diff --git a/.gitignore b/.gitignore
index aab3498028..8110f7d18f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,5 @@
 !/subprojects/packagefiles
 !/subprojects/*.wrap
 /build/
+.hvigor/
 .DS_Store
diff --git a/DOCS/BENCHMARK_METHODOLOGY.md b/DOCS/BENCHMARK_METHODOLOGY.md
new file mode 100644
index 0000000000..d09b0ae1ca
--- /dev/null
+++ b/DOCS/BENCHMARK_METHODOLOGY.md
@@ -0,0 +1,22 @@
+# Phase 6 Benchmark 方法
+
+## 执行
+
+```sh
+python3 benchmark/runner/run_emulator.py startup_local --repeat 20
+python3 benchmark/runner/run_emulator.py seek_local --repeat 50
+python3 benchmark/runner/run_emulator.py stress_lifecycle --repeat 100
+python3 benchmark/runner/run_emulator.py play_pause --repeat 200
+```
+
+runner 通过 hdc/uitest 驱动 `Playback Lab`，每次 load 使用内置 `sample.mp4`，记录 timeline、错误、状态和进程采样。startup 的首轮标为 cold-ish，后续为 warm；OS page cache 未被强制清空。seek 使用加载后立即触发的原生 `+10s`，避免短样片在输入框多次 keyEvent 期间自然结束。
+
+每个场景输出逐次 JSON 和 min/max/avg/median/P90/P95。百分位采用排序后的 nearest-rank；负时间线值是 unavailable，不参与统计。错误单独保留，不从成功样本中删除。
+
+## 采样边界
+
+- VmRSS、VmSize、Threads、fd count 和原始 CPU jiffies 来自 `/proc`；PSS、精确 native heap、可靠 CPU permille 未被模拟器公开，输出 null/原始值。
+- host wall time 包含 hdc 往返，只用于发现自动化超时，不作为启动性能结论。
+- `firstAudioCallbackMs` 是 Playback Lab 诊断轮询观察到 callback_count>0 的时间；要取得 callback 内精确时间需独立 tracing，因此不把它当作硬件时钟证据。
+- `stress_lifecycle` 覆盖 load/stop；release/recreate 需要新 XComponent surface，另行作为实体设备/手工场景。
+- HTTPS、HLS、鉴权、网络字幕必须使用受控 fixture；本轮没有把公网失败当作性能数据。
diff --git a/DOCS/BUFFERING_MODEL.md b/DOCS/BUFFERING_MODEL.md
new file mode 100644
index 0000000000..fc73a93589
--- /dev/null
+++ b/DOCS/BUFFERING_MODEL.md
@@ -0,0 +1,7 @@
+# Buffering Model
+
+buffering 是 MPV `cache-buffering` 属性与网络状态的边沿诊断，不是 UI 的瞬时文案。进入时记录 `bufferingEnterCount` 和起始 monotonic 时间；退出时累加 `bufferingTotalMs`，并更新 `bufferingMaxSingleMs`。重复的同值属性通知不会重复计数。
+
+网络快照同时保留 protocol、host、HTTP status、redirect count、cache duration/bytes、current bitrate、range support 和最近 seek result。`networkWaitMs` 只计算已观察到的 network-open 到 first-byte/file-loaded 间隔；file:// 输入为 -1。
+
+本地短片通常在首帧后很快 EOF，因此 buffering 计数为 0 不代表网络流在真实设备上不会重缓冲。受控 HTTP Range fixture 已在 Phase 5 验证；HTTPS/HLS、鉴权和弱网重缓冲应在实体设备用固定服务端脚本复测。
diff --git a/DOCS/PERFORMANCE_CHANGES.md b/DOCS/PERFORMANCE_CHANGES.md
new file mode 100644
index 0000000000..f458ae7681
--- /dev/null
+++ b/DOCS/PERFORMANCE_CHANGES.md
@@ -0,0 +1,18 @@
+# Phase 6 性能改动与证据
+
+## 已采用
+
+1. **事件驱动渲染更新**：`render.cpp` 不再每 16ms 无条件调用 `mpv_render_context_update`，只在 mpv callback/窗口事件唤醒时更新；为避免个别会话漏回调，最多每 250ms 做一次安全探测。5 次 startup 的 update 累计从优化前 617 降到最终实现 364，且 20 次 startup 未复现永久 BUFFERING。
