src/utils/cea-608-parser.ts
import OutputFilter from './output-filter';
import { logger } from '../utils/logger';
/**
*
* This code was ported from the dash.js project at:
* https://github.com/Dash-Industry-Forum/dash.js/blob/development/externals/cea608-parser.js
* https://github.com/Dash-Industry-Forum/dash.js/commit/8269b26a761e0853bb21d78780ed945144ecdd4d#diff-71bc295a2d6b6b7093a1d3290d53a4b2
*
* The original copyright appears below:
*
* The copyright in this software is being made available under the BSD License,
* included below. This software may be subject to other third party and contributor
* rights, including patent rights, and no such rights are granted under this license.
*
* Copyright (c) 2015-2016, DASH Industry Forum.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
* 2. Neither the name of Dash Industry Forum nor the names of its
* contributors may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/**
* Exceptions from regular ASCII. CodePoints are mapped to UTF-16 codes
*/
const specialCea608CharsCodes = {
0x2a: 0xe1, // lowercase a, acute accent
0x5c: 0xe9, // lowercase e, acute accent
0x5e: 0xed, // lowercase i, acute accent
0x5f: 0xf3, // lowercase o, acute accent
0x60: 0xfa, // lowercase u, acute accent
0x7b: 0xe7, // lowercase c with cedilla
0x7c: 0xf7, // division symbol
0x7d: 0xd1, // uppercase N tilde
0x7e: 0xf1, // lowercase n tilde
0x7f: 0x2588, // Full block
// THIS BLOCK INCLUDES THE 16 EXTENDED (TWO-BYTE) LINE 21 CHARACTERS
// THAT COME FROM HI BYTE=0x11 AND LOW BETWEEN 0x30 AND 0x3F
// THIS MEANS THAT \x50 MUST BE ADDED TO THE VALUES
0x80: 0xae, // Registered symbol (R)
0x81: 0xb0, // degree sign
0x82: 0xbd, // 1/2 symbol
0x83: 0xbf, // Inverted (open) question mark
0x84: 0x2122, // Trademark symbol (TM)
0x85: 0xa2, // Cents symbol
0x86: 0xa3, // Pounds sterling
0x87: 0x266a, // Music 8'th note
0x88: 0xe0, // lowercase a, grave accent
0x89: 0x20, // transparent space (regular)
0x8a: 0xe8, // lowercase e, grave accent
0x8b: 0xe2, // lowercase a, circumflex accent
0x8c: 0xea, // lowercase e, circumflex accent
0x8d: 0xee, // lowercase i, circumflex accent
0x8e: 0xf4, // lowercase o, circumflex accent
0x8f: 0xfb, // lowercase u, circumflex accent
// THIS BLOCK INCLUDES THE 32 EXTENDED (TWO-BYTE) LINE 21 CHARACTERS
// THAT COME FROM HI BYTE=0x12 AND LOW BETWEEN 0x20 AND 0x3F
0x90: 0xc1, // capital letter A with acute
0x91: 0xc9, // capital letter E with acute
0x92: 0xd3, // capital letter O with acute
0x93: 0xda, // capital letter U with acute
0x94: 0xdc, // capital letter U with diaresis
0x95: 0xfc, // lowercase letter U with diaeresis
0x96: 0x2018, // opening single quote
0x97: 0xa1, // inverted exclamation mark
0x98: 0x2a, // asterisk
0x99: 0x2019, // closing single quote
0x9a: 0x2501, // box drawings heavy horizontal
0x9b: 0xa9, // copyright sign
0x9c: 0x2120, // Service mark
0x9d: 0x2022, // (round) bullet
0x9e: 0x201c, // Left double quotation mark
0x9f: 0x201d, // Right double quotation mark
0xa0: 0xc0, // uppercase A, grave accent
0xa1: 0xc2, // uppercase A, circumflex
0xa2: 0xc7, // uppercase C with cedilla
0xa3: 0xc8, // uppercase E, grave accent
0xa4: 0xca, // uppercase E, circumflex
0xa5: 0xcb, // capital letter E with diaresis
0xa6: 0xeb, // lowercase letter e with diaresis
0xa7: 0xce, // uppercase I, circumflex
0xa8: 0xcf, // uppercase I, with diaresis
0xa9: 0xef, // lowercase i, with diaresis
0xaa: 0xd4, // uppercase O, circumflex
0xab: 0xd9, // uppercase U, grave accent
0xac: 0xf9, // lowercase u, grave accent
0xad: 0xdb, // uppercase U, circumflex
0xae: 0xab, // left-pointing double angle quotation mark
0xaf: 0xbb, // right-pointing double angle quotation mark
// THIS BLOCK INCLUDES THE 32 EXTENDED (TWO-BYTE) LINE 21 CHARACTERS
// THAT COME FROM HI BYTE=0x13 AND LOW BETWEEN 0x20 AND 0x3F
0xb0: 0xc3, // Uppercase A, tilde
0xb1: 0xe3, // Lowercase a, tilde
0xb2: 0xcd, // Uppercase I, acute accent
0xb3: 0xcc, // Uppercase I, grave accent
0xb4: 0xec, // Lowercase i, grave accent
0xb5: 0xd2, // Uppercase O, grave accent
