vp3.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

            t2 = (int32_t)(xC2S6 * ip[6]);
            t1 >>= 16;
            t2 >>= 16;
            H_ = t1 - t2;


            _Ed = E_ - G_;
            _Gd = E_ + G_;

            _Add = F_ + _Ad;
            _Bdd = _Bd - H_;

            _Fd = F_ - _Ad;
            _Hd = _Bd + H_;

            /*  Final sequence of operations over-write original inputs. */
            ip[0] = (int16_t)((_Gd + _Cd )   >> 0);
            ip[7] = (int16_t)((_Gd - _Cd )   >> 0);

            ip[1] = (int16_t)((_Add + _Hd )  >> 0);
            ip[2] = (int16_t)((_Add - _Hd )  >> 0);

            ip[3] = (int16_t)((_Ed + _Dd )   >> 0);
            ip[4] = (int16_t)((_Ed - _Dd )   >> 0);

            ip[5] = (int16_t)((_Fd + _Bdd )  >> 0);
            ip[6] = (int16_t)((_Fd - _Bdd )  >> 0);

        }

        ip += 8;            /* next row */
    }

    ip = intermediate_data;

    for ( i = 0; i < 8; i++) {
        /* Check for non-zero values (bitwise or faster than ||) */
        if ( ip[0 * 8] | ip[1 * 8] | ip[2 * 8] | ip[3 * 8] |
             ip[4 * 8] | ip[5 * 8] | ip[6 * 8] | ip[7 * 8] ) {

            t1 = (int32_t)(xC1S7 * ip[1*8]);
            t2 = (int32_t)(xC7S1 * ip[7*8]);
            t1 >>= 16;
            t2 >>= 16;
            A_ = t1 + t2;

            t1 = (int32_t)(xC7S1 * ip[1*8]);
            t2 = (int32_t)(xC1S7 * ip[7*8]);
            t1 >>= 16;
            t2 >>= 16;
            B_ = t1 - t2;

            t1 = (int32_t)(xC3S5 * ip[3*8]);
            t2 = (int32_t)(xC5S3 * ip[5*8]);
            t1 >>= 16;
            t2 >>= 16;
            C_ = t1 + t2;

            t1 = (int32_t)(xC3S5 * ip[5*8]);
            t2 = (int32_t)(xC5S3 * ip[3*8]);
            t1 >>= 16;
            t2 >>= 16;
            D_ = t1 - t2;


            t1 = (int32_t)(xC4S4 * (A_ - C_));
            t1 >>= 16;
            _Ad = t1;

            t1 = (int32_t)(xC4S4 * (B_ - D_));
            t1 >>= 16;
            _Bd = t1;


            _Cd = A_ + C_;
            _Dd = B_ + D_;

            t1 = (int32_t)(xC4S4 * (ip[0*8] + ip[4*8]));
            t1 >>= 16;
            E_ = t1;

            t1 = (int32_t)(xC4S4 * (ip[0*8] - ip[4*8]));
            t1 >>= 16;
            F_ = t1;

            t1 = (int32_t)(xC2S6 * ip[2*8]);
            t2 = (int32_t)(xC6S2 * ip[6*8]);
            t1 >>= 16;
            t2 >>= 16;
            G_ = t1 + t2;

            t1 = (int32_t)(xC6S2 * ip[2*8]);
            t2 = (int32_t)(xC2S6 * ip[6*8]);
            t1 >>= 16;
            t2 >>= 16;
            H_ = t1 - t2;


            _Ed = E_ - G_;
            _Gd = E_ + G_;

            _Add = F_ + _Ad;
            _Bdd = _Bd - H_;

            _Fd = F_ - _Ad;
            _Hd = _Bd + H_;

            _Gd += IdctAdjustBeforeShift;
            _Add += IdctAdjustBeforeShift;
            _Ed += IdctAdjustBeforeShift;
            _Fd += IdctAdjustBeforeShift;

            /* Final sequence of operations over-write original inputs. */
            op[0*8] = (int16_t)((_Gd + _Cd )   >> 4);
            op[7*8] = (int16_t)((_Gd - _Cd )   >> 4);

            op[1*8] = (int16_t)((_Add + _Hd )  >> 4);
            op[2*8] = (int16_t)((_Add - _Hd )  >> 4);

            op[3*8] = (int16_t)((_Ed + _Dd )   >> 4);
            op[4*8] = (int16_t)((_Ed - _Dd )   >> 4);

            op[5*8] = (int16_t)((_Fd + _Bdd )  >> 4);
            op[6*8] = (int16_t)((_Fd - _Bdd )  >> 4);

