array -> jpeg
此腳本不應該直接安裝，它是一個供其他腳本使用的函式庫。欲使用本函式庫，請在腳本 metadata 寫上： // @require https://update.gf.qytechs.cn/scripts/39428/258126/bv7_jpeg_encoder_b.js
// ==UserScript==
// @name bv7_jpeg_encoder_b
// @namespace bv7
// @version 0.1
// @description array -> jpeg
// @author bv7
// ==/UserScript==
// include file:///D:/projects/JSProjects/bv7bbc/bv7_bbc_dark/bv_dev_canvas*.html
// require https://greasyfork.org/scripts/38665-bv7-jpeg2array-b/code/bv7_jpeg2array_b.user.js
// require https://greasyfork.org/scripts/39257-bv7-canvas-b/code/bv7_canvas_b.js
// require https://raw.githubusercontent.com/owencm/javascript-jpeg-encoder/master/jpeg_encoder_basic.js
// run-at document-idle
// grant GM_xmlhttpRequest
class JpegEncoder {
constructor() {
this.zigZag = [
0x00, 0x01, 0x05, 0x06, 0x0E, 0x0F, 0x1B, 0x1C,
0x02, 0x04, 0x07, 0x0D, 0x10, 0x1A, 0x1D, 0x2A,
0x03, 0x08, 0x0C, 0x11, 0x19, 0x1E, 0x29, 0x2B,
0x09, 0x0B, 0x12, 0x18, 0x1F, 0x28, 0x2C, 0x35,
0x0A, 0x13, 0x17, 0x20, 0x27, 0x2D, 0x34, 0x36,
0x14, 0x16, 0x21, 0x26, 0x2E, 0x33, 0x37, 0x3C,
0x15, 0x22, 0x25, 0x2F, 0x32, 0x38, 0x3B, 0x3D,
0x23, 0x24, 0x30, 0x31, 0x39, 0x3A, 0x3E, 0x3F
];
this.std_dc_luminance_nrcodes = [
0x00, 0x01, 0x05, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
];
this.std_dc_luminance_values = [
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0A, 0x0B
];
this.std_ac_luminance_nrcodes = [
0x00, 0x02, 0x01, 0x03, 0x03, 0x02, 0x04, 0x03,
0x05, 0x05, 0x04, 0x04, 0x00, 0x00, 0x01, 0x7D
];
this.std_ac_luminance_values = [
0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xA1, 0x08,
0x23, 0x42, 0xB1, 0xC1, 0x15, 0x52, 0xD1, 0xF0,
0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0A, 0x16,
0x17, 0x18, 0x19, 0x1A, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2A, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
0x7A, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7,
0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6,
0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5,
0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, 0xD3, 0xD4,
0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xE1, 0xE2,
0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA,
0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8,
0xF9, 0xFA
];
this.std_dc_chrominance_nrcodes = [
0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00
];
this.std_dc_chrominance_values = [
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0A, 0x0B
];
this.std_ac_chrominance_nrcodes = [
0x00, 0x02, 0x01, 0x02, 0x04, 0x04, 0x03, 0x04,
0x07, 0x05, 0x04, 0x04, 0x00, 0x01, 0x02, 0x77
];
this.std_ac_chrominance_values = [
0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
0xA1, 0xB1, 0xC1, 0x09, 0x23, 0x33, 0x52, 0xF0,
0x15, 0x62, 0x72, 0xD1, 0x0A, 0x16, 0x24, 0x34,
