P3: Build repeatable load tests for 8 feeds, ISO recording, and stream output

[iamfatness]

Problem

We need objective confidence that CoreVideo can handle target production loads on realistic hardware.

Outcomes

• Load test plan and scripts measure CPU, GPU, memory, dropped frames, stale frames, encoder sessions, disk write rate, and OBS render time.
• Tests cover 8 1080p feeds, 8 ISO records, and simultaneous RTMP/SRT program stream.
• Results define recommended hardware tiers and settings.

Acceptance criteria

• Test report is generated for at least one NVIDIA system and one fallback CPU encode scenario.
• Failures produce actionable metrics, not just subjective observations.
• CI/local smoke tests cover non-meeting pieces of the pipeline.

[iamfatness]

Follow-up: also wired tests/speaker-director-test.cpp into CMake as CoreVideoSpeakerDirectorTest so active-speaker timing, manual take/release, video filtering, and exclusions are now part of local verification. Verified both CoreVideoOutputHealthTest and CoreVideoSpeakerDirectorTest.

[iamfatness]

Progress update: added scripts/Measure-CoreVideoLoad.ps1 and README usage notes. It samples obs64, ZoomObsEngine, and ffmpeg CPU seconds, working set, private memory, handles, and thread counts into CSV + summary files under artifacts/load-tests, so 8-feed/ISO/program-stream runs can be compared repeatably across builds. Smoke-tested with a 1-second run and removed local artifacts before commit.

[iamfatness]

Pushed 39956b4 to improve repeatable load-test reporting.

What changed:

• scripts/Measure-CoreVideoLoad.ps1 now accepts -ExpectedFeeds, -ExpectedIsoRecorders, and -RequireObs.
• Summary now includes final process count, CPU delta, average CPU percent of total system CPU, max handles, and max threads.
• Script writes a .summary.json report alongside raw sample CSV and summary CSV.
• Script emits warnings when ZoomObsEngine is missing, OBS is required but not running, expected ffmpeg ISO recorder processes are missing, or engine CPU is high in an 8-feed target test.
• README now documents the 8-feed/8-ISO measurement command.

Validation:

• 1-second script smoke test wrote CSV + summary CSV + summary JSON successfully.
• ctest --test-dir build-vs-release -C Release --output-on-failure (8/8 passed)
• git diff --check

[iamfatness]

Added load-test process drop detection in d655d5d.

What changed:

• scripts/Measure-CoreVideoLoad.ps1 now reports MinCount, MaxCount, FinalCount, and ZeroCountSamples for obs64, ZoomObsEngine, and ffmpeg.
• FinalCount now uses the actual final sample instead of the last non-zero sample, so end-of-run crashes/exits are visible.
• Warnings now flag OBS disappearance, engine disappearance/restart loops, and ffmpeg ISO recorder count drops during the run.
• README load-test docs now call out mid-run process drop detection.

Validation:

• .�scripts\Measure-CoreVideoLoad.ps1 -DurationSeconds 1 -SampleSeconds 1 -ExpectedFeeds 0 -ExpectedIsoRecorders 0 -OutputPath artifacts\load-tests\smoke-load.csv
• git diff --check
• cmake --build build-vs-release --config Release --target obs-zoom-plugin --parallel
• ctest --test-dir build-vs-release -C Release --output-on-failure (8/8 passed)