Amazon Nova Reel を使用してテキストプロンプトからビデオを生成する

Amazon Nova Reel を使用して、テキストプロンプトからビデオを生成します。

"""
This example demonstrates how to use Amazon Nova Reel to generate a video from a text prompt.

It shows how to:
- Set up the Amazon Bedrock runtime client
- Configure a text-to-video request
- Submit an asynchronous job for video generation
- Poll for job completion status
- Access the generated video from S3
"""

import random
import time

import boto3

# Replace with your own S3 bucket to store the generated video
# Format: s3://your-bucket-name
OUTPUT_S3_URI = "s3://REPLACE-WITH-YOUR-S3-BUCKET-NAME"


def start_text_to_video_generation_job(bedrock_runtime, prompt, output_s3_uri):
    """
    Starts an asynchronous text-to-video generation job using Amazon Nova Reel.

    :param bedrock_runtime: The Bedrock runtime client
    :param prompt: The text description of the video to generate
    :param output_s3_uri: S3 URI where the generated video will be stored

    :return: The invocation ARN of the async job
    """
    # Specify the model ID for text-to-video generation
    model_id = "amazon.nova-reel-v1:0"

    # Generate a random seed between 0 and 2,147,483,646
    # This helps ensure unique video generation results
    seed = random.randint(0, 2147483646)

    # Configure the video generation request with additional parameters
    model_input = {
        "taskType": "TEXT_VIDEO",
        "textToVideoParams": {"text": prompt},
        "videoGenerationConfig": {
            "fps": 24,
            "durationSeconds": 6,
            "dimension": "1280x720",
            "seed": seed,
        },
    }

    # Specify the S3 location for the output video
    output_config = {"s3OutputDataConfig": {"s3Uri": output_s3_uri}}

    # Invoke the model asynchronously
    response = bedrock_runtime.start_async_invoke(
        modelId=model_id, modelInput=model_input, outputDataConfig=output_config
    )

    invocation_arn = response["invocationArn"]

    return invocation_arn


def query_job_status(bedrock_runtime, invocation_arn):
    """
    Queries the status of an asynchronous video generation job.

    :param bedrock_runtime: The Bedrock runtime client
    :param invocation_arn: The ARN of the async invocation to check

    :return: The runtime response containing the job status and details
    """
    return bedrock_runtime.get_async_invoke(invocationArn=invocation_arn)


def main():
    """
    Main function that demonstrates the complete workflow for generating
    a video from a text prompt using Amazon Nova Reel.
    """
    # Create a Bedrock Runtime client
    # Note: Credentials will be loaded from the environment or AWS CLI config
    bedrock_runtime = boto3.client("bedrock-runtime", region_name="us-east-1")

    # Configure the text prompt and output location
    prompt = "Closeup of a cute old steampunk robot. Camera zoom in."

    # Verify the S3 URI has been set to a valid bucket
    if "REPLACE-WITH-YOUR-S3-BUCKET-NAME" in OUTPUT_S3_URI:
        print("ERROR: You must replace the OUTPUT_S3_URI with your own S3 bucket URI")
        return

    print("Submitting video generation job...")
    invocation_arn = start_text_to_video_generation_job(
        bedrock_runtime, prompt, OUTPUT_S3_URI
    )
    print(f"Job started with invocation ARN: {invocation_arn}")

    # Poll for job completion
    while True:
        print("\nPolling job status...")
        job = query_job_status(bedrock_runtime, invocation_arn)
        status = job["status"]

        if status == "Completed":
            bucket_uri = job["outputDataConfig"]["s3OutputDataConfig"]["s3Uri"]
            print(f"\nSuccess! The video is available at: {bucket_uri}/output.mp4")
            break
        elif status == "Failed":
            print(
                f"\nVideo generation failed: {job.get('failureMessage', 'Unknown error')}"
            )
            break
        else:
            print("In progress. Waiting 15 seconds...")
            time.sleep(15)


if __name__ == "__main__":
    main()