0xb6: 0xf2, // Lowercase o, grave accent
0xb7: 0xd5, // Uppercase O, tilde
0xb8: 0xf5, // Lowercase o, tilde
0xb9: 0x7b, // Open curly brace
0xba: 0x7d, // Closing curly brace
0xbb: 0x5c, // Backslash
0xbc: 0x5e, // Caret
0xbd: 0x5f, // Underscore
0xbe: 0x7c, // Pipe (vertical line)
0xbf: 0x223c, // Tilde operator
0xc0: 0xc4, // Uppercase A, umlaut
0xc1: 0xe4, // Lowercase A, umlaut
0xc2: 0xd6, // Uppercase O, umlaut
0xc3: 0xf6, // Lowercase o, umlaut
0xc4: 0xdf, // Esszett (sharp S)
0xc5: 0xa5, // Yen symbol
0xc6: 0xa4, // Generic currency sign
0xc7: 0x2503, // Box drawings heavy vertical
0xc8: 0xc5, // Uppercase A, ring
0xc9: 0xe5, // Lowercase A, ring
0xca: 0xd8, // Uppercase O, stroke
0xcb: 0xf8, // Lowercase o, strok
0xcc: 0x250f, // Box drawings heavy down and right
0xcd: 0x2513, // Box drawings heavy down and left
0xce: 0x2517, // Box drawings heavy up and right
0xcf: 0x251b, // Box drawings heavy up and left
};
/**
* Utils
*/
const getCharForByte = function (byte: number) {
let charCode = byte;
if (specialCea608CharsCodes.hasOwnProperty(byte)) {
charCode = specialCea608CharsCodes[byte];
}
return String.fromCharCode(charCode);
};
const NR_ROWS = 15;
const NR_COLS = 100;
// Tables to look up row from PAC data
const rowsLowCh1 = {
0x11: 1,
0x12: 3,
0x15: 5,
0x16: 7,
0x17: 9,
0x10: 11,
0x13: 12,
0x14: 14,
};
const rowsHighCh1 = {
0x11: 2,
0x12: 4,
0x15: 6,
0x16: 8,
0x17: 10,
0x13: 13,
0x14: 15,
};
const rowsLowCh2 = {
0x19: 1,
0x1a: 3,
0x1d: 5,
0x1e: 7,
0x1f: 9,
0x18: 11,
0x1b: 12,
0x1c: 14,
};
const rowsHighCh2 = {
0x19: 2,
0x1a: 4,
0x1d: 6,
0x1e: 8,
0x1f: 10,
0x1b: 13,
0x1c: 15,
};
const backgroundColors = [
'white',
'green',
'blue',
'cyan',
'red',
'yellow',
'magenta',
'black',
'transparent',
];
enum VerboseLevel {
ERROR = 0,
TEXT = 1,
WARNING = 2,
INFO = 2,
DEBUG = 3,
DATA = 3,
}
class CaptionsLogger {
public time: number | null = null;
public verboseLevel: VerboseLevel = VerboseLevel.ERROR;
log(severity: VerboseLevel, msg: string): void {
if (this.verboseLevel >= severity) {
logger.log(`${this.time} [${severity}] ${msg}`);
}
}
}
const numArrayToHexArray = function (numArray: number[]): string[] {
const hexArray: string[] = [];
for (let j = 0; j < numArray.length; j++) {
hexArray.push(numArray[j].toString(16));
}
return hexArray;
};
type PenStyles = {
foreground: string | null;
underline: boolean;
italics: boolean;
background: string;
flash: boolean;
};
class PenState {
public foreground: string;
public underline: boolean;
public italics: boolean;
public background: string;
public flash: boolean;
constructor(
foreground?: string,
underline?: boolean,
italics?: boolean,
background?: string,
flash?: boolean
) {
this.foreground = foreground || 'white';
this.underline = underline || false;
this.italics = italics || false;
this.background = background || 'black';
this.flash = flash || false;
}
reset() {
this.foreground = 'white';
this.underline = false;
this.italics = false;
this.background = 'black';
this.flash = false;
}
setStyles(styles: Partial<PenStyles>) {
const attribs = [
'foreground',
'underline',
'italics',
'background',
'flash',
];
for (let i = 0; i < attribs.length; i++) {
const style = attribs[i];
if (styles.hasOwnProperty(style)) {
this[style] = styles[style];
}
}
}
isDefault() {
return (
this.foreground === 'white' &&
!this.underline &&
!this.italics &&
this.background === 'black' &&
!this.flash
);
}
equals(other: PenState) {
return (
this.foreground === other.foreground &&
this.underline === other.underline &&
this.italics === other.italics &&
this.background === other.background &&
this.flash === other.flash
);
}
copy(newPenState: PenState) {
this.foreground = newPenState.foreground;
this.underline = newPenState.underline;
this.italics = newPenState.italics;
this.background = newPenState.background;
this.flash = newPenState.flash;
}
toString(): string {
return (
'color=' +
this.foreground +
', underline=' +
this.underline +
', italics=' +
this.italics +
', background=' +
this.background +
', flash=' +
this.flash
);
}
}
/**
* Unicode character with styling and background.
