HarmonyOS 鸿蒙Next SoundPool如何播放rawfile中的mp3？

使用SoundPool开发音频播放功能可参考如下文档的demo：
https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/using-soundpool-for-playback-0000001774120626
加载rawfile目录资源，需要通过
load(fd: number, offset: number, length: number, callback: AsyncCallback): void 或者
load(fd: number, offset: number, length: number): Promise实现：
可参考Api文档进行上述方法搜索查看demo：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-inner-multimedia-soundpool-0000001774281610
看一下上面文档里面的demo，load(uri: string, callback: AsyncCallback): void，加载音频资源。使用callback方式异步获取资源ID，入参uri通过获取文件fd生成以"fd://"开头的文件描述字符串。
该方法不支持加载rawfile目录资源，需要通过load(fd: number, offset: number, length: number, callback: AsyncCallback): void或者load(fd: number, offset: number, length: number): Promise实现。
也可参考以下demo：

import audio from '@ohos.multimedia.audio';
import media from '@ohos.multimedia.media';
import { BusinessError } from '@ohos.base';
import common from '@ohos.app.ability.common';
let soundPool: media.SoundPool;
let streamIda: number = 0;
let soundIda: number = 0;
let audioRendererInfo: audio.AudioRendererInfo = {
  usage: audio.StreamUsage.STREAM_USAGE_MUSIC,
  rendererFlags: 1
}
let PlayParameters: media.PlayParameters = {
  loop: 0, // 循环4次
  rate: audio.AudioRendererRate.RENDER_RATE_NORMAL, // 正常倍速
  leftVolume: 0.9, // range = 0.0-1.0
  rightVolume: 0.9, // range = 0.0-1.0
  priority: 3, // 最低优先级
}
@Entry
@Component
struct SoundPoolDemo {
  @State message: string = '播放音频';
  async aboutToAppear(): Promise<void> {
    create();
  }
  async aboutToDisappear() {
    release();
  }
  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
        Button('play').onClick((event: ClickEvent) => {
          PlaySoundPool1();
        })
      }
      .width('100%')
    }
    .height('100%')
  }
}
async function create() {
  //创建soundPool实例
  soundPool = await media.createSoundPool(10, audioRendererInfo);
  //注册监听
  loadCallback();
  finishPlayCallback();
  setErrorCallback();
  CreatAudio('audio1.mp3')
}
async function CreatAudio(path:string) {
  // 加载音频资源
  let context = getContext(SoundPoolDemo) as common.UIAbilityContext;
  let fileDescriptor = await context.resourceManager.getRawFd(path);
  soundPool.load(fileDescriptor.fd,fileDescriptor.offset,fileDescriptor.length).then((soundId1: number) => {
    console.info('soundPool load uri success 1');
    soundIda=soundId1;
    console.log(`${soundId1}`)
  }).catch((err: BusinessError) => {
    console.error('soundPool load failed and catch error is ' + err.message);
  })
}
async function loadCallback() {
  // 加载完成回调
  soundPool.on('loadComplete', (soundId_: number) => {
    console.info('loadComplete, soundId: ' + soundId_);
  })
}
//设置播放完成监听
async function finishPlayCallback() {
  // 播放完成回调
  soundPool.on('playFinished', () => {
    console.info("recive play finished message");
    // 可进行下次播放
  })
}
//设置错误类型监听
function setErrorCallback() {
  soundPool.on('error', (error) => {
    console.error('error happened,message is :' + error.code);
    console.error('error happened,message is :' + error.message);
  })
}
async function PlaySoundPool1() {
  console.log("play");
  // 开始播放,这边play也可带播放播放的参数PlayParameters
  streamIda = await soundPool.play(soundIda,PlayParameters);
}
async function unload(){
  //终止指定流的播放
  soundPool.stop(streamIda);
  // 卸载音频资源
  await soundPool.unload(soundIda);
}
async function release() {
  if (streamIda!=0) {
    //终止指定流的播放
    soundPool.stop(streamIda);
    // 卸载音频资源
    await soundPool.unload(soundIda);
  }
  //关闭监听
  setOffCallback();
  // 释放SoundPool
  await soundPool.release();
}
//关闭监听
function setOffCallback() {
  soundPool.off('loadComplete');
  soundPool.off('playFinished');
  soundPool.off('error');
}