1817 lines
54 KiB
JavaScript
1817 lines
54 KiB
JavaScript
/**
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* mux.js
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*
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* Copyright (c) Brightcove
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* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
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*
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* Reads in-band caption information from a video elementary
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* stream. Captions must follow the CEA-708 standard for injection
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* into an MPEG-2 transport streams.
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* @see https://en.wikipedia.org/wiki/CEA-708
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* @see https://www.gpo.gov/fdsys/pkg/CFR-2007-title47-vol1/pdf/CFR-2007-title47-vol1-sec15-119.pdf
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*/
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'use strict';
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// -----------------
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// Link To Transport
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// -----------------
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var Stream = require('../utils/stream');
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var cea708Parser = require('../tools/caption-packet-parser');
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var CaptionStream = function(options) {
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options = options || {};
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CaptionStream.prototype.init.call(this);
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// parse708captions flag, default to true
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this.parse708captions_ = typeof options.parse708captions === 'boolean' ?
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options.parse708captions :
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true;
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this.captionPackets_ = [];
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this.ccStreams_ = [
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new Cea608Stream(0, 0), // eslint-disable-line no-use-before-define
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new Cea608Stream(0, 1), // eslint-disable-line no-use-before-define
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new Cea608Stream(1, 0), // eslint-disable-line no-use-before-define
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new Cea608Stream(1, 1) // eslint-disable-line no-use-before-define
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];
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if (this.parse708captions_) {
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this.cc708Stream_ = new Cea708Stream({captionServices: options.captionServices}); // eslint-disable-line no-use-before-define
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}
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this.reset();
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// forward data and done events from CCs to this CaptionStream
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this.ccStreams_.forEach(function(cc) {
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cc.on('data', this.trigger.bind(this, 'data'));
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cc.on('partialdone', this.trigger.bind(this, 'partialdone'));
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cc.on('done', this.trigger.bind(this, 'done'));
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}, this);
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if (this.parse708captions_) {
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this.cc708Stream_.on('data', this.trigger.bind(this, 'data'));
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this.cc708Stream_.on('partialdone', this.trigger.bind(this, 'partialdone'));
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this.cc708Stream_.on('done', this.trigger.bind(this, 'done'));
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}
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};
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CaptionStream.prototype = new Stream();
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CaptionStream.prototype.push = function(event) {
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var sei, userData, newCaptionPackets;
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// only examine SEI NALs
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if (event.nalUnitType !== 'sei_rbsp') {
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return;
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}
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// parse the sei
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sei = cea708Parser.parseSei(event.escapedRBSP);
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// no payload data, skip
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if (!sei.payload) {
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return;
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}
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// ignore everything but user_data_registered_itu_t_t35
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if (sei.payloadType !== cea708Parser.USER_DATA_REGISTERED_ITU_T_T35) {
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return;
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}
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// parse out the user data payload
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userData = cea708Parser.parseUserData(sei);
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// ignore unrecognized userData
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if (!userData) {
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return;
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}
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// Sometimes, the same segment # will be downloaded twice. To stop the
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// caption data from being processed twice, we track the latest dts we've
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// received and ignore everything with a dts before that. However, since
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// data for a specific dts can be split across packets on either side of
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// a segment boundary, we need to make sure we *don't* ignore the packets
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// from the *next* segment that have dts === this.latestDts_. By constantly
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// tracking the number of packets received with dts === this.latestDts_, we
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// know how many should be ignored once we start receiving duplicates.
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if (event.dts < this.latestDts_) {
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// We've started getting older data, so set the flag.
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this.ignoreNextEqualDts_ = true;
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return;
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} else if ((event.dts === this.latestDts_) && (this.ignoreNextEqualDts_)) {
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this.numSameDts_--;
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if (!this.numSameDts_) {
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// We've received the last duplicate packet, time to start processing again
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this.ignoreNextEqualDts_ = false;
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}
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return;
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}
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// parse out CC data packets and save them for later
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newCaptionPackets = cea708Parser.parseCaptionPackets(event.pts, userData);
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this.captionPackets_ = this.captionPackets_.concat(newCaptionPackets);
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if (this.latestDts_ !== event.dts) {
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this.numSameDts_ = 0;
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}
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this.numSameDts_++;
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this.latestDts_ = event.dts;
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};
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CaptionStream.prototype.flushCCStreams = function(flushType) {
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this.ccStreams_.forEach(function(cc) {
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return flushType === 'flush' ? cc.flush() : cc.partialFlush();
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}, this);
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};
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CaptionStream.prototype.flushStream = function(flushType) {
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// make sure we actually parsed captions before proceeding
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if (!this.captionPackets_.length) {
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this.flushCCStreams(flushType);
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return;
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}
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// In Chrome, the Array#sort function is not stable so add a
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// presortIndex that we can use to ensure we get a stable-sort
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this.captionPackets_.forEach(function(elem, idx) {
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elem.presortIndex = idx;
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});
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// sort caption byte-pairs based on their PTS values
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this.captionPackets_.sort(function(a, b) {
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if (a.pts === b.pts) {
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return a.presortIndex - b.presortIndex;
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}
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return a.pts - b.pts;
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});
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this.captionPackets_.forEach(function(packet) {
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if (packet.type < 2) {
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// Dispatch packet to the right Cea608Stream
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this.dispatchCea608Packet(packet);
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} else {
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// Dispatch packet to the Cea708Stream
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this.dispatchCea708Packet(packet);
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}
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}, this);
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this.captionPackets_.length = 0;
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this.flushCCStreams(flushType);
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};
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CaptionStream.prototype.flush = function() {
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return this.flushStream('flush');
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};
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// Only called if handling partial data
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CaptionStream.prototype.partialFlush = function() {
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return this.flushStream('partialFlush');
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};
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CaptionStream.prototype.reset = function() {
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this.latestDts_ = null;
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this.ignoreNextEqualDts_ = false;
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this.numSameDts_ = 0;
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this.activeCea608Channel_ = [null, null];
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this.ccStreams_.forEach(function(ccStream) {
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ccStream.reset();
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});
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};
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// From the CEA-608 spec:
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/*
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* When XDS sub-packets are interleaved with other services, the end of each sub-packet shall be followed
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* by a control pair to change to a different service. When any of the control codes from 0x10 to 0x1F is
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* used to begin a control code pair, it indicates the return to captioning or Text data. The control code pair
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* and subsequent data should then be processed according to the FCC rules. It may be necessary for the
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* line 21 data encoder to automatically insert a control code pair (i.e. RCL, RU2, RU3, RU4, RDC, or RTD)
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* to switch to captioning or Text.
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*/
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// With that in mind, we ignore any data between an XDS control code and a
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// subsequent closed-captioning control code.
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CaptionStream.prototype.dispatchCea608Packet = function(packet) {
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// NOTE: packet.type is the CEA608 field
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if (this.setsTextOrXDSActive(packet)) {
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this.activeCea608Channel_[packet.type] = null;
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} else if (this.setsChannel1Active(packet)) {
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this.activeCea608Channel_[packet.type] = 0;
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} else if (this.setsChannel2Active(packet)) {
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this.activeCea608Channel_[packet.type] = 1;
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}
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if (this.activeCea608Channel_[packet.type] === null) {
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// If we haven't received anything to set the active channel, or the
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// packets are Text/XDS data, discard the data; we don't want jumbled
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// captions
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return;
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}
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this.ccStreams_[(packet.type << 1) + this.activeCea608Channel_[packet.type]].push(packet);
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};
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CaptionStream.prototype.setsChannel1Active = function(packet) {
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return ((packet.ccData & 0x7800) === 0x1000);
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};
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CaptionStream.prototype.setsChannel2Active = function(packet) {
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return ((packet.ccData & 0x7800) === 0x1800);
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};
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CaptionStream.prototype.setsTextOrXDSActive = function(packet) {
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return ((packet.ccData & 0x7100) === 0x0100) ||
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((packet.ccData & 0x78fe) === 0x102a) ||
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((packet.ccData & 0x78fe) === 0x182a);
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};
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CaptionStream.prototype.dispatchCea708Packet = function(packet) {
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if (this.parse708captions_) {
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this.cc708Stream_.push(packet);
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}
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};
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// ----------------------
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// Session to Application
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// ----------------------
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// This hash maps special and extended character codes to their
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// proper Unicode equivalent. The first one-byte key is just a
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// non-standard character code. The two-byte keys that follow are
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// the extended CEA708 character codes, along with the preceding
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// 0x10 extended character byte to distinguish these codes from
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// non-extended character codes. Every CEA708 character code that
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// is not in this object maps directly to a standard unicode
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// character code.
