Diagnostic conclusion from the JoyAI-Echo engine: conditioning is fed to the sampler
unchanged (gemma+connector, which Studio already produces), so the ONLY missing sampler
feature is generate_BidirectionalMemory's cross-shot paired AV memory bank. This lands the
VIDEO half: a managed set of clean prior-shot frames injected into each scene so identity
carries across the whole chain — JoyAI's story-level consistency.
Generalizes the single-anchor mid_scene_guide to N frames, reusing the same LTX
guide-attention primitive (_append_guide_latent). _JoyAIMemoryBank holds the policy
(num_fix opening shots pinned as a global anchor + rolling most-recent window capped at
max_size, matching configs/inference.yaml: max_size 7, num_fix_frames 3, center select).
Harvest one clean frame per finished scene; inject the bank before each continuation scene;
supersedes mid_scene_guide when on. Honors the 0.25 audio-safe strength floor.
Off by default, so the audio protect/pass-through invariant is unchanged. Paired audio
memory + v2a_grad_scale coupling is the next phase (needs the ltx_core v2a term).
Inputs: joyai_memory, joyai_memory_size, joyai_fix_frames, joyai_frame_select,
joyai_memory_strength. Threaded through batch-training; logged in run_mechanisms + the
refinement sampler-context. New test_joyai_memory.py covers the bank policy (6 tests).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
