Ported from JVET-TuC with small improvements on certificate handling

Changed parameter names as suggested to upscaledOutputWidth/Height + fixed conflict with SPS conformance window. Also added the functionality to the encoder (for the reconstructed output).

Override SPS using --OutputWidth and --OutputHeight when upscaling output picture (see --UpscaledOutput)

Includes:
- fix signalling of fixed frame rates in encoder
- fix computation of frame rate in decoder
- fix access to SPS/VPS data for frame rate computation in decoder
- code clean up

Express frame rate as ratio of two integer values throughout code
using struct Fraction

Add support for defining fractional frame rate from command line

Roman_Guskov authored 2 years ago and Nikolay Shostak committed 2 years ago

Decoder expects that 2 fields of one frame are stored in pcListPic next to each other.

But in case of Multilayer there will be some distance between field pictures. For example:

- POC0 (TopField) Layer0
- POC0 (TopField) Layer1
- POC0 (TopField) Layer2
- POC1 (BottomField) Layer0
- POC1 (BottomField) Layer1
- POC1 (BottomField) Layer2

Decoder needs to search for a second field picture.
It should belong to the same layer as the first field picture.

Also, POCs of first and second field are not necessary differ by one. So, I removed those checks

Changes include:
- use [[maybe_unused]] instead of cast to (void)
- use generic lambda function and remove related comment about C++11
- update MSVC version check
- don't condition '#pragma once' on MSVC version