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// The transparent space and non-breaking transparent space are
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// technically not fully supported since there is no code to
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// make them transparent, so they have normal non-transparent
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// stand-ins.
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// The special closed caption (CC) character isn't a standard
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// unicode character, so a fairly similar unicode character was
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// chosen in it's place.
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var CHARACTER_TRANSLATION_708 = {
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0x7f: 0x266a, // ♪
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0x1020: 0x20, // Transparent Space
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0x1021: 0xa0, // Nob-breaking Transparent Space
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0x1025: 0x2026, // …
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0x102a: 0x0160, // Š
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0x102c: 0x0152, // Œ
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0x1030: 0x2588, // █
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0x1031: 0x2018, // ‘
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0x1032: 0x2019, // ’
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0x1033: 0x201c, // “
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0x1034: 0x201d, // ”
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0x1035: 0x2022, // •
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0x1039: 0x2122, // ™
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0x103a: 0x0161, // š
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0x103c: 0x0153, // œ
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0x103d: 0x2120, // ℠
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0x103f: 0x0178, // Ÿ
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0x1076: 0x215b, // ⅛
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0x1077: 0x215c, // ⅜
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0x1078: 0x215d, // ⅝
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0x1079: 0x215e, // ⅞
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0x107a: 0x23d0, // ⏐
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0x107b: 0x23a4, // ⎤
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0x107c: 0x23a3, // ⎣
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0x107d: 0x23af, // ⎯
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0x107e: 0x23a6, // ⎦
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0x107f: 0x23a1, // ⎡
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0x10a0: 0x3138 // ㄸ (CC char)
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};
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var get708CharFromCode = function(code) {
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var newCode = CHARACTER_TRANSLATION_708[code] || code;
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if ((code & 0x1000) && code === newCode) {
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// Invalid extended code
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return '';
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}
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return String.fromCharCode(newCode);
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};
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var within708TextBlock = function(b) {
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return (0x20 <= b && b <= 0x7f) || (0xa0 <= b && b <= 0xff);
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};
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var Cea708Window = function(windowNum) {
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this.windowNum = windowNum;
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this.reset();
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};
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Cea708Window.prototype.reset = function() {
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this.clearText();
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this.pendingNewLine = false;
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this.winAttr = {};
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this.penAttr = {};
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this.penLoc = {};
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this.penColor = {};
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// These default values are arbitrary,
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// defineWindow will usually override them
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this.visible = 0;
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this.rowLock = 0;
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this.columnLock = 0;
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this.priority = 0;
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this.relativePositioning = 0;
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this.anchorVertical = 0;
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this.anchorHorizontal = 0;
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this.anchorPoint = 0;
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this.rowCount = 1;
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this.virtualRowCount = this.rowCount + 1;
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this.columnCount = 41;
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this.windowStyle = 0;
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this.penStyle = 0;
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};
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Cea708Window.prototype.getText = function() {
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return this.rows.join('\n');
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};
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Cea708Window.prototype.clearText = function() {
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this.rows = [''];
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this.rowIdx = 0;
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};
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Cea708Window.prototype.newLine = function(pts) {
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if (this.rows.length >= this.virtualRowCount && typeof this.beforeRowOverflow === 'function') {
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this.beforeRowOverflow(pts);
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}
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if (this.rows.length > 0) {
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this.rows.push('');
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this.rowIdx++;
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}
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// Show all virtual rows since there's no visible scrolling
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while (this.rows.length > this.virtualRowCount) {
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this.rows.shift();
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this.rowIdx--;
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}
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};
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Cea708Window.prototype.isEmpty = function() {
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if (this.rows.length === 0) {
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||
return true;
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||
} else if (this.rows.length === 1) {
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return this.rows[0] === '';
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}
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||
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return false;
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};
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Cea708Window.prototype.addText = function(text) {
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this.rows[this.rowIdx] += text;
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||
};
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Cea708Window.prototype.backspace = function() {
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if (!this.isEmpty()) {
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var row = this.rows[this.rowIdx];
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this.rows[this.rowIdx] = row.substr(0, row.length - 1);
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}
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};
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var Cea708Service = function(serviceNum, encoding, stream) {
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this.serviceNum = serviceNum;
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this.text = '';
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this.currentWindow = new Cea708Window(-1);
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this.windows = [];
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||
this.stream = stream;
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||
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// Try to setup a TextDecoder if an `encoding` value was provided
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if (typeof encoding === 'string') {
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this.createTextDecoder(encoding);
|
||
}
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||
};
|
||
|
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/**
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* Initialize service windows
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* Must be run before service use
|
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*
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* @param {Integer} pts PTS value
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* @param {Function} beforeRowOverflow Function to execute before row overflow of a window
|
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*/
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Cea708Service.prototype.init = function(pts, beforeRowOverflow) {
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this.startPts = pts;
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|
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for (var win = 0; win < 8; win++) {
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this.windows[win] = new Cea708Window(win);
|
||
|
||
if (typeof beforeRowOverflow === 'function') {
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this.windows[win].beforeRowOverflow = beforeRowOverflow;
|
||
}
|
||
}
|
||
};
|
||
|
||
/**
|
||
* Set current window of service to be affected by commands
|
||
*
|
||
* @param {Integer} windowNum Window number
|
||
*/
|
||
Cea708Service.prototype.setCurrentWindow = function(windowNum) {
|
||
this.currentWindow = this.windows[windowNum];
|
||
};
|
||
|
||
/**
|
||
* Try to create a TextDecoder if it is natively supported
|
||
*/
|
||
Cea708Service.prototype.createTextDecoder = function(encoding) {
|
||
if (typeof TextDecoder === 'undefined') {
|
||
this.stream.trigger('log', {
|
||
level: 'warn',
|
||
message: 'The `encoding` option is unsupported without TextDecoder support'
|
||
});
|
||
} else {
|
||
try {
|
||
this.textDecoder_ = new TextDecoder(encoding);
|
||
} catch (error) {
|
||
this.stream.trigger('log', {
|
||
level: 'warn',
|
||
message: 'TextDecoder could not be created with ' + encoding + ' encoding. ' + error
|
||
});
|
||
}
|
||
}
|
||
}
|
||
|
||
var Cea708Stream = function(options) {
|
||
options = options || {};
|
||
Cea708Stream.prototype.init.call(this);
|
||
|
||
var self = this;
|
||
var captionServices = options.captionServices || {};
|
||
var captionServiceEncodings = {};
|
||
var serviceProps;
|
||
|
||
// Get service encodings from captionServices option block
|
||
Object.keys(captionServices).forEach(serviceName => {
|
||
serviceProps = captionServices[serviceName];
|
||
|
||
if (/^SERVICE/.test(serviceName)) {
|
||
captionServiceEncodings[serviceName] = serviceProps.encoding;
|
||
}
|
||
});
|
||
|
||
this.serviceEncodings = captionServiceEncodings;
|
||
this.current708Packet = null;
|
||
this.services = {};
|
||
|
||
this.push = function(packet) {
|
||
if (packet.type === 3) {
|
||
// 708 packet start
|
||
self.new708Packet();
|
||
self.add708Bytes(packet);
|
||
} else {
|
||
if (self.current708Packet === null) {
|
||
// This should only happen at the start of a file if there's no packet start.
|
||
self.new708Packet();
|
||
}
|
||
|
||
self.add708Bytes(packet);
|
||
}
|
||
};
|
||
};
|
||
Cea708Stream.prototype = new Stream();
|
||
|
||
/**
|
||
* Push current 708 packet, create new 708 packet.
|
||
*/
|
||
Cea708Stream.prototype.new708Packet = function() {
|
||
if (this.current708Packet !== null) {
|
||
this.push708Packet();
|
||
}
|
||
|
||
this.current708Packet = {
|
||
data: [],
|
||
ptsVals: []
|
||
};
|
||
};
|
||
|
||
/**
|
||
* Add pts and both bytes from packet into current 708 packet.
