AWS 转录过程完成后调用另一个 lambda

Invoke another lambda after the AWS transcribe process is completed

我有一个 lambda,它会在任何人将音频文件上传到存储桶时触发。我需要使用 AWS Transcribe 异步处理文件。我写了代码来做到这一点,但问题是它只检查一次,它不是在文件处理完成后调用处理函数。

下面是 AWS 转录的 Whosebug link,但我们必须等待响应,直到作业完成并且 lambda 函数超时 5 分钟。之后执行将停止。

// 创建一个异步客户端对象来调用 AWS Transcribe

private AmazonTranscribeAsync asyncClient = AmazonTranscribeAsyncClientBuilder.standard().build();

// 以下是调用 AWS API 并上传音频文件的方法

private void startText(String guid, String bucket) {
    String jobName = UUID.randomUUID().toString();
    StartTranscriptionJobRequest request = new StartTranscriptionJobRequest();
    request.withLanguageCode(LanguageCode.EnUS);

    Settings channel_settings = new Settings();
    channel_settings.setChannelIdentification(true);
    channel_settings.withChannelIdentification(true);

    Media media = new Media();
    media.setMediaFileUri(s3.getUrl(bucket, guid).toString());
    request.withMedia(media);
    request.setTranscriptionJobName(jobName);
    request.withMediaFormat(getFileFormat(guid));
    request.withSettings(channel_settings);
    asyncClient.startTranscriptionJobAsync(request, new AsyncTranscriptionJobHandler());
}

// 异步处理程序方法

private class AsyncTranscriptionJobHandler implements AsyncHandler<StartTranscriptionJobRequest, StartTranscriptionJobResult>
{
    public void onError(Exception e) {
        System.out.println(e.getMessage());
        System.exit(1);
    }

    @Override
    public void onSuccess(StartTranscriptionJobRequest request, StartTranscriptionJobResult result) {
        logger.log(result.getTranscriptionJob().getTranscriptionJobName());
        TranscriptionJob transcriptionJob = result.getTranscriptionJob(); 
        if (transcriptionJob.getTranscriptionJobStatus().equals(TranscriptionJobStatus.COMPLETED.name())) {
            logger.log("completed");
        } else if(transcriptionJob.getTranscriptionJobStatus().equals(TranscriptionJobStatus.FAILED.name())) {
            logger.log("failed");
        } else if(transcriptionJob.getTranscriptionJobStatus().equals(TranscriptionJobStatus.IN_PROGRESS.name())) {
            logger.log("processing");
        }

    }
}

这里的技巧是不等待转录完成,而是在一个lambda中调用它,然后在转录完成后触发一个单独的lambda。

AWS Transcribe 使用 CloudWatch Events 在作业完成或失败时发出通知 (https://docs.aws.amazon.com/transcribe/latest/dg/cloud-watch-events.html) which are a supported event source for lambda (https://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html#supported-event-source-cloudwatch-events)