snow.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

        if(y+3<(unsigned)height) horizontal_decompose97i(b4, width);
        if(y+4<(unsigned)height) horizontal_decompose97i(b5, width);
if(width>400){
STOP_TIMER("horizontal_decompose97i")
}}

{START_TIMER
        if(y+3<(unsigned)height) vertical_decompose97iH0(b3, b4, b5, width);
        if(y+2<(unsigned)height) vertical_decompose97iL0(b2, b3, b4, width);
        if(y+1<(unsigned)height) vertical_decompose97iH1(b1, b2, b3, width);
        if(y+0<(unsigned)height) vertical_decompose97iL1(b0, b1, b2, width);

if(width>400){
STOP_TIMER("vertical_decompose97i")
}}

        b0=b2;
        b1=b3;
        b2=b4;
        b3=b5;
    }
}

void ff_spatial_dwt(DWTELEM *buffer, int width, int height, int stride, int type, int decomposition_count){
    int level;

    for(level=0; level<decomposition_count; level++){
        switch(type){
        case DWT_97: spatial_decompose97i(buffer, width>>level, height>>level, stride<<level); break;
        case DWT_53: spatial_decompose53i(buffer, width>>level, height>>level, stride<<level); break;
        }
    }
}

static void horizontal_compose53i(IDWTELEM *b, int width){
    IDWTELEM temp[width];
    const int width2= width>>1;
    const int w2= (width+1)>>1;
    int x;

#if 0
    int A1,A2,A3,A4;
    A2= temp[1       ];
    A4= temp[0       ];
    A1= temp[0+width2];
    A1 -= (A2 + A4)>>1;
    A4 += (A1 + 1)>>1;
    b[0+width2] = A1;
    b[0       ] = A4;
    for(x=1; x+1<width2; x+=2){
        A3= temp[x+width2];
        A4= temp[x+1     ];
        A3 -= (A2 + A4)>>1;
        A2 += (A1 + A3 + 2)>>2;
        b[x+width2] = A3;
        b[x       ] = A2;

        A1= temp[x+1+width2];
        A2= temp[x+2       ];
        A1 -= (A2 + A4)>>1;
        A4 += (A1 + A3 + 2)>>2;
        b[x+1+width2] = A1;
        b[x+1       ] = A4;
    }
    A3= temp[width-1];
    A3 -= A2;
    A2 += (A1 + A3 + 2)>>2;
    b[width -1] = A3;
    b[width2-1] = A2;
#else
    inv_lift(temp   , b   , b+w2, 1, 1, 1, width,  1, 2, 2, 0, 1);
    inv_lift(temp+w2, b+w2, temp, 1, 1, 1, width, -1, 0, 1, 1, 1);
#endif
    for(x=0; x<width2; x++){
        b[2*x    ]= temp[x   ];
        b[2*x + 1]= temp[x+w2];
    }
    if(width&1)
        b[2*x    ]= temp[x   ];
}

static void vertical_compose53iH0(IDWTELEM *b0, IDWTELEM *b1, IDWTELEM *b2, int width){
    int i;

    for(i=0; i<width; i++){
        b1[i] += (b0[i] + b2[i])>>1;
    }
}

static void vertical_compose53iL0(IDWTELEM *b0, IDWTELEM *b1, IDWTELEM *b2, int width){
    int i;

    for(i=0; i<width; i++){
        b1[i] -= (b0[i] + b2[i] + 2)>>2;
    }
}

static void spatial_compose53i_buffered_init(dwt_compose_t *cs, slice_buffer * sb, int height, int stride_line){
    cs->b0 = slice_buffer_get_line(sb, mirror(-1-1, height-1) * stride_line);
    cs->b1 = slice_buffer_get_line(sb, mirror(-1  , height-1) * stride_line);
    cs->y = -1;
}

static void spatial_compose53i_init(dwt_compose_t *cs, IDWTELEM *buffer, int height, int stride){
    cs->b0 = buffer + mirror(-1-1, height-1)*stride;
    cs->b1 = buffer + mirror(-1  , height-1)*stride;
    cs->y = -1;
}

static void spatial_compose53i_dy_buffered(dwt_compose_t *cs, slice_buffer * sb, int width, int height, int stride_line){
    int y= cs->y;

    IDWTELEM *b0= cs->b0;
    IDWTELEM *b1= cs->b1;
    IDWTELEM *b2= slice_buffer_get_line(sb, mirror(y+1, height-1) * stride_line);
    IDWTELEM *b3= slice_buffer_get_line(sb, mirror(y+2, height-1) * stride_line);

{START_TIMER
        if(y+1<(unsigned)height) vertical_compose53iL0(b1, b2, b3, width);
        if(y+0<(unsigned)height) vertical_compose53iH0(b0, b1, b2, width);
STOP_TIMER("vertical_compose53i*")}