+2. **核心快照合并**：`PlaybackEngine` 对 100ms 内的重复 `get_snapshot/get_tracks/get_media_info/get_network_info` 做合并，动作仍立即提交到 MPV，状态最多延迟一个合并窗口。200 次 play/pause 末次面板显示 `coreSyncSkipped=239`；无 error，状态为 PAUSED。
+3. **NAPI 诊断轮询降频**：Playback Lab 面板由 250ms 调整为 500ms；播放控制、音频 callback 和渲染线程不依赖该轮询。这样减少纯 UI 诊断序列化，不改变 MPV 时钟。旧/新间隔在 `Index.ets` 可审计，运行中由 `getStateCalls`、`serializeUsTotal` 记录。
+4. **session id 原子读取**：渲染线程不再为每次唤醒获取 `PlaybackEngine` 快照互斥锁，session 更新仍由核心快照写入 release/acquire atomic；首帧 session 隔离 smoke 和 stress 均通过。
+
+## 未采用
+
+- 不做主动丢帧、降低音频采样率或缩小视频分辨率；这些会改变播放质量。
+- 不做 GPU mapper、OHCodec 直出或 FFmpeg-Harmony 源码改动；实体设备 capability 和 fence 证据不足。
+- 不把 PSS、heap、CPU permille、2 小时长跑结果伪装成已测数据。
+
+## 回归与开销
+
+默认构建、软件构建和 FFmpeg-Harmony 构建均通过。默认 HAP 在模拟器上完成 startup/seek/audio 状态面板、load/stop 100 次和 play/pause 100 次。release/profile 构建未启用持续 tracing；诊断仅累加轻量计数和受控序列化时间。
diff --git a/DOCS/PERFORMANCE_METRICS.md b/DOCS/PERFORMANCE_METRICS.md
new file mode 100644
index 0000000000..c471eefab0
--- /dev/null
+++ b/DOCS/PERFORMANCE_METRICS.md
@@ -0,0 +1,20 @@
+# Phase 6 性能指标
+
+所有时间均为单调时钟相对当前 load session 的毫秒数。`-1` 表示该事件没有发生或无法可靠观察；runner 会把负值转换为 `null`，不参与百分位统计。
+
+| 类别 | 字段/来源 | 语义 | 模拟器可用性 |
+| --- | --- | --- | --- |
+| 启动 | `timeline.startupTotalMs` / `firstSwapMs` | load 到首个成功 EGL swap | 可用 |
+| 启动分段 | create、initialize、load、START_FILE、FILE_LOADED、decoder reconfig、render context | 各阶段首次事件 | 可用，缺失阶段为 -1 |
+| 网络 | `firstByteMs`、`networkWaitMs`、HTTP status、206/range | 只记录观察到的请求/日志证据 | HTTP fixture 可用，HTTPS/HLS pending |
+| seek | `seekCommandLatencyMs`、`seekRecoveryMs`、`seekFirstSwapMs` | seek request/command 到恢复首帧/首 swap | 相对 `+10s` 可用 |
+| buffering | enter/exit 次数、累计时长、单次最大时长 | cache-buffering 状态边沿 | 字段可用；本地短片通常为 0 |
+| 音频 | renderer start、首 callback、submitted/played、delay、starvation、flush/reset | 首 callback 时间由诊断轮询观察，不冒充 callback 内精确时间 | 模拟器字段可用，设备路由 pending |
+| 视频 | dropped、late、mistimed、decoder frames、render count | MPV stats 或 renderer 计数 | 计数接口可用，部分 MPV 值可能为 -1 |
+| 内存 | `/proc/<pid>/status` VmRSS/VmSize | 进程 RSS/虚拟地址空间 | 可用；PSS/精确 heap 为 null |
+| CPU | `/proc/<pid>/stat` utime+stime | 原始 jiffies | 原始值可用；未取得可靠 tick/采样归一化，不输出 permille |
+| 线程/资源 | Threads、`/proc/<pid>/fd` | 进程线程和 fd 快照 | 可用；fd=0 视为不可用 |
+| NAPI | getState 次数、序列化微秒、估算 payload | NAPI 状态导出成本 | 可用；payload 是上界估算，不是分配追踪 |
+| 渲染诊断 | render update/frame update、core sync/skipped | 优化前后计数及合并效果 | 可用 |
+
+NAPI 返回使用 Number 以保持 Inspector 可序列化；大整数仅用于内部原子计数。任何未被设备或 API 真实提供的数据都保持 unavailable，不由模型推断。
diff --git a/DOCS/PHASE6_STATUS.md b/DOCS/PHASE6_STATUS.md
new file mode 100644
index 0000000000..f0fa8ff934
--- /dev/null
