From 9cc551008d170001dfb2511866efd77e19d7ad90 Mon Sep 17 00:00:00 2001
From: wukko <me@wukko.me>
Date: Sun, 29 Jun 2025 13:45:39 +0600
Subject: [PATCH] web/ffmpeg: define multithreading support outside of web
 worker context

there's no navigator.maxTouchPoints in web worker context, so previously there was no way to detect whether safari is running on ipad or not
---
 web/src/lib/libav.ts                       |  7 -------
 web/src/lib/task-manager/runners/ffmpeg.ts |  7 ++++++-
 web/src/lib/task-manager/workers/ffmpeg.ts | 14 ++++++++++----
 3 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/web/src/lib/libav.ts b/web/src/lib/libav.ts
index 598000f2..6c154022 100644
--- a/web/src/lib/libav.ts
+++ b/web/src/lib/libav.ts
@@ -5,12 +5,6 @@ import EncodeLibAV from "@imput/libav.js-encode-cli";
 import type { FfprobeData } from "fluent-ffmpeg";
 import type { FFmpegProgressCallback, FFmpegProgressEvent, FFmpegProgressStatus, RenderParams } from "$lib/types/libav";
 
-const ua = navigator.userAgent.toLowerCase();
-const iPhone = ua.includes("iphone os");
-const iPad = !iPhone && ua.includes("mac os") && navigator.maxTouchPoints > 0;
-const iOS = iPhone || iPad;
-const modernIOS = iOS && Number(ua.match(/version\/(\d+)/)?.[1]) >= 18;
-
 export default class LibAVWrapper {
     libav: Promise<LibAVInstance> | null;
     concurrency: number;
@@ -38,7 +32,6 @@ export default class LibAVWrapper {
             this.libav = constructor({
                 ...options,
                 variant: undefined,
-                yesthreads: !iOS || modernIOS,
                 base: '/_libav'
             });
         }
diff --git a/web/src/lib/task-manager/runners/ffmpeg.ts b/web/src/lib/task-manager/runners/ffmpeg.ts
index 43d75cbe..1710456f 100644
--- a/web/src/lib/task-manager/runners/ffmpeg.ts
+++ b/web/src/lib/task-manager/runners/ffmpeg.ts
@@ -1,5 +1,6 @@
 import FFmpegWorker from "$lib/task-manager/workers/ffmpeg?worker";
 
+import { device } from "$lib/device";
 import { killWorker } from "$lib/task-manager/run-worker";
 import { updateWorkerProgress } from "$lib/state/task-manager/current-tasks";
 import { pipelineTaskDone, itemError, queue } from "$lib/state/task-manager/queue";
@@ -34,7 +35,11 @@ export const runFFmpegWorker = async (
             startAttempts++;
             if (startAttempts <= 10) {
                 killWorker(worker, unsubscribe, startCheck);
-                return await runFFmpegWorker(workerId, parentId, files, args, output, variant);
+                return await runFFmpegWorker(
+                    workerId, parentId,
+                    files, args, output,
+                    variant, device.supports.multithreading
+                );
             } else {
                 killWorker(worker, unsubscribe, startCheck);
                 return itemError(parentId, workerId, "queue.worker_didnt_start");
diff --git a/web/src/lib/task-manager/workers/ffmpeg.ts b/web/src/lib/task-manager/workers/ffmpeg.ts
index cfb4868d..4a9c0499 100644
--- a/web/src/lib/task-manager/workers/ffmpeg.ts
+++ b/web/src/lib/task-manager/workers/ffmpeg.ts
@@ -1,7 +1,13 @@
 import LibAVWrapper from "$lib/libav";
 import type { FileInfo } from "$lib/types/libav";
 
-const ffmpeg = async (variant: string, files: File[], args: string[], output: FileInfo) => {
+const ffmpeg = async (
+    variant: string,
+    files: File[],
+    args: string[],
+    output: FileInfo,
+    yesthreads: boolean
+) => {
     if (!(files && output && args)) {
         self.postMessage({
             cobaltFFmpegWorker: {
@@ -25,7 +31,7 @@ const ffmpeg = async (variant: string, files: File[], args: string[], output: Fi
         })
     });
 
-    ff.init({ variant });
+    ff.init({ variant, yesthreads });
 
     const error = (code: string) => {
         self.postMessage({
@@ -121,7 +127,7 @@ const ffmpeg = async (variant: string, files: File[], args: string[], output: Fi
 
 self.onmessage = async (event: MessageEvent) => {
     const ed = event.data.cobaltFFmpegWorker;
-    if (ed?.variant && ed?.files && ed?.args && ed?.output) {
-        await ffmpeg(ed.variant, ed.files, ed.args, ed.output);
+    if (ed?.variant && ed?.files && ed?.args && ed?.output && ed?.yesthreads) {
+        await ffmpeg(ed.variant, ed.files, ed.args, ed.output, ed.yesthreads);
     }
 }