/* © 2023 Samuel Bradshaw https://github.com/samuelbradshaw/transcript-tracer-js */ // Global state variables var ttIsInitialized = false; var ttTranscripts; var ttMediaPlayers; var ttActivePlayer; var ttLinkedDataByMediaUrl = {}; // Configuration variables (see README.md) var ttBlockSelector = null; var ttPhraseSelector = null; var ttAlignmentFuzziness = 0; var ttTimeOffset = 0; var ttAutoScroll = null; var ttClickable = false; // Prepare transcripts and media players function loadTranscriptTracer(options=null) { if (document.readyState == 'loading') { // Wait for document to load document.addEventListener('DOMContentLoaded', function() { loadTranscriptTracer(options); }); return; } // Save user-provided options to configuration variables if (options) { if ('blockSelector' in options) ttBlockSelector = options.blockSelector; if ('phraseSelector' in options) ttPhraseSelector = options.phraseSelector; if ('alignmentFuzziness' in options) ttAlignmentFuzziness = options.alignmentFuzziness; if ('timeOffset' in options) ttTimeOffset = options.timeOffset; if ('autoScroll' in options) ttAutoScroll = options.autoScroll; if ('clickable' in options) ttClickable = options.clickable; } // Reset Transcript Tracer to prevent unexpected behavior if loadTranscriptTracer() is called more than once if (ttIsInitialized) { if (ttTranscripts) for (const transcript of ttTranscripts) { unlinkTranscript(transcript); transcript.dataset.ttTranscript = ''; } ttTranscripts = null; ttMediaPlayers = null; ttActivePlayer = null; ttLinkedDataByMediaUrl = {}; document.querySelectorAll('.tt-word, .tt-whitespace').forEach(element => { element.outerHTML = element.innerHTML; }); } // Set a few global state variables ttIsInitialized = true; ttTranscripts = document.getElementsByClassName('tt-transcript'); ttMediaPlayers = document.querySelectorAll('audio, video'); // Prepare transcript for alignment by adding spans and classes for (let t = 0; t < ttTranscripts.length; t++) { var transcript = ttTranscripts[t]; // Skip transcript if it's not linked to any media files if (!transcript.dataset.ttMediaUrls) continue; transcript.dataset.ttTranscript = t; // Loop through text nodes to add spans (tt-word, tt-whitespace) // Method of iterating text nodes thanks to https://stackoverflow.com/a/34700627/1349044 var iter = document.createNodeIterator(transcript, NodeFilter.SHOW_TEXT); var textNode; while (textNode = iter.nextNode()) { const text = textNode.textContent; if (text.replace(/\s/g, '').length != 0) { var spannedText = '' + text.replace(/(\s+)/g, '$1') + ''; spannedText = spannedText.replaceAll('', ''); // Replace text node with spanned text const template = document.createElement('template'); template.innerHTML = spannedText; textNode.parentNode.insertBefore(template.content, textNode); textNode.parentNode.removeChild(textNode); } } } for (const mediaPlayer of ttMediaPlayers) { // Link related transcript(s) linkTranscripts(mediaPlayer); // Add event listener to media player mediaPlayer.addEventListener('play', function(e) { if (ttActivePlayer != e.currentTarget) { if (ttActivePlayer) { ttActivePlayer.pause(); ttActivePlayer.removeEventListener('timeupdate', ttTimeUpdate); } ttActivePlayer = e.currentTarget; if (ttCurrentTranscript) clearHighlightedWords(ttCurrentTranscript); if (ttCurrentEvent) ttCurrentEvent = null; } ttActivePlayer.addEventListener('timeupdate', ttTimeUpdate); var currentTranscript = ttTranscripts[ttLinkedDataByMediaUrl[ttActivePlayer.dataset.ttLinkedMediaUrl].transcriptIndex]; currentTranscript.dataset.ttCurrentMediaUrl = ttActivePlayer.dataset.ttLinkedMediaUrl; }); mediaPlayer.addEventListener('ended', function(e) { if (ttCurrentTranscript) clearHighlightedWords(ttCurrentTranscript); if (ttCurrentEvent) ttCurrentEvent = null; }); } } // Link media player to relevant transcripts function linkTranscripts(mediaPlayer) { var trackElement = mediaPlayer.querySelector('track[kind="metadata"]') var mediaPlayerSourceUrls = []; var mediaPlayerSrc = mediaPlayer.getAttribute('src'); var mediaPlayerSourceElements = mediaPlayer.querySelectorAll('source'); if (mediaPlayerSrc) mediaPlayerSourceUrls.push(mediaPlayerSrc); if (mediaPlayerSourceElements) for (const s of mediaPlayerSourceElements) mediaPlayerSourceUrls.push(s.src); // If there's nothing to link, return if (!trackElement || !trackElement.getAttribute('src') || mediaPlayerSourceUrls.length == 0) return; // Fetch WebVTT content and link related transcripts for (const transcript of ttTranscripts) { for (const mediaUrl of mediaPlayerSourceUrls) { if (transcript.dataset.ttMediaUrls.includes(mediaUrl)) { mediaPlayer.dataset.ttLinkedMediaUrl = mediaUrl; unlinkTranscript(transcript); fetch(trackElement.src) .then(r => r.text()) .then(vttContent => linkTranscript(mediaPlayer, vttContent, transcript)); break; } } } function linkTranscript(mediaPlayer, vttContent, transcript) { var wordTimings = parseVttToWordTimings(vttContent); transcript.dataset.ttCurrentMediaUrl = mediaPlayer.dataset.ttLinkedMediaUrl; function normalizedWord(word) { // Convert to lowercase, normalize, and remove anything that's not a letter or number return word.toLowerCase().normalize('NFD').replace(/[^\p{L}\p{N}]/gu, ''); } // Add metadata to block and phrase containers (if ttBlockSelector and ttPhraseSelector are defined) var blockContainers = ttBlockSelector ? transcript.querySelectorAll(ttBlockSelector) : []; for (let c = 0; c < blockContainers.length; c++) blockContainers[c].dataset.ttBlock = c; var phraseContainers = ttPhraseSelector ? transcript.querySelectorAll(ttPhraseSelector) : []; for (let c = 0; c < phraseContainers.length; c++) phraseContainers[c].dataset.ttPhrase = c; // Add metadata to each word span, and build timed events list var timedEvents = []; var wordTimingsIndex = 0; var wordSpans = transcript.getElementsByClassName('tt-word'); for (let s = 0; s < wordSpans.length; s++) { var span = wordSpans[s]; // Find the next word timing object that matches the current span's text var initialWordTimingsIndex = wordTimingsIndex; var maxFuzzyWordTimingsIndex = Math.min(wordTimingsIndex + ttAlignmentFuzziness, wordTimings.length - 1); while (normalizedWord(span.innerText) != normalizedWord(wordTimings[wordTimingsIndex].text) && wordTimingsIndex <= maxFuzzyWordTimingsIndex) { wordTimingsIndex += 1; } if (normalizedWord(span.innerText) != normalizedWord(wordTimings[wordTimingsIndex].text)) { // Could not find matching word within the fuzziness range wordTimingsIndex = initialWordTimingsIndex; continue; } // Get the block, phrase, and word index blockIndex = ttBlockSelector ? (span.closest(ttBlockSelector)?.dataset?.ttBlock ?? null) : wordTimings[wordTimingsIndex].blockIndex; phraseIndex = ttPhraseSelector ? (span.closest(ttPhraseSelector)?.dataset?.ttPhrase ?? null) : wordTimings[wordTimingsIndex].phraseIndex; wordIndex = wordTimings[wordTimingsIndex].wordIndex; // Add block, phrase, and word index as metadata on the span span.dataset.ttBlock = blockIndex; span.dataset.ttPhrase = phraseIndex; span.dataset.ttWord = wordIndex; // Add timed event to timed events list if (timedEvents.length != 0 && wordTimings[wordTimingsIndex].startSeconds == timedEvents[timedEvents.length-1].seconds) { timedEvents[timedEvents.length-1].currentWordIndexes.push(wordIndex); } else { timedEvents.push({ 'seconds': wordTimings[wordTimingsIndex].startSeconds, 'currentWordIndexes': [wordIndex], 