mirror of
https://github.com/shaka-project/shaka-player.git
synced 2026-06-16 16:16:40 +03:00
Álvaro Velad Galván
374 lines
9.2 KiB
JavaScript
374 lines
9.2 KiB
JavaScript
/*! @license
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* Shaka Player
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* Copyright 2016 Google LLC
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* SPDX-License-Identifier: Apache-2.0
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*/
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goog.provide('shaka.cea.Cea608Memory');
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goog.require('shaka.cea.CeaUtils');
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goog.require('shaka.text.Cue');
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/**
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* CEA-608 captions memory/buffer.
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*/
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shaka.cea.Cea608Memory = class {
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/**
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* @param {number} fieldNum Field number.
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* @param {number} channelNum Channel number.
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*/
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constructor(fieldNum, channelNum) {
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/**
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* Buffer for storing decoded characters.
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* @private @const {!Array<!Array<!shaka.cea.CeaUtils.StyledChar>>}
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*/
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this.rows_ = [];
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/**
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* Current row.
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* @private {number}
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*/
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this.row_ = 1;
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/**
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* Number of rows in the scroll window. Used for rollup mode.
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* @private {number}
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*/
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this.scrollRows_ = 0;
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/**
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* Field number.
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* @private {number}
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*/
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this.fieldNum_ = fieldNum;
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/**
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* Channel number.
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* @private {number}
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*/
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this.channelNum_ = channelNum;
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/**
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* @private {boolean}
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*/
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this.underline_ = false;
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/**
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* @private {boolean}
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*/
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this.italics_ = false;
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/**
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* @private {string}
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*/
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this.textColor_ = shaka.cea.CeaUtils.DEFAULT_TXT_COLOR;
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/**
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* @private {string}
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*/
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this.backgroundColor_ = shaka.cea.CeaUtils.DEFAULT_BG_COLOR;
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/**
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* @private {?number}
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*/
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this.offset_ = null;
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/**
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* @private {?number}
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*/
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this.indent_ = null;
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this.reset();
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}
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/**
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* Emits a closed caption based on the state of the buffer.
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* @param {number} startTime Start time of the cue.
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* @param {number} endTime End time of the cue.
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* @return {?shaka.extern.ICaptionDecoder.ClosedCaption}
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*/
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forceEmit(startTime, endTime) {
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const Cea608Memory = shaka.cea.Cea608Memory;
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const stream = `CC${((this.fieldNum_<< 1) | this.channelNum_) + 1}`;
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const topLevelCue = new shaka.text.Cue(
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startTime, endTime, /* payload= */ '');
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topLevelCue.lineInterpretation =
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shaka.text.Cue.lineInterpretation.PERCENTAGE;
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let line = Cea608Memory.ROW_TO_LINE_CONVERSION_.get(this.row_);
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if (line) {
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topLevelCue.line = line;
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}
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if (this.indent_ != null && this.offset_ != null) {
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topLevelCue.position = 10 + Math.min(70, this.indent_ * 10) +
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this.offset_ * 2.5;
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}
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const ret = shaka.cea.CeaUtils.getParsedCaption(
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topLevelCue, stream, this.rows_, startTime, endTime);
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// If the text and its lines are larger than what we can show on the
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// screen, we move the lines up so that the text does not come out of the
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// video.
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if (ret && (this.row_ + ret.cue.nestedCues.length - 3) > 15) {
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const newLinePosition = this.row_ + 3 - ret.cue.nestedCues.length;
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line = Cea608Memory.ROW_TO_LINE_CONVERSION_.get(newLinePosition);
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if (line) {
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topLevelCue.line = line;
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}
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}
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return ret;
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}
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/**
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* Resets the memory buffer.
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*/
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reset() {
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this.resetAllRows();
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this.row_ = 1;
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}
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/**
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* @return {number}
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*/
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getRow() {
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return this.row_;
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}
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/**
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* @param {number} row
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*/
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setRow(row) {
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this.row_ = row;
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}
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/**
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* @return {number}
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*/
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getScrollSize() {
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return this.scrollRows_;
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}
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/**
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* @param {number} scrollRows
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*/
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setScrollSize(scrollRows) {
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this.scrollRows_ = scrollRows;
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}
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/**
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* Adds a character to the buffer.
