# 开始使用语音转语音功能
以下章节通过示例与分步讲解，介绍如何使用 Amazon Nova 2 Sonic 实现简易的实时音频流应用程序。这个简化版本演示了使用 Amazon Nova 2 Sonic 模型创建音频对话所需的核心功能。
我们的 [Nova 示例 GitHub 存储库](https://github.com/aws-samples/amazon-nova-samples)中列出了以下示例。
连接时长限制为 8 分钟，[GitHub](https://github.com/aws-samples/amazon-nova-samples/tree/main/speech-to-speech/amazon-nova-2-sonic/repeatable-patterns/session-continuation/console-python) 上提供了连接续约与对话持续方案。
## 说明导入和配置
本节会导入必要的库并设置音频配置参数：
+ `asyncio`：用于异步编程
+ `base64`：用于对音频数据进行编码和解码
+ `pyaudio`：用于音频采集和播放
+ Amazon Bedrock SDK 流组件
+ 音频常量定义了音频采集的格式（16 kHz 采样率，单声道）
```
import os
import asyncio
import base64
import json
import uuid
import pyaudio
from aws_sdk_bedrock_runtime.client import BedrockRuntimeClient, InvokeModelWithBidirectionalStreamOperationInput
from aws_sdk_bedrock_runtime.models import InvokeModelWithBidirectionalStreamInputChunk, BidirectionalInputPayloadPart
from aws_sdk_bedrock_runtime.config import Config, HTTPAuthSchemeResolver, SigV4AuthScheme
from smithy_aws_core.identity import EnvironmentCredentialsResolver
# Audio configuration
INPUT_SAMPLE_RATE = 16000
OUTPUT_SAMPLE_RATE = 24000
CHANNELS = 1
FORMAT = pyaudio.paInt16
CHUNK_SIZE = 1024
```
## 定义 `SimpleNovaSonic` 类
`SimpleNovaSonic` 类是处理 Amazon Nova Sonic 交互的主类：
+ `model_id`：Amazon Nova Sonic 模型 ID (`amazon.nova-2-sonic-v1:0`)
+ `region`：AWS 区域，默认为 `us-east-1`
+ 用于提示和内容跟踪的唯一 ID
+ 用于音频播放的异步队列
```
class SimpleNovaSonic:
def __init__(self, model_id='amazon.nova-2-sonic-v1:0', region='us-east-1'):
self.model_id = model_id
self.region = region
self.client = None
self.stream = None
self.response = None
self.is_active = False
self.prompt_name = str(uuid.uuid4())
self.content_name = str(uuid.uuid4())
self.audio_content_name = str(uuid.uuid4())
self.audio_queue = asyncio.Queue()
self.display_assistant_text = False
```
## 初始化客户端
此方法使用以下信息来配置 Amazon Bedrock 客户端：
+ 指定区域的相应端点
+ 使用环境变量作为 AWS 凭证的身份证信息
+ 适用于 AWS API 调用的 SigV4 身份证方案
```
def _initialize_client(self):
"""Initialize the Bedrock client."""
config = Config(
endpoint_uri=f"https://bedrock-runtime.{self.region}.amazonaws.com",
region=self.region,
aws_credentials_identity_resolver=EnvironmentCredentialsResolver(),
auth_scheme_resolver=HTTPAuthSchemeResolver(),
auth_schemes={"aws.auth#sigv4": SigV4AuthScheme(service="bedrock")}
)
self.client = BedrockRuntimeClient(config=config)
```
## 处理事件
这个辅助方法将 JSON 事件发送到双向流，该流用于与 Amazon Nova Sonic 模型的所有通信：
```
async def send_event(self, event_json):
"""Send an event to the stream."""
event = InvokeModelWithBidirectionalStreamInputChunk(
value=BidirectionalInputPayloadPart(bytes_=event_json.encode('utf-8'))
)
await self.stream.input_stream.send(event)
```
## 启动会话
这个方法可启动会话并设置其余事件来启动音频流。这些事件需要按相同的顺序发送。
```
async def start_session(self):
"""Start a new session with Nova Sonic."""
