PyTorch随笔 - 获取TensorRT(TRT)模型输入和输出_python trt

获取TensorRT(TRT)模型输入和输出，用于创建TRT的模型服务使用，具体参考脚本check_trt_script.py，如下：

• 脚本输入：TRT的模型路径和输入图像尺寸
• 脚本输出：模型的输入和输出结点信息，同时验证TRT模型是否可用

#!/usr/bin/env python
# -- coding: utf-8 --
"""
Copyright (c) 2021. All rights reserved.
Created by C. L. Wang on 16.9.21
"""

import argparse

import numpy as np


def check_trt(model_path, image_size):
    """
    检查TRT模型
    """
    import pycuda.driver as cuda
    import tensorrt as trt
    # 必须导入包，import pycuda.autoinit，否则报错
    import pycuda.autoinit

    print('[Info] model_path: {}'.format(model_path))
    img_shape = (1, 3, image_size, image_size)
    print('[Info] img_shape: {}'.format(img_shape))

    trt_logger = trt.Logger(trt.Logger.WARNING)
    trt_path = model_path  # TRT模型路径
    with open(trt_path, 'rb') as f, trt.Runtime(trt_logger) as runtime:
        engine = runtime.deserialize_cuda_engine(f.read())
        for binding in engine:
            binding_idx = engine.get_binding_index(binding)
            size = engine.get_binding_shape(binding_idx)
            dtype = trt.nptype(engine.get_binding_dtype(binding))
            print("[Info] binding: {}, binding_idx: {}, size: {}, dtype: {}"
                  .format(binding, binding_idx, size, dtype))

    input_image = np.random.randn(*img_shape).astype(np.float32)  # 图像尺寸
    input_image = np.ascontiguousarray(input_image)
    print('[Info] input_image: {}'.format(input_image.shape))

    with engine.create_execution_context() as context:
        stream = cuda.Stream()
        bindings = [0] * len(engine)

        for binding in engine:
            idx = engine.get_binding_index(binding)

            if engine.binding_is_input(idx):
                input_memory = cuda.mem_alloc(input_image.nbytes)
                bindings[idx] = int(input_memory)
                cuda.memcpy_htod_async(input_memory, input_image, stream)
            else:
                dtype = trt.nptype(engine.get_binding_dtype(binding))
                shape = context.get_binding_shape(idx)

                output_buffer = np.empty(shape, dtype=dtype)
                output_buffer = np.ascontiguousarray(output_buffer)
                output_memory = cuda.mem_alloc(output_buffer.nbytes)
                bindings[idx] = int(output_memory)

        context.execute_async_v2(bindings, stream.handle)
        stream.synchronize()

        cuda.memcpy_dtoh(output_buffer, output_memory)
    print("[Info] output_buffer: {}".format(output_buffer))


def parse_args():
    """
    处理脚本参数
    """
    parser = argparse.ArgumentParser(description='检查TRT模型')
    parser.add_argument('-m', dest='model_path', required=True, help='TRT模型路径', type=str)
    parser.add_argument('-s', dest='image_size', required=False, help='图像尺寸，如336', type=int, default=336)

    args = parser.parse_args()

    arg_model_path = args.model_path
    print("[Info] 模型路径: {}".format(arg_model_path))

    arg_image_size = args.image_size
    print("[Info] image_size: {}".format(arg_image_size))

    return arg_model_path, arg_image_size


def main():
    arg_model_path, arg_image_size = parse_args()
    check_trt(arg_model_path, arg_image_size)  # 检查TRT模型


if __name__ == '__main__':
    main()
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注意：必须导入包，import pycuda.autoinit，否则cuda.Stream()报错，如下：

输出信息如下：

[Info] 模型路径: ../mydata/trt_models/model_best_c2_20210915_cuda.trt
[Info] image_size: 336
[Info] model_path: ../mydata/trt_models/model_best_c2_20210915_cuda.trt
[Info] img_shape: (1, 3, 336, 336)
[Info] binding: input_0, binding_idx: 0, size: (1, 3, 336, 336), dtype: <class 'numpy.float32'>
[Info] binding: output_0, binding_idx: 1, size: (1, 2), dtype: <class 'numpy.float32'>
[Info] input_image: (1, 3, 336, 336)
[Info] output_buffer: [[ 0.23275298 -0.2184143 ]]
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有效信息为：

• 输入结点binding: input_0，输入尺寸size: (1, 3, 336, 336)，输入类型dtype: <class 'numpy.float32'>
• 输出结果binding: output_0，输出尺寸size: (1, 2)，输出类型dtype: <class 'numpy.float32'>

相应的json文件如下：

{
    "model_path": "model_best_c2_20210915_cuda.trt",
    "model_format": "trt",
    "quant_type": "FP32",
    "gpu_index": 0,
    "inputs": {
        "input_0": {
            "shapes": [
                1,
                3,
                336,
                336
            ],
            "type": "FP32"
        }
    },
    "outputs": {
        "output_0": {
            "shapes": [
                1,
                2
            ],
            "type": "FP32"
        }
    }
}
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