architecturecurrent

Codec direction (non-normative)

The active, non-normative research direction for Avelune video, audio, and browser architecture.

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This file records the active design direction and may change without changing a candidate bitstream.

Video

Research targets:

  • constrained recursive partitions rather than maximal combinatorial partition grammars;

  • explicit frame dependency graphs;

  • approximately 2 s encoder-default independent epochs, to be measured against 1/4/8 s;

  • conventional block motion plus an experimental coarse motion lattice with local corrections;

  • non-overlapping integer transforms first; lapped transforms are not the default because their neighbor/partition coupling has historically made intra coding and variable block structure harder;

  • scalar inverse quantization with most perceptual intelligence pushed into the encoder;

  • independently restartable, interleaved rANS entropy states with table selection/deltas rather than per-symbol probability mutation;

  • palette, transform-skip and intra block-copy as first-class screen-content candidates;

  • patch dictionary only if it materially wins over simpler screen tools;

  • exactly one normative reconstruction-filter stage if experiments show sufficient gain.

Audio

Research targets:

  • one common transform/energy/residual path for general audio;

  • transient-dependent time resolution;

  • per-band stereo coupling;

  • optional LPC/pitch whitening, retained only if speech gains do not compromise general audio simplicity/performance;

  • rANS-family entropy coding if the video experiments validate its decoder tradeoffs.

Browser

Required correctness baseline: ordinary single-threaded wasm32. Primary optimization target: WebAssembly SIMD. Threads are optional acceleration rather than a correctness dependency.