jsvpx/vp8/common/filter.js

Javascript implementation of libvpx

'use strict';
//bilinear_filters
var vp8_bilinear_filters =
        [
            new Int16Array([0, 0, 128, 0, 0, 0]),
            new Int16Array([0, 0, 112, 16, 0, 0]),
            new Int16Array([0, 0, 96, 32, 0, 0]),
            new Int16Array([0, 0, 80, 48, 0, 0]),
            new Int16Array([0, 0, 64, 64, 0, 0]),
            new Int16Array([0, 0, 48, 80, 0, 0]),
            new Int16Array([0, 0, 32, 96, 0, 0]),
            new Int16Array([0, 0, 16, 112, 0, 0])
        ];
vp8_bilinear_filters[0].shape = 1;
vp8_bilinear_filters[1].shape = 1;
vp8_bilinear_filters[2].shape = 1;
vp8_bilinear_filters[3].shape = 1;
vp8_bilinear_filters[4].shape = 1;
vp8_bilinear_filters[5].shape = 1;
vp8_bilinear_filters[6].shape = 1;
vp8_bilinear_filters[7].shape = 1;

// sixtap_filters
var vp8_sub_pel_filters =
        [
            new Int16Array([0, 0, 128, 0, 0, 0]),
            new Int16Array([0, -6, 123, 12, -1, 0]),
            new Int16Array([2, -11, 108, 36, -8, 1]),
            new Int16Array([0, -9, 93, 50, -6, 0]),
            new Int16Array([3, -16, 77, 77, -16, 3]),
            new Int16Array([0, -6, 50, 93, -9, 0]),
            new Int16Array([1, -8, 36, 108, -11, 2]),
            new Int16Array([0, -1, 12, 123, -6, 0])
        ];
vp8_sub_pel_filters[0].shape = 1;
vp8_sub_pel_filters[1].shape = 2;
vp8_sub_pel_filters[2].shape = 0;
vp8_sub_pel_filters[3].shape = 2;
vp8_sub_pel_filters[4].shape = 0;
vp8_sub_pel_filters[5].shape = 2;
vp8_sub_pel_filters[6].shape = 0;
vp8_sub_pel_filters[7].shape = 2;


var VP8_FILTER_SHIFT = 7;

function filter_block2d_first_pass(output,
         src, src_ptr,
        reference_stride, vp8_filter) {
            
    var r = 0, c = 0;
    var Temp = 0;
    var output_off = 0;
    
    var filter0 = vp8_filter[0] | 0;
    var filter1 = vp8_filter[1] | 0;
    var filter2 = vp8_filter[2] | 0;
    var filter3 = vp8_filter[3] | 0;
    var filter4 = vp8_filter[4] | 0;
    var filter5 = vp8_filter[5] | 0;

    for (r = 0; r < 9; r++) {
        for (c = 0; c < 4; c++){
            Temp = (src[src_ptr - 2] * filter0) +
                    (src[src_ptr - 1] * filter1) +
                    (src[src_ptr] * filter2) +
                    (src[src_ptr + 1] * filter3) +
                    (src[src_ptr + 2] * filter4) +
                    (src[src_ptr + 3] * filter5) +
                    64;
            
            
            Temp >>= VP8_FILTER_SHIFT;
            
            Temp = Math.min(Math.max(Temp, 0), 255);
      
            output[output_off + c] = Temp;
            src_ptr++;
        }

        src_ptr += reference_stride - 4;
        output_off += 16;
    }
}

function filter_block2d_first_pass_shape_2(output,
        src, src_ptr,
        reference_stride, vp8_filter) {
            
    var r = 0, c = 0;
    var Temp = 0;
    var output_off = 0;

    var filter1 = vp8_filter[1] | 0;
    var filter2 = vp8_filter[2] | 0;
    var filter3 = vp8_filter[3] | 0;
    var filter4 = vp8_filter[4] | 0;


    for (r = 0; r < 9; r++) {
        for (c = 0; c < 4; c++){
            Temp = 
                    (src[src_ptr - 1] * filter1) +
                    (src[src_ptr] * filter2) +
                    (src[src_ptr + 1] * filter3) +
                    (src[src_ptr + 2] * filter4) +
                    
                    64;
            
            
            Temp >>= VP8_FILTER_SHIFT;
            /*
            if (Temp < 0) {
                Temp = 0;
            } else if (Temp > 255) {
                Temp = 255;
            }
            */

            Temp = Math.min(Math.max(Temp, 0), 255);


      
            output[output_off + c] = Temp;
            src_ptr++;
        }

        src_ptr += reference_stride - 4;
        output_off += 16;
    }
}

function filter_block2d_first_pass_shape_1(output,
        src, src_ptr,
        reference_stride, vp8_filter) {
            
    var r = 0, c = 0;
    var Temp = 0;
    var output_off = 0;

    var filter2 = vp8_filter[2] | 0;
    var filter3 = vp8_filter[3] | 0;

    for (r = 0; r < 9; r++) {
        for (c = 0; c < 4; c++){
            Temp = 
                    (src[src_ptr] * filter2) +
                    (src[src_ptr + 1] * filter3) +
                    64;
            