0xE1, 0x25, 0xF1, 0x17, 0x18, 0x19, 0x1A, 0x26,
0x27, 0x28, 0x29, 0x2A, 0x35, 0x36, 0x37, 0x38,
0x39, 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
0x49, 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
0x69, 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
0x79, 0x7A, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96,
0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5,
0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4,
0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3,
0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2,
0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA,
0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9,
0xEA, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8,
0xF9, 0xFA
];
this.YDC_HT = new Uint8Array(0x0B);
this.UVDC_HT = new Uint8Array(0x0B);
this.YAC_HT = new Int8Array(0xFA);
this.UVAC_HT = new Int8Array(0xFA);
this.YDC_HT2 = new Uint8Array(0x0B);
this.UVDC_HT2 = new Uint8Array(0x0B);
this.YAC_HT2 = new Uint8Array(0xFA);
this.UVAC_HT2 = new Uint8Array(0xFA);
this.YTable = new Uint8Array(0x40 );
this.UVTable = new Uint8Array(0x40 );
this.fdtbl_Y = [];
this.fdtbl_UV = new Float32Array(0x08);
this.outputfDCTQuant = new Uint16Array(0x40 );
this.DU = new Int16Array(0x40 );
this.category = new Uint8Array(0xFFFE);
this.bitcode = new Uint16Array(0xFFFE);
this.RGB_YUV_TABLE = new Uint32Array(0x0800);
this.YDU = new Int16Array(0x40 );
this.UDU = new Int16Array(0x40 );
this.VDU = new Int16Array(0x40 );
this.initHuffmanTbl();
this.initCategoryNumber();
this.initRGBYUVTable();
}
// IO functions
writeBits(value, posval) {
while (posval >= 0) {
if (value & (1 << posval)) this.bytenew |= (1 << this.bytepos);
posval--;
this.bytepos--;
if (this.bytepos < 0) {
this.writeByte(this.bytenew);
if (this.bytenew == 0xFF) this.writeByte(0x00);
this.bytepos = 7;
this.bytenew = 0;
}
}
}
writeByte(value) {
this.byteout.push(String.fromCharCode(value)); // write char directly instead of converting later
}
writeWord(value) {
this.writeByte((value >> 8) & 0xFF);
this.writeByte((value ) & 0xFF);
}
writeAPP0() {
this.writeWord(0xFFE0); // marker
this.writeWord(0x0010); // length
this.writeByte(0x4A ); // J
this.writeByte(0x46 ); // F
this.writeByte(0x49 ); // I
this.writeByte(0x46 ); // F
this.writeByte(0x00 ); // = "JFIF",'\0'
this.writeByte(0x01 ); // versionhi
this.writeByte(0x01 ); // versionlo
this.writeByte(0x00 ); // xyunits
this.writeWord(0x0001); // xdensity
this.writeWord(0x0001); // ydensity
this.writeByte(0x00 ); // thumbnwidth
this.writeByte(0x00 ); // thumbnheight
}
writeDQT() {
this.writeWord(0xFFDB); // marker
this.writeWord(0x0084); // length
this.writeByte(0x00 );
this.YTable.forEach((v) => this.writeByte(v));
this.writeByte(0x01 );
this.UVTable.forEach((v) => this.writeByte(v));
}
writeSOF0(width, height) {