        } else {

            op[0*8] = 0;
            op[7*8] = 0;
            op[1*8] = 0;
            op[2*8] = 0;
            op[3*8] = 0;
            op[4*8] = 0;
            op[5*8] = 0;
            op[6*8] = 0;
        }

        ip++;            /* next column */
        op++;
    }
}

void vp3_idct_put(int16_t *input_data, int16_t *dequant_matrix, 
    uint8_t *dest, int stride)
{
    int16_t transformed_data[64];
    int16_t *op;
    int i, j;

    vp3_idct_c(input_data, dequant_matrix, transformed_data);

    /* place in final output */
    op = transformed_data;
    for (i = 0; i < 8; i++) {
        for (j = 0; j < 8; j++) {
            if (*op < -128)
                *dest = 0;
            else if (*op > 127)
                *dest = 255;
            else
                *dest = (uint8_t)(*op + 128);
            op++;
            dest++;
        }
        dest += (stride - 8);
    }
}

void vp3_idct_add(int16_t *input_data, int16_t *dequant_matrix, 
    uint8_t *dest, int stride)
{
    int16_t transformed_data[64];
    int16_t *op;
    int i, j;
    int16_t sample;

    vp3_idct_c(input_data, dequant_matrix, transformed_data);

    /* place in final output */
    op = transformed_data;
    for (i = 0; i < 8; i++) {
        for (j = 0; j < 8; j++) {
            sample = *dest + *op;
            if (sample < 0)
                *dest = 0;
            else if (sample > 255)
                *dest = 255;
            else
                *dest = (uint8_t)(sample & 0xFF);
            op++;
            dest++;
        }
        dest += (stride - 8);
    }
}

/************************************************************************
 * VP3 specific functions
 ************************************************************************/

/*
 * This function sets up all of the various blocks mappings:
 * superblocks <-> fragments, macroblocks <-> fragments,
 * superblocks <-> macroblocks
 *
 * Returns 0 is successful; returns 1 if *anything* went wrong.
 */
static int init_block_mapping(Vp3DecodeContext *s) 
{
    int i, j;
    signed int hilbert_walk_y[16];
    signed int hilbert_walk_c[16];
    signed int hilbert_walk_mb[4];

    int current_fragment = 0;
    int current_width = 0;
    int current_height = 0;
    int right_edge = 0;
    int bottom_edge = 0;
    int superblock_row_inc = 0;
    int *hilbert = NULL;
    int mapping_index = 0;

    int current_macroblock;
    int c_fragment;

    signed char travel_width[16] = {
         1,  1,  0, -1, 
         0,  0,  1,  0,
         1,  0,  1,  0,
         0, -1,  0,  1
    };

    signed char travel_height[16] = {
         0,  0,  1,  0,
         1,  1,  0, -1,
         0,  1,  0, -1,
        -1,  0, -1,  0
    };

    signed char travel_width_mb[4] = {
         1,  0,  1,  0
    };

    signed char travel_height_mb[4] = {
         0,  1,  0, -1
    };

    debug_vp3("  vp3: initialize block mapping tables\n");

    /* figure out hilbert pattern per these frame dimensions */
    hilbert_walk_y[0]  = 1;
    hilbert_walk_y[1]  = 1;
    hilbert_walk_y[2]  = s->fragment_width;
    hilbert_walk_y[3]  = -1;
    hilbert_walk_y[4]  = s->fragment_width;
    hilbert_walk_y[5]  = s->fragment_width;
    hilbert_walk_y[6]  = 1;
    hilbert_walk_y[7]  = -s->fragment_width;
    hilbert_walk_y[8]  = 1;
    hilbert_walk_y[9]  = s->fragment_width;
    hilbert_walk_y[10]  = 1;
    hilbert_walk_y[11] = -s->fragment_width;
    hilbert_walk_y[12] = -s->fragment_width;
    hilbert_walk_y[13] = -1;
    hilbert_walk_y[14] = -s->fragment_width;
    hilbert_walk_y[15] = 1;

    hilbert_walk_c[0]  = 1;
    hilbert_walk_c[1]  = 1;
    hilbert_walk_c[2]  = s->fragment_width / 2;
    hilbert_walk_c[3]  = -1;
    hilbert_walk_c[4]  = s->fragment_width / 2;
    hilbert_walk_c[5]  = s->fragment_width / 2;
    hilbert_walk_c[6]  = 1;
    hilbert_walk_c[7]  = -s->fragment_width / 2;
    hilbert_walk_c[8]  = 1;
    hilbert_walk_c[9]  = s->fragment_width / 2;
    hilbert_walk_c[10]  = 1;
    hilbert_walk_c[11] = -s->fragment_width / 2;
    hilbert_walk_c[12] = -s->fragment_width / 2;
    hilbert_walk_c[13] = -1;
    hilbert_walk_c[14] = -s->fragment_width / 2;
    hilbert_walk_c[15] = 1;

    hilbert_walk_mb[0] = 1;
    hilbert_walk_mb[1] = s->macroblock_width;
    hilbert_walk_mb[2] = 1;
    hilbert_walk_mb[3] = -s->macroblock_width;

