NapCatQQ/packages/napcat-common/src/audio.ts

import fsPromise from 'fs/promises';
import path from 'node:path';
import { randomUUID } from 'crypto';
import { EncodeResult, getDuration, getWavFileInfo, isSilk, isWav } from 'silk-wasm';
import { LogWrapper } from '@/napcat-common/log';
import { EncodeArgs } from '@/napcat-common/audio-worker';
import { FFmpegService } from '@/napcat-common/ffmpeg';
import { runTask } from './worker';
import { fileURLToPath } from 'node:url';

const ALLOW_SAMPLE_RATE = [8000, 12000, 16000, 24000, 32000, 44100, 48000];

function getWorkerPath () {
  // return new URL(/* @vite-ignore */ './audio-worker.mjs', import.meta.url).href;
  return path.join(path.dirname(fileURLToPath(import.meta.url)), 'audio-worker.mjs');
}

async function guessDuration (pttPath: string, logger: LogWrapper) {
  const pttFileInfo = await fsPromise.stat(pttPath);
  const duration = Math.max(1, Math.floor(pttFileInfo.size / 1024 / 3)); // 3kb/s
  logger.log('通过文件大小估算语音的时长:', duration);
  return duration;
}

async function handleWavFile (
  file: Buffer,
  filePath: string,
  pcmPath: string
): Promise<{ input: Buffer; sampleRate: number }> {
  const { fmt } = getWavFileInfo(file);
  if (!ALLOW_SAMPLE_RATE.includes(fmt.sampleRate)) {
    const result = await FFmpegService.convert(filePath, pcmPath);
    return { input: await fsPromise.readFile(pcmPath), sampleRate: result.sampleRate };
  }
  return { input: file, sampleRate: fmt.sampleRate };
}

export async function encodeSilk (filePath: string, TEMP_DIR: string, logger: LogWrapper) {
  try {
    const file = await fsPromise.readFile(filePath);
    const pttPath = path.join(TEMP_DIR, randomUUID());
    if (!isSilk(file)) {
      logger.log(`语音文件${filePath}需要转换成silk`);
      const pcmPath = `${pttPath}.pcm`;
      // const { input, sampleRate } = isWav(file) ? await handleWavFile(file, filePath, pcmPath): { input: await FFmpegService.convert(filePath, pcmPath) ? await fsPromise.readFile(pcmPath) : Buffer.alloc(0), sampleRate: 24000 };
      let input: Buffer;
      let sampleRate: number;
      if (isWav(file)) {
        const result = await handleWavFile(file, filePath, pcmPath);
        input = result.input;
        sampleRate = result.sampleRate;
      } else {
        const result = await FFmpegService.convert(filePath, pcmPath);
        input = await fsPromise.readFile(pcmPath);
        sampleRate = result.sampleRate;
      }
      const silk = await runTask<EncodeArgs, EncodeResult>(getWorkerPath(), { input, sampleRate });
      fsPromise.unlink(pcmPath).catch((e) => logger.logError('删除临时文件失败', pcmPath, e));
      await fsPromise.writeFile(pttPath, Buffer.from(silk.data));
      logger.log(`语音文件${filePath}转换成功!`, pttPath, '时长:', silk.duration);
      return {
        converted: true,
        path: pttPath,
        duration: silk.duration / 1000,
      };
    } else {
      let duration = 0;
      try {
        duration = getDuration(file) / 1000;
      } catch (e: unknown) {
        logger.log('获取语音文件时长失败, 使用文件大小推测时长', filePath, (e as Error).stack);
        duration = await guessDuration(filePath, logger);
      }
      return {
        converted: false,
        path: filePath,
        duration,
      };
    }
  } catch (error: unknown) {
    logger.logError('convert silk failed', error);
    return {};
  }
}