How to get Word Level Timestamps using Azure Speech to Text and the Python SDK?

问题

My code currently is able to read an audio file and transcribe it using Azure Speech to Text, with help from an example that I found on GitHub. However, I need to include the timestamps for all the words in the transcription. According to the documentation, this functionality was added in version 1.5.0, and is accessed through the method request_word_level_timestamps(). But even when I have called it, I get the same response as before. I cannot figure out how to use it from the documentation. Does anyone know how it works?

I'm using Python SDK version 1.5.1.

import azure.cognitiveservices.speech as speechsdk
import time
from allennlp.predictors.predictor import Predictor
import json 

inputPath = "(inputlocation)"
outputPath = "(outputlocation)"

# 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., "westus").
speech_key, service_region = "apikey", "region"
speech_config = speechsdk.SpeechConfig(subscription=speech_key,     region=service_region)
speech_config.request_word_level_timestamps()
speech_config.output_format=speechsdk.OutputFormat.Detailed
#print("VALUE: " +     speech_config.get_property(property_id=speechsdk.PropertyId.SpeechServic    eResponse_RequestWordLevelTimestamps))
filename = input("Enter filename: ")

print(speech_config)

try:
    audio_config = speechsdk.audio.AudioConfig(filename= inputPath +     filename)

    # Creates a recognizer with the given settings
    speech_recognizer =     speechsdk.SpeechRecognizer(speech_config=speech_config,     audio_config=audio_config)


def start():
    done = False
    #output = ""
    fileOpened = open(outputPath+ filename[0: len(filename) - 4] + "_MS_recognized.txt", "w+")
    fileOpened.truncate(0)
    fileOpened.close()

    def stop_callback(evt):
        print("Closing on {}".format(evt))
        speech_recognizer.stop_continuous_recognition()
        nonlocal done
        done = True

    def add_to_res(evt):
        #nonlocal output
        #print("Recognized: {}".format(evt.result.text))
        #output = output + evt.result.text + "\n"
        fileOpened = open( outputPath + filename[0: len(filename) - 4] + "_MS_recognized.txt", "a")
        fileOpened.write(evt.result.text + "\n")
        fileOpened.close()
        #print(output)

    # Connect callbacks to the events fired by the speech recognizer
    speech_recognizer.recognizing.connect(lambda evt: print('RECOGNIZING: {}'.format(evt)))
    speech_recognizer.recognized.connect(lambda evt: print('RECOGNIZED: {}'.format(evt)))
    speech_recognizer.recognized.connect(add_to_res)
    speech_recognizer.session_started.connect(lambda evt: print('SESSION STARTED: {}'.format(evt)))
    speech_recognizer.session_stopped.connect(lambda evt: print('SESSION STOPPED {}'.format(evt)))
    speech_recognizer.canceled.connect(lambda evt: print('CANCELED {}'.format(evt)))
    # stop continuous recognition on either session stopped or canceled events
    speech_recognizer.session_stopped.connect(stop_callback)
    speech_recognizer.canceled.connect(stop_callback)

    # Start continuous speech recognition
    speech_recognizer.start_continuous_recognition()
    while not done:
        time.sleep(.5)
    # </SpeechContinuousRecognitionWithFile>


    # 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.

start()

except Exception as e: 
    print("File does not exist")
    #print(e)

The results only contain session_id and a result object which includes result_id, text and reason.

回答1:

Per a comment on how will it help for continuous recognition, if you set up the SpeechConfig with request_word_level_timestamps(), you can run this as continuous recognition. You can inspect the json results with evt.result.json.

For example,

speech_config = speechsdk.SpeechConfig(subscription=speech_key, region=service_region)
speech_config.request_word_level_timestamps()

then your speech recognizer:

speech_recognizer = speechsdk.SpeechRecognizer(speech_config=speech_config, audio_config=audio_config)

When you're connecting callbacks to the events fired by the speech_recognizer, you can see word-level timestamps with:

speech_recognizer.recognized.connect(lambda evt: print('JSON: {}'.format(evt.result.json)))

My issue is that the Translation object doesn't contain word-level as it doesn't accept a speech_config.

回答2:

I refered to your code and follow the offical tutorial Quickstart: Recognize speech with the Speech SDK for Python to write the sample code below, it works to print the Offset and Duration value for each word. I used an audio file named whatstheweatherlike.wav comes from samples/csharp/sharedcontent/console/whatstheweatherlike.wav of the GitHub Repo Azure-Samples/cognitive-services-speech-sdk.

Here is my sample code and its result.

import azure.cognitiveservices.speech as speechsdk

speech_key, service_region = "<your api key>", "<your region>"
speech_config = speechsdk.SpeechConfig(subscription=speech_key, region=service_region)
speech_config.request_word_level_timestamps()

audio_config = speechsdk.audio.AudioConfig(filename='whatstheweatherlike.wav')
speech_recognizer = speechsdk.SpeechRecognizer(speech_config=speech_config, audio_config=audio_config)
result = speech_recognizer.recognize_once()

# print(result.json)
# If without `request_word_level_timestamps`, the result:
# {"DisplayText":"What's the weather like?","Duration":13400000,"Offset":400000,"RecognitionStatus":"Success"}
# Enable `request_word_level_timestamps`, the result includes word level timestamps.
# {"Duration":13400000,"NBest":[{"Confidence":0.9761951565742493,"Display":"What's the weather like?","ITN":"What's the weather like","Lexical":"what's the weather like","MaskedITN":"What's the weather like","Words":[{"Duration":3800000,"Offset":600000,"Word":"what's"},{"Duration":1200000,"Offset":4500000,"Word":"the"},{"Duration":2900000,"Offset":5800000,"Word":"weather"},{"Duration":4700000,"Offset":8800000,"Word":"like"}]},{"Confidence":0.9245584011077881,"Display":"what is the weather like","ITN":"what is the weather like","Lexical":"what is the weather like","MaskedITN":"what is the weather like","Words":[{"Duration":2900000,"Offset":600000,"Word":"what"},{"Duration":700000,"Offset":3600000,"Word":"is"},{"Duration":1300000,"Offset":4400000,"Word":"the"},{"Duration":2900000,"Offset":5800000,"Word":"weather"},{"Duration":4700000,"Offset":8800000,"Word":"like"}]}],"Offset":400000,"RecognitionStatus":"Success"}

import json
stt = json.loads(result.json)
confidences_in_nbest = [item['Confidence'] for item in stt['NBest']]
best_index = confidences_in_nbest.index(max(confidences_in_nbest))
words = stt['NBest'][best_index]['Words']
print(words)

print(f"Word\tOffset\tDuration")
for word in words:
    print(f"{word['Word']}\t{word['Offset']}\t{word['Duration']}")

The output of the script above is:

[{'Duration': 3800000, 'Offset': 600000, 'Word': "what's"}, {'Duration': 1200000, 'Offset': 4500000, 'Word': 'the'}, {'Duration': 2900000, 'Offset': 5800000, 'Word': 'weather'}, {'Duration': 4700000, 'Offset': 8800000, 'Word': 'like'}]
Word    Offset  Duration
what's  600000  3800000
the     4500000 1200000
weather 5800000 2900000
like    8800000 4700000

Hope it helps.

来源：https://stackoverflow.com/questions/56842391/how-to-get-word-level-timestamps-using-azure-speech-to-text-and-the-python-sdk