if not self.client:
self._initialize_client()
# Initialize the stream
self.stream = await self.client.invoke_model_with_bidirectional_stream(
InvokeModelWithBidirectionalStreamOperationInput(model_id=self.model_id)
)
self.is_active = True
# Send session start event
session_start = '''
{
"event": {
"sessionStart": {
"inferenceConfiguration": {
"maxTokens": 1024,
"topP": 0.9,
"temperature": 0.7
},
"turnDetectionConfiguration": {
"endpointingSensitivity": "HIGH"
}
}
}
}
'''
await self.send_event(session_start)
# Send prompt start event
prompt_start = f'''
{{
"event": {{
"promptStart": {{
"promptName": "{self.prompt_name}",
"textOutputConfiguration": {{
"mediaType": "text/plain"
}},
"audioOutputConfiguration": {{
"mediaType": "audio/lpcm",
"sampleRateHertz": 24000,
"sampleSizeBits": 16,
"channelCount": 1,
"voiceId": "matthew",
"encoding": "base64",
"audioType": "SPEECH"
}}
}}
}}
}}
'''
await self.send_event(prompt_start)
# Send system prompt
text_content_start = f'''
{{
"event": {{
"contentStart": {{
"promptName": "{self.prompt_name}",
"contentName": "{self.content_name}",
"type": "TEXT",
"interactive": true,
"role": "SYSTEM",
"textInputConfiguration": {{
"mediaType": "text/plain"
}}
}}
}}
}}
'''
await self.send_event(text_content_start)
system_prompt = "You are a friendly assistant. The user and you will engage in a spoken dialog " \
"exchanging the transcripts of a natural real-time conversation. Keep your responses short, " \
"generally two or three sentences for chatty scenarios."
text_input = f'''
{{
"event": {{
"textInput": {{
"promptName": "{self.prompt_name}",
"contentName": "{self.content_name}",
"content": "{system_prompt}"
}}
}}
}}
'''
await self.send_event(text_input)
text_content_end = f'''
{{
"event": {{
"contentEnd": {{
"promptName": "{self.prompt_name}",
"contentName": "{self.content_name}"
}}
}}
}}
'''
await self.send_event(text_content_end)
# Start processing responses
self.response = asyncio.create_task(self._process_responses())
```
## 处理音频输入
以下方法可处理音频输入生命周期：
+ `start_audio_input`：配置并启动音频输入流
+ `send_audio_chunk`：编码音频片段并发送给模型
+ `end_audio_input`：正确关闭音频输入流
```
async def start_audio_input(self):
"""Start audio input stream."""
audio_content_start = f'''
{{
"event": {{
"contentStart": {{
"promptName": "{self.prompt_name}",
"contentName": "{self.audio_content_name}",
"type": "AUDIO",
"interactive": true,
"role": "USER",
"audioInputConfiguration": {{
"mediaType": "audio/lpcm",
"sampleRateHertz": 16000,
"sampleSizeBits": 16,
"channelCount": 1,
"audioType": "SPEECH",
"encoding": "base64"
}}
}}
}}
}}
'''
await self.send_event(audio_content_start)
async def send_audio_chunk(self, audio_bytes):
"""Send an audio chunk to the stream."""
if not self.is_active:
return
blob = base64.b64encode(audio_bytes)
audio_event = f'''
{{
"event": {{
"audioInput": {{
"promptName": "{self.prompt_name}",
"contentName": "{self.audio_content_name}",
"content": "{blob.decode('utf-8')}"
}}
}}
}}
'''
await self.send_event(audio_event)
async def end_audio_input(self):
"""End audio input stream."""
audio_content_end = f'''
{{
"event": {{
"contentEnd": {{
"promptName": "{self.prompt_name}",
"contentName": "{self.audio_content_name}"
}}
}}
}}
'''
await self.send_event(audio_content_end)
```
## 结束会话
这个方法通过以下方式正确关闭会话：
+ 发送 `promptEnd` 事件
+ 发送 `sessionEnd` 事件
+ 关闭输入流
```
async def end_session(self):
"""End the session."""
if not self.is_active:
return
prompt_end = f'''
{{
"event": {{
"promptEnd": {{
"promptName": "{self.prompt_name}"
}}
}}
}}
'''
await self.send_event(prompt_end)
session_end = '''
{
"event": {
"sessionEnd": {}
}
}
'''
await self.send_event(session_end)
# close the stream
await self.stream.input_stream.close()
```
## 处理回复
此方法可持续处理来自模型的回复并执行以下操作：
+ 等待流的输出。
+ 解析 JSON 回复。
+ 通过打印到具有自动语音识别和转录功能的控制台来处理文本输出。
+ 通过解码和排队等候播放来处理音频输出。
```
async def _process_responses(self):
"""Process responses from the stream."""
