test(mediabunny): [PKG-MB-09] preserve long-run AV tolerance breach

2026-10-08 10:56:15 -08:00 · 2026-09-16 11:54:08 +08:00
1 parent 58a648fd05
commit 78e3107b68
@@ -0,0 +1,270 @@
+{
+  "schemaVersion": 1,
+  "task": "PKG-MB-09",
+  "risk": "MB-SYNC-01",
+  "status": "running-threshold-breach",
+  "terminalResultObserved": false,
+  "thresholdSeconds": 0.25,
+  "sourceSnapshot": {
+    "path": "refactor/.cache/mb09-hour-first-av-breach.json",
+    "sha256": "045ef64a10a183afd1910e297b1486942043c944cc157ba16b39db9fdc78ec1a"
+  },
+  "capturedAt": "2026-09-16T03:51:20.798Z",
+  "scope": "Existing per-five-second samples, not a root-cause conclusion or terminal result",
+  "cases": [
+    {
+      "case": "mediabunny-MediaBunny-sust-71bde-layback-with-published-core-chromium",
+      "firstBreachIndex": 352,
+      "totalSamples": 385,
+      "aroundBreach": [
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+          "visibility": "visible",
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+        }
+      ],
+      "latest": {
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+        "visibility": "visible",
+        "paused": false,
+        "error": null,
+        "maxAVError": 0.5489999999997508
+      }
+    },
+    {
+      "case": "mediabunny-MediaBunny-sust-828df-layback-with-candidate-core-chromium",
+      "firstBreachIndex": 352,
+      "totalSamples": 385,
+      "aroundBreach": [
+        {
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+          "visibility": "visible",
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+        },
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+        },
+        {
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+        },
+        {
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+        "error": null,
+        "maxAVError": 0.5699999999999363
+      }
+    }
+  ]
+}
@@ -0,0 +1,32 @@
+# PKG-MB-09：长测中的 AV 阈值越界
+
+这是一份运行中检查点，不是终结报告。长测进程继续运行，被测源码、产物、素材和
+原有阈值没有修改，也没有重启用例或将结果标为通过。
+
+## 已观察到的事实
+
+首批两个 Chromium 场景都使用已安装的 MediaBunny 2.0.0，分别搭配发布核心和候选核心。
+约第 1762 秒，累计最大解码帧时间戳/AudioContext 主时钟偏差从约 25ms 增至
+229ms / 156ms；约第 1767 秒，两组分别升至约 549ms / 570ms，超过原有 250ms 门槛。
+对应采样仍为 visible、1×、未暂停、无媒体错误；媒体时钟和绘制计数继续增加，活动
+音频节点和迭代器未突破原上限。参见[固定采样快照](../baselines/mb-hour-av-breach.json)。
+
+两组几乎同时发生越界，但都使用同一候选 proxy；这不能证明历史 proxy 也失败，
+不能归因于特定核心，也不能仅据同时出现就认定是系统调度问题。
+观察后的 CPU/内存读数不是事发时剖析，不用它推导根因。
+
+## 源码核对及后续
+
+当前默认 `dropLateFrames` 为 false；`video-frames.ts` 的默认策略允许读取并绘制
+落后帧，开启丢帧才会按容差跳过。`video-renderer.ts` 的已排队帧绘制还需结合实际
+调度进一步诊断。这是现有源码事实，不足以证明本次偏差的具体来源。
+测试统计的是每次 drawImage 的帧时间戳/音频时钟差，不是声音输出测量或用户可见
+帧呈现的独立测量；短暂追赶、持续漂移与宿主阻塞需要分别验证。
+
+登记 MB-SYNC-01，保持 PKG-MB-09 doing。等待当前运行产生阶段统计、清理结果和
+最终报告后，再设计有限的调度/帧追赶对照，复现后修复项目缺陷并回归。
+不得直接更改公开默认丢帧行为、扩大 250ms 门槛、缩短长测，或重跑直到通过。
+当前已足以拒绝将这两个场景称为长播放通过，但最终进程退出状态仍需实际观察。
+
+本检查点只改证据、风险和文档；计划/风险校验及风险校验器测试完成后单独提交。
+不开始正式复盘，不推送或发布。
@@ -669,7 +669,7 @@
