feat & improvements & refactor: new structure, better garbage collection, better docs, better performance, added tests

src/ffmpeg.ts

@@ -0,0 +1,83 @@
+import { spawn } from 'node:child_process';
+import type { ChildProcessByStdio } from 'node:child_process';
+import { createRequire } from 'node:module';
+import type { Readable } from 'node:stream';
+
+import { AudioManagerConfigError } from './errors';
+import type { FfmpegOptions } from './types';
+
+const requireFromCurrentModule = createRequire(__filename);
+
+const DEFAULT_INPUT_ARGS = ['-hide_banner', '-loglevel', 'error', '-nostdin'] as const;
+const DEFAULT_OUTPUT_ARGS = ['-vn', '-f', 's16le', '-ar', '48000', '-ac', '2', 'pipe:1'] as const;
+const FORCE_KILL_TIMEOUT_MS = 2_000;
+
+export type FfmpegProcessHandle = {
+    process: ChildProcessByStdio<null, Readable, Readable>;
+    stop(): void;
+};
+
+export function resolveFfmpegExecutable(options: FfmpegOptions = {}): string {
+    if (options.executablePath?.trim()) {
+        return options.executablePath;
+    }
+
+    if ((options.mode ?? 'native') === 'native') {
+        return 'ffmpeg';
+    }
+
+    try {
+        const executable = requireFromCurrentModule('ffmpeg-static') as unknown;
+
+        if (typeof executable === 'string' && executable.length > 0) {
+            return executable;
+        }
+    } catch (error) {
+        throw new AudioManagerConfigError(
+            `Unable to resolve ffmpeg-static. Install it or pass ffmpeg.executablePath. Cause: ${String(error)}`,
+        );
+    }
+
+    throw new AudioManagerConfigError('ffmpeg-static did not expose an executable path.');
+}
+
+export function startFfmpeg(input: string, options: FfmpegOptions = {}): FfmpegProcessHandle {
+    const executable = resolveFfmpegExecutable(options);
+    const args = [
+        ...(options.inputArgs ?? DEFAULT_INPUT_ARGS),
+        '-i',
+        input,
+        ...(options.outputArgs ?? DEFAULT_OUTPUT_ARGS),
+    ];
+    const childProcess = spawn(executable, args, { stdio: ['ignore', 'pipe', 'pipe'] });
+
+    childProcess.once('error', () => undefined);
+    childProcess.stderr.resume();
+
+    return {
+        process: childProcess,
+        stop: (): void => {
+            stopProcess(childProcess);
+        },
+    };
+}
+
+function stopProcess(childProcess: ChildProcessByStdio<null, Readable, Readable>): void {
+    childProcess.stdout.destroy();
+    childProcess.stderr.destroy();
+    childProcess.removeAllListeners();
+
+    if (childProcess.killed || childProcess.exitCode !== null || childProcess.signalCode !== null) {
+        return;
+    }
+
+    childProcess.kill('SIGTERM');
+
+    const forceKillTimeout = setTimeout(() => {
+        if (!childProcess.killed && childProcess.exitCode === null && childProcess.signalCode === null) {
+            childProcess.kill('SIGKILL');
+        }
+    }, FORCE_KILL_TIMEOUT_MS);
+
+    forceKillTimeout.unref();
+}