DALI Release 0.27.0

The DALI 0.27.0 is not yet a major release, so the features, functionality, and performance might be limited.

Using DALI 0.27.0

To upgrade to DALI 0.27.0 from an older version of DALI, follow the installation and usage information in the DALI User Guide.

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:
    • CoordTransform Operator for applying a linear transformation to points or vectors (#2288).
    • GaussianBlur Gpu Operator (#2314, #2311).
    • Nemo ASR Reader (#2234).
    • Resize 3D - operator can now process 3D inputs (#2226).
    • Add Translate affine transform generator (#2297).

      In the next release, it will be moved to a dedicated module.

  • Use true scalars (except in classification readers) - 0-dim Tensors represent scalar values (#2318).
  • Adjust documentation after review (#2175).
  • Support for ZSTD compression for TIFF files (#2273).
  • Support for Run-Length Encodings and Pixelwise Masks in COCO Reader (#2248).
  • Support more types in Lookup table (#2290).

Fixed Issues

This DALI release includes the following fixes.

  • Fixes crash in RandomBBoxCrop when no labels are provided (#2265).
  • Fix minor issues reported by static analysis (#2276).
  • Fix detection pipeline test on Ampere (#2304).

Breaking Changes

There are no breaking changes in this release.

Deprecated Features

There are no breaking changes in this 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 frequency that is less than 10-15 frames, the returned frames might be out of sync.

  • The DALI TensorFlow plugin might not be compatible with TensorFlow versions 1.15.0 and later.

    To use DALI with the TensorFlow version that does not have a prebuilt plugin binary that is shipped with DALI, make sure that the compiler that is used to build TensorFlow exists on the system during the plugin installation. (Depending on the particular version, you can use GCC 4.8.4, GCC 4.8.5, or GCC 5.4.)

  • Due to some known issues with meltdown/spectra mitigations and DALI, DALI shows the 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