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The main advantages of Decoder Validation Kit (VQ DVK)

2021-05-13
Alexander Dydychkin
Written by Alexander Dydychkin Follow on Medium

Introduction

DVK is a Bitstream and software toolchain for Decoder IP design and compliance validation. It is a must have tool for chip RTL design, target appliance integration (such as a smartphone, smart TV, Set Top Box), software stack verification before shipment to customer. It is carefully structured to become as compact as possible, address maximum coverage and minimize validation time during the design process.

Photo by John Cameron on Unsplash

Photo by John Cameron on Unsplash

DVK definition

VQ DVK means:

  • A Video Decoder Certification

  • A comprehensive set of test bitstreams, a configurable encoder and analytic tools to verify a decoder compliance with the standard plus graphic reports

  • A powerful validation environment for VVC, AV1 HEVC, VP9 decoder developers

  • A tool which allows to compare test decoder’s output with the «known correct» results

  • An instrument aimed to determine anomalies in decoder design to save validation and support costs

We have different tools for each codec - VVC, AV1, HEVC, VP9. Each of them is dissimilar in a set of streams and their number. For example, VQ DVK VVC consists of the following bitstream groups:

  • Syntax - handy tiny size (small resolution and 1-2 frames only) to maximize coverage of each syntax element and cross-coverage of essential pairs. One test stream - one feature, make individual «coding block» design independently. Good for initial RTL design.

  • Stress - include all the features covered by the Syntax streams, in higher resolution and more frames. Good for an advanced stage of decoder design.

  • Performance - test the limits of hardware decoder’s speed. Good for final validation to prove compliance to Level requirements.

  • Error resilience - set of non-fully-compliant bitstreams to test decoder’s robustness to errors and ability to recover. Good for final validation to deliver viable end user product.

Key features

In this article, we will address the key features of VQ DVK, namely:

  • Integration

  • Special streams

  • Crosscoverage

  • Analytic tools

Integration

Immediate “out the box” benefits. DVK compliance streams can be immediately integrated into any CI or validation pipelines to proof the customer`s product.

Streams can be easily integrated in any CI and product pipeline – for example Gitlab CI and software decode

Streams can be easily integrated in any CI and product pipeline – for example Gitlab CI and software decode

Special streams

Need something special? Not a problem! Special streams can be requested by DVK team (should be discussed in contract) or can be easily generated using very flexible design of encoder: DVK's encoder based on reference with support of configuration files. With the help of configuration files, users can generate any stream they want because any syntax element can be defined with on/off or particular values such as “pps_init_qp_minus26" (one of the VVC's syntax elements example). As an additional example, using this approach, there can be generated the stream if all the elements of “filmgrain” group (AV1 example) are enabled to test this feature during validation.

Some configs files for AV1 streams, each focused on particular elements

Some configs files for AV1 streams, each focused on particular elements

The part of the config file for AV1

The part of the config file for AV1

Crosscoverage

Sometimes simple 1D coverage is not enough. That is why DVK introduce CrossCoverage in VVC reports. CrossCoverage is 2D reports: to reduce costs, it needs to be smart, so in some situations there is a need to check element coverage with some background knowledge – another element.

Cross coverage report for VVC streams, green means both elements enabled, gray – not reachable by design

Cross coverage report for VVC streams, green means both elements enabled, gray – not reachable by design

Analytic tools

Analytic tools are the special tools to generate code, syntax and cross coverage reports (in cross-platform html-format) and to analyze the streams and check if streams set can be lowered.

All Analytic tools for AV1

All Analytic tools for AV1

And what is very important, analytic tools can be used with any set of streams. So, if an organization already has their video library of streams, they can be easily analyzed, reduced or compared by the tools.

AV1 reporter generates HTML report for over 1.4K streams in CI

AV1 reporter generates HTML report for over 1.4K streams in CI