 - PKG-MB-06: [记录](baselines/mb-audio-source.json) [记录](changes/2026-09-12-PKG-MB-06-audio.md) [记录](baselines/mb-audio-validation.json)
 - PKG-MB-07: [记录](baselines/mb-hls-source.json) [记录](changes/2026-09-12-PKG-MB-07-hls.md) [记录](baselines/mb-hls-validation.json)
 - PKG-MB-08: [记录](baselines/mb-entry-source.json) [记录](changes/2026-09-12-PKG-MB-08-entry-checkpoint.md) [记录](baselines/mb-entry-checkpoint.json) [记录](baselines/mb-capability-source.json) [记录](changes/2026-09-12-PKG-MB-08-capability.md) [记录](baselines/mb-capability-validation.json)
- PKG-MB-09: [记录](changes/2026-09-12-PKG-MB-09-native-pip-checkpoint.md) [记录](baselines/mb-native-pip-checkpoint.json) [记录](changes/2026-09-12-PKG-MB-09-sustained-playback-checkpoint.md) [记录](baselines/mb-sustained-validation.json) [记录](baselines/mb-sustained-media.json) [记录](changes/2026-09-16-PKG-MB-09-hour-soak.md) [记录](baselines/mb-hour-soak-start.json)
+- PKG-MB-09: [记录](changes/2026-09-12-PKG-MB-09-native-pip-checkpoint.md) [记录](baselines/mb-native-pip-checkpoint.json) [记录](changes/2026-09-12-PKG-MB-09-sustained-playback-checkpoint.md) [记录](baselines/mb-sustained-validation.json) [记录](baselines/mb-sustained-media.json) [记录](changes/2026-09-16-PKG-MB-09-hour-soak.md) [记录](baselines/mb-hour-soak-start.json) [记录](changes/2026-09-16-PKG-MB-09-av-breach.md) [记录](baselines/mb-hour-av-breach.json)
 - PKG-IFRAME-01: [记录](changes/2026-09-12-PKG-IFRAME-01-contract.md) [记录](baselines/iframe-release.json) [记录](baselines/iframe-contract.md) [记录](baselines/iframe-contract-validation.json)
 - PKG-IFRAME-02: [记录](changes/2026-09-12-PKG-IFRAME-02-behavior.md) [记录](baselines/iframe-behavior-validation.json)
 - PKG-IFRAME-03: [记录](changes/2026-09-12-PKG-IFRAME-03-requests-checkpoint.md) [记录](baselines/iframe-requests-checkpoint.json) [记录](changes/2026-09-12-PKG-IFRAME-03-boundaries-checkpoint.md) [记录](baselines/iframe-boundaries-checkpoint.json) [记录](iframe-message-boundary.md) [记录](changes/2026-09-13-PKG-IFRAME-03-navigation.md) [记录](baselines/iframe-navigation-validation.json) [记录](iframe-document-protocol.md)
@@ -1,5 +1,12 @@
 # 进度与证据

+## PKG-MB-09 长测 AV 阈值越界（运行未终结）
+
+首批两个Chromium组合约1767秒时累计最大帧/音频时钟差达到549ms/570ms，超过
+250ms门槛。仍visible、未暂停、无媒体错误，绘制/时钟继续推进；不能据此归因于核心
+或系统。新增MB-SYNC-01并保留[快照与诊断边界](changes/2026-09-16-PKG-MB-09-av-breach.md)。
+被测输入不变，原进程继续，等待阶段统计/清理和终结报告；不称为通过，不重启到绿。
+
 ## DOC-03 校正根 AI 接续指引

 根AGENTS仍引用MediaBunny五个旧JS路径及过期源码风格，现已核对并改为实际TS入口，
@@ -291,3 +291,4 @@
 | SITE-EDITOR-VAST-01 | resolved / 已复现 | Monaco browser consumer still assumes the workspace VAST namespace after the approved npm-root restoration | SITE-EDITOR-VAST-01 |
 | CI-JASSUB-SOURCE-01 | resolved / 已复现 | Default native JASSUB source runs select only the published plugin and omit the current source | CI-JASSUB-SOURCE-01 |
 | DANMUKU-INSTALLED-GAP-01 | resolved / 已复现 | Windows WebKit installed Danmuku candidate misses two rows after a native main-thread gap | PKG-DANMUKU-08, PKG-DANMUKU-START-01 |