* @constructor
*/
class StyledUnicodeChar {
uchar: string;
penState: PenState;
constructor(
uchar?: string,
foreground?: string,
underline?: boolean,
italics?: boolean,
background?: string,
flash?: boolean
) {
this.uchar = uchar || ' '; // unicode character
this.penState = new PenState(
foreground,
underline,
italics,
background,
flash
);
}
reset() {
this.uchar = ' ';
this.penState.reset();
}
setChar(uchar: string, newPenState: PenState) {
this.uchar = uchar;
this.penState.copy(newPenState);
}
setPenState(newPenState: PenState) {
this.penState.copy(newPenState);
}
equals(other: StyledUnicodeChar) {
return this.uchar === other.uchar && this.penState.equals(other.penState);
}
copy(newChar: StyledUnicodeChar) {
this.uchar = newChar.uchar;
this.penState.copy(newChar.penState);
}
isEmpty(): boolean {
return this.uchar === ' ' && this.penState.isDefault();
}
}
/**
* CEA-608 row consisting of NR_COLS instances of StyledUnicodeChar.
* @constructor
*/
export class Row {
public chars: StyledUnicodeChar[];
public pos: number;
public currPenState: PenState;
public cueStartTime?: number;
logger: CaptionsLogger;
constructor(logger: CaptionsLogger) {
this.chars = [];
for (let i = 0; i < NR_COLS; i++) {
this.chars.push(new StyledUnicodeChar());
}
this.logger = logger;
this.pos = 0;
this.currPenState = new PenState();
}
equals(other: Row) {
let equal = true;
for (let i = 0; i < NR_COLS; i++) {
if (!this.chars[i].equals(other.chars[i])) {
equal = false;
break;
}
}
return equal;
}
copy(other: Row) {
for (let i = 0; i < NR_COLS; i++) {
this.chars[i].copy(other.chars[i]);
}
}
isEmpty(): boolean {
let empty = true;
for (let i = 0; i < NR_COLS; i++) {
if (!this.chars[i].isEmpty()) {
empty = false;
break;
}
}
return empty;
}
/**
* Set the cursor to a valid column.
*/
setCursor(absPos: number) {
if (this.pos !== absPos) {
this.pos = absPos;
}
if (this.pos < 0) {
this.logger.log(
VerboseLevel.DEBUG,
'Negative cursor position ' + this.pos
);
this.pos = 0;
} else if (this.pos > NR_COLS) {
this.logger.log(
VerboseLevel.DEBUG,
'Too large cursor position ' + this.pos
);
this.pos = NR_COLS;
}
}
/**
* Move the cursor relative to current position.
*/
moveCursor(relPos: number) {
const newPos = this.pos + relPos;
if (relPos > 1) {
for (let i = this.pos + 1; i < newPos + 1; i++) {
this.chars[i].setPenState(this.currPenState);
}
}
this.setCursor(newPos);
}
/**
* Backspace, move one step back and clear character.
*/
backSpace() {
this.moveCursor(-1);
this.chars[this.pos].setChar(' ', this.currPenState);
}
insertChar(byte: number) {
if (byte >= 0x90) {
// Extended char
this.backSpace();
}
const char = getCharForByte(byte);
if (this.pos >= NR_COLS) {
this.logger.log(
VerboseLevel.ERROR,
'Cannot insert ' +
byte.toString(16) +
' (' +
char +
') at position ' +
this.pos +
'. Skipping it!'
);
return;
}
this.chars[this.pos].setChar(char, this.currPenState);
this.moveCursor(1);
}
clearFromPos(startPos: number) {
let i: number;
for (i = startPos; i < NR_COLS; i++) {
this.chars[i].reset();
}
}
clear() {
this.clearFromPos(0);
this.pos = 0;
this.currPenState.reset();
}
clearToEndOfRow() {
this.clearFromPos(this.pos);
}
getTextString() {
const chars: string[] = [];
let empty = true;
for (let i = 0; i < NR_COLS; i++) {
const char = this.chars[i].uchar;
if (char !== ' ') {
empty = false;
}
chars.push(char);
}
if (empty) {
return '';
} else {
return chars.join('');
}
}
setPenStyles(styles: Partial<PenStyles>) {
this.currPenState.setStyles(styles);
const currChar = this.chars[this.pos];
currChar.setPenState(this.currPenState);
}
}
/**
* Keep a CEA-608 screen of 32x15 styled characters
* @constructor
*/
export class CaptionScreen {
rows: Row[];
currRow: number;
nrRollUpRows: number | null;
lastOutputScreen: CaptionScreen | null;
logger: CaptionsLogger;
constructor(logger: CaptionsLogger) {
this.rows = [];
for (let i = 0; i < NR_ROWS; i++) {
this.rows.push(new Row(logger));
} // Note that we use zero-based numbering (0-14)
this.logger = logger;
this.currRow = NR_ROWS - 1;
this.nrRollUpRows = null;
this.lastOutputScreen = null;
this.reset();
}
reset() {
for (let i = 0; i < NR_ROWS; i++) {
this.rows[i].clear();
}
this.currRow = NR_ROWS - 1;
}
equals(other: CaptionScreen): boolean {
let equal = true;
for (let i = 0; i < NR_ROWS; i++) {
if (!this.rows[i].equals(other.rows[i])) {
equal = false;
break;
}
}
return equal;
}
copy(other: CaptionScreen) {
for (let i = 0; i < NR_ROWS; i++) {
this.rows[i].copy(other.rows[i]);
}
}
isEmpty(): boolean {
let empty = true;
for (let i = 0; i < NR_ROWS; i++) {
if (!this.rows[i].isEmpty()) {
empty = false;
break;
}
}
return empty;
}
backSpace() {
const row = this.rows[this.currRow];
row.backSpace();
}
clearToEndOfRow() {
const row = this.rows[this.currRow];
row.clearToEndOfRow();
}
/**
* Insert a character (without styling) in the current row.
