From 2869a7daba329b06c8bf1e77506b90eea42cef84 Mon Sep 17 00:00:00 2001
From: Pushpender Saini <54404738+PushpenderSaini0@users.noreply.github.com>
Date: Thu, 22 Jun 2023 16:50:11 +0530
Subject: [PATCH] Add SRT export

---
 src/components/Transcript.tsx | 87 +++++++++++++++++++++--------------
 src/utils/AudioUtils.ts       | 57 +++++++++++++++++++----
 2 files changed, 99 insertions(+), 45 deletions(-)

diff --git a/src/components/Transcript.tsx b/src/components/Transcript.tsx
index 4ba47721..7aed8073 100644
--- a/src/components/Transcript.tsx
+++ b/src/components/Transcript.tsx
@@ -1,7 +1,7 @@
 import { useRef, useEffect } from "react";
 
 import { TranscriberData } from "../hooks/useTranscriber";
-import { formatAudioTimestamp } from "../utils/AudioUtils";
+import { formatAudioTimestamp, formatSrtTimeRange } from "../utils/AudioUtils";
 
 interface Props {
     transcribedData: TranscriberData | undefined;
@@ -38,14 +38,32 @@ export default function Transcript({ transcribedData }: Props) {
         const blob = new Blob([jsonData], { type: "application/json" });
         saveBlob(blob, "transcript.json");
     };
+    const exportSRT = () => {
+        let chunks = transcribedData?.chunks ?? [];
+        let srt = "";
+        for (let i = 0; i < chunks.length; i++) {
+            srt += `${i + 1}\n`;
+            // TODO - Check why 2nd timestamp is number | null
+            srt += `${formatSrtTimeRange(chunks[i].timestamp[0], chunks[i].timestamp[1] ?? chunks[i].timestamp[0])}\n`;
+            srt += `${chunks[i].text}\n\n`;
+        }
+        const blob = new Blob([srt], { type: "text/plain" });
+        saveBlob(blob, "transcript.srt");
+    }
+
+    const exportButtons = [
+        { name: "TXT", onClick: exportTXT, },
+        { name: "JSON", onClick: exportJSON, },
+        { name: "SRT", onClick: exportSRT, },
+    ]
 
     // Scroll to the bottom when the component updates
     useEffect(() => {
         if (divRef.current) {
             const diff = Math.abs(
                 divRef.current.offsetHeight +
-                    divRef.current.scrollTop -
-                    divRef.current.scrollHeight,
+                divRef.current.scrollTop -
+                divRef.current.scrollHeight,
             );
 
             if (diff <= 64) {
@@ -56,38 +74,37 @@ export default function Transcript({ transcribedData }: Props) {
     });
 