this.writeWord(0xFFC0); // marker
this.writeWord(0x0011); // length, truecolor YUV JPG
this.writeByte(0x08 ); // precision
this.writeWord(height);
this.writeWord(width );
this.writeByte(0x03 ); // nrofcomponents
this.writeByte(0x01 ); // IdY
this.writeByte(0x11 ); // HVY
this.writeByte(0x00 ); // QTY
this.writeByte(0x02 ); // IdU
this.writeByte(0x11 ); // HVU
this.writeByte(0x01 ); // QTU
this.writeByte(0x03 ); // IdV
this.writeByte(0x11 ); // HVV
this.writeByte(0x01 ); // QTV
}
writeDHT() {
this.writeWord(0xFFC4); // marker
this.writeWord(0x01A2); // length
this.writeByte(0x00 ); // HTYDCinfo
this.std_dc_luminance_nrcodes.forEach((v) => this.writeByte(v));
this.std_dc_luminance_values.forEach((v) => this.writeByte(v));
this.writeByte(0x10 ); // HTYACinfo
this.std_ac_luminance_nrcodes.forEach((v) => this.writeByte(v));
this.std_ac_luminance_values.forEach((v) => this.writeByte(v));
this.writeByte(0x01 ); // HTUDCinfo
this.std_dc_chrominance_nrcodes.forEach((v) => this.writeByte(v));
this.std_dc_chrominance_values.forEach((v) => this.writeByte(v));
this.writeByte(0x11 ); // HTUACinfo
this.std_ac_chrominance_nrcodes.forEach((v) => this.writeByte(v));
this.std_ac_chrominance_values.forEach((v) => this.writeByte(v));
}
writeSOS() {
this.writeWord(0xFFDA); // marker
this.writeWord(0x000C); // length
this.writeByte(0x03 ); // nrofcomponents
this.writeByte(0x01 ); // IdY
this.writeByte(0x00 ); // HTY
this.writeByte(0x02 ); // IdU
this.writeByte(0x11 ); // HTU
this.writeByte(0x03 ); // IdV
this.writeByte(0x11 ); // HTV
this.writeByte(0x00 ); // Ss
this.writeByte(0x3F ); // Se
this.writeByte(0x00 ); // Bf
}
computeHuffmanTbl(nrcodes, std_table, HT, HT2) {
let a, j;
let codevalue = 0;
let pos_in_table = 0;
nrcodes.forEach((nrcodesK, k) => {
for (j = 0; j < nrcodesK; j++) {
HT[a = std_table[pos_in_table++]] = codevalue++;
HT2[a ] = k;
}
codevalue *= 2;
});
}
initHuffmanTbl() {
this.computeHuffmanTbl(this.std_dc_luminance_nrcodes , this.std_dc_luminance_values , this.YDC_HT , this.YDC_HT2 );
this.computeHuffmanTbl(this.std_dc_chrominance_nrcodes, this.std_dc_chrominance_values, this.UVDC_HT, this.UVDC_HT2);
this.computeHuffmanTbl(this.std_ac_luminance_nrcodes , this.std_ac_luminance_values , this.YAC_HT , this.YAC_HT2 );
this.computeHuffmanTbl(this.std_ac_chrominance_nrcodes, this.std_ac_chrominance_values, this.UVAC_HT, this.UVAC_HT2);
}
initCategoryNumber() {
let cat, nr, nrlower, nrupper, nrn;
for (cat = 0, nrlower = 1, nrupper = 2; cat < 15; cat++, nrlower = nrupper, nrupper <<= 1) {
for (nr = nrlower, nrn = nrlower - 1; nr < nrupper; nr++, nrn--) { //Positive & Negative numbers
this.category[0x7FFF + nr] = this.category[0x7FFF - nr] = cat;
this.bitcode[ 0x7FFF + nr] = nr;
this.bitcode[ 0x7FFF - nr] = nrn;
}
}
}
initRGBYUVTable() {
for(let i = 0x0000; i < 0x0100; i++) {
