jiti-meet/modules/simulcast/SimulcastUtils.js

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2015-01-09 15:32:35 +00:00
var SimulcastLogger = require("./SimulcastLogger");
/**
*
* @constructor
*/
function SimulcastUtils() {
this.logger = new SimulcastLogger("SimulcastUtils", 1);
}
/**
*
* @type {{}}
* @private
*/
SimulcastUtils.prototype._emptyCompoundIndex = {};
/**
*
* @param lines
* @param videoSources
* @private
*/
SimulcastUtils.prototype._replaceVideoSources = function (lines, videoSources) {
var i, inVideo = false, index = -1, howMany = 0;
this.logger.info('Replacing video sources...');
for (i = 0; i < lines.length; i++) {
if (inVideo && lines[i].substring(0, 'm='.length) === 'm=') {
// Out of video.
break;
}
if (!inVideo && lines[i].substring(0, 'm=video '.length) === 'm=video ') {
// In video.
inVideo = true;
}
if (inVideo && (lines[i].substring(0, 'a=ssrc:'.length) === 'a=ssrc:'
|| lines[i].substring(0, 'a=ssrc-group:'.length) === 'a=ssrc-group:')) {
if (index === -1) {
index = i;
}
howMany++;
}
}
// efficiency baby ;)
lines.splice.apply(lines,
[index, howMany].concat(videoSources));
};
SimulcastUtils.prototype.isValidDescription = function (desc)
{
return desc && desc != null
&& desc.type && desc.type != ''
&& desc.sdp && desc.sdp != '';
};
SimulcastUtils.prototype._getVideoSources = function (lines) {
var i, inVideo = false, sb = [];
this.logger.info('Getting video sources...');
for (i = 0; i < lines.length; i++) {
if (inVideo && lines[i].substring(0, 'm='.length) === 'm=') {
// Out of video.
break;
}
if (!inVideo && lines[i].substring(0, 'm=video '.length) === 'm=video ') {
// In video.
inVideo = true;
}
if (inVideo && lines[i].substring(0, 'a=ssrc:'.length) === 'a=ssrc:') {
// In SSRC.
sb.push(lines[i]);
}
if (inVideo && lines[i].substring(0, 'a=ssrc-group:'.length) === 'a=ssrc-group:') {
sb.push(lines[i]);
}
}
return sb;
};
SimulcastUtils.prototype.parseMedia = function (lines, mediatypes) {
var i, res = [], type, cur_media, idx, ssrcs, cur_ssrc, ssrc,
ssrc_attribute, group, semantics, skip = true;
this.logger.info('Parsing media sources...');
for (i = 0; i < lines.length; i++) {
if (lines[i].substring(0, 'm='.length) === 'm=') {
type = lines[i]
.substr('m='.length, lines[i].indexOf(' ') - 'm='.length);
skip = mediatypes !== undefined && mediatypes.indexOf(type) === -1;
if (!skip) {
cur_media = {
'type': type,
'sources': {},
'groups': []
};
res.push(cur_media);
}
} else if (!skip && lines[i].substring(0, 'a=ssrc:'.length) === 'a=ssrc:') {
idx = lines[i].indexOf(' ');
ssrc = lines[i].substring('a=ssrc:'.length, idx);
if (cur_media.sources[ssrc] === undefined) {
cur_ssrc = {'ssrc': ssrc};
cur_media.sources[ssrc] = cur_ssrc;
}
ssrc_attribute = lines[i].substr(idx + 1).split(':', 2)[0];
cur_ssrc[ssrc_attribute] = lines[i].substr(idx + 1).split(':', 2)[1];
if (cur_media.base === undefined) {
cur_media.base = cur_ssrc;
}
} else if (!skip && lines[i].substring(0, 'a=ssrc-group:'.length) === 'a=ssrc-group:') {
idx = lines[i].indexOf(' ');
semantics = lines[i].substr(0, idx).substr('a=ssrc-group:'.length);
ssrcs = lines[i].substr(idx).trim().split(' ');
group = {
'semantics': semantics,
'ssrcs': ssrcs
};
cur_media.groups.push(group);
} else if (!skip && (lines[i].substring(0, 'a=sendrecv'.length) === 'a=sendrecv' ||
lines[i].substring(0, 'a=recvonly'.length) === 'a=recvonly' ||
lines[i].substring(0, 'a=sendonly'.length) === 'a=sendonly' ||
lines[i].substring(0, 'a=inactive'.length) === 'a=inactive')) {
cur_media.direction = lines[i].substring('a='.length);
}
}
return res;
};
/**
* The _indexOfArray() method returns the first a CompoundIndex at which a
* given element can be found in the array, or _emptyCompoundIndex if it is
* not present.
*
* Example:
*
* _indexOfArray('3', [ 'this is line 1', 'this is line 2', 'this is line 3' ])
*
* returns {row: 2, column: 14}
*
* @param needle
* @param haystack
* @param start
* @returns {}
* @private
*/
SimulcastUtils.prototype._indexOfArray = function (needle, haystack, start) {
var length = haystack.length, idx, i;
if (!start) {
start = 0;
}
for (i = start; i < length; i++) {
idx = haystack[i].indexOf(needle);
if (idx !== -1) {
return {row: i, column: idx};
}
}
return this._emptyCompoundIndex;
};
SimulcastUtils.prototype._removeSimulcastGroup = function (lines) {
var i;
for (i = lines.length - 1; i >= 0; i--) {
if (lines[i].indexOf('a=ssrc-group:SIM') !== -1) {
lines.splice(i, 1);
}
}
};
SimulcastUtils.prototype._compileVideoSources = function (videoSources) {
var sb = [], ssrc, addedSSRCs = [];
this.logger.info('Compiling video sources...');
// Add the groups
if (videoSources.groups && videoSources.groups.length !== 0) {
videoSources.groups.forEach(function (group) {
if (group.ssrcs && group.ssrcs.length !== 0) {
sb.push([['a=ssrc-group:', group.semantics].join(''), group.ssrcs.join(' ')].join(' '));
// if (group.semantics !== 'SIM') {
group.ssrcs.forEach(function (ssrc) {
addedSSRCs.push(ssrc);
sb.splice.apply(sb, [sb.length, 0].concat([
["a=ssrc:", ssrc, " cname:", videoSources.sources[ssrc].cname].join(''),
["a=ssrc:", ssrc, " msid:", videoSources.sources[ssrc].msid].join('')]));
});
//}
}
});
}
// Then add any free sources.
if (videoSources.sources) {
for (ssrc in videoSources.sources) {
if (addedSSRCs.indexOf(ssrc) === -1) {
sb.splice.apply(sb, [sb.length, 0].concat([
["a=ssrc:", ssrc, " cname:", videoSources.sources[ssrc].cname].join(''),
["a=ssrc:", ssrc, " msid:", videoSources.sources[ssrc].msid].join('')]));
}
}
}
return sb;
};
module.exports = SimulcastUtils;