stream: generalize/decompose somewhat

src/modules/stream/cut.js

@@ -1,5 +1,5 @@
 import { strict as assert } from 'node:assert';
-import { spawn } from 'node:child_process';
+import { spawn } from './shared.js';
 import { path as ffprobe } from 'ffprobe-static';
 
 function mapFormat(format) {

src/modules/stream/shared.js

@@ -0,0 +1,38 @@
+import { spawn as _node_spawn } from 'child_process'
+
+export function killProcess(p) {
+    // ask the process to terminate itself gracefully
+    p?.kill('SIGTERM');
+    setTimeout(() => {
+        if (p?.exitCode === null)
+            // brutally murder the process if it didn't quit
+            p?.kill('SIGKILL');
+    }, 5000);
+}
+
+export function pipe(from, to, done) {
+    from.on('error', done)
+        .on('close', done);
+
+    to.on('error', done)
+      .on('close', done);
+
+    from.pipe(to);
+}
+
+export function wrapCommand(command, args = []) {
+    if (process.env.PROCESSING_PRIORITY && process.platform !== "win32") {
+        return ['nice', ['-n', process.env.PROCESSING_PRIORITY, command, ...args]]
+    }
+
+    return [command, args]
+}
+
+export function spawn(command, args, opts) {
+    opts = {
+        ...opts,
+        windowsHide: true
+    };
+
+    return _node_spawn(...wrapCommand(command, args), opts);
+}

src/modules/stream/types.js

@@ -1,6 +1,6 @@
-import { spawn } from "child_process";
 import ffmpeg from "ffmpeg-static";
 import { ffmpegArgs, genericUserAgent } from "../config.js";
+import { spawn, pipe, killProcess } from "./shared.js";
 import { metadataManager } from "../sub/utils.js";
 import { request } from "undici";
 import { create as contentDisposition } from "content-disposition-header";
@@ -15,33 +15,6 @@ function closeResponse(res) {
     return res.destroy();
 }
 
-function killProcess(p) {
-    // ask the process to terminate itself gracefully
-    p?.kill('SIGTERM');
-    setTimeout(() => {
-        if (p?.exitCode === null)
-            // brutally murder the process if it didn't quit
-            p?.kill('SIGKILL');
-    }, 5000);
-}
-
-function pipe(from, to, done) {
-    from.on('error', done)
-        .on('close', done);
-
-    to.on('error', done)
-      .on('close', done);
-
-    from.pipe(to);
-}
-
-function getCommand(args) {
-    if (process.env.PROCESSING_PRIORITY && process.platform !== "win32") {
-        return ['nice', ['-n', process.env.PROCESSING_PRIORITY, ffmpeg, ...args]]
-    }
-    return [ffmpeg, args]
-}
-
 export async function streamDefault(streamInfo, res) {
     const abortController = new AbortController();
     const shutdown = () => (closeRequest(abortController), closeResponse(res));
@@ -98,8 +71,7 @@ export async function streamLiveRender(streamInfo, res) {
         }
         args.push('-f', format, 'pipe:4');
 
-        process = spawn(...getCommand(args), {
+        process = spawn(ffmpeg, args, {
-            windowsHide: true,
             stdio: [
                 'inherit', 'inherit', 'inherit',
                 'pipe', 'pipe'
@@ -140,18 +112,18 @@ export function streamAudioOnly(streamInfo, res) {
         )
 
         if (streamInfo.metadata) {
-            args = args.concat(metadataManager(streamInfo.metadata))
+            args.push(...metadataManager(streamInfo.metadata))
         }
-        let arg = streamInfo.copy ? ffmpegArgs["copy"] : ffmpegArgs["audio"];
+
-        args = args.concat(arg);
+        args.push(...ffmpegArgs[streamInfo.copy ? "copy" : "audio"]);
 
         if (ffmpegArgs[streamInfo.audioFormat]) {
-            args = args.concat(ffmpegArgs[streamInfo.audioFormat])
+            args.push(...ffmpegArgs[streamInfo.audioFormat]);
         }
+
         args.push('-f', streamInfo.audioFormat === "m4a" ? "ipod" : streamInfo.audioFormat, 'pipe:3');
 
-        process = spawn(...getCommand(args), {
+        process = spawn(ffmpeg, args, {
-            windowsHide: true,
             stdio: [
                 'inherit', 'inherit', 'inherit',
                 'pipe'
@@ -198,8 +170,7 @@ export function streamVideoOnly(streamInfo, res) {
         }
         args.push('-f', format, 'pipe:3');
 
-        process = spawn(...getCommand(args), {
+        process = spawn(ffmpeg, args, {
-            windowsHide: true,
             stdio: [
                 'inherit', 'inherit', 'inherit',
                 'pipe'
@@ -235,8 +206,7 @@ export function convertToGif(streamInfo, res) {
         args = args.concat(ffmpegArgs["gif"]);
         args.push('-f', "gif", 'pipe:3');
 
-        process = spawn(...getCommand(args), {
+        process = spawn(ffmpeg, args, {
-            windowsHide: true,
             stdio: [
                 'inherit', 'inherit', 'inherit',
                 'pipe'