     return (
-        <div
-            ref={divRef}
-            className='w-full flex flex-col my-2 p-4 max-h-[20rem] overflow-y-auto'
-        >
-            {transcribedData &&
-                transcribedData.chunks.map((chunk, i) => (
-                    <div
-                        key={`${i}-${chunk.text}`}
-                        className='w-full flex flex-row mb-2 bg-white rounded-lg p-4 shadow-xl shadow-black/5 ring-1 ring-slate-700/10'
-                    >
-                        <div className='mr-5'>
-                            {formatAudioTimestamp(chunk.timestamp[0])}
+        <>
+            <div
+                ref={divRef}
+                className='w-full flex flex-col my-2 p-4 max-h-[20rem] overflow-y-auto'
+            >
+                {transcribedData &&
+                    transcribedData.chunks.map((chunk, i) => (
+                        <div
+                            key={`${i}-${chunk.text}`}
+                            className='w-full flex flex-row mb-2 bg-white rounded-lg p-4 shadow-xl shadow-black/5 ring-1 ring-slate-700/10'
+                        >
+                            <div className='mr-5'>
+                                {formatAudioTimestamp(chunk.timestamp[0])}
+                            </div>
+                            {chunk.text}
                         </div>
-                        {chunk.text}
-                    </div>
-                ))}
-            {transcribedData && !transcribedData.isBusy && (
-                <div className='w-full text-right'>
-                    <button
-                        onClick={exportTXT}
-                        className='text-white bg-green-500 hover:bg-green-600 focus:ring-4 focus:ring-green-300 font-medium rounded-lg text-sm px-4 py-2 text-center mr-2 dark:bg-green-600 dark:hover:bg-green-700 dark:focus:ring-green-800 inline-flex items-center'
-                    >
-                        Export TXT
-                    </button>
-                    <button
-                        onClick={exportJSON}
-                        className='text-white bg-green-500 hover:bg-green-600 focus:ring-4 focus:ring-green-300 font-medium rounded-lg text-sm px-4 py-2 text-center mr-2 dark:bg-green-600 dark:hover:bg-green-700 dark:focus:ring-green-800 inline-flex items-center'
-                    >
-                        Export JSON
-                    </button>
-                </div>
-            )}
-        </div>
+                    ))}
+            </div>
+            {
+                transcribedData && !transcribedData.isBusy && (
+                    < div className='w-full text-right mx-2'>
+                        {exportButtons.map((button, i) => (
+                            <button key={i}
+                                onClick={button.onClick}
+                                className='text-white bg-green-500 hover:bg-green-600 focus:ring-4 focus:ring-green-300 font-medium rounded-lg text-sm px-4 py-2 text-center mr-2 dark:bg-green-600 dark:hover:bg-green-700 dark:focus:ring-green-800 inline-flex items-center'>
+                                Export {button.name}
+                            </button>
+                        ))}
+                    </div >
+                )
+            }
+        </>
     );
 }
diff --git a/src/utils/AudioUtils.ts b/src/utils/AudioUtils.ts
index 82e848b6..307f4945 100644
--- a/src/utils/AudioUtils.ts
+++ b/src/utils/AudioUtils.ts
@@ -1,14 +1,51 @@
-function padTime(time: number) {
-    return String(time).padStart(2, "0");
+const HOURS_IN_SECONDS = 3600;
+const MINUTES_IN_SECONDS = 60;
+
+function padTime(time: number, padding: number = 2) {
+    return String(time).padStart(padding, "0");
+}
+
+function formatTimestamp(time: number) {
+
+    const hours = Math.floor(time / HOURS_IN_SECONDS);
+    const hoursRemainder = time - hours * HOURS_IN_SECONDS;
+
+    const minutes = Math.floor(hoursRemainder / MINUTES_IN_SECONDS);
+    const minutesRemainder = hoursRemainder - minutes * MINUTES_IN_SECONDS;
+
+    const seconds = Math.floor(minutesRemainder);
+    const secondsRemainder = minutesRemainder - seconds;
+
+    const milliseconds = Math.floor(secondsRemainder * 1000);
+
+    return { hours, minutes, seconds, milliseconds };
 }
 
 export function formatAudioTimestamp(time: number) {
-    const hours = (time / (60 * 60)) | 0;
-    time -= hours * (60 * 60);
-    const minutes = (time / 60) | 0;
-    time -= minutes * 60;
-    const seconds = time | 0;
-    return `${hours ? padTime(hours) + ":" : ""}${padTime(minutes)}:${padTime(
-        seconds,
-    )}`;
+
+    const { hours, minutes, seconds } = formatTimestamp(time);
+
+    // Hide hours if not needed
+    const hoursString = hours ? padTime(hours) + ":" : "";
+    const minutesString = padTime(minutes) + ":";
+    const secondsString = padTime(seconds);
+
+    return `${hoursString}${minutesString}${secondsString}`;
 }
+
+function formatSrtTimestamp(time: number) {
+
+    const { hours, minutes, seconds, milliseconds } = formatTimestamp(time);
+
+    const hoursString = padTime(hours) + ":";
+    const minutesString = padTime(minutes) + ":";
+    const secondsString = padTime(seconds) + ",";
+    const millisecondsString = padTime(milliseconds, 3);
+
+    return `${hoursString}${minutesString}${secondsString}${millisecondsString}`;
+}
+
+
+export function formatSrtTimeRange(start: number, end: number) {
+    return `${formatSrtTimestamp(start)} --> ${formatSrtTimestamp(end)}`;
+}
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