AV1 statistics extraction with dav1d

Currently development of rav1e and other AV1 encoders use open source AV1 analysis tools to extract metadata which is produced at decode time. This data is useful for reporting statistics and ultimately to fine-tune parameters. However, there is an inadequate amount of advanced analysis which would give more in-depth statistics. Access to this information would allow a deeper understanding of how specific changes impact factors such as bitrate, objective quality.

AV1 instrument tools are found in the reference decoder (libaom) which is a large codebase making it hard to extend. This project aims to create lightweight AV1 analysis tools in the dav1d codebase. It will achieve this by adding a decoder metadata extraction tool the dav1d example decoder with structured output so that rapid testing can be performed in an automated fashion. Once the relevant metadata is extracted, the tool will produce visualisations and report on other metrics that can be used for tuning encoder parameters.

The desire is to create a light-weight tool that gives detailed information about encoded streams for use in encoder development, conformance and regression testing and third-party analysis.