*/
insertChar(char: number) {
const row = this.rows[this.currRow];
row.insertChar(char);
}
setPen(styles: Partial<PenStyles>) {
const row = this.rows[this.currRow];
row.setPenStyles(styles);
}
moveCursor(relPos: number) {
const row = this.rows[this.currRow];
row.moveCursor(relPos);
}
setCursor(absPos: number) {
this.logger.log(VerboseLevel.INFO, 'setCursor: ' + absPos);
const row = this.rows[this.currRow];
row.setCursor(absPos);
}
setPAC(pacData: PACData) {
this.logger.log(VerboseLevel.INFO, 'pacData = ' + JSON.stringify(pacData));
let newRow = pacData.row - 1;
if (this.nrRollUpRows && newRow < this.nrRollUpRows - 1) {
newRow = this.nrRollUpRows - 1;
}
// Make sure this only affects Roll-up Captions by checking this.nrRollUpRows
if (this.nrRollUpRows && this.currRow !== newRow) {
// clear all rows first
for (let i = 0; i < NR_ROWS; i++) {
this.rows[i].clear();
}
// Copy this.nrRollUpRows rows from lastOutputScreen and place it in the newRow location
// topRowIndex - the start of rows to copy (inclusive index)
const topRowIndex = this.currRow + 1 - this.nrRollUpRows;
// We only copy if the last position was already shown.
// We use the cueStartTime value to check this.
const lastOutputScreen = this.lastOutputScreen;
if (lastOutputScreen) {
const prevLineTime = lastOutputScreen.rows[topRowIndex].cueStartTime;
const time = this.logger.time;
if (prevLineTime && time !== null && prevLineTime < time) {
for (let i = 0; i < this.nrRollUpRows; i++) {
this.rows[newRow - this.nrRollUpRows + i + 1].copy(
lastOutputScreen.rows[topRowIndex + i]
);
}
}
}
}
this.currRow = newRow;
const row = this.rows[this.currRow];
if (pacData.indent !== null) {
const indent = pacData.indent;
const prevPos = Math.max(indent - 1, 0);
row.setCursor(pacData.indent);
pacData.color = row.chars[prevPos].penState.foreground;
}
const styles: PenStyles = {
foreground: pacData.color,
underline: pacData.underline,
italics: pacData.italics,
background: 'black',
flash: false,
};
this.setPen(styles);
}
/**
* Set background/extra foreground, but first do back_space, and then insert space (backwards compatibility).
*/
setBkgData(bkgData: Partial<PenStyles>) {
this.logger.log(VerboseLevel.INFO, 'bkgData = ' + JSON.stringify(bkgData));
this.backSpace();
this.setPen(bkgData);
this.insertChar(0x20); // Space
}
setRollUpRows(nrRows: number | null) {
this.nrRollUpRows = nrRows;
}
rollUp() {
if (this.nrRollUpRows === null) {
this.logger.log(
VerboseLevel.DEBUG,
'roll_up but nrRollUpRows not set yet'
);
return; // Not properly setup
}
this.logger.log(VerboseLevel.TEXT, this.getDisplayText());
const topRowIndex = this.currRow + 1 - this.nrRollUpRows;
const topRow = this.rows.splice(topRowIndex, 1)[0];
topRow.clear();
this.rows.splice(this.currRow, 0, topRow);
this.logger.log(VerboseLevel.INFO, 'Rolling up');
// this.logger.log(VerboseLevel.TEXT, this.get_display_text())
}
/**
* Get all non-empty rows with as unicode text.