|
||
*/
|
||
Cea708Stream.prototype.add708Bytes = function(packet) {
|
||
var data = packet.ccData;
|
||
var byte0 = data >>> 8;
|
||
var byte1 = data & 0xff;
|
||
|
||
// I would just keep a list of packets instead of bytes, but it isn't clear in the spec
|
||
// that service blocks will always line up with byte pairs.
|
||
this.current708Packet.ptsVals.push(packet.pts);
|
||
this.current708Packet.data.push(byte0);
|
||
this.current708Packet.data.push(byte1);
|
||
};
|
||
|
||
/**
|
||
* Parse completed 708 packet into service blocks and push each service block.
|
||
*/
|
||
Cea708Stream.prototype.push708Packet = function() {
|
||
var packet708 = this.current708Packet;
|
||
var packetData = packet708.data;
|
||
var serviceNum = null;
|
||
var blockSize = null;
|
||
var i = 0;
|
||
var b = packetData[i++];
|
||
|
||
packet708.seq = b >> 6;
|
||
packet708.sizeCode = b & 0x3f; // 0b00111111;
|
||
|
||
for (; i < packetData.length; i++) {
|
||
b = packetData[i++];
|
||
serviceNum = b >> 5;
|
||
blockSize = b & 0x1f; // 0b00011111
|
||
|
||
if (serviceNum === 7 && blockSize > 0) {
|
||
// Extended service num
|
||
b = packetData[i++];
|
||
serviceNum = b;
|
||
}
|
||
|
||
this.pushServiceBlock(serviceNum, i, blockSize);
|
||
|
||
if (blockSize > 0) {
|
||
i += blockSize - 1;
|
||
}
|
||
}
|
||
};
|
||
|
||
/**
|
||
* Parse service block, execute commands, read text.
|
||
*
|
||
* Note: While many of these commands serve important purposes,
|
||
* many others just parse out the parameters or attributes, but
|
||
* nothing is done with them because this is not a full and complete
|
||
* implementation of the entire 708 spec.
|
||
*
|
||
* @param {Integer} serviceNum Service number
|
||
* @param {Integer} start Start index of the 708 packet data
|
||
* @param {Integer} size Block size
|
||
*/
|
||
Cea708Stream.prototype.pushServiceBlock = function(serviceNum, start, size) {
|
||
var b;
|
||
var i = start;
|
||
var packetData = this.current708Packet.data;
|
||
var service = this.services[serviceNum];
|
||
|
||
if (!service) {
|
||
service = this.initService(serviceNum, i);
|
||
}
|
||
|
||
for (; i < start + size && i < packetData.length; i++) {
|
||
b = packetData[i];
|
||
|
||
if (within708TextBlock(b)) {
|
||
i = this.handleText(i, service);
|
||
} else if (b === 0x18) {
|
||
i = this.multiByteCharacter(i, service);
|
||
} else if (b === 0x10) {
|
||
i = this.extendedCommands(i, service);
|
||
} else if (0x80 <= b && b <= 0x87) {
|
||
i = this.setCurrentWindow(i, service);
|
||
} else if (0x98 <= b && b <= 0x9f) {
|
||
i = this.defineWindow(i, service);
|
||
} else if (b === 0x88) {
|
||
i = this.clearWindows(i, service);
|
||
} else if (b === 0x8c) {
|
||
i = this.deleteWindows(i, service);
|
||
} else if (b === 0x89) {
|
||
i = this.displayWindows(i, service);
|
||
} else if (b === 0x8a) {
|
||
i = this.hideWindows(i, service);
|
||
} else if (b === 0x8b) {
|
||
i = this.toggleWindows(i, service);
|
||
} else if (b === 0x97) {
|
||
i = this.setWindowAttributes(i, service);
|
||
} else if (b === 0x90) {
|
||
i = this.setPenAttributes(i, service);
|
||
} else if (b === 0x91) {
|
||
i = this.setPenColor(i, service);
|
||
} else if (b === 0x92) {
|
||
i = this.setPenLocation(i, service);
|
||
} else if (b === 0x8f) {
|
||
service = this.reset(i, service);
|
||
} else if (b === 0x08) {
|
||
// BS: Backspace
|
||
service.currentWindow.backspace();
|
||
} else if (b === 0x0c) {
|
||
// FF: Form feed
|
||
service.currentWindow.clearText();
|
||
} else if (b === 0x0d) {
|
||
// CR: Carriage return
|
||
service.currentWindow.pendingNewLine = true;
|
||
} else if (b === 0x0e) {
|
||
// HCR: Horizontal carriage return
|
||
service.currentWindow.clearText();
|
||
} else if (b === 0x8d) {
|
||
// DLY: Delay, nothing to do
|
||
i++;
|
||
} else if (b === 0x8e) {
|
||
// DLC: Delay cancel, nothing to do
|
||
} else if (b === 0x03) {
|
||
// ETX: End Text, don't need to do anything
|
||
} else if (b === 0x00) {
|
||
// Padding
|
||
} else {
|
||
// Unknown command
|
||
}
|
||
}
|
||
};
|
||
|
||
/**
|
||
* Execute an extended command
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.extendedCommands = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[++i];
|
||
if (within708TextBlock(b)) {
|
||
i = this.handleText(i, service, {isExtended: true});
|
||
} else {
|
||
// Unknown command
|
||
}
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Get PTS value of a given byte index
|
||
*
|
||
* @param {Integer} byteIndex Index of the byte
|
||
* @return {Integer} PTS
|
||
*/
|
||
Cea708Stream.prototype.getPts = function(byteIndex) {
|
||
// There's 1 pts value per 2 bytes
|
||
return this.current708Packet.ptsVals[Math.floor(byteIndex / 2)];
|
||
};
|
||
|
||
/**
|
||
* Initializes a service
|
||
*
|
||
* @param {Integer} serviceNum Service number
|
||
* @return {Service} Initialized service object
|
||
*/
|
||
Cea708Stream.prototype.initService = function(serviceNum, i) {
|
||
var serviceName = 'SERVICE' + serviceNum;
|
||
var self = this;
|
||
var serviceName;
|
||
var encoding;
|
||
|
||
if (serviceName in this.serviceEncodings) {
|
||
encoding = this.serviceEncodings[serviceName];
|
||
}
|
||
|
||
this.services[serviceNum] = new Cea708Service(serviceNum, encoding, self);
|
||
this.services[serviceNum].init(this.getPts(i), function(pts) {
|
||
self.flushDisplayed(pts, self.services[serviceNum]);
|
||
});
|
||
|
||
return this.services[serviceNum];
|
||
};
|
||
|
||
/**
|
||
* Execute text writing to current window
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.handleText = function(i, service, options) {
|
||
var isExtended = options && options.isExtended;
|
||
var isMultiByte = options && options.isMultiByte;
|
||
var packetData = this.current708Packet.data;
|
||
var extended = isExtended ? 0x1000 : 0x0000;
|
||
var currentByte = packetData[i];
|
||
var nextByte = packetData[i + 1];
|
||
var win = service.currentWindow;
|
||
var char;
|
||
var charCodeArray;
|
||
|
||
// Converts an array of bytes to a unicode hex string.
|
||
function toHexString(byteArray) {
|
||
return byteArray.map((byte) => {
|
||
return ('0' + (byte & 0xFF).toString(16)).slice(-2);
|
||
}).join('');
|
||
};
|
||
|
||
if (isMultiByte) {
|
||
charCodeArray = [currentByte, nextByte];
|
||
i++;
|
||
} else {
|
||
charCodeArray = [currentByte];
|
||
}
|
||
|
||
// Use the TextDecoder if one was created for this service
|
||
if (service.textDecoder_ && !isExtended) {
|
||
char = service.textDecoder_.decode(new Uint8Array(charCodeArray));
|
||
} else {
|
||
// We assume any multi-byte char without a decoder is unicode.
|
||
if (isMultiByte) {
|
||
const unicode = toHexString(charCodeArray);
|
||
// Takes a unicode hex string and creates a single character.