'phraseIndex': phraseIndex, 'blockIndex': blockIndex, }); } wordTimingsIndex += 1; } // For a given element, find the first parent element containing relevant children function findRelevantParent(startingElement, endingElement, childSelector, relevantChildSelector) { var currentElement = startingElement; while (currentElement && currentElement != endingElement) { var currentElement = currentElement.parentElement; var children = currentElement.querySelectorAll(childSelector); var relevantChildren = document.querySelectorAll(relevantChildSelector); if (children.length == relevantChildren.length) { // Relevant parent found return currentElement; } else if (children.length > relevantChildren.length) { // Failed to find a relevant parent break; } } return null; } // Add metadata to block and phrase containers (if ttBlockSelector and ttPhraseSelector aren't defined) if (!ttBlockSelector) { var count = wordTimings[wordTimings.length-1].blockIndex + 1; for (let c = 0; c < count; c++) { var startingElement = document.querySelector(`[data-tt-block="${c}"]`); var blockContainer = findRelevantParent(startingElement, transcript, '[data-tt-word]', `[data-tt-word][data-tt-block="${c}"]`); if (blockContainer) blockContainer.dataset.ttBlock = c; } } if (!ttPhraseSelector) { var count = wordTimings[wordTimings.length-1].phraseIndex + 1; for (let c = 0; c < count; c++) { var startingElement = document.querySelector(`[data-tt-phrase="${c}"]`); var phraseContainer = findRelevantParent(startingElement, transcript, '[data-tt-word]', `[data-tt-word][data-tt-phrase="${c}"]`); if (phraseContainer) phraseContainer.dataset.ttPhrase = c; } } // Sort timed events list by time timedEvents = timedEvents.sort(function(a, b) { return a.seconds - b.seconds; }) // Add reference data to ttLinkedDataByMediaUrl var transcriptIndex = parseInt(transcript.dataset.ttTranscript); ttLinkedDataByMediaUrl[mediaPlayer.dataset.ttLinkedMediaUrl] = { 'transcriptIndex': transcriptIndex, 'wordTimings': wordTimings, 'timedEvents': timedEvents, 'mediaElement': mediaPlayer, 'textTrackData': mediaPlayer.textTracks[0], } // Add click listeners to words if (ttClickable) { for (const word of document.querySelectorAll('.tt-word')) { word.addEventListener('click', handleWordClick); } for (const word of document.querySelectorAll('.tt-word')) { word.addEventListener('dblclick', handleWordDBClick); } } } } // Unlink transcript from previous VTT function unlinkTranscript(transcript) { clearHighlightedWords(transcript); var ttLinkedElements = transcript.querySelectorAll('[data-tt-word]'); for (const element of ttLinkedElements) { element.dataset.ttWord = ''; element.dataset.ttPhrase = ''; element.dataset.ttBlock = ''; } var mediaUrl = transcript.dataset.ttCurrentMediaUrl; if (mediaUrl) { delete ttLinkedDataByMediaUrl[mediaUrl] transcript.dataset.ttCurrentMediaUrl = ''; } for (const word of document.querySelectorAll('.tt-word')) { word.removeEventListener('click', handleWordClick); } for (const word of document.querySelectorAll('.tt-word')) { word.removeEventListener('dblclick', handleWordDBClick); } } // Convert WebVTT into a wordTimings list function parseVttToWordTimings(vttContent) { var wordTimings = []; // Split WebVTT at each double line break var vttSegments = vttContent.split(/\r?\n\r?