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/*
* noVNC: HTML5 VNC client
* Copyright (C) 2019 The noVNC Authors
* (c) 2012 Michael Tinglof, Joe Balaz, Les Piech (Mercuri.ca)
* Licensed under MPL 2.0 (see LICENSE.txt)
*
* See README.md for usage and integration instructions.
*
*/
import * as Log from '../util/logging.js';
import Inflator from "../inflator.js";
export default class TightDecoder {
constructor() {
this._ctl = null;
this._filter = null;
this._numColors = 0;
this._palette = new Uint8Array(1024); // 256 * 4 (max palette size * max bytes-per-pixel)
this._len = 0;
this._zlibs = [];
for (let i = 0; i < 4; i++) {
this._zlibs[i] = new Inflator();
}
}
decodeRect(x, y, width, height, sock, display, depth) {
if (this._ctl === null) {
if (sock.rQwait("TIGHT compression-control", 1)) {
return false;
}
this._ctl = sock.rQshift8();
// Reset streams if the server requests it
for (let i = 0; i < 4; i++) {
if ((this._ctl >> i) & 1) {
this._zlibs[i].reset();
Log.Info("Reset zlib stream " + i);
}
}
// Figure out filter
this._ctl = this._ctl >> 4;
}
let ret;
if (this._ctl === 0x08) {
ret = this._fillRect(x, y, width, height,
sock, display, depth);
} else if (this._ctl === 0x09) {
ret = this._jpegRect(x, y, width, height,
sock, display, depth);
} else if (this._ctl === 0x0A) {
ret = this._pngRect(x, y, width, height,
sock, display, depth);
} else if ((this._ctl & 0x80) == 0) {
ret = this._basicRect(this._ctl, x, y, width, height,
sock, display, depth);
} else {
throw new Error("Illegal tight compression received (ctl: " +
this._ctl + ")");
}
if (ret) {
this._ctl = null;
}
return ret;
}
_fillRect(x, y, width, height, sock, display, depth) {
if (sock.rQwait("TIGHT", 3)) {
return false;
}
const rQi = sock.rQi;
const rQ = sock.rQ;
display.fillRect(x, y, width, height,
[rQ[rQi + 2], rQ[rQi + 1], rQ[rQi]], false);
sock.rQskipBytes(3);
return true;
}
_jpegRect(x, y, width, height, sock, display, depth) {
let data = this._readData(sock);
if (data === null) {
return false;
}
display.imageRect(x, y, "image/jpeg", data);
return true;
}
_pngRect(x, y, width, height, sock, display, depth) {
throw new Error("PNG received in standard Tight rect");
}
_basicRect(ctl, x, y, width, height, sock, display, depth) {
if (this._filter === null) {
if (ctl & 0x4) {
if (sock.rQwait("TIGHT", 1)) {
return false;
}
this._filter = sock.rQshift8();
} else {
// Implicit CopyFilter
this._filter = 0;
}
}
let streamId = ctl & 0x3;
let ret;
switch (this._filter) {
case 0: // CopyFilter
ret = this._copyFilter(streamId, x, y, width, height,
sock, display, depth);
break;
case 1: // PaletteFilter
ret = this._paletteFilter(streamId, x, y, width, height,
sock, display, depth);
break;
case 2: // GradientFilter
ret = this._gradientFilter(streamId, x, y, width, height,
sock, display, depth);
break;
default:
throw new Error("Illegal tight filter received (ctl: " +
this._filter + ")");
}
if (ret) {
this._filter = null;
}
return ret;
}
_copyFilter(streamId, x, y, width, height, sock, display, depth) {
const uncompressedSize = width * height * 3;
let data;
if (uncompressedSize < 12) {
if (sock.rQwait("TIGHT", uncompressedSize)) {
return false;
}
data = sock.rQshiftBytes(uncompressedSize);
} else {
data = this._readData(sock);
if (data === null) {
return false;
}
data = this._zlibs[streamId].inflate(data, true, uncompressedSize);