*/
getDisplayText(asOneRow?: boolean) {
asOneRow = asOneRow || false;
const displayText: string[] = [];
let text = '';
let rowNr = -1;
for (let i = 0; i < NR_ROWS; i++) {
const rowText = this.rows[i].getTextString();
if (rowText) {
rowNr = i + 1;
if (asOneRow) {
displayText.push('Row ' + rowNr + ": '" + rowText + "'");
} else {
displayText.push(rowText.trim());
}
}
}
if (displayText.length > 0) {
if (asOneRow) {
text = '[' + displayText.join(' | ') + ']';
} else {
text = displayText.join('\n');
}
}
return text;
}
getTextAndFormat() {
return this.rows;
}
}
// var modes = ['MODE_ROLL-UP', 'MODE_POP-ON', 'MODE_PAINT-ON', 'MODE_TEXT'];
type CaptionModes =
| 'MODE_ROLL-UP'
| 'MODE_POP-ON'
| 'MODE_PAINT-ON'
| 'MODE_TEXT'
| null;
class Cea608Channel {
chNr: number;
outputFilter: OutputFilter;
mode: CaptionModes;
verbose: number;
displayedMemory: CaptionScreen;
nonDisplayedMemory: CaptionScreen;
lastOutputScreen: CaptionScreen;
currRollUpRow: Row;
writeScreen: CaptionScreen;
cueStartTime: number | null;
logger: CaptionsLogger;
constructor(
channelNumber: number,
outputFilter: OutputFilter,
logger: CaptionsLogger
) {
this.chNr = channelNumber;
this.outputFilter = outputFilter;
this.mode = null;
this.verbose = 0;
this.displayedMemory = new CaptionScreen(logger);
this.nonDisplayedMemory = new CaptionScreen(logger);
this.lastOutputScreen = new CaptionScreen(logger);
this.currRollUpRow = this.displayedMemory.rows[NR_ROWS - 1];
this.writeScreen = this.displayedMemory;
this.mode = null;
this.cueStartTime = null; // Keeps track of where a cue started.
this.logger = logger;
}
reset() {
this.mode = null;
this.displayedMemory.reset();
this.nonDisplayedMemory.reset();
this.lastOutputScreen.reset();
this.outputFilter.reset();
this.currRollUpRow = this.displayedMemory.rows[NR_ROWS - 1];
this.writeScreen = this.displayedMemory;
this.mode = null;
this.cueStartTime = null;
}
getHandler(): OutputFilter {
return this.outputFilter;
}
setHandler(newHandler: OutputFilter) {
this.outputFilter = newHandler;
}
setPAC(pacData: PACData) {
this.writeScreen.setPAC(pacData);
}
setBkgData(bkgData: Partial<PenStyles>) {
this.writeScreen.setBkgData(bkgData);
}
setMode(newMode: CaptionModes) {
if (newMode === this.mode) {
return;
}
this.mode = newMode;
this.logger.log(VerboseLevel.INFO, 'MODE=' + newMode);
if (this.mode === 'MODE_POP-ON') {
this.writeScreen = this.nonDisplayedMemory;
} else {
this.writeScreen = this.displayedMemory;
this.writeScreen.reset();
}
if (this.mode !== 'MODE_ROLL-UP') {
this.displayedMemory.nrRollUpRows = null;
this.nonDisplayedMemory.nrRollUpRows = null;
}
this.mode = newMode;
}
insertChars(chars: number[]) {
for (let i = 0; i < chars.length; i++) {
this.writeScreen.insertChar(chars[i]);
}
const screen =
this.writeScreen === this.displayedMemory ? 'DISP' : 'NON_DISP';
this.logger.log(
VerboseLevel.INFO,
screen + ': ' + this.writeScreen.getDisplayText(true)
);
if (this.mode === 'MODE_PAINT-ON' || this.mode === 'MODE_ROLL-UP') {
this.logger.log(
VerboseLevel.TEXT,
'DISPLAYED: ' + this.displayedMemory.getDisplayText(true)
);
this.outputDataUpdate();
}
}
ccRCL() {
// Resume Caption Loading (switch mode to Pop On)
this.logger.log(VerboseLevel.INFO, 'RCL - Resume Caption Loading');
this.setMode('MODE_POP-ON');
}
ccBS() {
// BackSpace
this.logger.log(VerboseLevel.INFO, 'BS - BackSpace');
if (this.mode === 'MODE_TEXT') {
return;
}
this.writeScreen.backSpace();
if (this.writeScreen === this.displayedMemory) {
this.outputDataUpdate();
}
}
ccAOF() {
// Reserved (formerly Alarm Off)
}
ccAON() {
// Reserved (formerly Alarm On)
}
ccDER() {
// Delete to End of Row
this.logger.log(VerboseLevel.INFO, 'DER- Delete to End of Row');
this.writeScreen.clearToEndOfRow();
this.outputDataUpdate();
}
ccRU(nrRows: number | null) {
// Roll-Up Captions-2,3,or 4 Rows
this.logger.log(VerboseLevel.INFO, 'RU(' + nrRows + ') - Roll Up');
this.writeScreen = this.displayedMemory;
this.setMode('MODE_ROLL-UP');
this.writeScreen.setRollUpRows(nrRows);
}
ccFON() {
