_x = s->mb_x * 16 + xoff + mx;
    src_y = s->mb_y * 16 + yoff + my;
    uvsrc_x = s->mb_x * 8 + (xoff >> 1) + (mx >> 1);
    uvsrc_y = s->mb_y * 8 + (yoff >> 1) + (my >> 1);
    srcY += src_y * s->linesize + src_x;
    srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
    srcV += uvsrc_y * s->uvlinesize + uvsrc_x;
    if(   (unsigned)(src_x - !!lx*2) > s->h_edge_pos - !!lx*2 - (width <<3) - 3
       || (unsigned)(src_y - !!ly*2) > s->v_edge_pos - !!ly*2 - (height<<3) - 3){
        uint8_t *uvbuf= s->edge_emu_buffer + 20 * s->linesize;

        srcY -= 2 + 2*s->linesize;
        ff_emulated_edge_mc(s->edge_emu_buffer, srcY, s->linesize, (width<<3)+4, (height<<3)+4,
                            src_x - 2, src_y - 2, s->h_edge_pos, s->v_edge_pos);
        srcY = s->edge_emu_buffer + 2 + 2*s->linesize;
        ff_emulated_edge_mc(uvbuf     , srcU, s->uvlinesize, (width<<2)+1, (height<<2)+1,
                            uvsrc_x, uvsrc_y, s->h_edge_pos >> 1, s->v_edge_pos >> 1);
        ff_emulated_edge_mc(uvbuf + 16, srcV, s->uvlinesize, (width<<2)+1, (height<<2)+1,
                            uvsrc_x, uvsrc_y, s->h_edge_pos >> 1, s->v_edge_pos >> 1);
        srcU = uvbuf;
        srcV = uvbuf + 16;
    }
    Y = s->dest[0] + xoff      + yoff     *s->linesize;
    U = s->dest[1] + (xoff>>1) + (yoff>>1)*s->uvlinesize;
    V = s->dest[2] + (xoff>>1) + (yoff>>1)*s->uvlinesize;

    if(block_type == RV34_MB_P_16x8){
        qpel_mc[1][dxy](Y, srcY, s->linesize);
        Y    += 8;
        srcY += 8;
    }else if(block_type == RV34_MB_P_8x16){
        qpel_mc[1][dxy](Y, srcY, s->linesize);
        Y    += 8 * s->linesize;
        srcY += 8 * s->linesize;
    }
    is16x16 = (block_type != RV34_MB_P_8x8) && (block_type != RV34_MB_P_16x8) && (block_type != RV34_MB_P_8x16);
    qpel_mc[!is16x16][dxy](Y, srcY, s->linesize);
    chroma_mc[2-width]   (U, srcU, s->uvlinesize, height*4, uvmx, uvmy);
    chroma_mc[2-width]   (V, srcV, s->uvlinesize, height*4, uvmx, uvmy);
}

static void rv34_mc_1mv(RV34DecContext *r, const int block_type,
                        const int xoff, const int yoff, int mv_off,
                        const int width, const int height, int dir)
{
    rv34_mc(r, block_type, xoff, yoff, mv_off, width, height, dir, r->rv30,
            r->rv30 ? r->s.dsp.put_rv30_tpel_pixels_tab
                    : r->s.dsp.put_h264_qpel_pixels_tab,
            r->s.dsp.put_h264_chroma_pixels_tab);
}

static void rv34_mc_2mv(RV34DecContext *r, const int block_type)
{
    rv34_mc(r, block_type, 0, 0, 0, 2, 2, 0, r->rv30,
            r->rv30 ? r->s.dsp.put_rv30_tpel_pixels_tab