            
            Temp >>= VP8_FILTER_SHIFT;
            /*
            if (Temp < 0) {
                Temp = 0;
            } else if (Temp > 255) {
                Temp = 255;
            }
      */
            Temp = Math.min(Math.max(Temp, 0), 255);
            
            output[output_off + c] = Temp;
            src_ptr++;
        }

        src_ptr += reference_stride - 4;
        output_off += 16;
    }
}

function filter_block2d_second_pass(output,
        output_off,
        output_stride,
        reference,
        cols,
        rows,
        filter
        ) {
    
    var reference_off = 32;
    var r = 0, c = 0, Temp = 0;
    var filter0 = filter[0] | 0;
    var filter1 = filter[1] | 0;
    var filter2 = filter[2] | 0;
    var filter3 = filter[3] | 0;
    var filter4 = filter[4] | 0;
    var filter5 = filter[5] | 0;

    for (r = 0; r < rows; r++) {
        for (c = 0; c < cols; c++) {
            Temp = (reference[reference_off - 32] * filter0) +
                    (reference[reference_off - 16] * filter1) +
                    (reference[reference_off] * filter2) +
                    (reference[reference_off + 16] * filter3) +
                    (reference[reference_off + 32] * filter4) +
                    (reference[reference_off + 48] * filter5) +
                    64;
            Temp >>= 7;
            /*
            if (Temp < 0) {
                Temp = 0;
            } else if (Temp > 255) {
                Temp = 255;
            }
      */

            Temp = Math.min(Math.max(Temp, 0), 255);
            output[output_off + c] = Temp;
            
            reference_off++;
        }

        reference_off += 16 - cols;
        output_off += output_stride;
    }

}

function filter_block2d_second_pass_shape_1(output,
        output_off,
        output_stride,
        reference,
        cols,
        rows,
        filter
        ) {
    
    var reference_off = 32;
    
    var r = 0, c = 0, Temp = 0;
    var filter2 = filter[2] | 0;
    var filter3 = filter[3] | 0;

    for (r = 0; r < rows; r++) {
        for (c = 0; c < cols; c++) {
            Temp = 
                    (reference[reference_off] * filter2) +
                    (reference[reference_off + 16] * filter3) +
                    64;
            Temp >>= 7;
            
            /*
            if (Temp < 0) {
                Temp = 0;
            } else if (Temp > 255) {
                Temp = 255;
            }
      */
            Temp = Math.min(Math.max(Temp, 0), 255);
            
            output[output_off + c] = Temp;
            
            reference_off++;
        }

        reference_off += 16 - cols;
        output_off += output_stride;
    }

}

function filter_block2d_second_pass_shape_2(output,
        output_off,
        output_stride,
        reference,
        cols,
        rows,
        filter
        ) {
    var r = 0, c = 0, Temp = 0;

    var reference_off = 32;
    
    var filter1 = filter[1] | 0;
    var filter2 = filter[2] | 0;
    var filter3 = filter[3] | 0;
    var filter4 = filter[4] | 0;

    for (r = 0; r < rows; r++) {
        for (c = 0; c < cols; c++) {
            Temp = 
                    (reference[reference_off - 16] * filter1) +
                    (reference[reference_off] * filter2) +
                    (reference[reference_off + 16] * filter3) +
                    (reference[reference_off + 32] * filter4) +
                    64;
            Temp >>= 7;
            /*
            if (Temp < 0) {
                Temp = 0;
            } else if (Temp > 255) {
                Temp = 255;
            }
      */
            Temp = Math.min(Math.max(Temp, 0), 255);
            output[output_off + c] = Temp;
            
            reference_off++;
        }

        reference_off += 16 - cols;
        output_off += output_stride;
    }
}

//likely filter_block2d
var temp = new Uint8Array(336);

function filter_block2d(output, output_off,
        output_stride, reference,
        reference_off, reference_stride,
        cols, rows,
        mx, my, filters) {


    if (filters[mx].shape === 1) {
        
        filter_block2d_first_pass_shape_1(temp,
                reference, reference_off - 2 * reference_stride, reference_stride,
                filters[mx]);
    } else if(filters[mx].shape === 2) {
        filter_block2d_first_pass_shape_2(temp,
                reference, reference_off - 2 * reference_stride, reference_stride,
                filters[mx]);
    } else {
        filter_block2d_first_pass(temp,
                reference, reference_off - 2 * reference_stride, reference_stride,
                filters[mx]);
    }
    
    if (filters[my].shape === 1) {
        
        filter_block2d_second_pass_shape_1(output, output_off, output_stride,
                temp, 4, 4, filters[my]);
    } else if (filters[my].shape === 2) {
        filter_block2d_second_pass_shape_2(output, output_off, output_stride,
                temp, 4, 4, filters[my]);
    } else {
        filter_block2d_second_pass(output, output_off, output_stride,
                temp, 4, 4, filters[my]);
    }

    
}



//subpixel_predict
function filter_block(return_off,
        output,
        output_off,
        reference,
        reference_off,
        stride,
        mv_,
        filters) {

    //reference_off += ((mv_.y >> 3) * stride) + (mv_.x >> 3);

    if (mv_.as_int[0])
    {
        filter_block2d(output, output_off, stride, reference, reference_off, stride, 4, 4, mv_.x & 7, mv_.y & 7,
                filters);

    }


}

module.exports = {};
module.exports.vp8_sub_pel_filters = vp8_sub_pel_filters;
module.exports.vp8_bilinear_filters = vp8_bilinear_filters;
module.exports.filter_block2d_first_pass = filter_block2d_first_pass;
module.exports.filter_block2d_second_pass = filter_block2d_second_pass;
module.exports.sixtap_2d = filter_block2d;
module.exports.filter_block = filter_block;
module.exports.filter_block2d = filter_block2d;