AWS Polly v3：SynthesizeSpeech 'mp3'，AudioStream 不是 instanceOf Buffer

问题描述

我正在将 Javascript（节点）中的 AWS Polly 代码从 v2 转换为 v3。

使用 AWS Polly v3 synthesizeSpeech() 时，如何将返回的 data.AudioStream 转换为 Buffer 的实例？

以下 JavaScript 代码使用 v2，返回的 audio.AudioStream 是 Buffer 的实例：

const { Polly } = require('aws-sdk');

// Create an Polly client
const polly = new Polly({
    signatureversion: 'v4',region: process.env.AWS_DEFAULT_REGION
});

const params = {
    OutputFormat: 'mp3',VoiceId: voiceId,TextType: 'ssml',Text: '<speak><prosody rate="85%">Hello World</prosody></speak>'
};

// ***

return await polly
    .synthesizeSpeech(params)
    .promise()
    .then(data => {
         if (data.AudioStream instanceof Buffer) {
             return data.AudioStream
         } else {
             console.error('AudioStream not instanceof Buffer');
             return null;
         }
     })

以下使用 v3 的 JavaScript 代码，其来自 synthesizeSpeech() 的响应包含 audio.AudioStream 不是 Buffer 的实例，而是以 IncomingMessage 开头:

const {
    Polly
} = require("@aws-sdk/client-polly");

// Create an Polly client
const polly = new Polly({
    signatureversion: 'v4',region: process.env.AWS_DEFAULT_REGION
});

// ***

const params = {
    OutputFormat: 'mp3',Text: '<speak><prosody rate="85%">Hello World</prosody></speak>'
};

return await polly
    .synthesizeSpeech(params)
    .then(data => {
         if (data.AudioStream instanceof Buffer) {
             return data.AudioStream
         } else {
             console.error('AudioStream not instanceof Buffer');
             return null;
         }
     })

我都使用 PollyClient 和 SynthesizeSpeechCommand 尝试了以下 v3，结果相同

const {
    PollyClient,SynthesizeSpeechCommand
} = require("@aws-sdk/client-polly");

const client = new PollyClient({
    region: process.env.AWS_DEFAULT_REGION
});

// ***

const command = new SynthesizeSpeechCommand({
    OutputFormat: 'mp3',Text:'hello world,this is alex',VoiceId: 'Kimberly',TextType: 'text'
});

return client
    .send(command)
    .then((data) => {
        if (data.AudioStream instanceof Buffer) {
            return data.AudioStream
        } else {
            console.error('AudioStream not instanceof Buffer');
            console.log('data.AudioStream:',data.AudioStream);
            return null;
        }
    })
    .catch((error) => {
        console.error(error);
    });

v3 data.AudioStream 的内容是：

IncomingMessage {
  _readableState:
   ReadableState {
     objectMode: false,highWaterMark: 16384,buffer: BufferList { head: null,tail: null,length: 0 },length: 0,pipes: null,***

感谢您的阅读，感谢您的任何反馈。

解决方法

现在是一个 ReadableStream 对象。

   import { Readable } from "stream";
    //...
    if (data.AudioStream instanceof Readable) {
      console.log("Readable");
      data.AudioStream.pipe(fs.createWriteStream("fileName.mp3"));
    } else {
      console.log("no Readable");
    }
    //...

您可以在此处找到有关此更改的详细信息： https://github.com/aws/aws-sdk-js-v3/issues/1096#issuecomment-620900466

,

就我个人而言，我发现使用 async/await 而不是流回调更容易...

 t1 <- melt(df[Dept == "CA"],id.vars=c("Manager","PF","Yearlybonus","Quaterlybonus","monthlybonus"))
  

注意：我使用的是 node14，因此可以在顶部使用 import { PollyClient,SynthesizeSpeechCommand,SynthesizeSpeechInput } from "@aws-sdk/client-polly"; import fs from 'fs'; async function go() { const client = new PollyClient(yourClientOptions) const command = new SynthesizeSpeechCommand(yourCommandOptions) try { let data = await client.send(command) if (!data || !data.AudioStream) throw Error(`bad response`); await saveStream(data.AudioStream,"output.mp3") } catch(err) { console.log(err) } } async function saveStream(fromStream,filename) { return new Promise((resolve,reject) => { let toStream = fs.createWriteStream(filename) toStream.on('finish',resolve); toStream.on('error',reject); fromStream.pipe(toStream) }) } go() ，但您也可以轻松使用 import。