// Flash On
this.logger.log(VerboseLevel.INFO, 'FON - Flash On');
this.writeScreen.setPen({ flash: true });
}
ccRDC() {
// Resume Direct Captioning (switch mode to PaintOn)
this.logger.log(VerboseLevel.INFO, 'RDC - Resume Direct Captioning');
this.setMode('MODE_PAINT-ON');
}
ccTR() {
// Text Restart in text mode (not supported, however)
this.logger.log(VerboseLevel.INFO, 'TR');
this.setMode('MODE_TEXT');
}
ccRTD() {
// Resume Text Display in Text mode (not supported, however)
this.logger.log(VerboseLevel.INFO, 'RTD');
this.setMode('MODE_TEXT');
}
ccEDM() {
// Erase Displayed Memory
this.logger.log(VerboseLevel.INFO, 'EDM - Erase Displayed Memory');
this.displayedMemory.reset();
this.outputDataUpdate(true);
}
ccCR() {
// Carriage Return
this.logger.log(VerboseLevel.INFO, 'CR - Carriage Return');
this.writeScreen.rollUp();
this.outputDataUpdate(true);
}
ccENM() {
// Erase Non-Displayed Memory
this.logger.log(VerboseLevel.INFO, 'ENM - Erase Non-displayed Memory');
this.nonDisplayedMemory.reset();
}
ccEOC() {
// End of Caption (Flip Memories)
this.logger.log(VerboseLevel.INFO, 'EOC - End Of Caption');
if (this.mode === 'MODE_POP-ON') {
const tmp = this.displayedMemory;
this.displayedMemory = this.nonDisplayedMemory;
this.nonDisplayedMemory = tmp;
this.writeScreen = this.nonDisplayedMemory;
this.logger.log(
VerboseLevel.TEXT,
'DISP: ' + this.displayedMemory.getDisplayText()
);
}
this.outputDataUpdate(true);
}
ccTO(nrCols: number) {
// Tab Offset 1,2, or 3 columns
this.logger.log(VerboseLevel.INFO, 'TO(' + nrCols + ') - Tab Offset');
this.writeScreen.moveCursor(nrCols);
}
ccMIDROW(secondByte: number) {
// Parse MIDROW command
const styles: Partial<PenStyles> = { flash: false };
styles.underline = secondByte % 2 === 1;
styles.italics = secondByte >= 0x2e;
if (!styles.italics) {
const colorIndex = Math.floor(secondByte / 2) - 0x10;
const colors = [
'white',
'green',
'blue',
'cyan',
'red',
'yellow',
'magenta',
];
styles.foreground = colors[colorIndex];
} else {
styles.foreground = 'white';
}
this.logger.log(VerboseLevel.INFO, 'MIDROW: ' + JSON.stringify(styles));
this.writeScreen.setPen(styles);
}
outputDataUpdate(dispatch: boolean = false) {
const time = this.logger.time;
if (time === null) {
return;
}
if (this.outputFilter) {
if (this.cueStartTime === null && !this.displayedMemory.isEmpty()) {
// Start of a new cue
this.cueStartTime = time;
} else {
if (!this.displayedMemory.equals(this.lastOutputScreen)) {
this.outputFilter.newCue(
this.cueStartTime!,
time,
this.lastOutputScreen
);
if (dispatch && this.outputFilter.dispatchCue) {
this.outputFilter.dispatchCue();
}
this.cueStartTime = this.displayedMemory.isEmpty() ? null : time;
}
}
this.lastOutputScreen.copy(this.displayedMemory);
}
}
cueSplitAtTime(t: number) {
if (this.outputFilter) {
if (!this.displayedMemory.isEmpty()) {
if (this.outputFilter.newCue) {
this.outputFilter.newCue(this.cueStartTime!, t, this.displayedMemory);
}
this.cueStartTime = t;
}
}
}
}
interface PACData {
row: number;
indent: number | null;
color: string | null;
underline: boolean;
italics: boolean;
}
type SupportedField = 1 | 3;
type Channels = 0 | 1 | 2; // Will be 1 or 2 when parsing captions
type CmdHistory = {
a: number | null;
b: number | null;
};
class Cea608Parser {
channels: Array<Cea608Channel | null>;
currentChannel: Channels = 0;
cmdHistory: CmdHistory;
logger: CaptionsLogger;
constructor(field: SupportedField, out1: OutputFilter, out2: OutputFilter) {
const logger = new CaptionsLogger();
this.channels = [
null,
new Cea608Channel(field, out1, logger),
new Cea608Channel(field + 1, out2, logger),
];
this.cmdHistory = createCmdHistory();
this.logger = logger;
}
getHandler(channel: number) {
return (this.channels[channel] as Cea608Channel).getHandler();
}
setHandler(channel: number, newHandler: OutputFilter) {
(this.channels[channel] as Cea608Channel).setHandler(newHandler);
}
/**
* Add data for time t in forms of list of bytes (unsigned ints). The bytes are treated as pairs.
