TAO Converter with Multitask Classification

The tao-converter tool is provided with the TAO Toolkit to facilitate the deployment of TAO trained models on TensorRT and/or Deepstream. This section elaborates on how to generate a TensorRT engine using tao-converter.

For deployment platforms with an x86-based CPU and discrete GPUs, the tao-converter is distributed within the TAO docker. Therefore, we suggest using the docker to generate the engine. However, this requires that the user adhere to the same minor version of TensorRT as distributed with the docker. The TAO docker includes TensorRT version 8.0.

For an x86 platform with discrete GPUs, the default TAO package includes the tao-converter built for TensorRT 8.2.5.1 with CUDA 11.4 and CUDNN 8.2. However, for any other version of CUDA and TensorRT, please refer to the overview section for download. Once the tao-converter is downloaded, follow the instructions below to generate a TensorRT engine.

1. Unzip the zip file on the target machine.

2. Install the OpenSSL package using the command:

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   Copied!

               
   
               
   sudo apt-get install libssl-dev
           

3. Export the following environment variables:

            

            
$ export TRT_LIB_PATH=”/usr/lib/x86_64-linux-gnu”
$ export TRT_INC_PATH=”/usr/include/x86_64-linux-gnu”
        

4. Run the tao-converter using the sample command below and generate the engine.

For the Jetson platform, the tao-converter is available to download in the NVIDIA developer zone. You may choose the version you wish to download as listed in the overview section. Once the tao-converter is downloaded, please follow the instructions below to generate a TensorRT engine.

1. Unzip the zip file on the target machine.

2. Install the OpenSSL package using the command:

   Copy

   Copied!

               
   
               
   sudo apt-get install libssl-dev
           

3. Export the following environment variables:

            

            
$ export TRT_LIB_PATH=”/usr/lib/aarch64-linux-gnu”
$ export TRT_INC_PATH=”/usr/include/aarch64-linux-gnu”
        

1. For Jetson devices, TensorRT comes pre-installed with Jetpack. If you are using older JetPack, upgrade to JetPack-5.0DP.

2. Run the tao-converter using the sample command below and generate the engine.

            

            
tao model converter -k <encryption_key>
                  -d <input_dimensions>
                  -o <comma separated output nodes>
                  [-c <path to calibration cache file>]
                  [-e <path to output engine>]
                  [-b <calibration batch size>]
                  [-m <maximum batch size of the TRT engine>]
                  [-t <engine datatype>]
                  [-w <maximum workspace size of the TRT Engine>]
                  [-i <input dimension ordering>]
                  [-p <optimization_profiles>]
                  [-s]
                  [-u <DLA_core>]
                  [-h]
                  input_file
        

Required Arguments

• input_file: The path to the .etlt model exported using export.

• -k: The key used to encode the .tlt model when traning.

• -d: A comma-separated list of input dimensions that should match the dimensions used for tao model multitask_classification export. Unlike tao model multitask_classification export, this cannot be inferred from the calibration data. This parameter is not required for new models introduced in TAO Toolkit v3.0 (e.g. LPRNet, UNet, GazeNet).

• -o: A comma-separated list of output blob names that should match the printout when using tao model multitask_classification export. The number of outputs is equal to the number of tasks.

Optional Arguments

• -e: The path to save the engine to. The default value is ./saved.engine.

• -t: The desired engine data type. This argument generates a calibration cache if in INT8 mode. The default value is fp32. The options are {fp32, fp16, int8}.

• -w: Maximum workspace size for the TensorRT engine. The default value is 1073741824(1<<30).

• -i: The input dimension ordering; all other TAO commands use NCHW. The default value is nchw. The options are {nchw, nhwc, nc}. For classification, you can omit this argument since the default value is nchw.

• -p: Optimization profiles for .etlt models with dynamic shape. The argument format is a comma-separated list of optimization profile shapes in the format <input_name>,<min_shape>,<opt_shape>,<max_shape>, where each shape has the format <n>x<c>x<h>x<w>. This argument can be specified multiple times if there are multiple input tensors for the model. This is only useful for new models introduced in TAO v3.0. This parameter is not required for models that existed in TAO v2.0.

• -s: A Boolean to apply TensorRT strict type constraints when building the TensorRT engine.

• -u: Specifies the DLA core index when building the TensorRT engine on Jetson devices.

INT8 Mode Arguments

• -c: The path to the calibration cache file, which is only used in INT8 mode. The default value is ./cal.bin.

• -b: The batch size used during the export step for INT8 calibration cache generation. The default value is 8.

• -m: The maximum batch size for the TensorRT engine. The default value is 16. If you encounter out-of-memory issues, decrease the batch size accordingly.