DALI Release 0.20.0 Beta

The DALI 0.20.0 is a beta release, therefore, all features, functionality, and performance will likely be limited.

Using DALI 0.20.0 Beta

To upgrade to DALI 0.20.0 beta from an older version of DALI, follow the installation instructions in the DALI Quick Start Guide.

Refer to the DALI Developer Guide for usage details.

Note: The internal DALI C++ API used for operator’s implementation, and the C++ API that enables using DALI as a library from native code, is not yet officially supported. Hence these APIs may change in the next release without advance notice.

Key Features and Enhancements

This DALI release includes the following key features and enhancements.

  • Added operators:
    • Spectrogram for GPU (#1786)
    • MelFilterBank for GPU (#1796)
  • Allow align-only behavior in Pad operator by treating shape argument as minimum shape (#1764)

  • Added data_ptr method to Tensor and TensorList (#1773) - it enables __array_interface__and __cuda_array_interface__ support.

  • Extended shape support in DALI Dataset for TensorFlow (#1723)

  • Documentation improvements: layouts, Python API.

  • Added Gluon iterator plugin (#1683)

Fixed Issues

This DALI release includes the following fixes.

  • Implemented several fixes in the documentation and build system.

  • Fixed precision loss in CropWindowGenerator (#1735)

  • Fixed BBFlip stream synchronization issue (#1738)

Deprecated Features

  • CUDA 9 support will soon end in a future release

Known Issues

  • The video loader operator requires that the key frames occur at a minimum every 10 to 15 frames of the video stream. If the key frames occur at a lesser frequency, then the returned frames may be out of sync.

  • The DALI TensorFlow plugin may not be compatible with TensorFlow versions 1.15.0 and/or later. If the user wants to use DALI with the TensorFlow version which doesn’t have prebuilt plugin binary shipped with DALI it requires the gcc compiler that matches the one used to build TensorFlow (gcc 4.8.4 or gcc, 4.8.5 or 5.4, depending on the particular version) is present on the system.

  • Due to some known issues with meltdown/spectra mitigations and DALI, DALI shows best performance when running in Docker with escalated privileges, for example:
    • privileged=yes in Extra Settings for AWS data points
    • --privileged or --security-opt seccomp=unconfined for bare Docker