try:
while self.is_active:
output = await self.stream.await_output()
result = await output[1].receive()
if result.value and result.value.bytes_:
response_data = result.value.bytes_.decode('utf-8')
json_data = json.loads(response_data)
if 'event' in json_data:
# Handle content start event
if 'contentStart' in json_data['event']:
content_start = json_data['event']['contentStart']
# set role
self.role = content_start['role']
# Check for speculative content
if 'additionalModelFields' in content_start:
additional_fields = json.loads(content_start['additionalModelFields'])
if additional_fields.get('generationStage') == 'SPECULATIVE':
self.display_assistant_text = True
else:
self.display_assistant_text = False
# Handle text output event
elif 'textOutput' in json_data['event']:
text = json_data['event']['textOutput']['content']
if (self.role == "ASSISTANT" and self.display_assistant_text):
print(f"Assistant: {text}")
elif self.role == "USER":
print(f"User: {text}")
# Handle audio output
elif 'audioOutput' in json_data['event']:
audio_content = json_data['event']['audioOutput']['content']
audio_bytes = base64.b64decode(audio_content)
await self.audio_queue.put(audio_bytes)
except Exception as e:
print(f"Error processing responses: {e}")
```
## 播放音频
这个方法将执行以下任务：
+ 初始化 `PyAudio` 输入流
+ 持续从队列中检索音频数据
+ 通过扬声器播放音频
+ 完成后正确清理资源
```
async def play_audio(self):
"""Play audio responses."""
p = pyaudio.PyAudio()
stream = p.open(
format=FORMAT,
channels=CHANNELS,
rate=OUTPUT_SAMPLE_RATE,
output=True
)
```
尝试执行：
```
while self.is_active:
audio_data = await self.audio_queue.get()
stream.write(audio_data)
except Exception as e:
print(f"Error playing audio: {e}")
finally:
stream.stop_stream()
stream.close()
p.terminate()
```
## 捕获音频
这个方法将执行以下任务：
+ 初始化 `PyAudio` 输出流
+ 启动音频输入会话
+ 持续捕获来自麦克风的音频片段
+ 将每个片段发送到 Amazon Nova Sonic 模型
+ 完成后正确清理资源
```
async def capture_audio(self):
"""Capture audio from microphone and send to Nova Sonic."""
p = pyaudio.PyAudio()
stream = p.open(
format=FORMAT,
channels=CHANNELS,
rate=INPUT_SAMPLE_RATE,
input=True,
frames_per_buffer=CHUNK_SIZE
)
print("Starting audio capture. Speak into your microphone...")
print("Press Enter to stop...")
await self.start_audio_input()
```
尝试执行：
```
while self.is_active:
audio_data = stream.read(CHUNK_SIZE, exception_on_overflow=False)
await self.send_audio_chunk(audio_data)
await asyncio.sleep(0.01)
except Exception as e:
print(f"Error capturing audio: {e}")
finally:
stream.stop_stream()
stream.close()
p.terminate()
print("Audio capture stopped.")
await self.end_audio_input()
```
## 运行主函数
主函数通过执行以下操作来协调整个过程：
+ 创建 Amazon Nova 2 Sonic 客户端
+ 启动会话
+ 创建用于音频播放和采集的并发任务
+ 等待用户按 **Enter** 键停止
+ 正确结束会话并清理任务
```
async def main():
# Create Nova Sonic client
nova_client = SimpleNovaSonic()
# Start session
await nova_client.start_session()
# Start audio playback task
playback_task = asyncio.create_task(nova_client.play_audio())
# Start audio capture task
capture_task = asyncio.create_task(nova_client.capture_audio())
# Wait for user to press Enter to stop
await asyncio.get_event_loop().run_in_executor(None, input)
# End session
nova_client.is_active = False
# First cancel the tasks
tasks = []
if not playback_task.done():
tasks.append(playback_task)
if not capture_task.done():
tasks.append(capture_task)
for task in tasks:
task.cancel()
if tasks:
await asyncio.gather(*tasks, return_exceptions=True)
# cancel the response task
if nova_client.response and not nova_client.response.done():
nova_client.response.cancel()
await nova_client.end_session()
print("Session ended")
if __name__ == "__main__":
# Set AWS credentials if not using environment variables
# os.environ['AWS_ACCESS_KEY_ID'] = "your-access-key"
# os.environ['AWS_SECRET_ACCESS_KEY'] = "your-secret-key"
# os.environ['AWS_DEFAULT_REGION'] = "us-east-1"
asyncio.run(main())
```