this.RGB_YUV_TABLE[i ] = 0x004C8B * i ;
this.RGB_YUV_TABLE[i + 0x0100] = 0x009646 * i ;
this.RGB_YUV_TABLE[i + 0x0200] = 0x001D2F * i + 0x008000;
this.RGB_YUV_TABLE[i + 0x0300] = - 0x002B33 * i ;
this.RGB_YUV_TABLE[i + 0x0400] = - 0x0054CD * i ;
this.RGB_YUV_TABLE[i + 0x0500] = 0x008000 * i + 0x807FFF;
this.RGB_YUV_TABLE[i + 0x0600] = - 0x006B2F * i ;
this.RGB_YUV_TABLE[i + 0x0700] = - 0x0014D1 * i ;
}
}
initQuantTables(sf) {
let i, t;
let row;
let col;
[
0x10, 0x0B, 0x0A, 0x10, 0x18, 0x28, 0x33, 0x3D,
0x0C, 0x0C, 0x0E, 0x13, 0x1A, 0x3A, 0x3C, 0x37,
0x0E, 0x0D, 0x10, 0x18, 0x28, 0x39, 0x45, 0x38,
0x0E, 0x11, 0x16, 0x1D, 0x33, 0x57, 0x50, 0x3E,
0x12, 0x16, 0x25, 0x38, 0x44, 0x6D, 0x67, 0x4D,
0x18, 0x23, 0x37, 0x40, 0x51, 0x68, 0x71, 0x5C,
0x31, 0x40, 0x4E, 0x57, 0x67, 0x79, 0x78, 0x65,
0x48, 0x5C, 0x5F, 0x62, 0x70, 0x64, 0x67, 0x63
].forEach((v, i) => this.YTable[this.zigZag[i]] = (t = 0 | ((v * sf + 50) / 100)) < 1 ? 1 : t > 0xFF ? 0xFF : t);
[
0x11, 0x12, 0x18, 0x2F, 0x63, 0x63, 0x63, 0x63,
0x12, 0x15, 0x1A, 0x42, 0x63, 0x63, 0x63, 0x63,
0x18, 0x1A, 0x38, 0x63, 0x63, 0x63, 0x63, 0x63,
0x2F, 0x42, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63
].forEach((v, i) => this.UVTable[this.zigZag[i]] = (t = 0 | ((v * sf + 50) / 100)) < 1 ? 1 : t > 0xFF ? 0xFF : t);
let aasf = [
1.0, 1.387039845, 1.306562965, 1.175875602,
1.0, 0.785694958, 0.541196100, 0.275899379
];
for (i = 0, row = 0; row < 8; row++) for (col = 0; col < 8; col++, i++) {
this.fdtbl_Y[i] = 1.0 / (this.YTable [this.zigZag[i]] * aasf[row] * aasf[col] * 8.0);
this.fdtbl_UV[i] = 1.0 / (this.UVTable[this.zigZag[i]] * aasf[row] * aasf[col] * 8.0);
}
}
fDCTQuant(data, fdtbl) { // DCT & quantization core
let d0, d1, d2, d3, d4, d5, d6, d7;
let t0, t1, t2, t3, t4, t5, t6, t7;
// Pass 1: process rows.
let i, p;
for (i = p = 0; i < 8; ++i, p += 8) { // advance pointer to next row
d0 = data[p ];
d1 = data[p + 1];
d2 = data[p + 2];
d3 = data[p + 3];
d4 = data[p + 4];
d5 = data[p + 5];
d6 = data[p + 6];
d7 = data[p + 7];
t0 = d0 + d7;
t7 = d0 - d7;
t1 = d1 + d6;
t6 = d1 - d6;
t2 = d2 + d5;
t5 = d2 - d5;
t3 = d3 + d4;
t4 = d3 - d4;
// Even part
d0 = t0 + t3; // phase 2
d1 = t1 + t2;
d2 = t1 - t2;
d3 = t0 - t3;
data[p ] = d0 + d1; // phase 3
data[p + 4] = d0 - d1;
d0 = (d2 + d3) * 0.707106781; // c4
data[p + 2] = d3 + d0; // phase 5
data[p + 6] = d3 - d0;
// Odd part
d0 = t4 + t5; // phase 2
d1 = t5 + t6;
d2 = t6 + t7;
// The rotator is modified from fig 4-8 to avoid extra negations.
d3 = 0.382683433 * (d0 - d2); // c6
t2 = 0.541196100 * d0 + d3; // c2-c6
t4 = 1.306562965 * d2 + d3; // c2+c6
t3 = 0.707106781 * d1 ; // c4
d1 = t7 + t3; // phase 5
d3 = t7 - t3;
data[p + 1] = d1 + t4; // phase 6
data[p + 3] = d3 - t2;
data[p + 5] = d3 + t2;
data[p + 7] = d1 - t4;
}
// Pass 2: process columns.