    /* iterate through each superblock (all planes) and map the fragments */
    for (i = 0; i < s->superblock_count; i++) {
        debug_init("    superblock %d (u starts @ %d, v starts @ %d)\n",
            i, s->u_superblock_start, s->v_superblock_start);

        /* time to re-assign the limits? */
        if (i == 0) {

            /* start of Y superblocks */
            right_edge = s->fragment_width;
            bottom_edge = s->fragment_height;
            current_width = -1;
            current_height = 0;
            superblock_row_inc = 3 * s->fragment_width - 
                (s->y_superblock_width * 4 - s->fragment_width);
            hilbert = hilbert_walk_y;

            /* the first operation for this variable is to advance by 1 */
            current_fragment = -1;

        } else if (i == s->u_superblock_start) {

            /* start of U superblocks */
            right_edge = s->fragment_width / 2;
            bottom_edge = s->fragment_height / 2;
            current_width = -1;
            current_height = 0;
            superblock_row_inc = 3 * (s->fragment_width / 2) - 
                (s->c_superblock_width * 4 - s->fragment_width / 2);
            hilbert = hilbert_walk_c;

            /* the first operation for this variable is to advance by 1 */
            current_fragment = s->u_fragment_start - 1;

        } else if (i == s->v_superblock_start) {

            /* start of V superblocks */
            right_edge = s->fragment_width / 2;
            bottom_edge = s->fragment_height / 2;
            current_width = -1;
            current_height = 0;
            superblock_row_inc = 3 * (s->fragment_width / 2) - 
                (s->c_superblock_width * 4 - s->fragment_width / 2);
            hilbert = hilbert_walk_c;

            /* the first operation for this variable is to advance by 1 */
            current_fragment = s->v_fragment_start - 1;

        }

        if (current_width >= right_edge - 1) {
            /* reset width and move to next superblock row */
            current_width = -1;
            current_height += 4;

            /* fragment is now at the start of a new superblock row */
            current_fragment += superblock_row_inc;
        }

        /* iterate through all 16 fragments in a superblock */
        for (j = 0; j < 16; j++) {
            current_fragment += hilbert[j];
            current_width += travel_width[j];
            current_height += travel_height[j];

            /* check if the fragment is in bounds */
            if ((current_width < right_edge) &&
                (current_height < bottom_edge)) {
                s->superblock_fragments[mapping_index] = current_fragment;
                debug_init("    mapping fragment %d to superblock %d, position %d (%d/%d x %d/%d)\n", 
                    s->superblock_fragments[mapping_index], i, j,
                    current_width, right_edge, current_height, bottom_edge);
            } else {
                s->superblock_fragments[mapping_index] = -1;
                debug_init("    superblock %d, position %d has no fragment (%d/%d x %d/%d)\n", 
                    i, j,
                    current_width, right_edge, current_height, bottom_edge);
            }

            mapping_index++;
        }
    }

    /* initialize the superblock <-> macroblock mapping; iterate through
     * all of the Y plane superblocks to build this mapping */
    right_edge = s->macroblock_width;
    bottom_edge = s->macroblock_height;
    current_width = -1;
    current_height = 0;
    superblock_row_inc = s->macroblock_width -
        (s->y_superblock_width * 2 - s->macroblock_width);;
    hilbert = hilbert_walk_mb;
    mapping_index = 0;
    current_macroblock = -1;
    for (i = 0; i < s->u_superblock_start; i++) {

        if (current_width >= right_edge - 1) {
            /* reset width and move to next superblock row */
            current_width = -1;
            current_height += 2;

            /* macroblock is now at the start of a new superblock row */
            current_macroblock += superblock_row_inc;
        }

        /* iterate through each potential macroblock in the superblock */
        for (j = 0; j < 4; j++) {
            current_macroblock += hilbert_walk_mb[j];
            current_width += travel_width_mb[j];
            current_height += travel_height_mb[j];

            /* check if the macroblock is in bounds */
            if ((current_width < right_edge) &&
                (current_height < bottom_edge)) {
                s->superblock_macroblocks[mapping_index] = current_macroblock;
                debug_init("    mapping macroblock %d to superblock %d, position %d (%d/%d x %d/%d)\n",
                    s->superblock_macroblocks[mapping_index], i, j,
                    current_width, right_edge, current_height, bottom_edge);