Add fluent-ffmpeg dependency and refactor AAC to FLAC conversion logic

src/helpers/utils.ts

@@ -1,6 +1,9 @@
 import { FlacStreamTagger } from "flac-stream-tagger";
 import Ffmpeg from "fluent-ffmpeg";
 import ffmpegPath from "ffmpeg-static";
+import { PassThrough } from "stream";
+
+Ffmpeg.setFfmpegPath(ffmpegPath as string);
 
 export default class {
     authHeaders: { [key: string]: string }
@@ -10,18 +13,20 @@ export default class {
     }
 
     async convertAacToFlac(buffer: ArrayBuffer) {
-        const fileId = Bun.nanoseconds().toString(36);
+        const inputStream = new PassThrough();
+        inputStream.end(Buffer.from(buffer));
 
-        Bun.write(`tmp/${fileId}.aac`, Buffer.from(buffer))
+        const outputChunks: Buffer[] = [];
 
-        await Bun.$`${ffmpegPath} -i tmp/${fileId}.aac -c:a flac tmp/${fileId}.flac`.quiet()
-
-        await Bun.file(`tmp/${fileId}.aac`).delete();
-        const flac = Bun.file(`tmp/${fileId}.flac`)
-        const audioBuffer = await flac.arrayBuffer();
-        await flac.delete()
-
-        return audioBuffer;
+        await new Promise((resolve, reject) => {
+            Ffmpeg(inputStream)
+                .audioCodec("flac")
+                .format("flac")
+                .on("error", reject)
+                .on("end", resolve)
+                .pipe()
+                .on("data", chunk => outputChunks.push(chunk));
+        });
     }
 
     async fetchTrack(id: number) {