|
||
char = String.fromCharCode(parseInt(unicode, 16));
|
||
} else {
|
||
char = get708CharFromCode(extended | currentByte);
|
||
}
|
||
}
|
||
|
||
if (win.pendingNewLine && !win.isEmpty()) {
|
||
win.newLine(this.getPts(i));
|
||
}
|
||
|
||
win.pendingNewLine = false;
|
||
win.addText(char);
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Handle decoding of multibyte character
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.multiByteCharacter = function (i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var firstByte = packetData[i + 1];
|
||
var secondByte = packetData[i + 2];
|
||
|
||
if (within708TextBlock(firstByte) && within708TextBlock(secondByte)) {
|
||
i = this.handleText(++i, service, {isMultiByte: true});
|
||
} else {
|
||
// Unknown command
|
||
}
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the CW# command.
|
||
*
|
||
* Set the current window.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.setCurrentWindow = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[i];
|
||
var windowNum = b & 0x07;
|
||
|
||
service.setCurrentWindow(windowNum);
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the DF# command.
|
||
*
|
||
* Define a window and set it as the current window.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.defineWindow = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[i];
|
||
var windowNum = b & 0x07;
|
||
service.setCurrentWindow(windowNum);
|
||
var win = service.currentWindow;
|
||
|
||
b = packetData[++i];
|
||
win.visible = (b & 0x20) >> 5; // v
|
||
win.rowLock = (b & 0x10) >> 4; // rl
|
||
win.columnLock = (b & 0x08) >> 3; // cl
|
||
win.priority = b & 0x07; // p
|
||
|
||
b = packetData[++i];
|
||
win.relativePositioning = (b & 0x80) >> 7; // rp
|
||
win.anchorVertical = b & 0x7f; // av
|
||
|
||
b = packetData[++i];
|
||
win.anchorHorizontal = b; // ah
|
||
|
||
b = packetData[++i];
|
||
win.anchorPoint = (b & 0xf0) >> 4; // ap
|
||
win.rowCount = b & 0x0f; // rc
|
||
|
||
b = packetData[++i];
|
||
win.columnCount = b & 0x3f; // cc
|
||
|
||
b = packetData[++i];
|
||
win.windowStyle = (b & 0x38) >> 3; // ws
|
||
win.penStyle = b & 0x07; // ps
|
||
|
||
// The spec says there are (rowCount+1) "virtual rows"
|
||
win.virtualRowCount = win.rowCount + 1;
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the SWA command.
|
||
*
|
||
* Set attributes of the current window.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.setWindowAttributes = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[i];
|
||
var winAttr = service.currentWindow.winAttr;
|
||
|
||
b = packetData[++i];
|
||
winAttr.fillOpacity = (b & 0xc0) >> 6; // fo
|
||
winAttr.fillRed = (b & 0x30) >> 4; // fr
|
||
winAttr.fillGreen = (b & 0x0c) >> 2; // fg
|
||
winAttr.fillBlue = b & 0x03; // fb
|
||
|
||
b = packetData[++i];
|
||
winAttr.borderType = (b & 0xc0) >> 6; // bt
|
||
winAttr.borderRed = (b & 0x30) >> 4; // br
|
||
winAttr.borderGreen = (b & 0x0c) >> 2; // bg
|
||
winAttr.borderBlue = b & 0x03; // bb
|
||
|
||
b = packetData[++i];
|
||
winAttr.borderType += (b & 0x80) >> 5; // bt
|
||
winAttr.wordWrap = (b & 0x40) >> 6; // ww
|
||
winAttr.printDirection = (b & 0x30) >> 4; // pd
|
||
winAttr.scrollDirection = (b & 0x0c) >> 2; // sd
|
||
winAttr.justify = b & 0x03; // j
|
||
|
||
b = packetData[++i];
|
||
winAttr.effectSpeed = (b & 0xf0) >> 4; // es
|
||
winAttr.effectDirection = (b & 0x0c) >> 2; // ed
|
||
winAttr.displayEffect = b & 0x03; // de
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Gather text from all displayed windows and push a caption to output.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
*/
|
||
Cea708Stream.prototype.flushDisplayed = function(pts, service) {
|
||
var displayedText = [];
|
||
|
||
// TODO: Positioning not supported, displaying multiple windows will not necessarily
|
||
// display text in the correct order, but sample files so far have not shown any issue.
|
||
for (var winId = 0; winId < 8; winId++) {
|
||
if (service.windows[winId].visible && !service.windows[winId].isEmpty()) {
|
||
displayedText.push(service.windows[winId].getText());
|
||
}
|
||
}
|
||
|
||
service.endPts = pts;
|
||
service.text = displayedText.join('\n\n');
|
||
this.pushCaption(service);
|
||
|
||
service.startPts = pts;
|
||
};
|
||
|
||
/**
|
||
* Push a caption to output if the caption contains text.
|
||
*
|
||
* @param {Service} service The service object to be affected
|
||
*/
|
||
Cea708Stream.prototype.pushCaption = function(service) {
|
||
if (service.text !== '') {
|
||
this.trigger('data', {
|
||
startPts: service.startPts,
|
||
endPts: service.endPts,
|
||
text: service.text,
|
||
stream: 'cc708_' + service.serviceNum
|
||
});
|
||
|
||
service.text = '';
|
||
service.startPts = service.endPts;
|
||
}
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the DSW command.
|
||
*
|
||
* Set visible property of windows based on the parsed bitmask.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.displayWindows = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[++i];
|
||
var pts = this.getPts(i);
|
||
|
||
this.flushDisplayed(pts, service);
|
||
|
||
for (var winId = 0; winId < 8; winId++) {
|
||
if (b & (0x01 << winId)) {
|
||
service.windows[winId].visible = 1;
|
||
}
|
||
}
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the HDW command.
|
||
*
|
||
* Set visible property of windows based on the parsed bitmask.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.hideWindows = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[++i];
|
||
var pts = this.getPts(i);
|
||
|
||
this.flushDisplayed(pts, service);
|
||
|
||
for (var winId = 0; winId < 8; winId++) {
|
||
if (b & (0x01 << winId)) {
|
||
service.windows[winId].visible = 0;
|
||
}
|
||
}
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the TGW command.
|
||
*
|
||
* Set visible property of windows based on the parsed bitmask.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.toggleWindows = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[++i];
|
||
var pts = this.getPts(i);
|
||
|
||
this.flushDisplayed(pts, service);
|
||
|
||
for (var winId = 0; winId < 8; winId++) {
|
||
if (b & (0x01 << winId)) {
|
||
service.windows[winId].visible ^= 1;
|
||
}
|
||
}
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the CLW command.
|
||
*
|
||
* Clear text of windows based on the parsed bitmask.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.clearWindows = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[++i];
|
||
var pts = this.getPts(i);
|
||
|
||
this.flushDisplayed(pts, service);
|
||
|
||
for (var winId = 0; winId < 8; winId++) {
|
||
if (b & (0x01 << winId)) {
|
||
service.windows[winId].clearText();
|
||
}
|
||
}
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the DLW command.
|
||
*
|
||
* Re-initialize windows based on the parsed bitmask.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.deleteWindows = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[++i];
|
||
var pts = this.getPts(i);
|
||
|
||
this.flushDisplayed(pts, service);
|
||
|
||
for (var winId = 0; winId < 8; winId++) {
|
||
if (b & (0x01 << winId)) {
|
||
service.windows[winId].reset();
|
||
}
|
||
}
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the SPA command.
|
||
*
|
||
* Set pen attributes of the current window.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.setPenAttributes = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[i];
|
||
var penAttr = service.currentWindow.penAttr;
|
||
|
||
b = packetData[++i];
|
||
penAttr.textTag = (b & 0xf0) >> 4; // tt
|
||
penAttr.offset = (b & 0x0c) >> 2; // o
|
||
penAttr.penSize = b & 0x03; // s
|
||
|
||
b = packetData[++i];
|
||
penAttr.italics = (b & 0x80) >> 7; // i
|
||
penAttr.underline = (b & 0x40) >> 6; // u
|
||
penAttr.edgeType = (b & 0x38) >> 3; // et
|
||
penAttr.fontStyle = b & 0x07; // fs
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the SPC command.