{START_TIMER
        if(y-1<(unsigned)height) horizontal_compose53i(b0, width);
        if(y+0<(unsigned)height) horizontal_compose53i(b1, width);
STOP_TIMER("horizontal_compose53i")}

    cs->b0 = b2;
    cs->b1 = b3;
    cs->y += 2;
}

static void spatial_compose53i_dy(dwt_compose_t *cs, IDWTELEM *buffer, int width, int height, int stride){
    int y= cs->y;
    IDWTELEM *b0= cs->b0;
    IDWTELEM *b1= cs->b1;
    IDWTELEM *b2= buffer + mirror(y+1, height-1)*stride;
    IDWTELEM *b3= buffer + mirror(y+2, height-1)*stride;

{START_TIMER
        if(y+1<(unsigned)height) vertical_compose53iL0(b1, b2, b3, width);
        if(y+0<(unsigned)height) vertical_compose53iH0(b0, b1, b2, width);
STOP_TIMER("vertical_compose53i*")}

{START_TIMER
        if(y-1<(unsigned)height) horizontal_compose53i(b0, width);
        if(y+0<(unsigned)height) horizontal_compose53i(b1, width);
STOP_TIMER("horizontal_compose53i")}

    cs->b0 = b2;
    cs->b1 = b3;
    cs->y += 2;
}

static void spatial_compose53i(IDWTELEM *buffer, int width, int height, int stride){
    dwt_compose_t cs;
    spatial_compose53i_init(&cs, buffer, height, stride);
    while(cs.y <= height)
        spatial_compose53i_dy(&cs, buffer, width, height, stride);
}


void ff_snow_horizontal_compose97i(IDWTELEM *b, int width){
    IDWTELEM temp[width];
    const int w2= (width+1)>>1;

    inv_lift (temp   , b      , b   +w2, 1, 1, 1, width,  W_DM, W_DO, W_DS, 0, 1);
    inv_lift (temp+w2, b   +w2, temp   , 1, 1, 1, width,  W_CM, W_CO, W_CS, 1, 1);
    inv_liftS(b      , temp   , temp+w2, 2, 1, 1, width,  W_BM, W_BO, W_BS, 0, 1);
    inv_lift (b+1    , temp+w2, b      , 2, 1, 2, width,  W_AM, W_AO, W_AS, 1, 0);
}

static void vertical_compose97iH0(IDWTELEM *b0, IDWTELEM *b1, IDWTELEM *b2, int width){
    int i;

    for(i=0; i<width; i++){
        b1[i] += (W_AM*(b0[i] + b2[i])+W_AO)>>W_AS;
    }
}

static void vertical_compose97iH1(IDWTELEM *b0, IDWTELEM *b1, IDWTELEM *b2, int width){
    int i;

    for(i=0; i<width; i++){
        b1[i] -= (W_CM*(b0[i] + b2[i])+W_CO)>>W_CS;
    }
}

static void vertical_compose97iL0(IDWTELEM *b0, IDWTELEM *b1, IDWTELEM *b2, int width){
    int i;

    for(i=0; i<width; i++){
#ifdef liftS
        b1[i] += (W_BM*(b0[i] + b2[i])+W_BO)>>W_BS;
#else
        b1[i] += (W_BM*(b0[i] + b2[i])+4*b1[i]+W_BO)>>W_BS;
#endif
    }
}

static void vertical_compose97iL1(IDWTELEM *b0, IDWTELEM *b1, IDWTELEM *b2, int width){
    int i;

    for(i=0; i<width; i++){
        b1[i] -= (W_DM*(b0[i] + b2[i])+W_DO)>>W_DS;
    }
}

void ff_snow_vertical_compose97i(IDWTELEM *b0, IDWTELEM *b1, IDWTELEM *b2, IDWTELEM *b3, IDWTELEM *b4, IDWTELEM *b5, int width){
    int i;

    for(i=0; i<width; i++){
        b4[i] -= (W_DM*(b3[i] + b5[i])+W_DO)>>W_DS;
        b3[i] -= (W_CM*(b2[i] + b4[i])+W_CO)>>W_CS;
#ifdef liftS
        b2[i] += (W_BM*(b1[i] + b3[i])+W_BO)>>W_BS;
#else
        b2[i] += (W_BM*(b1[i] + b3[i])+4*b2[i]+W_BO)>>W_BS;
#endif
        b1[i] += (W_AM*(b0[i] + b2[i])+W_AO)>>W_AS;
    }
}

static void spatial_compose97i_buffered_init(dwt_compose_t *cs, slice_buffer * sb, int height, int stride_line){
    cs->b0 = slice_buffer_get_line(sb, mirror(-3-1, height-1) * stride_line);
    cs->b1 = slice_buffer_get_line(sb, mirror(-3  , height-1) * stride_line);
    cs->b2 = slice_buffer_get_line(sb, mirror(-3+1, height-1) * stride_line);
    cs->b3 = slice_buffer_get_line(sb, mirror(-3+2, height-1) * stride_line);
    cs->y = -3;
}

static void spatial_compose97i_init(dwt_compose_t *cs, IDWTELEM *buffer, int height, int stride){
    cs->b0 = buffer + mirror(-3-1, height-1)*stride;
    cs->b1 = buffer + mirror(-3  , height-1)*stride;
    cs->b2 = buffer + mirror(-3+1, height-1)*stride;
    cs->b3 = buffer + mirror(-3+2, height-1)*stride;
    cs->y = -3;
}

static void spatial_compose97i_dy_buffered(DSPContext *dsp, dwt_compose_t *cs, slice_buffer * sb, int width, int height, int stride_line){
    int y = cs->y;

