Optimizations for RA, AI, and LD

Description

Optimizations to improve the BD-rate/cycles trade-offs for RA CRF, still-image, all-intra, and LD modes. Add support for LD CQP in all presets. Improvements to SC content coding. Reduce the LD RTC memory usage by ~10%.

This MR adds a new flag --rtc to enable/disable RTC-targeted settings when using LD; the setting is off by default.

RA CRF

still-image

all-intra

LD

Issue

Closes #2024 (closed), #1848 (closed), #2271 (closed)

Author(s)

@PhoenixWorth @hguermaz @psao123 @tahabenromdhane24 @Khalilkhemakhem

Performance impact

Data uploaded as plots (above).

• quality
• memory
• speed
• 8 bit
• 10 bit
• N/A

Test set

• obj-1-fast can be found here
• other
• N/A

Merge method

• Allow the maintainer to squash and merge when PR is ready to create a 1-commit to the master branch. The maintainer will be able to fix typos / combine commit messages to create a more readable 1-commit message or use whatever is stated in the 'Description' section
• I will clean up my commits and the maintainer shall use 'rebase and merge' to the master branch