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* @param {!shaka.cea.Cea608Memory.CharSet} set Character set.
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* @param {number} b CC byte to add.
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*/
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addChar(set, b) {
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// Valid chars are in the range [0x20, 0x7f]
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if (b < 0x20 || b > 0x7f) {
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return;
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}
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let char = '';
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switch (set) {
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case shaka.cea.Cea608Memory.CharSet.BASIC_NORTH_AMERICAN:
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if (shaka.cea.Cea608Memory.CharSet.BasicNorthAmericanChars.has(b)) {
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char =
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shaka.cea.Cea608Memory.CharSet.BasicNorthAmericanChars.get(b);
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} else {
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// Regular ASCII
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char = String.fromCharCode(b);
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}
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break;
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case shaka.cea.Cea608Memory.CharSet.SPECIAL_NORTH_AMERICAN:
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char =
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shaka.cea.Cea608Memory.CharSet.SpecialNorthAmericanChars.get(b);
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break;
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case shaka.cea.Cea608Memory.CharSet.SPANISH_FRENCH:
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// Extended charset does a BS over preceding char, 6.4.2 EIA-608-B.
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this.eraseChar();
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char =
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shaka.cea.Cea608Memory.CharSet.ExtendedSpanishFrench.get(b);
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break;
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case shaka.cea.Cea608Memory.CharSet.PORTUGUESE_GERMAN:
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this.eraseChar();
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char =
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shaka.cea.Cea608Memory.CharSet.ExtendedPortugueseGerman.get(b);
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break;
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}
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if (char) {
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const styledChar = new shaka.cea.CeaUtils.StyledChar(
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char, this.underline_, this.italics_,
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this.backgroundColor_, this.textColor_);
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this.rows_[this.row_].push(styledChar);
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}
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}
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/**
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* Erases a character from the buffer.
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*/
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eraseChar() {
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this.rows_[this.row_].pop();
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}
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/**
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* Moves rows of characters.
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* @param {number} dst Destination row index.
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* @param {number} src Source row index.
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* @param {number} count Count of rows to move.
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*/
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moveRows(dst, src, count) {
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if (src < 0 || dst < 0) {
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return;
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}
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if (dst >= src) {
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for (let i = count-1; i >= 0; i--) {
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this.rows_[dst + i] = this.rows_[src + i].map((e) => e);
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}
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} else {
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for (let i = 0; i < count; i++) {
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this.rows_[dst + i] = this.rows_[src + i].map((e) => e);
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}
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}
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}
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/**
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* Resets rows of characters.
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* @param {number} idx Starting index.
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* @param {number} count Count of rows to reset.
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*/
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resetRows(idx, count) {
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for (let i = 0; i <= count; i++) {
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this.rows_[idx + i] = [];
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}
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}
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/**
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* Resets the entire memory buffer.
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*/
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resetAllRows() {
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this.resetRows(0, shaka.cea.Cea608Memory.CC_ROWS);
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}
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/**
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* Erases entire memory buffer.
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* Doesn't change scroll state or number of rows.
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*/
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eraseBuffer() {
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this.row_ = (this.scrollRows_ > 0) ? this.scrollRows_ : 0;
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this.resetAllRows();
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}
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/**
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* @param {boolean} underline
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*/
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setUnderline(underline) {
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this.underline_ = underline;
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}
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/**
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* @param {boolean} italics
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*/
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setItalics(italics) {
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this.italics_ = italics;
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}
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/**
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* @param {string} color
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*/
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setTextColor(color) {
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this.textColor_ = color;
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}
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/**
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* @param {string} color
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*/
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setBackgroundColor(color) {
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this.backgroundColor_ = color;
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}
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/**
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* @param {number} offset
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*/
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setOffset(offset) {
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this.offset_ = offset;
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}
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/**
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* @param {?number} indent
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*/
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setIndent(indent) {
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this.indent_ = indent;
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}
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};
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/**
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* Maximum number of rows in the buffer.
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* @const {number}
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*/
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shaka.cea.Cea608Memory.CC_ROWS = 15;
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/**
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* Characters sets.