|
||
*
|
||
* Set pen color of the current window.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.setPenColor = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[i];
|
||
var penColor = service.currentWindow.penColor;
|
||
|
||
b = packetData[++i];
|
||
penColor.fgOpacity = (b & 0xc0) >> 6; // fo
|
||
penColor.fgRed = (b & 0x30) >> 4; // fr
|
||
penColor.fgGreen = (b & 0x0c) >> 2; // fg
|
||
penColor.fgBlue = b & 0x03; // fb
|
||
|
||
b = packetData[++i];
|
||
penColor.bgOpacity = (b & 0xc0) >> 6; // bo
|
||
penColor.bgRed = (b & 0x30) >> 4; // br
|
||
penColor.bgGreen = (b & 0x0c) >> 2; // bg
|
||
penColor.bgBlue = b & 0x03; // bb
|
||
|
||
b = packetData[++i];
|
||
penColor.edgeRed = (b & 0x30) >> 4; // er
|
||
penColor.edgeGreen = (b & 0x0c) >> 2; // eg
|
||
penColor.edgeBlue = b & 0x03; // eb
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Parse and execute the SPL command.
|
||
*
|
||
* Set pen location of the current window.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Integer} New index after parsing
|
||
*/
|
||
Cea708Stream.prototype.setPenLocation = function(i, service) {
|
||
var packetData = this.current708Packet.data;
|
||
var b = packetData[i];
|
||
var penLoc = service.currentWindow.penLoc;
|
||
|
||
// Positioning isn't really supported at the moment, so this essentially just inserts a linebreak
|
||
service.currentWindow.pendingNewLine = true;
|
||
|
||
b = packetData[++i];
|
||
penLoc.row = b & 0x0f; // r
|
||
|
||
b = packetData[++i];
|
||
penLoc.column = b & 0x3f; // c
|
||
|
||
return i;
|
||
};
|
||
|
||
/**
|
||
* Execute the RST command.
|
||
*
|
||
* Reset service to a clean slate. Re-initialize.
|
||
*
|
||
* @param {Integer} i Current index in the 708 packet
|
||
* @param {Service} service The service object to be affected
|
||
* @return {Service} Re-initialized service
|
||
*/
|
||
Cea708Stream.prototype.reset = function(i, service) {
|
||
var pts = this.getPts(i);
|
||
|
||
this.flushDisplayed(pts, service);
|
||
|
||
return this.initService(service.serviceNum, i);
|
||
};
|
||
|
||
|
||
// This hash maps non-ASCII, special, and extended character codes to their
|
||
// proper Unicode equivalent. The first keys that are only a single byte
|
||
// are the non-standard ASCII characters, which simply map the CEA608 byte
|
||
// to the standard ASCII/Unicode. The two-byte keys that follow are the CEA608
|
||
// character codes, but have their MSB bitmasked with 0x03 so that a lookup
|
||
// can be performed regardless of the field and data channel on which the
|
||
// character code was received.
|
||
var CHARACTER_TRANSLATION = {
|
||
0x2a: 0xe1, // á
|
||
0x5c: 0xe9, // é
|
||
0x5e: 0xed, // í
|
||
0x5f: 0xf3, // ó
|
||
0x60: 0xfa, // ú
|
||
0x7b: 0xe7, // ç
|
||
0x7c: 0xf7, // ÷
|
||
0x7d: 0xd1, // Ñ
|
||
0x7e: 0xf1, // ñ
|
||
0x7f: 0x2588, // █
|
||
0x0130: 0xae, // ®
|
||
0x0131: 0xb0, // °
|
||
0x0132: 0xbd, // ½
|
||
0x0133: 0xbf, // ¿
|
||
0x0134: 0x2122, // ™
|
||
0x0135: 0xa2, // ¢
|
||
0x0136: 0xa3, // £
|
||
0x0137: 0x266a, // ♪
|
||
0x0138: 0xe0, // à
|
||
0x0139: 0xa0, //
|
||
0x013a: 0xe8, // è
|
||
0x013b: 0xe2, // â
|
||
0x013c: 0xea, // ê
|
||
0x013d: 0xee, // î
|
||
0x013e: 0xf4, // ô
|
||
0x013f: 0xfb, // û
|
||
0x0220: 0xc1, // Á
|
||
0x0221: 0xc9, // É
|
||
0x0222: 0xd3, // Ó
|
||
0x0223: 0xda, // Ú
|
||
0x0224: 0xdc, // Ü
|
||
0x0225: 0xfc, // ü
|
||
0x0226: 0x2018, // ‘
|
||
0x0227: 0xa1, // ¡
|
||
0x0228: 0x2a, // *
|
||
0x0229: 0x27, // '
|
||
0x022a: 0x2014, // —
|
||
0x022b: 0xa9, // ©
|
||
0x022c: 0x2120, // ℠
|
||
0x022d: 0x2022, // •
|
||
0x022e: 0x201c, // “
|
||
0x022f: 0x201d, // ”
|
||
0x0230: 0xc0, // À
|
||
0x0231: 0xc2, // Â
|
||
0x0232: 0xc7, // Ç
|
||
0x0233: 0xc8, // È
|
||
0x0234: 0xca, // Ê
|
||
0x0235: 0xcb, // Ë
|
||
0x0236: 0xeb, // ë
|
||
0x0237: 0xce, // Î
|
||
0x0238: 0xcf, // Ï
|
||
0x0239: 0xef, // ï
|
||
0x023a: 0xd4, // Ô
|
||
0x023b: 0xd9, // Ù
|
||
0x023c: 0xf9, // ù
|
||
0x023d: 0xdb, // Û
|
||
0x023e: 0xab, // «
|
||
0x023f: 0xbb, // »
|
||
0x0320: 0xc3, // Ã
|
||
0x0321: 0xe3, // ã
|
||
0x0322: 0xcd, // Í
|
||
0x0323: 0xcc, // Ì
|
||
0x0324: 0xec, // ì
|
||
0x0325: 0xd2, // Ò
|
||
0x0326: 0xf2, // ò
|
||
0x0327: 0xd5, // Õ
|
||
0x0328: 0xf5, // õ
|
||
0x0329: 0x7b, // {
|
||
0x032a: 0x7d, // }
|
||
0x032b: 0x5c, // \
|
||
0x032c: 0x5e, // ^
|
||
0x032d: 0x5f, // _
|
||
0x032e: 0x7c, // |
|
||
0x032f: 0x7e, // ~
|
||
0x0330: 0xc4, // Ä
|
||
0x0331: 0xe4, // ä
|
||
0x0332: 0xd6, // Ö
|
||
0x0333: 0xf6, // ö
|
||
0x0334: 0xdf, // ß
|
||
0x0335: 0xa5, // ¥
|
||
0x0336: 0xa4, // ¤
|
||
0x0337: 0x2502, // │
|
||
0x0338: 0xc5, // Å
|
||
0x0339: 0xe5, // å
|
||
0x033a: 0xd8, // Ø
|
||
0x033b: 0xf8, // ø
|
||
0x033c: 0x250c, // ┌
|
||
0x033d: 0x2510, // ┐
|
||
0x033e: 0x2514, // └
|
||
0x033f: 0x2518 // ┘
|
||
};
|
||
|
||
var getCharFromCode = function(code) {
|
||
if (code === null) {
|
||
return '';
|
||
}
|
||
code = CHARACTER_TRANSLATION[code] || code;
|
||
return String.fromCharCode(code);
|
||
};
|
||
|
||
// the index of the last row in a CEA-608 display buffer
|
||
var BOTTOM_ROW = 14;
|
||
|
||
// This array is used for mapping PACs -> row #, since there's no way of
|
||
// getting it through bit logic.
|
||
var ROWS = [0x1100, 0x1120, 0x1200, 0x1220, 0x1500, 0x1520, 0x1600, 0x1620,
|
||
0x1700, 0x1720, 0x1000, 0x1300, 0x1320, 0x1400, 0x1420];
|
||
|
||
// CEA-608 captions are rendered onto a 34x15 matrix of character
|
||
// cells. The "bottom" row is the last element in the outer array.
|
||
// We keep track of positioning information as we go by storing the
|
||
// number of indentations and the tab offset in this buffer.
