Azure Cognitive Services- Spee
Speech 服务是认知服务的一种，提供了语音转文本，文本转语音, 语音翻译等，今天我们实战的是语音转文本（Speech To Text）。
STT支持两种访问方式，1.是SDK，2.是REST API。
其中:
SDK方式支持 识别麦克风的语音流 和 语音文件；
REST API方式仅支持语音文件；
准备工作：创建 认知服务之Speech服务：
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创建完成后，两个重要的参数可以在页面查看：
一. REST API方式将语音文件转换成文本：
Azure global的 Speech API 终结点请参考：
https://docs.microsoft.com/zh-cn/azure/cognitive-services/speech-service/rest-speech-to-text#regions-and-endpoints
Azure 中国区 的 Speech API 终结点：
截至到2020.2月，仅中国东部2区域已开通Speech服务，服务终结点为：
https://chinaeast2.stt.speech.azure.cn/speech/recognition/conversation/cognitiveservices/v1
对于Speech To Text来说，有两种身份验证方式：
其中Authorization Token有效期为10分钟。
为了简便，本文使用了Ocp-Apim-Subscription-Key的方式。
注意：如果要实现文本转语音，按照上表，则必须使用 Authorization Token形式进行身份验证。
构建请求的其他注意事项：
文件格式：
请求头：
需要注意的是，Key或者Authorization是二选一的关系。请求参数：
在Postman中的示例如下：
如果要在REST API中使用 Authorization Token，则需要先获得Token：
Global 获取Token的终结点：
https://docs.microsoft.com/zh-cn/azure/cognitive-services/speech-service/rest-speech-to-text#authentication
中国区获取Token的终结点：
截至2020.02，只有中国东部2有Speech服务，其Token终结点为：
https://chinaeast2.api.cognitive.azure.cn/sts/v1.0/issuetoken
Postman获取Token 参考如下：
二. SDK方式将语音文件转换成文本（Python示例）：
在官网可以看到类似的代码，但需要注意的是，该代码仅在Azure Global的Speech服务中正常工作，针对中国区，需要做特定的修改（见下文）。
import azure.cognitiveservices.speech as speechsdk # Creates an instance of a speech config with specified subscription key and service region. # Replace with your own subscription key and service region (e.g., "chinaeast2"). speech_key, service_region = "YourSubscriptionKey", "YourServiceRegion" speech_config = speechsdk.SpeechConfig(subscription=speech_key, region=service_region) # Creates an audio configuration that points to an audio file. # Replace with your own audio filename. audio_filename = "whatstheweatherlike.wav" audio_input = speechsdk.AudioConfig(filename=audio_filename) # Creates a recognizer with the given settings speech_recognizer = speechsdk.SpeechRecognizer(speech_config=speech_config, audio_config=audio_input) print("Recognizing first result...") # Starts speech recognition, and returns after a single utterance is recognized. The end of a # single utterance is determined by listening for silence at the end or until a maximum of 15 # seconds of audio is processed. The task returns the recognition text as result. # Note: Since recognize_once() returns only a single utterance, it is suitable only for single # shot recognition like command or query. # For long-running multi-utterance recognition, use start_continuous_recognition() instead. result = speech_recognizer.recognize_once() # Checks result. if result.reason == speechsdk.ResultReason.RecognizedSpeech: print("Recognized: {}".format(result.text)) elif result.reason == speechsdk.ResultReason.NoMatch: print("No speech could be recognized: {}".format(result.no_match_details)) elif result.reason == speechsdk.ResultReason.Canceled: cancellation_details = result.cancellation_details print("Speech Recognition canceled: {}".format(cancellation_details.reason)) if cancellation_details.reason == speechsdk.CancellationReason.Error: print("Error details: {}".format(cancellation_details.error_details))
代码提供页面：
https://docs.azure.cn/zh-cn/cognitive-services/speech-service/quickstarts/speech-to-text-from-file?tabs=linux&pivots=programming-language-python#create-a-python-application-that-uses-the-speech-sdk
针对中国区，需要使用自定义终结点的方式，才能正常使用SDK：
speech_key, service_region = "Your Key", "chinaeast2"template = "wss://{}.stt.speech.azure.cn/speech/recognition" \ "/conversation/cognitiveservices/v1?initialSilenceTimeoutMs={:d}&language=zh-CN"speech_config = speechsdk.SpeechConfig(subscription=speech_key,endpoint=template.format(service_region, int(initial_silence_timeout_ms)))中国区完整代码为：
#!/usr/bin/env python# coding: utf-8# Copyright (c) Microsoft. All rights reserved.# Licensed under the MIT license. See LICENSE.md file in the project root for full license information."""Speech recognition samples for the Microsoft Cognitive Services Speech SDK"""import timeimport wavetry: import azure.cognitiveservices.speech as speechsdkexcept ImportError: print(""" Importing the Speech SDK for Python failed. Refer to https://docs.microsoft.com/azure/cognitive-services/speech-service/quickstart-python for installation instructions. """) import sys sys.exit(1)# Set up the subscription info for the Speech Service:# Replace with your own subscription key and service region (e.g., "westus").speech_key, service_region = "your key", "chinaeast2"# Specify the path to an audio file containing speech (mono WAV / PCM with a sampling rate of 16# kHz).filename = "D:\FFOutput\speechtotext.wav"def speech_recognize_once_from_file_with_custom_endpoint_parameters(): """performs one-shot speech recognition with input from an audio file, specifying an endpoint with custom parameters""" initial_silence_timeout_ms = 15 * 1e3 template = "wss://{}.stt.speech.azure.cn/speech/recognition/conversation/cognitiveservices/v1?initialSilenceTimeoutMs={:d}&language=zh-CN" speech_config = speechsdk.SpeechConfig(subscription=speech_key, endpoint=template.format(service_region, int(initial_silence_timeout_ms))) print("Using endpoint", speech_config.get_property(speechsdk.PropertyId.SpeechServiceConnection_Endpoint)) audio_config = speechsdk.audio.AudioConfig(filename=filename) # Creates a speech recognizer using a file as audio input. # The default language is "en-us". speech_recognizer = speechsdk.SpeechRecognizer(speech_config=speech_config, audio_config=audio_config) result = speech_recognizer.recognize_once() # Check the result if result.reason == speechsdk.ResultReason.RecognizedSpeech: print("Recognized: {}".format(result.text)) elif result.reason == speechsdk.ResultReason.NoMatch: print("No speech could be recognized: {}".format(result.no_match_details)) elif result.reason == speechsdk.ResultReason.Canceled: cancellation_details = result.cancellation_details print("Speech Recognition canceled: {}".format(cancellation_details.reason)) if cancellation_details.reason == speechsdk.CancellationReason.Error: print("Error details: {}".format(cancellation_details.error_details))speech_recognize_once_from_file_with_custom_endpoint_parameters()需要注意的是，如果我们使用SDK识别麦克风中的语音，则将
speech_recognizer = speechsdk.SpeechRecognizer(speech_config=speech_config, audio_config=audio_config)
修改为如下即可（去掉audio_config参数）：
speech_recognizer = speechsdk.SpeechRecognizer(speech_config=speech_config)
公众号链接：https://mp.weixin.qq.com/s/NA9kQsVDfzTXEqHMTdDExA
语雀地址：https://www.yuque.com/seanyu/azure/blwb5i