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* @const @enum {number}
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*/
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shaka.cea.Cea608Memory.CharSet = {
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BASIC_NORTH_AMERICAN: 0,
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SPECIAL_NORTH_AMERICAN: 1,
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SPANISH_FRENCH: 2,
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PORTUGUESE_GERMAN: 3,
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};
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/**
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* Basic North American char set deviates from ASCII with these exceptions.
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* @private @const {!Map<number, string>}
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*/
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shaka.cea.Cea608Memory.CharSet.BasicNorthAmericanChars = new Map([
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[0x27, '’'], [0x2a, 'á'], [0x5c, 'é'], [0x5c, 'é'], [0x5e, 'í'], [0x5f, 'ó'],
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[0x60, 'ú'], [0x7b, 'ç'], [0x7c, '÷'], [0x7d, 'Ñ'], [0x7e, 'ñ'], [0x7f, '█'],
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]);
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/**
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* Special North American char set.
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* Note: Transparent Space is currently implemented as a regular space.
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* @private @const {!Map<number, string>}
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*/
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shaka.cea.Cea608Memory.CharSet.SpecialNorthAmericanChars = new Map([
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[0x30, '®'], [0x31, '°'], [0x32, '½'], [0x33, '¿'], [0x34, '™'], [0x35, '¢'],
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[0x36, '£'], [0x37, '♪'], [0x38, 'à'], [0x39, ' '], [0x3a, 'è'], [0x3b, 'â'],
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[0x3c, 'ê'], [0x3d, 'î'], [0x3e, 'ô'], [0x3f, 'û'],
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]);
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/**
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* Extended Spanish/Misc/French char set.
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* @private @const {!Map<number, string>}
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*/
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shaka.cea.Cea608Memory.CharSet.ExtendedSpanishFrench = new Map([
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[0x20, 'Á'], [0x21, 'É'], [0x22, 'Ó'], [0x23, 'Ú'], [0x24, 'Ü'], [0x25, 'ü'],
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[0x26, '‘'], [0x27, '¡'], [0x28, '*'], [0x29, '\''], [0x2a, '─'], [0x2b, '©'],
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[0x2c, '℠'], [0x2d, '·'], [0x2e, '“'], [0x2f, '”'], [0x30, 'À'], [0x31, 'Â'],
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[0x32, 'Ç'], [0x33, 'È'], [0x34, 'Ê'], [0x35, 'Ë'], [0x36, 'ë'], [0x37, 'Î'],
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[0x38, 'Ï'], [0x39, 'ï'], [0x3a, 'Ô'], [0x3b, 'Ù'], [0x3c, 'ù'], [0x3d, 'Û'],
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[0x3e, '«'], [0x3f, '»'],
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]);
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/**
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* Extended Portuguese/German/Danish char set.
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* @private @const {!Map<number, string>}
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*/
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shaka.cea.Cea608Memory.CharSet.ExtendedPortugueseGerman = new Map([
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[0x20, 'Ã'], [0x21, 'ã'], [0x22, 'Í'], [0x23, 'Ì'], [0x24, 'ì'], [0x25, 'Ò'],
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[0x26, 'ò'], [0x27, 'Õ'], [0x28, 'õ'], [0x29, '{'], [0x2a, '}'], [0x2b, '\\'],
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[0x2c, '^'], [0x2d, '_'], [0x2e, '|'], [0x2f, '~'], [0x30, 'Ä'], [0x31, 'ä'],
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[0x32, 'Ö'], [0x33, 'ö'], [0x34, 'ß'], [0x35, '¥'], [0x36, '¤'], [0x37, '│'],
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[0x38, 'Å'], [0x39, 'å'], [0x3a, 'Ø'], [0x3b, 'ø'], [0x3c, '┌'], [0x3d, '┐'],
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[0x3e, '└'], [0x3f, '┘'],
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]);
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/**
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* @private @const {!Map<number, number>}
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*/
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shaka.cea.Cea608Memory.ROW_TO_LINE_CONVERSION_ = new Map([
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[1, 10], [2, 15.33], [3, 20.66], [4, 26], [5, 31.33], [6, 36.66], [7, 42],
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[8, 47.33], [9, 52.66], [10, 58], [11, 63.33], [12, 68.66], [13, 74],
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[14, 79.33], [15, 84.66],
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]);
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