VideoTracker::set_budget (default 2 GiB of state, optional seconds per
propagate call) stops with Error::Budget; state_bytes reports what it holds.
Two runs of the same prompts give bit-identical masks.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Antialiased bilinear resize as PyTorch does it, the reference's mask-as-output
path (mask is the frame's output, the decoder makes the object pointer),
VideoTracker::prompt_mask, and mask-only prompts through the tracker interface.
Prompt frame logits exact, tracking forwards and backwards within 0.0019.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
TrackRequest takes a list of objects (each with its prompts on its frames) and
the tracker reports (object, frame, result); frame encodings are shared, objects
may start on different frames. VideoTracker::propagate_objects runs a subset.
Limits: 32 objects. Test: two discs, one prompted on frame 0 and one on frame 2.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
On real footage the stroke frame came out partial (clicks make SAM 2 pick a
part of the object). Measured on a multi-part figure: clicks only IoU 0.41,
with a box around the figure IoU 1.00. Chain::track now adds the box of the
classic engine's matte of the strokes to each prompt; a box stroke wins.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
ObjectTracker interface in the segment crate (prompts on some frames, the
clip tracked both ways, each frame streamed with confidence and an occluded
flag), implemented by SAM 2. MaskModel::tracker() is None for other models.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Sam2Mask wraps the image path behind the Roto Brush's MaskModel interface
(cached frame encoding, bilinear mask resize). The engine loads the verified
weights natively (not on wasm). Checked with the real file: install, notice,
load, use by Roto Brush 3.0, deselect.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Click on frame 2 of a 7-frame clip with an occlusion, tracked forwards and
backwards: IoU 1.0000 on all 9 frame results, worst mask-logit error 0.0038,
object scores equal to 3 decimals.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Per-object memory banks, prompts on any frame, forward and backward
propagation with streaming results, cancellation, object pointers with
temporal encoding, pruning of memories no later frame can use, and checked
input handling. Hostile-input and cancel tests.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Self and cross attention with axial 2-D RoPE (keys tiled over memory frames,
object-pointer tokens left unrotated). Max abs error 2.6e-5.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Mask down-sampler, feature fuser and projection, sine position encoding,
occlusion embedding and bfloat16 rounding of stored memories. Max abs error
3.5e-6 on the memory features, 6e-8 on the position encoding.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Encode 5.0 s -> 3.4 s per 1024x1024 frame in release on 16 threads (fused
softmax, queries scaled before the matmul, flat 2-D linear layers); a click
on an encoded frame is about 120 ms. Reference tests unchanged.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
A click on the synthetic image: mask logits within 1.1e-4 (range 11.6), IoU
head 1e-6, object score 2e-5, prompt embeddings 1e-7.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Weights loader with shape/finite validation (S2.10), patch embed, bicubic
positional embedding, window/global attention, query pooling. Reference test
(skips without weights): max abs error 2.6e-5 over all 12 blocks.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