*/
addData(time: number | null, byteList: number[]) {
let cmdFound: boolean;
let a: number;
let b: number;
let charsFound: number[] | boolean | null = false;
this.logger.time = time;
for (let i = 0; i < byteList.length; i += 2) {
a = byteList[i] & 0x7f;
b = byteList[i + 1] & 0x7f;
if (a === 0 && b === 0) {
continue;
} else {
this.logger.log(
VerboseLevel.DATA,
'[' +
numArrayToHexArray([byteList[i], byteList[i + 1]]) +
'] -> (' +
numArrayToHexArray([a, b]) +
')'
);
}
cmdFound = this.parseCmd(a, b);
if (!cmdFound) {
cmdFound = this.parseMidrow(a, b);
}
if (!cmdFound) {
cmdFound = this.parsePAC(a, b);
}
if (!cmdFound) {
cmdFound = this.parseBackgroundAttributes(a, b);
}
if (!cmdFound) {
charsFound = this.parseChars(a, b);
if (charsFound) {
const currChNr = this.currentChannel;
if (currChNr && currChNr > 0) {
const channel = this.channels[currChNr] as Cea608Channel;
channel.insertChars(charsFound);
} else {
this.logger.log(
VerboseLevel.WARNING,
'No channel found yet. TEXT-MODE?'
);
}
}
}
if (!cmdFound && !charsFound) {
this.logger.log(
VerboseLevel.WARNING,
"Couldn't parse cleaned data " +
numArrayToHexArray([a, b]) +
' orig: ' +
numArrayToHexArray([byteList[i], byteList[i + 1]])
);
}
}
}
/**
* Parse Command.
* @returns {Boolean} Tells if a command was found
*/
parseCmd(a: number, b: number) {
const { cmdHistory } = this;
const cond1 =
(a === 0x14 || a === 0x1c || a === 0x15 || a === 0x1d) &&
b >= 0x20 &&
b <= 0x2f;
const cond2 = (a === 0x17 || a === 0x1f) && b >= 0x21 && b <= 0x23;
if (!(cond1 || cond2)) {
return false;
}
if (hasCmdRepeated(a, b, cmdHistory)) {
setLastCmd(null, null, cmdHistory);
this.logger.log(
VerboseLevel.DEBUG,
'Repeated command (' + numArrayToHexArray([a, b]) + ') is dropped'
);
return true;
}
const chNr = a === 0x14 || a === 0x15 || a === 0x17 ? 1 : 2;
const channel = this.channels[chNr] as Cea608Channel;
if (a === 0x14 || a === 0x15 || a === 0x1c || a === 0x1d) {
if (b === 0x20) {
channel.ccRCL();
} else if (b === 0x21) {
channel.ccBS();
} else if (b === 0x22) {
channel.ccAOF();
} else if (b === 0x23) {
channel.ccAON();
} else if (b === 0x24) {
channel.ccDER();
} else if (b === 0x25) {
channel.ccRU(2);
} else if (b === 0x26) {
channel.ccRU(3);
} else if (b === 0x27) {
channel.ccRU(4);
} else if (b === 0x28) {
channel.ccFON();
} else if (b === 0x29) {
channel.ccRDC();
} else if (b === 0x2a) {
channel.ccTR();
} else if (b === 0x2b) {
channel.ccRTD();
} else if (b === 0x2c) {
channel.ccEDM();
} else if (b === 0x2d) {
channel.ccCR();
} else if (b === 0x2e) {
channel.ccENM();
} else if (b === 0x2f) {
channel.ccEOC();
}
} else {
// a == 0x17 || a == 0x1F
channel.ccTO(b - 0x20);
}
setLastCmd(a, b, cmdHistory);
this.currentChannel = chNr;
return true;
}
/**
* Parse midrow styling command
* @returns {Boolean}
*/
parseMidrow(a: number, b: number) {
let chNr: number = 0;
if ((a === 0x11 || a === 0x19) && b >= 0x20 && b <= 0x2f) {
if (a === 0x11) {
chNr = 1;
} else {
chNr = 2;
}
if (chNr !== this.currentChannel) {
this.logger.log(
VerboseLevel.ERROR,
'Mismatch channel in midrow parsing'
);
return false;
}
const channel = this.channels[chNr];
if (!channel) {
return false;
}
channel.ccMIDROW(b);
this.logger.log(
VerboseLevel.DEBUG,
'MIDROW (' + numArrayToHexArray([a, b]) + ')'
);
return true;
}
return false;
}
/**
* Parse Preable Access Codes (Table 53).
