Products – Electronic design services with Argon Design Ltd.



The Challenge

HEVC/H.265 is a new video coding standard. It is an evolution of H.264, with many new features and the flexibility to support all kinds of encode architectures, while reducing bandwidth costs by 50%.

The problem is that this extra complexity makes it much harder to verify that your decoder will be fully compatible with all HEVC bit-streams.

In order to provide comprehensive and demonstrable coverage, with provable confidence, we have used a novel compiler based technique to create Argon Streams.

Our Approach

We’ve written a compiler for the HEVC specification. The compiler directly understands the pseudo-code and equations contained in the HEVC specification and can translate them into a complete mathematical model of the coding process.

Argon Coverage Tool

The Argon Coverage Tool is an optional addition to Argon Streams, that analyses one or more test bit-streams and produces a detailed coverage report that can be viewed in Google Chrome.

The coverage report details exactly which sections of the specification are covered by any set, or subset, of test bit-streams and is cross-linked to an interactive version of the HEVC specification to show exactly which sections and equations are being fully verified.

The Argon Coverage Tool is available as both Windows and Linux executables.

Argon Streams

We’ve used the mathematical model produced by our compiler, to generate a set of videos that cover the entire space of valid HEVC bit-streams.

The Argon Coverage Tool allows us confirm that the bit-streams exercise and test every part of the HEVC specification.

The coverage includes:

  • complete coverage of every equation in the core specification
  • complete coverage of every transition in the CABAC engine
  • complete coverage of every extreme value in the pixel processing pipeline
  • complete coverage of all video resolutions in the standard

Each bit-stream consists of a short sequence of between 5 and 20 frames; this improves the execution speed and allows rapid pin pointing of the non conformances in your decoder design. Each frame has an embedded SEI checksum and we also provide MD5 digests of the output YUV files.

Argon Streams includes separate tests for Main, Main 10, Main 12, Main 10 4:2:2, Main 12 4:2:2, Main 4:4:4, Main10 4:4:4 and Main12 4:4:4 profiles, and now also includes a test set for the ARIB STD-B32 video coding specification.

Frame from Argon Streams

We have used Argon Streams and the Argon Coverage Tool to verify the HEVC reference decoder developed by the standards body. This process resulted in us reporting over 105 issues with the HEVC specification and reference decoder implementation.

Argon Coverage Report

Argon Streams includes an interactive Coverage Report which allows you to see which parts of the specification have been exercised by which test bit-streams. It includes a complete copy of the HEVC specification and allows you to click on the various equations to view which test bit-stream was the first to exercise that particular part of the specification.

The Coverage Report provides a number of different views of the test results:

  • branch coverage statistics for every equation and part of equation
  • tooltips to show exactly which bit-streams are used to test each equation
  • value coverage to show maximum and minimum values for each parsed and computed variable
  • value coverage statistics for every CABAC transition and every value of every CABAC decoded symbol
  • range coverage of theoretical and observed ranges for data in the pixel processing pipeline
  • cross coverage to show all combinations of values for multiple syntax elements

The short video clip below explains how to use the coverage report to explore the coverage results in detail.

For more information about Argon Streams

For verification of your AV1 decoder see

For verification of your VP9 decoder see

To enquire about Argon Streams please contact

Argon Streams Press Releases

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