How to use imsc - 3 common examples
To help you get started, we’ve selected a few imsc examples, based on popular ways it is used in public projects.
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Dash-Industry-Forum / dash.js / src / streaming / text / TextTracks.js View on Github 
function renderCaption(cue) {
if (captionContainer) {
const finalCue = document.createElement('div');
captionContainer.appendChild(finalCue);
previousISDState = renderHTML(cue.isd, finalCue, function (uri) {
const imsc1ImgUrnTester = /^(urn:)(mpeg:[a-z0-9][a-z0-9-]{0,31}:)(subs:)([0-9]+)$/;
const smpteImgUrnTester = /^#(.*)$/;
if (imsc1ImgUrnTester.test(uri)) {
const match = imsc1ImgUrnTester.exec(uri);
const imageId = parseInt(match[4], 10) - 1;
const imageData = btoa(cue.images[imageId]);
const dataUrl = 'data:image/png;base64,' + imageData;
return dataUrl;
} else if (smpteImgUrnTester.test(uri)) {
const match = smpteImgUrnTester.exec(uri);
const imageId = match[1];
const dataUrl = 'data:image/png;base64,' + cue.embeddedImages[imageId];
return dataUrl;
} else {
return null;
}if (currentImageId) {
accumulated_image_data = accumulated_image_data + contents;
}
}
};
if (!data) {
errorMsg = 'no ttml data to parse';
throw new Error(errorMsg);
}
content.data = data;
eventBus.trigger(Events.TTML_TO_PARSE, content);
const imsc1doc = fromXML(content.data, function (msg) {
errorMsg = msg;
}, metadataHandler);
eventBus.trigger(Events.TTML_PARSED, {ttmlString: content.data, ttmlDoc: imsc1doc});
const mediaTimeEvents = imsc1doc.getMediaTimeEvents();
for (i = 0; i < mediaTimeEvents.length; i++) {
let isd = generateISD(imsc1doc, mediaTimeEvents[i], function (error) {
errorMsg = error;
});
if (isd.contents.some(topLevelContents => topLevelContents.contents.length)) {
//be sure that mediaTimeEvents values are in the mp4 segment time ranges.
startTime = (mediaTimeEvents[i] + offsetTime) < startTimeSegment ? startTimeSegment : (mediaTimeEvents[i] + offsetTime);
endTime = (mediaTimeEvents[i + 1] + offsetTime) > endTimeSegment ? endTimeSegment : (mediaTimeEvents[i + 1] + offsetTime);}
content.data = data;
eventBus.trigger(Events.TTML_TO_PARSE, content);
const imsc1doc = fromXML(content.data, function (msg) {
errorMsg = msg;
}, metadataHandler);
eventBus.trigger(Events.TTML_PARSED, {ttmlString: content.data, ttmlDoc: imsc1doc});
const mediaTimeEvents = imsc1doc.getMediaTimeEvents();
for (i = 0; i < mediaTimeEvents.length; i++) {
let isd = generateISD(imsc1doc, mediaTimeEvents[i], function (error) {
errorMsg = error;
});
if (isd.contents.some(topLevelContents => topLevelContents.contents.length)) {
//be sure that mediaTimeEvents values are in the mp4 segment time ranges.
startTime = (mediaTimeEvents[i] + offsetTime) < startTimeSegment ? startTimeSegment : (mediaTimeEvents[i] + offsetTime);
endTime = (mediaTimeEvents[i + 1] + offsetTime) > endTimeSegment ? endTimeSegment : (mediaTimeEvents[i + 1] + offsetTime);
if (startTime < endTime) {
captionArray.push({
start: startTime,
end: endTime,
type: 'html',
cueID: getCueID(),
isd: isd,
images: images,
