DALI Release 0.26.0

The DALI 0.26.0 is not yet a major release, so the features, functionality, and performance might be limited.

Using DALI 0.26.0

To upgrade to DALI 0.26.0 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:
    • To learn the decoded image shape, added the PeekShape operator (#2205).
  • Added the ability to run DALI without a GPU (#2165).
  • Optimized single-channel audio resampling with SSE2 (#2240).
  • Added the ability to pass a DALI TensorList or a list of DALI Tensors to an exernal source (#2244).
  • Enhanced error messages to handle unsupported data types in the operators (#2211).
  • Added a more verbose message about unsupported videos (#2203).
  • If users requested it, used the copy kernel when making a contiguous batch during the ShareUserData process (#2200).

Fixed Issues

This DALI release includes the following fixes.

  • Fixed the lack of input type checking in a GPU variant of the Spectrogram operator (#2192).
  • Fixed the hw_decoder_load=0.0 for ImageDecoder-related tests that require deterministic results (#2232).
  • Fixed the NVTX annotations (#2215).
  • Fixed the VideoReader error checking when opening files (#2223).

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