|
||
var createDisplayBuffer = function() {
|
||
var result = [], i = BOTTOM_ROW + 1;
|
||
while (i--) {
|
||
result.push({ text: '', indent: 0, offset: 0 });
|
||
}
|
||
return result;
|
||
};
|
||
|
||
var Cea608Stream = function(field, dataChannel) {
|
||
Cea608Stream.prototype.init.call(this);
|
||
|
||
this.field_ = field || 0;
|
||
this.dataChannel_ = dataChannel || 0;
|
||
|
||
this.name_ = 'CC' + (((this.field_ << 1) | this.dataChannel_) + 1);
|
||
|
||
this.setConstants();
|
||
this.reset();
|
||
|
||
this.push = function(packet) {
|
||
var data, swap, char0, char1, text;
|
||
// remove the parity bits
|
||
data = packet.ccData & 0x7f7f;
|
||
|
||
// ignore duplicate control codes; the spec demands they're sent twice
|
||
if (data === this.lastControlCode_) {
|
||
this.lastControlCode_ = null;
|
||
return;
|
||
}
|
||
|
||
// Store control codes
|
||
if ((data & 0xf000) === 0x1000) {
|
||
this.lastControlCode_ = data;
|
||
} else if (data !== this.PADDING_) {
|
||
this.lastControlCode_ = null;
|
||
}
|
||
|
||
char0 = data >>> 8;
|
||
char1 = data & 0xff;
|
||
|
||
if (data === this.PADDING_) {
|
||
return;
|
||
|
||
} else if (data === this.RESUME_CAPTION_LOADING_) {
|
||
this.mode_ = 'popOn';
|
||
|
||
} else if (data === this.END_OF_CAPTION_) {
|
||
// If an EOC is received while in paint-on mode, the displayed caption
|
||
// text should be swapped to non-displayed memory as if it was a pop-on
|
||
// caption. Because of that, we should explicitly switch back to pop-on
|
||
// mode
|
||
this.mode_ = 'popOn';
|
||
this.clearFormatting(packet.pts);
|
||
// if a caption was being displayed, it's gone now
|
||
this.flushDisplayed(packet.pts);
|
||
|
||
// flip memory
|
||
swap = this.displayed_;
|
||
this.displayed_ = this.nonDisplayed_;
|
||
this.nonDisplayed_ = swap;
|
||
|
||
// start measuring the time to display the caption
|
||
this.startPts_ = packet.pts;
|
||
|
||
} else if (data === this.ROLL_UP_2_ROWS_) {
|
||
this.rollUpRows_ = 2;
|
||
this.setRollUp(packet.pts);
|
||
} else if (data === this.ROLL_UP_3_ROWS_) {
|
||
this.rollUpRows_ = 3;
|
||
this.setRollUp(packet.pts);
|
||
} else if (data === this.ROLL_UP_4_ROWS_) {
|
||
this.rollUpRows_ = 4;
|
||
this.setRollUp(packet.pts);
|
||
} else if (data === this.CARRIAGE_RETURN_) {
|
||
this.clearFormatting(packet.pts);
|
||
this.flushDisplayed(packet.pts);
|
||
this.shiftRowsUp_();
|
||
this.startPts_ = packet.pts;
|
||
|
||
} else if (data === this.BACKSPACE_) {
|
||
if (this.mode_ === 'popOn') {
|
||
this.nonDisplayed_[this.row_].text = this.nonDisplayed_[this.row_].text.slice(0, -1);
|
||
} else {
|
||
this.displayed_[this.row_].text = this.displayed_[this.row_].text.slice(0, -1);
|
||
}
|
||
} else if (data === this.ERASE_DISPLAYED_MEMORY_) {
|
||
this.flushDisplayed(packet.pts);
|
||
this.displayed_ = createDisplayBuffer();
|
||
} else if (data === this.ERASE_NON_DISPLAYED_MEMORY_) {
|
||
this.nonDisplayed_ = createDisplayBuffer();
|
||
|
||
} else if (data === this.RESUME_DIRECT_CAPTIONING_) {
|
||
if (this.mode_ !== 'paintOn') {
|
||
// NOTE: This should be removed when proper caption positioning is
|
||
// implemented
|
||
this.flushDisplayed(packet.pts);
|
||
this.displayed_ = createDisplayBuffer();
|
||
}
|
||
this.mode_ = 'paintOn';
|
||
this.startPts_ = packet.pts;
|
||
|
||
// Append special characters to caption text
|
||
} else if (this.isSpecialCharacter(char0, char1)) {
|
||
// Bitmask char0 so that we can apply character transformations
|
||
// regardless of field and data channel.
|
||
// Then byte-shift to the left and OR with char1 so we can pass the
|
||
// entire character code to `getCharFromCode`.
|
||
char0 = (char0 & 0x03) << 8;
|
||
text = getCharFromCode(char0 | char1);
|
||
this[this.mode_](packet.pts, text);
|
||
this.column_++;
|
||
|
||
// Append extended characters to caption text
|
||
} else if (this.isExtCharacter(char0, char1)) {
|
||
// Extended characters always follow their "non-extended" equivalents.
|
||
// IE if a "è" is desired, you'll always receive "eè"; non-compliant
|
||
// decoders are supposed to drop the "è", while compliant decoders
|
||
// backspace the "e" and insert "è".
|
||
|
||
// Delete the previous character
|
||
if (this.mode_ === 'popOn') {
|
||
this.nonDisplayed_[this.row_].text = this.nonDisplayed_[this.row_].text.slice(0, -1);
|
||
} else {
|
||
this.displayed_[this.row_].text = this.displayed_[this.row_].text.slice(0, -1);
|
||
}
|
||
|
||
// Bitmask char0 so that we can apply character transformations
|
||
// regardless of field and data channel.
|
||
// Then byte-shift to the left and OR with char1 so we can pass the
|
||
// entire character code to `getCharFromCode`.
|
||
char0 = (char0 & 0x03) << 8;
|
||
text = getCharFromCode(char0 | char1);
|
||
this[this.mode_](packet.pts, text);
|
||
this.column_++;
|
||
|
||
// Process mid-row codes
|
||
} else if (this.isMidRowCode(char0, char1)) {
|
||
// Attributes are not additive, so clear all formatting
|
||
this.clearFormatting(packet.pts);
|
||
|
||
// According to the standard, mid-row codes
|
||
// should be replaced with spaces, so add one now
|
||
this[this.mode_](packet.pts, ' ');
|
||
this.column_++;
|
||
|
||
if ((char1 & 0xe) === 0xe) {
|
||
this.addFormatting(packet.pts, ['i']);
|
||
}
|
||
|
||
if ((char1 & 0x1) === 0x1) {
|
||
this.addFormatting(packet.pts, ['u']);
|
||
}
|
||
|
||
// Detect offset control codes and adjust cursor
|
||
} else if (this.isOffsetControlCode(char0, char1)) {
|
||
// Cursor position is set by indent PAC (see below) in 4-column
|
||
// increments, with an additional offset code of 1-3 to reach any
|
||
// of the 32 columns specified by CEA-608. So all we need to do
|
||
// here is increment the column cursor by the given offset.
|
||
const offset = (char1 & 0x03);
|
||
|
||
// For an offest value 1-3, set the offset for that caption
|
||
// in the non-displayed array.
|
||
this.nonDisplayed_[this.row_].offset = offset;
|
||
|
||
this.column_ += offset;
|
||
|
||
// Detect PACs (Preamble Address Codes)
|
||
} else if (this.isPAC(char0, char1)) {
|
||
|
||
// There's no logic for PAC -> row mapping, so we have to just
|
||
// find the row code in an array and use its index :(
|
||
var row = ROWS.indexOf(data & 0x1f20);
|
||
|
||
// Configure the caption window if we're in roll-up mode
|
||
if (this.mode_ === 'rollUp') {
|
||
// This implies that the base row is incorrectly set.
|
||
// As per the recommendation in CEA-608(Base Row Implementation), defer to the number
|
||
// of roll-up rows set.
|
||
if (row - this.rollUpRows_ + 1 < 0) {
|
||
row = this.rollUpRows_ - 1;
|
||
}
|
||
|
||
this.setRollUp(packet.pts, row);
|
||
}
|
||
|
||
// Ensure the row is between 0 and 14, otherwise use the most
|
||
// recent or default row.
