DALI Release 0.17.0 Beta

The DALI 0.17.0 is a beta release, therefore, all features, functionality, and performance will likely be limited.

Using DALI 0.17.0 Beta

To upgrade to DALI 0.17.0 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.

  • New operators:
    • NormalDistribution (#1529)

  • New operators (CPU backend) with accompanying kernels for audio and signal processing:
  • Improvements to existing operators:
    • Sequence and 3D support in Flip operator (#1439)

    • Warp 3D (#1366, #1442)

    • Improve the accuracy of 3D rotation (#1466)

    • Various fixes and improvements to ColorTwist, BrightnessContrast and HSV operators

  • Added integration with PaddlePaddle.

  • Added Jupyter Notebooks with example usage of arithmetic ops (#1438)

Fixed Issues

This DALI release includes the following fixes.

  • Fixed race between consecutive invocations of Mixed-stage. (#1493)

  • Fixed ExternalSource for GPU (#1452)

  • Fixed stream usage in HSV and BrighnessContrast. (#1566)

  • Added wait for thread pool to finish work in BrightnessConstrast (#1549)

Breaking Changes

  • The asCPU method is no longer available and has been replaced with as_cpu.

Deprecated Features

  • DALI 0.17 is the last official release for Python 2.7, which reaches the end of life on January 1st, 2020. To stay up to date with DALI, upgrade to Python 3.5 or later.

  • ColorTwist operator was deprecated and replaced by BrightnessContrast and HSV operators cleanup (#1532)

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