    IDWTELEM *b0= cs->b0;
    IDWTELEM *b1= cs->b1;
    IDWTELEM *b2= cs->b2;
    IDWTELEM *b3= cs->b3;
    IDWTELEM *b4= slice_buffer_get_line(sb, mirror(y + 3, height - 1) * stride_line);
    IDWTELEM *b5= slice_buffer_get_line(sb, mirror(y + 4, height - 1) * stride_line);

{START_TIMER
    if(y>0 && y+4<height){
        dsp->vertical_compose97i(b0, b1, b2, b3, b4, b5, width);
    }else{
        if(y+3<(unsigned)height) vertical_compose97iL1(b3, b4, b5, width);
        if(y+2<(unsigned)height) vertical_compose97iH1(b2, b3, b4, width);
        if(y+1<(unsigned)height) vertical_compose97iL0(b1, b2, b3, width);
        if(y+0<(unsigned)height) vertical_compose97iH0(b0, b1, b2, width);
    }
if(width>400){
STOP_TIMER("vertical_compose97i")}}

{START_TIMER
        if(y-1<(unsigned)height) dsp->horizontal_compose97i(b0, width);
        if(y+0<(unsigned)height) dsp->horizontal_compose97i(b1, width);
if(width>400 && y+0<(unsigned)height){
STOP_TIMER("horizontal_compose97i")}}

    cs->b0=b2;
    cs->b1=b3;
    cs->b2=b4;
    cs->b3=b5;
    cs->y += 2;
}

static void spatial_compose97i_dy(dwt_compose_t *cs, IDWTELEM *buffer, int width, int height, int stride){
    int y = cs->y;
    IDWTELEM *b0= cs->b0;
    IDWTELEM *b1= cs->b1;
    IDWTELEM *b2= cs->b2;
    IDWTELEM *b3= cs->b3;
    IDWTELEM *b4= buffer + mirror(y+3, height-1)*stride;
    IDWTELEM *b5= buffer + mirror(y+4, height-1)*stride;

{START_TIMER
        if(y+3<(unsigned)height) vertical_compose97iL1(b3, b4, b5, width);
        if(y+2<(unsigned)height) vertical_compose97iH1(b2, b3, b4, width);
        if(y+1<(unsigned)height) vertical_compose97iL0(b1, b2, b3, width);
        if(y+0<(unsigned)height) vertical_compose97iH0(b0, b1, b2, width);
if(width>400){
STOP_TIMER("vertical_compose97i")}}

{START_TIMER
        if(y-1<(unsigned)height) ff_snow_horizontal_compose97i(b0, width);
        if(y+0<(unsigned)height) ff_snow_horizontal_compose97i(b1, width);
if(width>400 && b0 <= b2){
STOP_TIMER("horizontal_compose97i")}}

    cs->b0=b2;
    cs->b1=b3;
    cs->b2=b4;
    cs->b3=b5;
    cs->y += 2;
}

static void spatial_compose97i(IDWTELEM *buffer, int width, int height, int stride){
    dwt_compose_t cs;
    spatial_compose97i_init(&cs, buffer, height, stride);
    while(cs.y <= height)
        spatial_compose97i_dy(&cs, buffer, width, height, stride);
}

static void ff_spatial_idwt_buffered_init(dwt_compose_t *cs, slice_buffer * sb, int width, int height, int stride_line, int type, int decomposition_count){
    int level;
    for(level=decomposition_count-1; level>=0; level--){
        switch(type){
        case DWT_97: spatial_compose97i_buffered_init(cs+level, sb, height>>level, stride_line<<level); break;
        case DWT_53: spatial_compose53i_buffered_init(cs+level, sb, height>>level, stride_line<<level); break;
        }
    }
}

static void ff_spatial_idwt_init(dwt_compose_t *cs, IDWTELEM *buffer, int width, int height, int stride, int type, int decomposition_count){
    int level;
    for(level=decomposition_count-1; level>=0; level--){
        switch(type){
        case DWT_97: spatial_compose97i_init(cs+level, buffer, height>>level, stride<<level); break;
        case DWT_53: spatial_compose53i_init(cs+level, buffer, height>>level, stride<<level); break;
        }
    }
}

static void ff_spatial_idwt_slice(dwt_compose_t *cs, IDWTELEM *buffer, int width, int height, int stride, int type, int decomposition_count, int y){
    const int support = type==1 ? 3 : 5;
    int level;
    if(type==2) return;