diff --git a/web/src/lib/libav/encode.ts b/web/src/lib/libav/encode.ts
index a1415796..fd358462 100644
--- a/web/src/lib/libav/encode.ts
+++ b/web/src/lib/libav/encode.ts
@@ -4,53 +4,31 @@ import * as LibAVWebCodecs from "libavjs-webcodecs-bridge";
 import { BufferStream } from "./buffer-stream";
 import { BufferStream } from "../buffer-stream";
 import WebCodecsWrapper from "./webcodecs";
-import { browser } from "$app/environment";
+import LibAVWrapper from "./instance";
 
 const QUEUE_THRESHOLD_MIN = 16;
 const QUEUE_THRESHOLD_MAX = 128;
 
-export default class LibAVWrapper {
-    libav: Promise<LibAVInstance> | null;
-    webcodecs: WebCodecsWrapper | null;
-    concurrency: number;
-    onProgress?: FFmpegProgressCallback;
+export default class EncodeLibAV extends LibAVWrapper {
+    webcodecs: WebCodecsWrapper | null = null;
 
-    constructor(onProgress?: FFmpegProgressCallback) {
-        this.libav = null;
-        this.webcodecs = null;
-        this.concurrency = Math.min(4, browser ? navigator.hardwareConcurrency : 0);
-        this.onProgress = onProgress;
+    constructor() {
+        super(LibAV);
     }
 
-    init() {
-        if (this.concurrency && !this.libav) {
-            this.libav = LibAV.LibAV({
-                yesthreads: true,
-                base: '/_libav'
-            });
-
-            this.webcodecs = new WebCodecsWrapper(this.libav);
-        }
-    }
-
-    async terminate() {
-        if (this.libav) {
-            const libav = await this.libav;
-            libav.terminate();
+    async init() {
+        await super.init();
+        if (!this.webcodecs) {
+            this.webcodecs = new WebCodecsWrapper(
+                super.get().then(({ libav }) => libav)
+            );
         }
     }
 
     async #get() {
-        if (!this.libav) throw new Error("LibAV wasn't initialized");
-        const libav = await this.libav;
-
-        if (!this.webcodecs) {
-            throw new Error("unreachable");
-        }
-
         return {
-            libav,
-            webcodecs: this.webcodecs
+            ...await super.get(),
+            webcodecs: this.webcodecs!
         };
     }
 
diff --git a/web/src/lib/libav/instance.ts b/web/src/lib/libav/instance.ts
new file mode 100644
index 00000000..4327897f
--- /dev/null
+++ b/web/src/lib/libav/instance.ts
@@ -0,0 +1,56 @@
+import mime from "mime";
+import LibAV, { type LibAV as LibAVInstance } from "@imput/libav.js-remux-cli";
+import { browser } from "$app/environment";
+
+export default class LibAVWrapper {
+    #libav__constructor: typeof LibAV;
+    #libav: Promise<LibAVInstance> | null;
+    #useThreads: boolean;
+    concurrency: number;
+
+    constructor(ctor: typeof LibAV, threads = true) {
+        this.#libav = null;
+        this.#useThreads = threads;
+        this.#libav__constructor = ctor;
+        this.concurrency = Math.min(4, browser ? navigator.hardwareConcurrency : 0);
+    }
+
+    async init() {
+        if (!this.#libav) {
+            this.#libav = this.#libav__constructor.LibAV({
+                yesthreads: this.#useThreads,
+                base: '/_libav'
+            });
+        }
+    }
+
+    async terminate() {
+        if (this.#libav) {
+            const libav = await this.#libav;
+            libav.terminate();
+        }
+    }
+
+    protected async get() {
+        if (!this.#libav) throw new Error("LibAV wasn't initialized");
+
+        return {
+            libav: await this.#libav
+        };
+    }
+
+    static getExtensionFromType(blob: Blob) {
+        const extensions = mime.getAllExtensions(blob.type);
+        const overrides = ['mp3', 'mov'];
+
+        if (!extensions)
+            return;
+
+        for (const override of overrides)
+            if (extensions?.has(override))
+                return override;
+
+        return [...extensions][0];
+    }
+
+}
diff --git a/web/src/lib/libav/remux.ts b/web/src/lib/libav/remux.ts
index c3371a5e..3a19b2ed 100644
--- a/web/src/lib/libav/remux.ts
+++ b/web/src/lib/libav/remux.ts
@@ -1,38 +1,19 @@
 import mime from "mime";
-import LibAV, { type LibAV as LibAVInstance } from "@imput/libav.js-remux-cli";
+import LibAV from "@imput/libav.js-remux-cli";
 import type { FFmpegProgressCallback, FFmpegProgressEvent, FFmpegProgressStatus, FileInfo, RenderParams } from "../types/libav";
 import type { FfprobeData } from "fluent-ffmpeg";
+import LibAVWrapper from "./instance";
 
-export default class LibAVWrapper {
-    libav: Promise<LibAVInstance> | null;
-    concurrency: number;
+export default class RemuxLibAV extends LibAVWrapper {
     onProgress?: FFmpegProgressCallback;
 
     constructor(onProgress?: FFmpegProgressCallback) {
-        this.libav = null;
-        this.concurrency = Math.min(4, navigator.hardwareConcurrency);
+        super(LibAV);
         this.onProgress = onProgress;
     }
 
-    async init() {
-        if (!this.libav) {
-            this.libav = LibAV.LibAV({
-                yesthreads: true,
-                base: '/_libav'
-            });
-        }
-    }
-
-    async #get() {
-        if (!this.libav) throw new Error("LibAV wasn't initialized");
-
-        return {
-            libav: await this.libav
-        };
-    }
-
     async probe(blob: Blob) {
-        const { libav } = await this.#get();
+        const { libav } = await this.get();
 
         const OUT_FILE = 'output.json';
         await libav.mkreadaheadfile('input', blob);
@@ -69,22 +50,8 @@ export default class LibAVWrapper {
         return JSON.parse(text) as FfprobeData;
     }
 
-    static getExtensionFromType(blob: Blob) {
-        const extensions = mime.getAllExtensions(blob.type);
-        const overrides = ['mp3', 'mov'];
-
-        if (!extensions)
-            return;
-
-        for (const override of overrides)
-            if (extensions?.has(override))
-                return override;
-
-        return [...extensions][0];
-    }
-
     async remux({ blob, output, args }: RenderParams) {
-        const { libav } = await this.#get();
+        const { libav } = await this.get();
 
         const inputKind = blob.type.split("/")[0];
         const inputExtension = LibAVWrapper.getExtensionFromType(blob);