+| MB-SYNC-01 | open / 已复现 | Installed MediaBunny hour soak exceeds the original frame/audio-clock tolerance in both Chromium core combinations | PKG-MB-09 |
@@ -2,7 +2,7 @@
  "schemaVersion": 1,
  "task": "BASE-07",
  "sourceCommit": "e01f39ff",
-  "updatedAt": "2026-09-16T02:27:53.896Z",
+  "updatedAt": "2026-09-16T03:53:29.998Z",
  "note": "Open means closure evidence is outstanding; source-observed and unverified are not reproduced runtime bugs. A source issue already mitigated in the workspace still requires candidate regression evidence. No accepted-with-scope item is implied by baseline task completion.",
  "items": [
    {
@@ -6886,6 +6886,23 @@
        "refactor/baselines/danmuku-start-validation.json"
      ],
      "resolutionRationale": "The first sampling anchor was created only inside RAF. Reproduced in controlled first-frame and time-zero tests plus real Chromium/WebKit start-listener CPU stalls. Private playback-start anchoring preserves public queries and invalidation. Final source/installed three-engine timing, both installed runtime formats, scheduler regression and actual model load pass."
+    },
+    {
+      "id": "MB-SYNC-01",
+      "title": "Installed MediaBunny hour soak exceeds the original frame/audio-clock tolerance in both Chromium core combinations",
+      "confirmation": "reproduced",
+      "status": "open",
+      "owners": [
+        "PKG-MB-09"
+      ],
+      "evidence": [
+        "refactor/baselines/mb-hour-av-breach.json",
+        "refactor/changes/2026-09-16-PKG-MB-09-av-breach.md",
+        "test/soak/mediabunny.spec.js"
+      ],
+      "compatibleResolution": "Keep the running test and original 250ms gate. Distinguish delayed presentation, catch-up draws, sustained clock drift and host scheduling using bounded controls after preserving the terminal result; fix a reproduced project defect without changing the public dropLateFrames default.",
+      "closureCriteria": "Retain the first failing samples and terminal report; establish cause with appropriate historical/native controls, fix any confirmed project regression, and complete unchanged duration/cleanup requirements with a justified clock/presentation interpretation. A later passing run alone does not close this risk.",
+      "workspaceState": "Running-at-capture, not a final report: around 1767 seconds both Chromium cases using the same candidate proxy reach approximately 549ms/570ms max delta; visibility, advancing media/draws, node bounds and lack of media errors remain intact. Core-specific, historical-proxy and OS-cause claims are unproven."
    }
  ]
 }
@@ -4024,7 +4024,9 @@
        "baselines/mb-sustained-validation.json",
        "baselines/mb-sustained-media.json",
        "changes/2026-09-16-PKG-MB-09-hour-soak.md",
-        "baselines/mb-hour-soak-start.json"
+        "baselines/mb-hour-soak-start.json",
+        "changes/2026-09-16-PKG-MB-09-av-breach.md",
+        "baselines/mb-hour-av-breach.json"
      ]
    },
    {