從串流輸入轉錄音訊

本節說明如何將串流音訊 (例如來自麥克風的輸入) 轉錄為文字。

串流語音辨識功能可讓您將音訊串流至 Speech-to-Text，並在處理音訊時即時接收串流語音辨識結果。另請參閱串流語音辨識要求的音訊限制。串流語音辨識只能透過 gRPC 使用。

事前準備

Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

Go to project selector

Make sure that billing is enabled for your Google Cloud project.

Enable the Speech-to-Text APIs.

Enable the APIs

Make sure that you have the following role or roles on the project: Cloud Speech Administrator

Check for the roles

1. In the Google Cloud console, go to the IAM page.

   Go to IAM
2. Select the project.

3. In the Principal column, find all rows that identify you or a group that you're included in. To learn which groups you're included in, contact your administrator.

4. For all rows that specify or include you, check the Role column to see whether the list of roles includes the required roles.

Grant the roles

1. In the Google Cloud console, go to the IAM page.

   前往「IAM」頁面
2. 選取專案。
3. 按一下「授予存取權」person_add。

4. 在「New principals」(新增主體) 欄位中，輸入您的使用者 ID。 這通常是 Google 帳戶的電子郵件地址。

5. 在「Select a role」(選取角色) 清單中，選取角色。
6. 如要授予其他角色，請按一下 add「新增其他角色」，然後新增每個其他角色。
7. 按一下 [Save]。

Install the Google Cloud CLI.

If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

To initialize the gcloud CLI, run the following command:

gcloud init

In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

Go to project selector

Make sure that billing is enabled for your Google Cloud project.

Enable the Speech-to-Text APIs.

Enable the APIs

Make sure that you have the following role or roles on the project: Cloud Speech Administrator

Check for the roles

1. In the Google Cloud console, go to the IAM page.

   Go to IAM
2. Select the project.

3. In the Principal column, find all rows that identify you or a group that you're included in. To learn which groups you're included in, contact your administrator.

4. For all rows that specify or include you, check the Role column to see whether the list of roles includes the required roles.

Grant the roles

1. In the Google Cloud console, go to the IAM page.

   前往「IAM」頁面
2. 選取專案。
3. 按一下「授予存取權」person_add。

4. 在「New principals」(新增主體) 欄位中，輸入您的使用者 ID。 這通常是 Google 帳戶的電子郵件地址。

5. 在「Select a role」(選取角色) 清單中，選取角色。
6. 如要授予其他角色，請按一下 add「新增其他角色」，然後新增每個其他角色。
7. 按一下 [Save]。

Install the Google Cloud CLI.

If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

To initialize the gcloud CLI, run the following command:

gcloud init

用戶端程式庫可以使用應用程式預設憑證，輕鬆向 Google API 進行驗證，然後傳送要求給這些 API。使用應用程式預設憑證，您可以在本機測試及部署應用程式，不必變更基礎程式碼。詳情請參閱「 驗證以使用用戶端程式庫」。

1. If you're using a local shell, then create local authentication credentials for your user account:

   gcloud auth application-default login

   You don't need to do this if you're using Cloud Shell.

   If an authentication error is returned, and you are using an external identity provider (IdP), confirm that you have signed in to the gcloud CLI with your federated identity.

此外，請確認您已安裝用戶端程式庫。

對本機檔案執行串流語音辨識

以下是對本機音訊檔案執行串流語音辨識的範例。串流要求中傳送的音訊大小上限為 25 KB。這項限制適用於初始 StreamingRecognize 要求和串流中每則訊息的大小。如果超出這項限制，系統就會擲回錯誤。

Python

import os

from google.cloud.speech_v2 import SpeechClient
from google.cloud.speech_v2.types import cloud_speech as cloud_speech_types

PROJECT_ID = os.getenv("GOOGLE_CLOUD_PROJECT")


def transcribe_streaming_v2(
    stream_file: str,
) -> cloud_speech_types.StreamingRecognizeResponse:
    """Transcribes audio from an audio file stream using Google Cloud Speech-to-Text API.
    Args:
        stream_file (str): Path to the local audio file to be transcribed.
            Example: "resources/audio.wav"
    Returns:
        list[cloud_speech_types.StreamingRecognizeResponse]: A list of objects.
            Each response includes the transcription results for the corresponding audio segment.
    """
    # Instantiates a client
    client = SpeechClient()

    # Reads a file as bytes
    with open(stream_file, "rb") as f:
        audio_content = f.read()

    # In practice, stream should be a generator yielding chunks of audio data
    chunk_length = len(audio_content) // 5
    stream = [
        audio_content[start : start + chunk_length]
        for start in range(0, len(audio_content), chunk_length)
    ]
    audio_requests = (
        cloud_speech_types.StreamingRecognizeRequest(audio=audio) for audio in stream
    )

    recognition_config = cloud_speech_types.RecognitionConfig(
        auto_decoding_config=cloud_speech_types.AutoDetectDecodingConfig(),
        language_codes=["en-US"],
        model="long",
    )
    streaming_config = cloud_speech_types.StreamingRecognitionConfig(
        config=recognition_config
    )
    config_request = cloud_speech_types.StreamingRecognizeRequest(
        recognizer=f"projects/{PROJECT_ID}/locations/global/recognizers/_",
        streaming_config=streaming_config,
    )

    def requests(config: cloud_speech_types.RecognitionConfig, audio: list) -> list:
        yield config
        yield from audio

    # Transcribes the audio into text
    responses_iterator = client.streaming_recognize(
        requests=requests(config_request, audio_requests)
    )
    responses = []
    for response in responses_iterator:
        responses.append(response)
        for result in response.results:
            print(f"Transcript: {result.alternatives[0].transcript}")

    return responses

雖然您可以將本機音訊檔案串流至 Speech-to-Text API，不過建議您執行同步音訊辨識。

清除所用資源

如要避免系統向您的 Google Cloud 帳戶收取本頁所用資源的費用，請按照下列步驟操作。

1. Optional: Revoke the authentication credentials that you created, and delete the local credential file.

   gcloud auth application-default revoke

2. Optional: Revoke credentials from the gcloud CLI.

   gcloud auth revoke

控制台

In the Google Cloud console, go to the Manage resources page.

Go to Manage resources

In the project list, select the project that you want to delete, and then click Delete.

In the dialog, type the project ID, and then click Shut down to delete the project.

gcloud

Delete a Google Cloud project:

gcloud projects delete PROJECT_ID

後續步驟

• 如要瞭解串流辨識功能，請參閱參考說明文件。
• 練習轉錄短音訊檔案。
• 瞭解如何轉錄長音訊檔案。
• 使用 Chirp 轉錄音訊檔案。
• 如要獲得最佳效能、準確率與其他提示，請參閱最佳做法說明文件。