\n/); if (vttSegments.length == 0 || !vttSegments[0].startsWith('WEBVTT')) { console.error('Error: Invalid VTT file. See https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API'); return; } // Loop through each segment of the WebVTT // WebVTT documentation: https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API var cueWordCounter = 0; var cuePhraseCounter = 0; var cueBlockCounter = 0; for (let s = 0; s < vttSegments.length; s++) { var segment = vttSegments[s]; // Skip segment if it's not a cue if (segment.startsWith('WEBVTT') || /^STYLE\s/.test(segment) || /^NOTE\s/.test(segment)) continue; // Convert VTT timestamps to seconds function convertVttTimestampToSeconds(vttTimestamp) { var parts = vttTimestamp.trim().split(':'); var seconds = 0; if (parts.length == 3) { // 00:02:01.003 seconds = (parseFloat(parts[0]) * 60 * 60) + (parseFloat(parts[1]) * 60) + parseFloat(parts[2]) } else { // 02:01.003 seconds = (parseFloat(parts[0]) * 60) + parseFloat(parts[1]) } return seconds; } // Parse cue var cueIdentifier = cuePayload = ''; var cueStartSeconds = cueEndSeconds = null; var segmentLines = segment.split(/\r?\n/); for (const line of segmentLines) { if (line.includes('-->')) { // Cue timings (single line) cueStartSeconds = wordStartSeconds = convertVttTimestampToSeconds(line.split('-->')[0].trim()); cueEndSeconds = convertVttTimestampToSeconds(line.split('-->')[1].trim()); } else if (cueStartSeconds == null) { // Cue identifier (optional) cueIdentifier += line; } else { // Cue payload (may be multiple lines) var adjustedLine = line.replace(/(<\d*:?\d+:\d+\.\d+>)\s/g, ' $1').replace(/(<\d*:?\d+:\d+\.\d+>)(<\d*:?\d+:\d+\.\d+>)/g, '$1 $2'); cuePayload += adjustedLine; var cueWords = adjustedLine.split(/\s/) for (let word of cueWords) { var matches = Array.from(word.matchAll(/(^<\d*:?\d+:\d+\.\d+>)?(.+$)/g)); if (matches.length == 1 && matches[0][1] != null) { match = matches[0]; wordStartSeconds = convertVttTimestampToSeconds(match[1].replace('<', '').replace('>', '')); word = match[2]; } // Push word to wordTimings list if (word) { wordTimings.push({ 'text': word, 'startSeconds': wordStartSeconds, 'endSeconds': cueEndSeconds, 'wordIndex': cueWordCounter, 'phraseIndex': cuePhraseCounter, 'blockIndex': cueBlockCounter, }) cueWordCounter += 1; } } cuePhraseCounter += 1; } } cueBlockCounter += 1; } return wordTimings; } // Respond to timeupdate event (progress as the audio or video is playing) var ttCurrentTranscript = null; var ttPreviousEvent = null; var ttCurrentEvent = null; var ttNextEvent = null; function ttTimeUpdate(e) { // If the current player isn't active or doesn't have data, return if (!ttActivePlayer || e.currentTarget != ttActivePlayer || !(ttActivePlayer.dataset.ttLinkedMediaUrl in ttLinkedDataByMediaUrl)) return; var adjustedCurrentTime = ttActivePlayer.currentTime + (ttTimeOffset * -1); var ttData = ttLinkedDataByMediaUrl[ttActivePlayer.dataset.ttLinkedMediaUrl]; // Make sure the correct transcript is selected if (!ttCurrentTranscript || ttCurrentTranscript.dataset.ttTranscript != ttData.transcriptIndex) { ttCurrentTranscript = document.querySelector(`[data-tt-transcript="${ttData.transcriptIndex}"]`); } // If before the first event, after the last event, or within the range of the current event, return if (ttCurrentEvent && (ttCurrentEvent.seconds < ttData.timedEvents[0].seconds || ttCurrentEvent.seconds > ttData.timedEvents[ttData.timedEvents.length-1].seconds)) return; if (ttCurrentEvent && ttNextEvent && ttCurrentEvent.seconds <= adjustedCurrentTime && ttNextEvent.seconds > adjustedCurrentTime) return; // Clear words that were highlighted from the previous event clearHighlightedWords(ttCurrentTranscript); // Add highlights for the current event for (let t = 0; t < ttData.timedEvents.length; t++) { if (ttData.timedEvents[t].seconds <= adjustedCurrentTime && (!ttData.timedEvents[t+1] || adjustedCurrentTime < ttData.timedEvents[t+1]?.seconds)) { ttPreviousEvent = ttData.timedEvents[t-1] || null; ttCurrentEvent = ttData.timedEvents[t]; ttNextEvent = ttData.timedEvents[t+1] || null; // Mark blocks if (ttCurrentEvent.blockIndex != null) { var blockElements = ttCurrentTranscript.querySelectorAll(`[data-tt-block="${ttCurrentEvent.blockIndex}"]`); for (let b = 0; b < blockElements.length; b++) blockElements[b].classList.add((b==0 && !blockElements[b].classList.contains('tt-word')) ? 