Mimir

Realtime cameras, microphones, chirplets, and field evidence organized into one coherent stream machine.

Research Claims Digest

4 min read

Research Claims Digest

Purpose

This is the claim-level digest from the research pass. It records what the external literature and open implementations change about Mimir’s design.

Chirplets / CSS / Receiver Design

Claim:

  • A generic chirplet transform is the broad signal-analysis tool.
  • A controlled chirp communication receiver should usually exploit waveform design: dechirp, bin score, then decode.

Mimir consequence:

  • The hot receiver should remain constrained by the known codebook and schedule.
  • Full chirplet transforms are reference tools, not first-line runtime code.
  • Symbol design should serve demodulation.

References:

  • Steve Mann chirplet transform.
  • Fast chirplet transform / FPGA implementation work.
  • LoRa/CSS demodulator literature and OpenLoRa.

Passive Delay / Distributed Microphones

Claim:

  • Delay and sampling-rate offset are different phenomena.
  • Distributed microphone arrays require explicit SRO estimation/compensation.
  • GCC-PHAT is useful for TDOA/delay evidence, not enough to own canonical time.

Mimir consequence:

  • Passive mode is a confidence-bearing witness.
  • Active codebook anchors remain the canonical-time path.
  • The actuator must include both fractional delay and SRO control.

References:

  • Wang/Doclo SRO estimation.
  • Schmalenstroeer/Haeb-Umbach clock skew work.
  • Didier distributed adaptive node-specific signal estimation.
  • GCC-PHAT refinements.

Room / Sound Field Reconstruction

Claim:

  • Sound-field reconstruction from sparse arrays is an inverse problem with geometry, bandwidth, regularization, and noise constraints.
  • Ambisonics works cleanly when the microphone array and calibration support the basis.
  • Equivalent-source / sparse reconstruction methods are useful when the source model is sparse and measurement model is known.

Mimir consequence:

  • Six heterogeneous mics are not automatically a high-order field mic.
  • The first honest target is synchronized stems plus source/constraint estimates.
  • Field reconstruction should expose uncertainty and avoid pretending unsupported spatial detail exists.

References:

  • Pyroomacoustics.
  • Spatial Audio Framework.
  • ManyEars.
  • near-field acoustic holography / equivalent source / compressive sensing papers.
  • ambisonics/arbitrary-array encoding notes.

Fractional Delay / SRO Actuation

Claim:

  • Farrow structures are standard for continuously variable fractional delay.
  • Variable-rate resampling or equivalent phase correction is required for drift.

Mimir consequence:

  • Microsecond reporting is incomplete until an actuator moves samples.
  • A Farrow proof is the right first native/Faust actuator slice.
  • Higher-quality polyphase/ASRC work comes after the control loop is proven.

References:

  • AMD Vitis Farrow filter docs.
  • MATLAB Farrow fractional delay notes.
  • joint SFO/Farrow papers.

Gaussian Splatting / Visual Fusion

Claim:

  • Practical 3DGS renderers use packed GPU buffers, projection, tile binning, sorting/order strategies, and optimized rasterization kernels.
  • Dynamic/4D Gaussian splatting extends splats over time, but production code is still research-shaped.
  • Online SLAM/sensor fusion variants are more relevant to Mimir than offline static scene training alone.

Mimir consequence:

  • Fensalir should own the GPU field.
  • Mimir should feed synchronized observations and constraints.
  • The first proof is live observation-to-claim-to-render, not full 4DGS training.

References:

  • GraphDeco 3DGS.
  • 4D Gaussian Splatting.
  • Spacetime Gaussians.
  • gsplat.
  • NVIDIA vk_gaussian_splatting.
  • StopThePop.
  • FlashGS.
  • Gaussian-SLAM / multi-sensor calibration papers.

Native Capture / GPU Resource Boundaries

Claim:

  • Windows KS/AVStream is the low-level video streaming surface under higher media frameworks.
  • D3D shared handles are the relevant resource-sharing family once camera payloads can become GPU resources.
  • ASIO callbacks and sample positions are the correct place to preserve driver clock timing.

Mimir consequence:

  • Media frameworks may remain diagnostics/fallbacks, but direct workers own production capture.
  • Fensalir owns D3D12 resource lifetime and imports.
  • Mimir should not route six cameras through stdout/JSON or managed pixel processing.

References:

  • Microsoft Kernel Streaming docs.
  • Microsoft DXGI shared handle docs.
  • ASIO specification / callback notes.
  • Focusrite channel/loopback documentation.

Strongest Design Conclusion

The research converges on one architecture:

controlled witness + calibrated sensors + rolling buffers
-> deterministic timeline/response models
-> native DSP and GPU field lowering
-> OBS-facing program output

The critical missing production step is not another filter. It is connecting measurement to actuation and field lowering:

  • streaming decoder state;
  • calibration-weighted likelihood;
  • fractional delay/SRO actuator;
  • native camera payload handles;
  • Fensalir contract lowering.

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