Initial start at sharing audio

Author: chrisvire

package-lock.json

@@ -24,6 +24,8 @@
     "devDependencies": {
         "@esbuild-plugins/node-globals-polyfill": "^0.2.3",
         "@esbuild-plugins/node-modules-polyfill": "^0.2.2",
+        "@ffmpeg/ffmpeg": "^0.12.1",
+        "@ffmpeg/util": "^0.12.0",
         "@sveltejs/adapter-static": "^2",
         "@sveltejs/kit": "^1",
         "@tailwindcss/typography": "^0.5.2",
@@ -60,6 +62,6 @@
         "vite": "^4"
     },
     "volta": {
-        "node": "16.17.0"
+        "node": "18.17.0"
     }
 }

package.json

@@ -0,0 +1,63 @@
+import { FFmpeg } from '@ffmpeg/ffmpeg';
+import type { FileData } from '@ffmpeg/ffmpeg/dist/esm/types';
+import { toBlobURL, fetchFile } from '@ffmpeg/util';
+
+//
+//-y -i /data/user/0/com.example.app.scripture/cache/B01___01_Matthew_____ENGWEBN2DA.mp3
+//-map_metadata 0 -ss 00:00:20.120 -to 00:00:28.960
+//-map 0:a -acodec copy -write_xing 0
+// "/storage/emulated/0/Android/data/com.example.app.scripture/files/WEB Gospels/Matthew_1_3.mp3"
+
+let ffmpeg: FFmpeg = null;
+let loaded = false;
+export async function loadFFmpeg() {
+    if (!ffmpeg) {
+        const baseURL = 'https://unpkg.com/@ffmpeg/core@0.12.1/dist/umd';
+        ffmpeg = new FFmpeg();
+        ffmpeg.on('log', ({ message }) => {
+            console.log(message);
+        });
+        // toBlobURL is used to bypass CORS issue, urls with the same
+        // domain can be used directly.
+        await ffmpeg.load({
+            coreURL: await toBlobURL(`${baseURL}/ffmpeg-core.js`, 'text/javascript'),
+            wasmURL: await toBlobURL(`${baseURL}/ffmpeg-core.wasm`, 'application/wasm')
+        });
+        loaded = true;
+    }
+}
+
+export async function convert(
+    inputPath: string,
+    timingStart: string,
+    timingEnd: string,
+    output: string
+): Promise<FileData> {
+    if (!loaded) {
+        await loadFFmpeg();
+    }
+
+    const input = 'input.' + inputPath.split('.').pop();
+    await ffmpeg.writeFile(input, await fetchFile(inputPath));
+    await ffmpeg.exec([
+        '-i',
+        input,
+        '-map_metadata',
+        '0',
+        '-ss',
+        timingStart,
+        '-to',
+        timingEnd,
+        '-map',
+        '0:a',
+        '-acodec',
+        'copy',
+        '-write_xing',
+        '0',
+        output
+    ]);
+    const data = await ffmpeg.readFile(output);
+    await ffmpeg.deleteFile(input);
+    await ffmpeg.deleteFile(output);
+    return data;
+}

src/lib/data/audio-convert.ts

@@ -295,3 +295,86 @@ export function seekToVerse(verseClicked) {
     //forces highlighting change
     updateTime();
 }
+
+// This algorithm is based on the Android code in
+// AudioVideoFileManager::getExtractAudioProcessingTask
+export function getTimingForVerseRange(verseRange: string) {
+    const timing = currentAudioPlayer.timing;
+
+    if (timing && timing.length > 0) {
+        // Ensure the final timing has its end time set properly
+        const lastTiming = timing[timing.length - 1];
+        if (lastTiming.endtime - lastTiming.starttime < 0.01) {
+            lastTiming.endtime = currentAudioPlayer.audio.duration;
+        }
+    }
+
+    let timing1 = null;
+    let timing2 = null;
+
+    const vs = verseRange.split('-');
+    if (vs.length === 1) {
+        const verse = vs[0];
+        timing1 = timing.find((t) => t.tag.includes(verse));
+        timing2 = timing1;
+    }
+    const startVerse = verseRange.split('-')[0];
+    const endVerse = verseRange.split('-')[1];
+    const startTiming = timing.find((t) => t.tag.includes(startVerse));
+    const endTiming = timing.find((t) => t.tag.includes(endVerse));
+    return {
+        start: startTiming,
+        end: endTiming
+    };
+}
+
+function getTimingForVerse(timings: Array<any>, verse: string) {
+    const result = [];
+    for (let i = 0; i < timings.length; i++) {
+        if (!isTimingForVerseRange(timings[i])) {
+            // This timing is for a single verse or phrases in a verse
+            // e.g. "4" - return timings 4a, 4b, 4c.
+            if (getVerseForTiming(timings[i]) === verse) {
+                result.push(timings[i]);
+            }
+        } else {
+        }
+    }
+}
+
+function getVerseForTiming(timing: any) {
+    function extractNumericalPart(inputString) {
+        let numericalPart = '';
+        let index = 0;
+
+        // Skip non-numerical characters at the beginning of the string
+        while (index < inputString.length && isNaN(parseInt(inputString[index]))) {
+            index++;
+        }
+
+        // Extract numerical characters until a non-numerical character is encountered
+        while (index < inputString.length && !isNaN(parseInt(inputString[index]))) {
+            numericalPart += inputString[index];
+            index++;
+        }
+
+        // Return the numerical part or null if no numerical part is found
+        return numericalPart.length > 0 ? numericalPart : null;
+    }
+
+    return extractNumericalPart(timing.tag);
+}
+
+function isVerseNumberInVerseRange(verse: string, verseRange: string) {
+    const vs = verseRange.split('-');
+    if (vs.length === 1) {
+        return verse === vs[0];
+    }
+    const startVerse = vs[0];
+    const endVerse = vs[1];
+    return verse >= startVerse && verse <= endVerse;
+}
+
+function isTimingForVerseRange(timing: any) {
+    return timing.tag && timing.tag.includes('-');
+}