|
||
if (row !== this.row_ && row >= 0 && row <= 14) {
|
||
// formatting is only persistent for current row
|
||
this.clearFormatting(packet.pts);
|
||
this.row_ = row;
|
||
}
|
||
// All PACs can apply underline, so detect and apply
|
||
// (All odd-numbered second bytes set underline)
|
||
if ((char1 & 0x1) && (this.formatting_.indexOf('u') === -1)) {
|
||
this.addFormatting(packet.pts, ['u']);
|
||
}
|
||
|
||
if ((data & 0x10) === 0x10) {
|
||
// We've got an indent level code. Each successive even number
|
||
// increments the column cursor by 4, so we can get the desired
|
||
// column position by bit-shifting to the right (to get n/2)
|
||
// and multiplying by 4.
|
||
const indentations = ((data & 0xe) >> 1);
|
||
|
||
this.column_ = indentations * 4;
|
||
// add to the number of indentations for positioning
|
||
this.nonDisplayed_[this.row_].indent += indentations;
|
||
}
|
||
|
||
if (this.isColorPAC(char1)) {
|
||
// it's a color code, though we only support white, which
|
||
// can be either normal or italicized. white italics can be
|
||
// either 0x4e or 0x6e depending on the row, so we just
|
||
// bitwise-and with 0xe to see if italics should be turned on
|
||
if ((char1 & 0xe) === 0xe) {
|
||
this.addFormatting(packet.pts, ['i']);
|
||
}
|
||
}
|
||
|
||
// We have a normal character in char0, and possibly one in char1
|
||
} else if (this.isNormalChar(char0)) {
|
||
if (char1 === 0x00) {
|
||
char1 = null;
|
||
}
|
||
text = getCharFromCode(char0);
|
||
text += getCharFromCode(char1);
|
||
this[this.mode_](packet.pts, text);
|
||
this.column_ += text.length;
|
||
|
||
} // finish data processing
|
||
|
||
};
|
||
};
|
||
Cea608Stream.prototype = new Stream();
|
||
// Trigger a cue point that captures the current state of the
|
||
// display buffer
|
||
Cea608Stream.prototype.flushDisplayed = function(pts) {
|
||
const logWarning = (index) => {
|
||
this.trigger('log', {
|
||
level: 'warn',
|
||
message: 'Skipping a malformed 608 caption at index ' + index + '.'
|
||
});
|
||
};
|
||
const content = [];
|
||
|
||
this.displayed_.forEach((row, i) => {
|
||
if (row && row.text && row.text.length) {
|
||
|
||
try {
|
||
// remove spaces from the start and end of the string
|
||
row.text = row.text.trim();
|
||
} catch (e) {
|
||
// Ordinarily, this shouldn't happen. However, caption
|
||
// parsing errors should not throw exceptions and
|
||
// break playback.
|
||
logWarning(i);
|
||
}
|
||
// See the below link for more details on the following fields:
|
||
// https://dvcs.w3.org/hg/text-tracks/raw-file/default/608toVTT/608toVTT.html#positioning-in-cea-608
|
||
if (row.text.length) {
|
||
content.push({
|
||
// The text to be displayed in the caption from this specific row, with whitespace removed.
|
||
text: row.text,
|
||
// Value between 1 and 15 representing the PAC row used to calculate line height.
|
||
line: i + 1,
|
||
// A number representing the indent position by percentage (CEA-608 PAC indent code).
|
||
// The value will be a number between 10 and 80. Offset is used to add an aditional
|
||
// value to the position if necessary.
|
||
position: 10 + Math.min(70, row.indent * 10) + (row.offset * 2.5),
|
||
});
|
||
}
|
||
}
|
||
else if (row === undefined || row === null) {
|
||
logWarning(i);
|
||
}
|
||
});
|
||
|
||
if (content.length) {
|
||
this.trigger('data', {
|
||
startPts: this.startPts_,
|
||
endPts: pts,
|
||
content,
|
||
stream: this.name_
|
||
});
|
||
}
|
||
};
|
||
|
||
/**
|
||
* Zero out the data, used for startup and on seek
|
||
*/
|
||
Cea608Stream.prototype.reset = function() {
|
||
this.mode_ = 'popOn';
|
||
// When in roll-up mode, the index of the last row that will
|
||
// actually display captions. If a caption is shifted to a row
|
||
// with a lower index than this, it is cleared from the display
|
||
// buffer
|
||
this.topRow_ = 0;
|
||
this.startPts_ = 0;
|
||
this.displayed_ = createDisplayBuffer();
|
||
this.nonDisplayed_ = createDisplayBuffer();
|
||
this.lastControlCode_ = null;
|
||
|
||
// Track row and column for proper line-breaking and spacing
|
||
this.column_ = 0;
|
||
this.row_ = BOTTOM_ROW;
|
||
this.rollUpRows_ = 2;
|
||
|
||
// This variable holds currently-applied formatting
|
||
this.formatting_ = [];
|
||
};
|
||
|
||
/**
|
||
* Sets up control code and related constants for this instance
|
||
*/
|
||
Cea608Stream.prototype.setConstants = function() {
|
||
// The following attributes have these uses:
|
||
// ext_ : char0 for mid-row codes, and the base for extended
|
||
// chars (ext_+0, ext_+1, and ext_+2 are char0s for
|
||
// extended codes)
|
||
// control_: char0 for control codes, except byte-shifted to the
|
||
// left so that we can do this.control_ | CONTROL_CODE
|
||
// offset_: char0 for tab offset codes
|
||
//
|
||
// It's also worth noting that control codes, and _only_ control codes,
|
||
// differ between field 1 and field2. Field 2 control codes are always
|
||
// their field 1 value plus 1. That's why there's the "| field" on the
|
||
// control value.
|
||
if (this.dataChannel_ === 0) {
|
||
this.BASE_ = 0x10;
|
||
this.EXT_ = 0x11;
|
||
this.CONTROL_ = (0x14 | this.field_) << 8;
|
||
this.OFFSET_ = 0x17;
|
||
} else if (this.dataChannel_ === 1) {
|
||
this.BASE_ = 0x18;
|
||
this.EXT_ = 0x19;
|
||
this.CONTROL_ = (0x1c | this.field_) << 8;
|
||
this.OFFSET_ = 0x1f;
|
||
}
|
||
|
||
// Constants for the LSByte command codes recognized by Cea608Stream. This
|
||
// list is not exhaustive. For a more comprehensive listing and semantics see
|
||
// http://www.gpo.gov/fdsys/pkg/CFR-2010-title47-vol1/pdf/CFR-2010-title47-vol1-sec15-119.pdf
|
||
// Padding
|
||
this.PADDING_ = 0x0000;
|
||
// Pop-on Mode
|
||
this.RESUME_CAPTION_LOADING_ = this.CONTROL_ | 0x20;
|
||
this.END_OF_CAPTION_ = this.CONTROL_ | 0x2f;
|
||
// Roll-up Mode
|
||
this.ROLL_UP_2_ROWS_ = this.CONTROL_ | 0x25;
|
||
this.ROLL_UP_3_ROWS_ = this.CONTROL_ | 0x26;
|
||
this.ROLL_UP_4_ROWS_ = this.CONTROL_ | 0x27;
|
||
this.CARRIAGE_RETURN_ = this.CONTROL_ | 0x2d;
|
||
// paint-on mode
|
||
this.RESUME_DIRECT_CAPTIONING_ = this.CONTROL_ | 0x29;
|
||
// Erasure
|
||
this.BACKSPACE_ = this.CONTROL_ | 0x21;
|
||
this.ERASE_DISPLAYED_MEMORY_ = this.CONTROL_ | 0x2c;
|
||
this.ERASE_NON_DISPLAYED_MEMORY_ = this.CONTROL_ | 0x2e;
|
||
};
|
||
|
||
/**
|
||
* Detects if the 2-byte packet data is a special character
|
||
*
|
||
* Special characters have a second byte in the range 0x30 to 0x3f,
|
||
* with the first byte being 0x11 (for data channel 1) or 0x19 (for
|
||
* data channel 2).
|
||
*
|
||
* @param {Integer} char0 The first byte
|
||
* @param {Integer} char1 The second byte
|
||
* @return {Boolean} Whether the 2 bytes are an special character
|
||
*/
|
||
Cea608Stream.prototype.isSpecialCharacter = function(char0, char1) {
|
||
return (char0 === this.EXT_ && char1 >= 0x30 && char1 <= 0x3f);
|
||
};
|
||
|
||
/**
|
||
* Detects if the 2-byte packet data is an extended character
|
||
*
|
||
* Extended characters have a second byte in the range 0x20 to 0x3f,
|
||
* with the first byte being 0x12 or 0x13 (for data channel 1) or
|
||
* 0x1a or 0x1b (for data channel 2).