for (i = p = 0; i < 8; ++i, p++) { // advance pointer to next column
d0 = data[p ];
d1 = data[p + 0x08];
d2 = data[p + 0x10];
d3 = data[p + 0x18];
d4 = data[p + 0x20];
d5 = data[p + 0x28];
d6 = data[p + 0x30];
d7 = data[p + 0x38];
t0 = d0 + d7;
t1 = d1 + d6;
t2 = d2 + d5;
t3 = d3 + d4;
t4 = d3 - d4;
t5 = d2 - d5;
t6 = d1 - d6;
t7 = d0 - d7;
// Even part
d0 = t0 + t3; // phase 2
d1 = t1 + t2;
d2 = t1 - t2;
d3 = t0 - t3;
data[p ] = d0 + d1; // phase 3
data[p + 0x20] = d0 - d1;
d0 = (d2 + d3) * 0.707106781; // c4
data[p + 0x10] = d3 + d0; // phase 5
data[p + 0x30] = d3 - d0;
// Odd part
d0 = t4 + t5; // phase 2
d1 = t5 + t6;
d2 = t6 + t7;
// The rotator is modified from fig 4-8 to avoid extra negations.
d3 = 0.382683433 * (d0 - d2); // c6
t2 = 0.541196100 * d0 + d3; // c2-c6
t4 = 1.306562965 * d2 + d3; // c2+c6
t3 = 0.707106781 * d1; // c4
d1 = t7 + t3; // phase 5
d3 = t7 - t3;
data[p + 0x08] = d1 + t4; // phase 6
data[p + 0x18] = d3 - t2;
data[p + 0x28] = d3 + t2;
data[p + 0x38] = d1 - t4;
}
// Quantize/descale the coefficients
// Apply the quantization and scaling factor & Round to nearest integer
for (i = 0; i < 64; ++i) this.outputfDCTQuant[i] = ((d0 = data[i] * fdtbl[i]) > 0.0) ? ((d0 + 0.5)|0) : ((d0 - 0.5)|0); //outputfDCTQuant[i] = fround(d0);
return this.outputfDCTQuant;
}
processDU(CDU, fdtbl, DC, HTDC, HTAC, HTDC2, HTAC2) {
let pos, i, a;
let EOB = HTAC[0x00];
let EOB2 = HTAC2[0x00];
let M16zeroes = HTAC[0xF0];
let M16zeroes2 = HTAC2[0xF0];
let DU_DCT = this.fDCTQuant(CDU, fdtbl);
//ZigZag reorder
for (i = 0; i < 64; ++i) this.DU[this.zigZag[i]] = DU_DCT[i];
let Diff = this.DU[0] - DC;
DC = this.DU[0];
//Encode DC
if (Diff == 0) this.writeBits(HTDC[0], HTDC2[0]); // Diff might be 0
else {
pos = 0x7FFF + Diff;
this.writeBits(HTDC[a = this.category[pos] + 1], HTDC2[a]);
this.writeBits(this.bitcode[pos], this.category[pos]);
}
//Encode ACs
let end0pos = 0x3F; // was const... which is crazy
while (end0pos > 0 && this.DU[end0pos] == 0) end0pos--;
if (end0pos == 0) this.writeBits(EOB, EOB2); //end0pos = first element in reverse order !=0
else {
let lng, startpos, nrzeroes, nrmarker;
end0pos++;
for (i = 1; i < end0pos; i++) {
startpos = i;
while (this.DU[i] == 0 && i < end0pos) ++i;
nrzeroes = i - startpos;
if (nrzeroes > 0x0F) {
lng = nrzeroes >> 4;
for (nrmarker = 0; nrmarker < lng; ++nrmarker) this.writeBits(M16zeroes, M16zeroes2);
nrzeroes = nrzeroes & 0x0F;
}
this.writeBits(HTAC[a = (nrzeroes << 4) + this.category[pos = 0x7FFF + this.DU[i]] + 1], HTAC2[a]);
this.writeBits(this.bitcode[pos], this.category[pos]);
}
if (end0pos != 0x40) this.writeBits(EOB, EOB2);
}
return DC;
}
