jsvpx/util/c_utils.js

Javascript implementation of libvpx

'use strict';

var MV_PROB_CNT = 19;

function copy_entropy_values(header, otherHeader) {

    var probs = otherHeader.coeff_probs.data_32;
    var to = header.coeff_probs.data_32;
    //header.coeff_probs = otherHeader.coeff_probs.slice(0);
    //for (var i = 0; i < 264; i++)
    to.set(probs);

    //load mv probs
    probs = otherHeader.mv_probs;
    //header can probably be done faster
    //for (var i = 0; i < MV_PROB_CNT; i++)
    header.mv_probs[0].set(probs[0]);

    //for (var i = 0; i < MV_PROB_CNT; i++)
    header.mv_probs[1].set(probs[1]);

    //load y mode probs
    probs = otherHeader.y_mode_probs_32;
    header.y_mode_probs_32[0] = probs[0];



    //load uv mode probs
    probs = otherHeader.uv_mode_probs;
    //for (var i = 0; i < 3; i++)
    header.uv_mode_probs[0] = probs[0];
    header.uv_mode_probs[1] = probs[1];
    header.uv_mode_probs[2] = probs[2];


    header.prob_inter = otherHeader.prob_inter;
    header.prob_last = otherHeader.prob_inter;
    header.prob_gf = otherHeader.prob_inter;
}

function memset(ptr, ptr_off, value, num) {

    var i = num;
    while (i--)
        ptr[ptr_off + i] = value;

}

function memset_32(ptr, ptr_off, value, num) {

    var i = num;//>> 2;
    var ptr_off_32 = ptr_off >> 2;
    var ptr_32 = ptr.data_32;
    var value_32 = value | value << 8 | value << 16 | value << 24;

    var num_32 = num >> 2;
    for (var i = 0; i < num_32; i++) {
        ptr_32[ptr_off_32 + (i >> 2)] = value_32;
    }

}

function memcpy(dst, dst_off, src, src_off, num) {
    dst.set(src.subarray(src_off, src_off + num), dst_off);
    /*
     var i = num;
     while (i--) {
     dst[dst_off + i] = src[src_off + i];
     }
     */
    return dst;

}


module.exports = {};
module.exports.copy_entropy_values = copy_entropy_values;
module.exports.memset = memset;
module.exports.memset_32 = memset_32;
module.exports.memcpy = memcpy;