'tt-current-block-container' : 'tt-current-block'); } // Mark phrases if (ttCurrentEvent.phraseIndex != null) { var phraseElements = ttCurrentTranscript.querySelectorAll(`[data-tt-phrase="${ttCurrentEvent.phraseIndex}"]`); for (let p = 0; p < phraseElements.length; p++) phraseElements[p].classList.add((p==0 && !phraseElements[p].classList.contains('tt-word')) ? 'tt-current-phrase-container' : 'tt-current-phrase'); } // Mark words if (ttCurrentEvent.currentWordIndexes.length > 0) { for (const wordIndex of ttCurrentEvent.currentWordIndexes) { var wordElements = ttCurrentTranscript.querySelectorAll(`[data-tt-word="${wordIndex}"]`); for (const wordElement of wordElements) wordElement.classList.add('tt-current-word'); } for (const wordElement of ttCurrentTranscript.getElementsByClassName('tt-word')) { if (wordElement.classList.contains('tt-current-word')) break; wordElement.classList.add('tt-previous-word'); } } // Auto-scroll to the highlighted text if (ttAutoScroll && !ttActivePlayer.paused && ttActivePlayer.duration != 0) { var scrollOptions = { behavior: 'smooth', block: 'center', inline: 'nearest' } if (ttAutoScroll == 'block' && ttPreviousEvent?.blockIndex != ttCurrentEvent.blockIndex) { document.querySelector('.tt-current-block-container').scrollIntoView(scrollOptions); } else if (ttAutoScroll == 'phrase' && ttPreviousEvent?.phraseIndex != ttCurrentEvent.phraseIndex) { document.querySelector('.tt-current-phrase-container').scrollIntoView(scrollOptions); } else if (ttAutoScroll == 'word') { document.querySelector('.tt-current-word').scrollIntoView(scrollOptions); } } break; } } } // Clear highlighted words in transcript function clearHighlightedWords(transcript) { if (!transcript) return; var ttHighlightedElements = transcript.querySelectorAll('[class*="tt-current"], [class*="tt-previous"]'); for (const element of ttHighlightedElements) { element.classList.remove('tt-current-block', 'tt-current-block-container', 'tt-current-phrase', 'tt-current-phrase-container', 'tt-current-word', 'tt-previous-word'); } } // Handle when a word in the transcript with an event listener is clicked function handleWordClick(e) { var wordElement = e.currentTarget; var wordIndex = wordElement.dataset.ttWord; var transcript = wordElement.closest('.tt-transcript'); var mediaUrl = transcript.dataset.ttCurrentMediaUrl; var startSeconds = ttLinkedDataByMediaUrl[mediaUrl].wordTimings[wordIndex].startSeconds ttLinkedDataByMediaUrl[mediaUrl].mediaElement.currentTime = startSeconds; var ttData = ttLinkedDataByMediaUrl[mediaUrl]; // Make sure the correct transcript is selected if (!ttCurrentTranscript || ttCurrentTranscript.dataset.ttTranscript != ttData.transcriptIndex) { ttCurrentTranscript = document.querySelector(`[data-tt-transcript="${ttData.transcriptIndex}"]`); } // Clear words that were highlighted from the previous event clearHighlightedWords(ttCurrentTranscript); // Mark words wordElement.classList.add('tt-current-word'); for (const wordElement of ttCurrentTranscript.getElementsByClassName('tt-word')) { if (wordElement.classList.contains('tt-current-word')) break; wordElement.classList.add('tt-previous-word'); } } // Handle when a word in the transcript with an event listener is clicked function handleWordDBClick(e) { var wordElement = e.currentTarget; var wordIndex = wordElement.dataset.ttWord; var transcript = wordElement.closest('.tt-transcript'); var mediaUrl = transcript.dataset.ttCurrentMediaUrl; var startSeconds = ttLinkedDataByMediaUrl[mediaUrl].wordTimings[wordIndex].startSeconds ttLinkedDataByMediaUrl[mediaUrl].mediaElement.currentTime = startSeconds; var ttData = ttLinkedDataByMediaUrl[mediaUrl]; // Make sure the correct transcript is selected if (!ttCurrentTranscript || ttCurrentTranscript.dataset.ttTranscript != ttData.transcriptIndex) { ttCurrentTranscript = document.querySelector(`[data-tt-transcript="${ttData.transcriptIndex}"]`); } // Clear words that were highlighted from the previous event clearHighlightedWords(ttCurrentTranscript); // Mark words wordElement.classList.add('tt-current-word'); for (const wordElement of ttCurrentTranscript.getElementsByClassName('tt-word')) { if (wordElement.classList.contains('tt-current-word')) break; wordElement.classList.add('tt-previous-word'); } // pause if (ttActivePlayer != null) { ttActivePlayer.pause() } } function handleSelection() { // selection var temp = document.getSelection(); if (temp.type != "Range") return; var startNode = temp.baseNode; var wordElement = startNode.parentNode; while (wordElement.className == "tt-whitespace") { wordElement = wordElement.nextElementSibling; } var wordIndex = wordElement.dataset.ttWord; var transcript = wordElement.closest('.tt-transcript'); var mediaUrl = transcript.dataset.ttCurrentMediaUrl; var startWordElement = wordElement; var startWordIndex = wordIndex; var startSeconds = ttLinkedDataByMediaUrl[mediaUrl].wordTimings[wordIndex].startSeconds; console.log(startSeconds); var endNode = temp.extentNode; var wordElement = endNode.parentNode; var need_adjustment = true; while (wordElement.className == "tt-whitespace") { wordElement = wordElement.nextElementSibling; need_adjustment = false; } var wordIndex = wordElement.dataset.ttWord; var transcript = wordElement.closest('.tt-transcript'); var mediaUrl = transcript.dataset.ttCurrentMediaUrl; var endSeconds = ttLinkedDataByMediaUrl[mediaUrl].wordTimings[wordIndex].endSeconds; // adjustment var targetEndIndex = parseInt(wordIndex)+1; if (!need_adjustment) targetEndIndex = wordIndex; targetEndIndex = targetEndIndex.toString(); if (targetEndIndex < ttLinkedDataByMediaUrl[mediaUrl].wordTimings.length) { endSeconds = ttLinkedDataByMediaUrl[mediaUrl].wordTimings[targetEndIndex].startSeconds; } var endWordIndex = parseInt(wordIndex); if (!need_adjustment) endWordIndex = endWordIndex - 1; endWordIndex = endWordIndex.toString(); // ? How to get this // var endWordElement = startWordElement; console.log(endSeconds); console.log(startWordElement); console.log(startWordIndex); console.log(endWordIndex); console.log(temp); // Mark selection var currentWordElement = startWordElement; while (true) { var isWhite = currentWordElement.className == "tt-whitespace"; var index = -1; if (!isWhite) { var index = currentWordElement.dataset.ttWord; } if (parseInt(index) > parseInt(endWordIndex)) { break; } if (isWhite) { var nextIndex = currentWordElement.nextElementSibling.dataset.ttWord; if (parseInt(nextIndex) > parseInt(endWordIndex)) { break; } } console.log(currentWordElement); currentWordElement = currentWordElement.nextElementSibling; // var wordElements = ttCurrentTranscript.querySelectorAll(`[data-tt-word="${wordIndex}"]`); // for (const wordElement of wordElements) wordElement.classList.add('tt-current-word'); } // for (const wordElement of ttCurrentTranscript.getElementsByClassName('tt-word')) { // if (wordElement.classList.contains('tt-current-word')) break; // wordElement.classList.add('tt-previous-word'); // } } loadTranscriptTracer({ blockSelector: null, phraseSelector: null, alignmentFuzziness: 0, timeOffset: 0, autoScroll: "word", clickable: true})