encode(imageData, quality = 0.92) { // image data object
this.byteout = []; // Initialize bit writer
this.bytenew = 0;
this.bytepos = 7;
let newSf = Math.floor(quality < 0.5 ? 50 / quality : 200 * (1 - quality));
if ((typeof this.sf) == 'undefined' || newSf !== this.sf) this.initQuantTables(this.sf = newSf);
// Add JPEG headers
this.writeWord(0xFFD8); // SOI
this.writeAPP0();
this.writeDQT();
this.writeSOF0(imageData.width, imageData.height);
this.writeDHT();
this.writeSOS();
let y1, y2, y3, pY3, pY1;
let x1, x2, x3, pX3, pX1;
let r, g, b;
let pos;
let quadWidth = imageData.width * 4;
let width32 = imageData.width * 32;
// Encode 8x8 macroblocks
let DCY = 0;
let DCU = 0;
let DCV = 0;
for (y1 = 0, pY1 = 0; y1 < imageData.height; y1 += 8, pY1 += width32) {
for (x1 = 0, pX1 = pY1; x1 < imageData.width; x1 += 8, pX1 += 32) {
for (y2 = pos = 0, y3 = y1, pY3 = pX1; y2 < 8; y2++, y3++, pY3 += quadWidth) {
for (x2 = 0, x3 = x1, pX3 = pY3; x2 < 8; x2++, x3++, pos++) {
if (y3 < imageData.height && x3 < imageData.width) {
r = imageData.data[pX3++];
g = imageData.data[pX3++];
b = imageData.data[pX3++];
pX3++;
} else r = g = b = 0; // padding
this.YDU[pos] = ((this.RGB_YUV_TABLE[r ] + this.RGB_YUV_TABLE[g + 0x0100] + this.RGB_YUV_TABLE[b + 0x0200]) >> 16) - 0x80;
this.UDU[pos] = ((this.RGB_YUV_TABLE[r + 0x0300] + this.RGB_YUV_TABLE[g + 0x0400] + this.RGB_YUV_TABLE[b + 0x0500]) >> 16) - 0x80;
this.VDU[pos] = ((this.RGB_YUV_TABLE[r + 0x0500] + this.RGB_YUV_TABLE[g + 0x0600] + this.RGB_YUV_TABLE[b + 0x0700]) >> 16) - 0x80;
}
}
DCY = this.processDU(this.YDU, this.fdtbl_Y , DCY, this.YDC_HT, this.YAC_HT, this.YDC_HT2, this.YAC_HT2);
DCU = this.processDU(this.UDU, this.fdtbl_UV, DCU, this.UVDC_HT, this.UVAC_HT, this.UVDC_HT2, this.UVAC_HT2);
DCV = this.processDU(this.VDU, this.fdtbl_UV, DCV, this.UVDC_HT, this.UVAC_HT, this.UVDC_HT2, this.UVAC_HT2);
}
}
////////////////////////////////////////////////////////////////
// Do the bit alignment of the EOI marker
if (this.bytepos >= 0) this.writeBits((1 << (this.bytepos + 1)) - 1, this.bytepos);
this.writeWord(0xFFD9); //EOI
let res = 'data:image/jpeg;base64,' + btoa(this.byteout.join(''));
this.byteout = [];
return res;
}
}
/*
let canvas = new Canvas();
canvas.width = 500;
canvas.height = 500;
canvas.getContext('2d').drawImage(document.getElementById('img1'), -20, 20, 600, 500, 20, -10, 300, 400, () => {
let jpegEncoder = new JpegEncoder();
let b64 = jpegEncoder.encode(canvas.context.imageData);
console.log('JpegEncode:', b64);
console.log('canvas.context.imageData =', canvas.context.imageData);
document.getElementById('imgBase64').src = b64;
});
document.body.appendChild(canvas.domCanvas);
*/