* @returns {Boolean} Tells if PAC found
*/
parsePAC(a: number, b: number): boolean {
let row: number;
const cmdHistory = this.cmdHistory;
const case1 =
((a >= 0x11 && a <= 0x17) || (a >= 0x19 && a <= 0x1f)) &&
b >= 0x40 &&
b <= 0x7f;
const case2 = (a === 0x10 || a === 0x18) && b >= 0x40 && b <= 0x5f;
if (!(case1 || case2)) {
return false;
}
if (hasCmdRepeated(a, b, cmdHistory)) {
setLastCmd(null, null, cmdHistory);
return true; // Repeated commands are dropped (once)
}
const chNr: Channels = a <= 0x17 ? 1 : 2;
if (b >= 0x40 && b <= 0x5f) {
row = chNr === 1 ? rowsLowCh1[a] : rowsLowCh2[a];
} else {
// 0x60 <= b <= 0x7F
row = chNr === 1 ? rowsHighCh1[a] : rowsHighCh2[a];
}
const channel = this.channels[chNr];
if (!channel) {
return false;
}
channel.setPAC(this.interpretPAC(row, b));
setLastCmd(a, b, cmdHistory);
this.currentChannel = chNr;
return true;
}
/**
* Interpret the second byte of the pac, and return the information.
* @returns {Object} pacData with style parameters.
*/
interpretPAC(row: number, byte: number): PACData {
let pacIndex;
const pacData: PACData = {
color: null,
italics: false,
indent: null,
underline: false,
row: row,
};
if (byte > 0x5f) {
pacIndex = byte - 0x60;
} else {
pacIndex = byte - 0x40;
}
pacData.underline = (pacIndex & 1) === 1;
if (pacIndex <= 0xd) {
pacData.color = [
'white',
'green',
'blue',
'cyan',
'red',
'yellow',
'magenta',
'white',
][Math.floor(pacIndex / 2)];
} else if (pacIndex <= 0xf) {
pacData.italics = true;
pacData.color = 'white';
} else {
pacData.indent = Math.floor((pacIndex - 0x10) / 2) * 4;
}
return pacData; // Note that row has zero offset. The spec uses 1.
}
/**
* Parse characters.
* @returns An array with 1 to 2 codes corresponding to chars, if found. null otherwise.
*/
parseChars(a: number, b: number): number[] | null {
let channelNr: Channels;
let charCodes: number[] | null = null;
let charCode1: number | null = null;
if (a >= 0x19) {
channelNr = 2;
charCode1 = a - 8;
} else {
channelNr = 1;
charCode1 = a;
}
if (charCode1 >= 0x11 && charCode1 <= 0x13) {
// Special character
let oneCode;
if (charCode1 === 0x11) {
oneCode = b + 0x50;
} else if (charCode1 === 0x12) {
oneCode = b + 0x70;
} else {
oneCode = b + 0x90;
}
this.logger.log(
VerboseLevel.INFO,
"Special char '" + getCharForByte(oneCode) + "' in channel " + channelNr
);
charCodes = [oneCode];
} else if (a >= 0x20 && a <= 0x7f) {
charCodes = b === 0 ? [a] : [a, b];
}
if (charCodes) {
const hexCodes = numArrayToHexArray(charCodes);
this.logger.log(
VerboseLevel.DEBUG,
'Char codes = ' + hexCodes.join(',')
);
setLastCmd(a, b, this.cmdHistory);
}
return charCodes;
}
/**
* Parse extended background attributes as well as new foreground color black.
* @returns {Boolean} Tells if background attributes are found
*/
parseBackgroundAttributes(a: number, b: number): boolean {
const case1 = (a === 0x10 || a === 0x18) && b >= 0x20 && b <= 0x2f;
const case2 = (a === 0x17 || a === 0x1f) && b >= 0x2d && b <= 0x2f;
if (!(case1 || case2)) {
return false;
}
let index: number;
const bkgData: Partial<PenStyles> = {};
if (a === 0x10 || a === 0x18) {
index = Math.floor((b - 0x20) / 2);
bkgData.background = backgroundColors[index];
if (b % 2 === 1) {
bkgData.background = bkgData.background + '_semi';
}
} else if (b === 0x2d) {
bkgData.background = 'transparent';
} else {
bkgData.foreground = 'black';
if (b === 0x2f) {
bkgData.underline = true;
}
}
const chNr: Channels = a <= 0x17 ? 1 : 2;
const channel: Cea608Channel = this.channels[chNr] as Cea608Channel;
channel.setBkgData(bkgData);
setLastCmd(a, b, this.cmdHistory);
return true;
}
/**
* Reset state of parser and its channels.
*/
reset() {
for (let i = 0; i < Object.keys(this.channels).length; i++) {
const channel = this.channels[i];
if (channel) {
channel.reset();
}
}
this.cmdHistory = createCmdHistory();
}
/**
* Trigger the generation of a cue, and the start of a new one if displayScreens are not empty.
*/
cueSplitAtTime(t: number) {
for (let i = 0; i < this.channels.length; i++) {
const channel = this.channels[i];
if (channel) {
channel.cueSplitAtTime(t);
}
}
}
}
function setLastCmd(
a: number | null,
b: number | null,
cmdHistory: CmdHistory
) {
cmdHistory.a = a;
cmdHistory.b = b;
}
function hasCmdRepeated(a: number, b: number, cmdHistory: CmdHistory) {
return cmdHistory.a === a && cmdHistory.b === b;
}
function createCmdHistory(): CmdHistory {
return {
a: null,
b: null,
};
}
export default Cea608Parser;
