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 Cloud 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

登入 Google Cloud 帳戶。如果您是 Google Cloud新手，歡迎 建立帳戶，親自評估產品在實際工作環境中的成效。新客戶還能獲得價值 $300 美元的免費抵免額，可用於執行、測試及部署工作負載。

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

Roles required to select or create a project

• Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
• Create a project: To create a project, you need the Project Creator role (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

Go to project selector

Verify that billing is enabled for your Google Cloud project.

Enable the Speech-to-Text APIs.

Roles required to enable APIs

To enable APIs, you need the Service Usage Admin IAM role (roles/serviceusage.serviceUsageAdmin), which contains the serviceusage.services.enable permission. Learn how to grant roles.

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.

   Go to IAM
2. Select the project.
3. Click Grant access.

4. In the New principals field, enter your user identifier. This is typically the email address for a Google Account.

5. Click Select a role, then search for the role.
6. To grant additional roles, click Add another role and add each additional role.
7. Click Save.

安裝 Google Cloud CLI。

注意：如果您先前已安裝 gcloud CLI，請執行 gcloud components update，確認您使用的是最新版本。

若您採用的是外部識別資訊提供者 (IdP)，請先使用聯合身分登入 gcloud CLI。

執行下列指令，初始化 gcloud CLI：

gcloud init

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

Roles required to select or create a project

• Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
• Create a project: To create a project, you need the Project Creator role (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

Go to project selector

Verify that billing is enabled for your Google Cloud project.

Enable the Speech-to-Text APIs.

Roles required to enable APIs

To enable APIs, you need the Service Usage Admin IAM role (roles/serviceusage.serviceUsageAdmin), which contains the serviceusage.services.enable permission. Learn how to grant roles.

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.

   Go to IAM
2. Select the project.
3. Click Grant access.

4. In the New principals field, enter your user identifier. This is typically the email address for a Google Account.

5. Click Select a role, then search for the role.
6. To grant additional roles, click Add another role and add each additional role.
7. Click Save.

安裝 Google Cloud CLI。

注意：如果您先前已安裝 gcloud CLI，請執行 gcloud components update，確認您使用的是最新版本。

若您採用的是外部識別資訊提供者 (IdP)，請先使用聯合身分登入 gcloud CLI。

執行下列指令，初始化 gcloud CLI：

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。有了應用程式預設憑證，您就能在本機測試應用程式並部署，不必變更基礎程式碼。詳情請參閱「 進行驗證以使用用戶端程式庫」一文。

1. 如果您使用本機殼層，請為使用者帳戶建立本機驗證憑證：

   gcloud auth application-default login

   如果您使用 Cloud Shell，則不需要執行這項操作。

   如果系統傳回驗證錯誤，且您使用外部識別資訊提供者 (IdP)，請確認您已 使用聯合身分登入 gcloud CLI。

此外，請務必安裝用戶端程式庫。

對本機檔案執行串流語音辨識

下列程式碼區塊包含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="chirp_3",
    )
    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

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

1. 選用：撤銷您建立的驗證憑證，並刪除本機憑證檔案。

   gcloud auth application-default revoke

2. 選用：從 gcloud CLI 撤銷憑證。

   gcloud auth revoke

控制台

注意：刪除專案會造成以下結果：

• 專案中的所有內容都會遭到刪除。如果使用現有專案來進行本文中的任務，刪除專案將一併移除當中已完成的其他任務'。
• 自訂專案 ID 會消失。當您之前建立這個專案時，可能建立了想要在日後使用的自訂專案 ID。如要保留使用該專案 ID 的網址 (例如 appspot.com 網址)，請刪除在該專案中選取的資源，而不是刪除整個專案。

如果打算探索多種架構、教學課程或快速入門導覽課程，重複使用專案可避免超出專案配額限制。

前往 Google Cloud 控制台的「Manage resources」(管理資源) 頁面。

前往「Manage resources」(管理資源)

在專案清單中選取要刪除的專案，然後點選「Delete」(刪除)。

在對話方塊中輸入專案 ID，然後按一下 [Shut down] (關閉) 以刪除專案。

gcloud

注意：刪除專案會造成以下結果：

• 專案中的所有內容都會遭到刪除。如果使用現有專案來進行本文中的任務，刪除專案將一併移除當中已完成的其他任務'。
• 自訂專案 ID 會消失。當您之前建立這個專案時，可能建立了想要在日後使用的自訂專案 ID。如要保留使用該專案 ID 的網址 (例如 appspot.com 網址)，請刪除在該專案中選取的資源，而不是刪除整個專案。

如果打算探索多種架構、教學課程或快速入門導覽課程，重複使用專案可避免超出專案配額限制。

刪除 Google Cloud 專案：

gcloud projects delete PROJECT_ID

後續步驟

• 如要瞭解串流辨識功能，請參閱參考文件。
• 瞭解如何轉錄短音訊檔案。
• 瞭解如何轉錄長音訊檔案。
• 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。