转录短音频文件

本页演示如何使用同步语音识别将短音频文件转录为文字。

同步语音识别功能可返回短音频（少于 60 秒）的识别文本。

Speech-to-Text 可以直接接收本地文件中的音频内容，也可以处理存储在 Cloud Storage 存储桶中的音频内容。请参阅配额和限制页面，了解同步语音识别请求的限制。

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.

      进入 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 Save（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.

        进入 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 Save（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。

      对本地文件执行同步语音识别

      以下是对本地音频文件执行同步语音识别的示例：

      Python

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

# TODO(developer): Update and un-comment below line
# PROJECT_ID = "your-project-id"

# Instantiates a client
client = SpeechClient()

# Reads a file as bytes
with open("resources/audio.wav", "rb") as f:
    audio_content = f.read()

config = cloud_speech.RecognitionConfig(
    auto_decoding_config=cloud_speech.AutoDetectDecodingConfig(),
    language_codes=["en-US"],
    model="long",
)

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}")

      对远程文件执行同步语音识别

      为方便您使用，Speech-to-Text API 可以直接对位于 Cloud Storage 的音频文件执行同步语音识别，而您无需在请求体中发送音频文件的内容。

      Speech-to-Text 使用服务账号访问 Cloud Storage 中的文件。默认情况下，服务账号可以访问同一项目中的 Cloud Storage 文件。

      服务账号电子邮件地址如下所示：

      service-PROJECT_NUMBER@gcp-sa-speech.iam.gserviceaccount.com

      如需转写另一个项目中的 Cloud Storage 文件，您可以向此服务账号授予另一个项目中的 Speech-to-Text Service Agent 角色：

      gcloud projects add-iam-policy-binding PROJECT_ID \
    --member=serviceAccount:service-PROJECT_NUMBER@gcp-sa-speech.iam.gserviceaccount.com \
    --role=roles/speech.serviceAgent

      如需详细了解项目 IAM 政策，请参阅管理对项目、文件夹和组织的访问权限

      您还可以通过向服务账号授予对特定 Cloud Storage 存储桶的权限，为服务账号授予更精细的访问权限：

      gcloud storage buckets add-iam-policy-binding gs://BUCKET_NAME \
    --member=serviceAccount:service-PROJECT_NUMBER@gcp-sa-speech.iam.gserviceaccount.com \
    --role=roles/storage.admin

      如需详细了解如何管理对 Cloud Storage 的访问权限，请参阅 Cloud Storage 文档中的创建和管理访问权限控制列表。

      以下是对 Cloud Storage 中的文件执行同步语音识别的示例：

      Python

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

# Instantiates a client
client = SpeechClient()

# TODO(developer): Update and un-comment below line
# PROJECT_ID = "your-project-id"

config = cloud_speech.RecognitionConfig(
    auto_decoding_config=cloud_speech.AutoDetectDecodingConfig(),
    language_codes=["en-US"],
    model="long",
)

request = cloud_speech.RecognizeRequest(
    recognizer=f"projects/{PROJECT_ID}/locations/global/recognizers/_",
    config=config,
    uri="gs://cloud-samples-data/speech/audio.flac",  # URI of the audio file in GCS
)

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

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

      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