fix(render): scope burst headroom to high refresh

[qiin2333]

改了啥呀

• 使用三级 future-lead 预算：<=60 FPS 半帧、61-119 FPS 一帧、>=119.88 FPS 两帧
• 119.88/120+ FPS 现在可保留三帧 decoder burst 的 PTS 间隔，第四帧才触发 catch-up
• 所有帧率继续使用 2 ms 稳态提交余量；30/60 FPS 的延迟边界不变
• 增加 30、60、90、119、119.88、120 FPS 边界测试，并修正 59.94 FPS 预算断言

为啥要改

一帧 future lead 已让 120 FPS 比 PR63 更容易跑满，但真机仍会间歇掉帧，说明这个小杂鱼硬解偶尔会一次吐出三帧。120 FPS 下把瞬时预算从约 10.33 ms 放宽到 18.67 ms，可以保留第三帧的 PTS 节奏；稳态 lead 仍是 2 ms，不固定增加两帧延迟。

NTSC 119.88 FPS 同样进入两帧预算。阈值精确设为 119.88，而不是宽泛的 119.0，因此真正的 119 FPS 自定义流仍保持一帧预算；90 FPS、30/60 FPS 的边界也不变。

验证

• c++ -std=c++17 -Wall -Wextra -Werror nativelib/src/main/cpp/presentation_scheduler.cpp nativelib/src/test/cpp/presentation_scheduler_test.cpp -I nativelib/src/main/cpp -o /tmp/moonlight_presentation_scheduler_test && /tmp/moonlight_presentation_scheduler_test
• npm run check
• node hvigorw.js assembleApp --mode project -p product=default -p buildMode=debug --no-daemon（DevEco SDK 6.1 / JBR 21，BUILD SUCCESSFUL）

[coderabbitai]

📝 Walkthrough

Walkthrough

调整 PTS 演示调度器的未来提前量预算，使其根据刷新率选择半帧、单帧或更大预算，并新增 120fps、90fps 及低刷新率 burst 场景测试。

Changes

PTS 未来提前量预算

Layer / File(s)	Summary
刷新率相关的预算计算 nativelib/src/main/cpp/presentation_scheduler.cpp, nativelib/src/main/cpp/presentation_scheduler.h	Configure 根据 safeFps 选择未来节奏预算，并将默认 maxFutureLeadNs_ 调整为更小的初始值。
Burst 调度行为验证 nativelib/src/test/cpp/presentation_scheduler_test.cpp	新增 120fps triple burst、90fps pair burst 和低刷新率半帧预算测试，并更新 fractional FPS 断言及测试入口。

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• AlkaidLab/moonlight-harmony#61：同样调整 PtsPresentationScheduler::Configure 的未来提前量计算及相关测试。
• AlkaidLab/moonlight-harmony#63：同样涉及未来提前量预算、帧规划流程及调度测试。
• AlkaidLab/moonlight-harmony#64：同样修改未来提前量计算及 fractional/120fps burst 测试断言。

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	标题准确概括了此次将 burst 预留空间限制到高刷新率场景的核心改动。

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/scope-high-refresh-pacing

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@nativelib/src/main/cpp/presentation_scheduler.cpp`:
- Around line 21-22: Lower the kTripleBurstFps threshold from 120.0 to a value
such as 119.0 so safeFps values of 119.88 FPS enter the triple-burst budget path
while preserving the existing threshold logic for other frame rates.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 61f7e187-98d4-4500-b6f4-0fca324ac6b7

📥 Commits

Reviewing files that changed from the base of the PR and between 78afe56 and bf45923.

📒 Files selected for processing (3)

• nativelib/src/main/cpp/presentation_scheduler.cpp
• nativelib/src/main/cpp/presentation_scheduler.h
• nativelib/src/test/cpp/presentation_scheduler_test.cpp