if (data.length != uncompressedSize) {
throw new Error("Incomplete zlib block");
}
}
display.blitRgbImage(x, y, width, height, data, 0, false);
return true;
}
_paletteFilter(streamId, x, y, width, height, sock, display, depth) {
if (this._numColors === 0) {
if (sock.rQwait("TIGHT palette", 1)) {
return false;
}
const numColors = sock.rQpeek8() + 1;
const paletteSize = numColors * 3;
if (sock.rQwait("TIGHT palette", 1 + paletteSize)) {
return false;
}
this._numColors = numColors;
sock.rQskipBytes(1);
sock.rQshiftTo(this._palette, paletteSize);
}
const bpp = (this._numColors <= 2) ? 1 : 8;
const rowSize = Math.floor((width * bpp + 7) / 8);
const uncompressedSize = rowSize * height;
let data;
if (uncompressedSize < 12) {
if (sock.rQwait("TIGHT", uncompressedSize)) {
return false;
}
data = sock.rQshiftBytes(uncompressedSize);
} else {
data = this._readData(sock);
if (data === null) {
return false;
}
data = this._zlibs[streamId].inflate(data, true, uncompressedSize);
if (data.length != uncompressedSize) {
throw new Error("Incomplete zlib block");
}
}
// Convert indexed (palette based) image data to RGB
if (this._numColors == 2) {
this._monoRect(x, y, width, height, data, this._palette, display);
} else {
this._paletteRect(x, y, width, height, data, this._palette, display);
}
this._numColors = 0;
return true;
}
_monoRect(x, y, width, height, data, palette, display) {
// Convert indexed (palette based) image data to RGB
// TODO: reduce number of calculations inside loop
const dest = this._getScratchBuffer(width * height * 4);
const w = Math.floor((width + 7) / 8);
const w1 = Math.floor(width / 8);
for (let y = 0; y < height; y++) {
let dp, sp, x;
for (x = 0; x < w1; x++) {
for (let b = 7; b >= 0; b--) {
dp = (y * width + x * 8 + 7 - b) * 4;
sp = (data[y * w + x] >> b & 1) * 3;
dest[dp] = palette[sp];
dest[dp + 1] = palette[sp + 1];
dest[dp + 2] = palette[sp + 2];
dest[dp + 3] = 255;
}
}
for (let b = 7; b >= 8 - width % 8; b--) {
dp = (y * width + x * 8 + 7 - b) * 4;
sp = (data[y * w + x] >> b & 1) * 3;
dest[dp] = palette[sp];
dest[dp + 1] = palette[sp + 1];
dest[dp + 2] = palette[sp + 2];
dest[dp + 3] = 255;
}
}
display.blitRgbxImage(x, y, width, height, dest, 0, false);
}
_paletteRect(x, y, width, height, data, palette, display) {
// Convert indexed (palette based) image data to RGB
const dest = this._getScratchBuffer(width * height * 4);
const total = width * height * 4;
for (let i = 0, j = 0; i < total; i += 4, j++) {
const sp = data[j] * 3;
dest[i] = palette[sp];
dest[i + 1] = palette[sp + 1];
dest[i + 2] = palette[sp + 2];
dest[i + 3] = 255;
}
display.blitRgbxImage(x, y, width, height, dest, 0, false);
}
_gradientFilter(streamId, x, y, width, height, sock, display, depth) {
throw new Error("Gradient filter not implemented");
}
_readData(sock) {
if (this._len === 0) {
if (sock.rQwait("TIGHT", 3)) {
return null;
}
let byte;
byte = sock.rQshift8();
this._len = byte & 0x7f;
if (byte & 0x80) {
byte = sock.rQshift8();
this._len |= (byte & 0x7f) << 7;
if (byte & 0x80) {
byte = sock.rQshift8();
this._len |= byte << 14;
}
}
}
if (sock.rQwait("TIGHT", this._len)) {
return null;
}
let data = sock.rQshiftBytes(this._len);
this._len = 0;
return data;
}
_getScratchBuffer(size) {
if (!this._scratchBuffer || (this._scratchBuffer.length < size)) {
this._scratchBuffer = new Uint8Array(size);
}
return this._scratchBuffer;
}
}