Preview performance and resource budgets
Measure real scenarios
Section titled “Measure real scenarios”Benchmark cold first frame, warm seek, rapid scrub, playback, multi-track composition, Material load, thumbnails, waveform work, export throughput, cancellation, and a long edit session using representative codecs, duration, resolution, frame rate, devices, and network.
Report latency distributions and terminal resource counts, not only an average FPS.
The nightly GitHub-hosted runner stores a complete raw performance observation for regression triage, but its shared CPU load and virtualized GPU are not a controlled reference device. Absolute SLOs remain fail-closed in the source-bound release gate on the reviewed reference machine. A nightly observation may therefore carry an Actions notice without making the correctness CI red; it never substitutes for release evidence.
Preview priorities
Section titled “Preview priorities”Cancel stale requests, use proxies, keep one main preview pipeline, lower interactive resolution, bound decode-ahead and cache, reuse compiled IR/Materials, and avoid synchronous work in pointer handlers. Review mode can trade latency for fidelity.
Canvas pixels
Section titled “Canvas pixels”CSS dimensions are not backing-store dimensions. Cap device-pixel-ratio scaling so a large display does not accidentally multiply decode, texture, readback, and composite cost beyond the product budget.
Provider and Session budgets
Section titled “Provider and Session budgets”Set hard limits for concurrent reads/decoders, queue length, compressed and decoded cache bytes, frame ownership, GPU textures/contexts, pending preview work, thumbnail jobs, and export concurrency. Admission should reject or wait for a bounded period, never grow without limit.
Material and track cost
Section titled “Material and track cost”Track node count, graph depth, passes, texture samples, intermediate surfaces, input dimensions, backend compilation, and per-frame time. Enforce static package budgets and runtime product tiers.
Competing work
Section titled “Competing work”Export, proxy generation, analysis, waveform, thumbnails, and autosave must not all consume unbounded CPU/GPU/I/O. Give interactive preview priority and expose a product scheduler for background jobs.
Statistics
Section titled “Statistics”Record first-frame/seek latency, render/decode time, dropped/cancelled frames, queue depth, audio underruns, cache hit/bytes, GPU/backend state, export fps, written bytes, memory, and cleanup outcome.
Long-session acceptance
Section titled “Long-session acceptance”Repeat open/import/scrub/play/edit/export/cancel/switch/dispose cycles. After bounded cache settling, workers, decoders, frames, contexts, listeners, timers, object URLs, and retained bytes must return to the documented budget.