|
||
*
|
||
* @param {Integer} char0 The first byte
|
||
* @param {Integer} char1 The second byte
|
||
* @return {Boolean} Whether the 2 bytes are an extended character
|
||
*/
|
||
Cea608Stream.prototype.isExtCharacter = function(char0, char1) {
|
||
return ((char0 === (this.EXT_ + 1) || char0 === (this.EXT_ + 2)) &&
|
||
(char1 >= 0x20 && char1 <= 0x3f));
|
||
};
|
||
|
||
/**
|
||
* Detects if the 2-byte packet is a mid-row code
|
||
*
|
||
* Mid-row codes have a second byte in the range 0x20 to 0x2f, with
|
||
* the first byte being 0x11 (for data channel 1) or 0x19 (for data
|
||
* channel 2).
|
||
*
|
||
* @param {Integer} char0 The first byte
|
||
* @param {Integer} char1 The second byte
|
||
* @return {Boolean} Whether the 2 bytes are a mid-row code
|
||
*/
|
||
Cea608Stream.prototype.isMidRowCode = function(char0, char1) {
|
||
return (char0 === this.EXT_ && (char1 >= 0x20 && char1 <= 0x2f));
|
||
};
|
||
|
||
/**
|
||
* Detects if the 2-byte packet is an offset control code
|
||
*
|
||
* Offset control codes have a second byte in the range 0x21 to 0x23,
|
||
* with the first byte being 0x17 (for data channel 1) or 0x1f (for
|
||
* data channel 2).
|
||
*
|
||
* @param {Integer} char0 The first byte
|
||
* @param {Integer} char1 The second byte
|
||
* @return {Boolean} Whether the 2 bytes are an offset control code
|
||
*/
|
||
Cea608Stream.prototype.isOffsetControlCode = function(char0, char1) {
|
||
return (char0 === this.OFFSET_ && (char1 >= 0x21 && char1 <= 0x23));
|
||
};
|
||
|
||
/**
|
||
* Detects if the 2-byte packet is a Preamble Address Code
|
||
*
|
||
* PACs have a first byte in the range 0x10 to 0x17 (for data channel 1)
|
||
* or 0x18 to 0x1f (for data channel 2), with the second byte in the
|
||
* range 0x40 to 0x7f.
|
||
*
|
||
* @param {Integer} char0 The first byte
|
||
* @param {Integer} char1 The second byte
|
||
* @return {Boolean} Whether the 2 bytes are a PAC
|
||
*/
|
||
Cea608Stream.prototype.isPAC = function(char0, char1) {
|
||
return (char0 >= this.BASE_ && char0 < (this.BASE_ + 8) &&
|
||
(char1 >= 0x40 && char1 <= 0x7f));
|
||
};
|
||
|
||
/**
|
||
* Detects if a packet's second byte is in the range of a PAC color code
|
||
*
|
||
* PAC color codes have the second byte be in the range 0x40 to 0x4f, or
|
||
* 0x60 to 0x6f.
|
||
*
|
||
* @param {Integer} char1 The second byte
|
||
* @return {Boolean} Whether the byte is a color PAC
|
||
*/
|
||
Cea608Stream.prototype.isColorPAC = function(char1) {
|
||
return ((char1 >= 0x40 && char1 <= 0x4f) || (char1 >= 0x60 && char1 <= 0x7f));
|
||
};
|
||
|
||
/**
|
||
* Detects if a single byte is in the range of a normal character
|
||
*
|
||
* Normal text bytes are in the range 0x20 to 0x7f.
|
||
*
|
||
* @param {Integer} char The byte
|
||
* @return {Boolean} Whether the byte is a normal character
|
||
*/
|
||
Cea608Stream.prototype.isNormalChar = function(char) {
|
||
return (char >= 0x20 && char <= 0x7f);
|
||
};
|
||
|
||
/**
|
||
* Configures roll-up
|
||
*
|
||
* @param {Integer} pts Current PTS
|
||
* @param {Integer} newBaseRow Used by PACs to slide the current window to
|
||
* a new position
|
||
*/
|
||
Cea608Stream.prototype.setRollUp = function(pts, newBaseRow) {
|
||
// Reset the base row to the bottom row when switching modes
|
||
if (this.mode_ !== 'rollUp') {
|
||
this.row_ = BOTTOM_ROW;
|
||
this.mode_ = 'rollUp';
|
||
// Spec says to wipe memories when switching to roll-up
|
||
this.flushDisplayed(pts);
|
||
this.nonDisplayed_ = createDisplayBuffer();
|
||
this.displayed_ = createDisplayBuffer();
|
||
}
|
||
|
||
if (newBaseRow !== undefined && newBaseRow !== this.row_) {
|
||
// move currently displayed captions (up or down) to the new base row
|
||
for (var i = 0; i < this.rollUpRows_; i++) {
|
||
this.displayed_[newBaseRow - i] = this.displayed_[this.row_ - i];
|
||
this.displayed_[this.row_ - i] = { text: '', indent: 0, offset: 0 };
|
||
}
|
||
}
|
||
|
||
if (newBaseRow === undefined) {
|
||
newBaseRow = this.row_;
|
||
}
|
||
|
||
this.topRow_ = newBaseRow - this.rollUpRows_ + 1;
|
||
};
|
||
|
||
// Adds the opening HTML tag for the passed character to the caption text,
|
||
// and keeps track of it for later closing
|
||
Cea608Stream.prototype.addFormatting = function(pts, format) {
|
||
this.formatting_ = this.formatting_.concat(format);
|
||
var text = format.reduce(function(text, format) {
|
||
return text + '<' + format + '>';
|
||
}, '');
|
||
this[this.mode_](pts, text);
|
||
};
|
||
|
||
// Adds HTML closing tags for current formatting to caption text and
|
||
// clears remembered formatting
|
||
Cea608Stream.prototype.clearFormatting = function(pts) {
|
||
if (!this.formatting_.length) {
|
||
return;
|
||
}
|
||
var text = this.formatting_.reverse().reduce(function(text, format) {
|
||
return text + '</' + format + '>';
|
||
}, '');
|
||
this.formatting_ = [];
|
||
this[this.mode_](pts, text);
|
||
};
|
||
|
||
// Mode Implementations
|
||
Cea608Stream.prototype.popOn = function(pts, text) {
|
||
var baseRow = this.nonDisplayed_[this.row_].text;
|
||
|
||
// buffer characters
|
||
baseRow += text;
|
||
this.nonDisplayed_[this.row_].text = baseRow;
|
||
};
|
||
|
||
Cea608Stream.prototype.rollUp = function(pts, text) {
|
||
var baseRow = this.displayed_[this.row_].text;
|
||
|
||
baseRow += text;
|
||
this.displayed_[this.row_].text = baseRow;
|
||
|
||
};
|
||
|
||
Cea608Stream.prototype.shiftRowsUp_ = function() {
|
||
var i;
|
||
// clear out inactive rows
|
||
for (i = 0; i < this.topRow_; i++) {
|
||
this.displayed_[i] = { text: '', indent: 0, offset: 0 };
|
||
}
|
||
for (i = this.row_ + 1; i < BOTTOM_ROW + 1; i++) {
|
||
this.displayed_[i] = { text: '', indent: 0, offset: 0 };
|
||
}
|
||
// shift displayed rows up
|
||
for (i = this.topRow_; i < this.row_; i++) {
|
||
this.displayed_[i] = this.displayed_[i + 1];
|
||
}
|
||
// clear out the bottom row
|
||
this.displayed_[this.row_] = { text: '', indent: 0, offset: 0 };
|
||
};
|
||
|
||
Cea608Stream.prototype.paintOn = function(pts, text) {
|
||
var baseRow = this.displayed_[this.row_].text;
|
||
|
||
baseRow += text;
|
||
this.displayed_[this.row_].text = baseRow;
|
||
};
|
||
|
||
// exports
|
||
module.exports = {
|
||
CaptionStream: CaptionStream,
|
||
Cea608Stream: Cea608Stream,
|
||
Cea708Stream: Cea708Stream
|
||
};
|