转录多通道音频

本页面介绍了如何使用 Speech-to-Text 转写包含多个通道的音频文件。多通道识别适用于 Speech-to-Text 支持的所有音频编码，最多支持 8 个通道。

如果您使用的是 AutoDetectDecodingConfig，则无需指定文件具有的音频通道数量。它是自动确定的。使用 ExplicitDecodingConfig 时，必须指定音频通道数。

通常情况下，对于录音中出现的每名讲话人，音频数据都会包含一个对应的通道。例如，通过电话交谈的两个人的音频可能包含两个通道，分别记录通话双方的线路。

在您发送包含多个通道的请求后，Speech-to-Text 会向您返回标识音频中不同通道的结果，并使用 channel_tag 字段标记每个结果的替代项。

准备工作

  1. 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.

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

    Go to project selector

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

  4. Enable the Speech-to-Text APIs.

    Enable the APIs

  5. 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 colunn 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
    2. 选择项目。
    3. 点击 授予访问权限。

    4. 在新的主账号字段中，输入您的用户标识符。 这通常是 Google 账号的电子邮件地址。

    5. 在选择角色列表中，选择一个角色。
    6. 如需授予其他角色，请点击 添加其他角色，然后添加其他各个角色。
    7. 点击保存。
    8. Install the Google Cloud CLI.

    9. To initialize the gcloud CLI, run the following command: 

      gcloud init

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

      Go to project selector

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

    12. Enable the Speech-to-Text APIs.

      Enable the APIs

    13. 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 colunn 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
      2. 选择项目。
      3. 点击 授予访问权限。

      4. 在新的主账号字段中，输入您的用户标识符。 这通常是 Google 账号的电子邮件地址。

      5. 在选择角色列表中，选择一个角色。
      6. 如需授予其他角色，请点击 添加其他角色，然后添加其他各个角色。
      7. 点击保存。
      8. Install the Google Cloud CLI.

      9. To initialize the gcloud CLI, run the following command: 

        gcloud init

        10. 客户端库可以使用应用默认凭据轻松进行 Google API 身份验证，并向这些 API 发送请求。借助应用默认凭据，您可以在本地测试应用并部署它，无需更改底层代码。如需了解详情，请参阅 使用客户端库时进行身份验证。

      10. 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.

      此外，请确保您已安装客户端库。

      对多通道文件执行同步语音识别

      以下示例展示了如何对本地多通道音频文件执行同步语音识别：

      Python

      import os

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

PROJECT_ID = os.environ["GOOGLE_CLOUD_PROJECT"]


def transcribe_multichannel_v2(
    audio_file: str,
) -> cloud_speech.RecognizeResponse:
    """Transcribe the given audio file synchronously with multichannel.
    Args:
        audio_file (str): Path to the local audio file to be transcribed.
            Example: "resources/two_channel_16k.wav"
    Returns:
        cloud_speech.RecognizeResponse: The full response object which includes the transcription results.
    """
    # Instantiates a client
    client = SpeechClient()

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

    config = cloud_speech.RecognitionConfig(
        auto_decoding_config=cloud_speech.AutoDetectDecodingConfig(),
        language_codes=["en-US"],
        model="long",
        features=cloud_speech.RecognitionFeatures(
            multi_channel_mode=cloud_speech.RecognitionFeatures.MultiChannelMode.SEPARATE_RECOGNITION_PER_CHANNEL,
        ),
    )

    request = cloud_speech.RecognizeRequest(
        recognizer=f"projects/{PROJECT_ID}/locations/global/recognizers/_",
        config=config,
        content=audio_content,
    )

    # Transcribes the audio into text
    response = client.recognize(request=request)

    for result in response.results:
        print(f"Transcript: {result.alternatives[0].transcript}")
        print(f"Channel tag: {result.channel_tag}")

    return response

      清理

      为避免因本页中使用的资源导致您的 Google Cloud 账号产生费用，请按照以下步骤操作。

      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

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

      Go to Manage resources

    15. In the project list, select the project that you want to delete, and then click Delete.
    16. In the dialog, type the project ID, and then click Shut down to delete the project.

      17. gcloud

      Delete a Google Cloud project:

      gcloud projects delete PROJECT_ID

      后续步骤