+++ b/DOCS/PHASE6_STATUS.md
@@ -0,0 +1,33 @@
+# Phase 6 状态
+
+状态：**CODE COMPLETE / EMULATOR BENCHMARKED / DEVICE BENCHMARK PENDING**。
+
+Phase 6 交付范围是可重复的 Playback Lab 性能时间线、资源采样、NAPI 诊断、四项低风险优化和模拟器回归。没有修改 GPU mapper，也没有修改 `Velix-FFmpeg-Harmony`。
+
+## 已完成
+
+- 启动、seek、buffering、音频、渲染、NAPI 和资源指标已接入稳定快照；未能可靠取得的 PSS、精确 heap、归一化 CPU 均明确返回 `null` 或文档标记为 unavailable。
+- `benchmark/runner/run_emulator.py` 支持 startup、seek、load/stop stress、play/pause stress，输出重复统计（min/max/avg/median/P90/P95）和逐次资源采样。
+- 渲染循环改为 mpv update callback 驱动，并保留 250ms 安全探测；快照同步增加 100ms 合并窗口；session id 读取改为 atomic；诊断轮询从 250ms 调整为 500ms。
+- default、software、FFmpeg-Harmony 三套 AArch64 libmpv 均通过符号和 OHOS ELF 校验；Playback Lab HAP 编译、安装和模拟器启动通过。
+
+## 模拟器结果
+
+测试设备：`127.0.0.1:5555`，本地 H.264/AAC MP4，软件解码，`ao_harmony`。
+
+| 场景 | 结果文件 | 关键结果 |
+| --- | --- | --- |
+| startup_local ×20 | `benchmark/results/startup_local-1787999362.json` | 首帧 P50 506ms，P95 1150ms；20/20 暴露时间线，无错误 |
+| seek_local ×50 | `benchmark/results/seek_local-1787999663.json` | 恢复 P50 277ms，P95 631ms；49/50 有恢复时间线，1 次 `SEEK` 命令错误 |
+| play_pause ×200 | `benchmark/results/play_pause-1788000475.json` | 无错误；末次 RSS 213228KB、线程 39、fd 1 |
+| load/stop ×100 | `benchmark/results/stress_lifecycle-1788000229.json` | 进程保持存活；RSS/线程/fd 采样完成，PSS 不可用 |
+
+优化前后计数基线：同等 5 次 startup 中，渲染 update 累计由 617 降至最终版本 364；NAPI/核心同步计数通过面板快照记录。200 次 play/pause 无错误，末次 `coreSyncSkipped=239`，说明合并窗口实际生效。
+
+最终 5 次 smoke 还观察到 `firstAudioCallbackMs` P50 256ms、`audioRendererStartMs` P50 720ms；这些值来自 500ms 诊断轮询，不能替代设备音频 trace。file:// 场景的 `networkWaitMs` 保持 -1，buffering 计数按真实状态边沿记录。
+
+## 尚待实体设备
+
+实体设备上的真实 PSS/heap、CPU 利用率、显示合成延迟、音频路由/A-V 偏差、OHCodec capability、长时间（2h）稳定性、HTTPS/HLS/鉴权/网络字幕仍未验证。Phase 7 建议先建立实体设备矩阵和受控 HTTPS/HLS fixture，再评估硬解直出和端到端 A/V 指标。
+
+许可边界沿用 MPV LGPL/ISC；本阶段未引入新的第三方依赖或商业资源。
diff --git a/DOCS/SEEK_PIPELINE.md b/DOCS/SEEK_PIPELINE.md
new file mode 100644
index 0000000000..5e9beaf9e7
--- /dev/null
+++ b/DOCS/SEEK_PIPELINE.md
@@ -0,0 +1,15 @@
+# Seek Pipeline
+
+```text
+seek request
+  -> mpv seek command
+  -> SEEK event / demux recovery
+  -> VIDEO_RECONFIG
+  -> PLAYBACK_RESTART
+  -> first video frame
+  -> first render / EGL swap
+```
+
+`seekCommandLatencyMs` 是 API request 到 command 提交的耗时；`seekRecoveryMs` 是 request 到 `PLAYBACK_RESTART` 的耗时；`seekFirstVisibleFrameMs` 是 request 到首个成功 swap 的耗时。若 MPV 没有产生对应事件，字段为 -1。每次新 seek 会重置上一次 seek 字段，不把旧会话值带入新会话。
+
+模拟器 runner 使用 `+10s` 相对 seek，50 次中 49 次产生 recovery，1 次返回稳定 `SEEK / error running command`；该失败保留在 JSON，不被隐藏。精确/百分比 seek 入口仍由公共 API 暴露，但短样片不足以让输入框自动化可靠覆盖，需更长受控 fixture。
diff --git a/DOCS/STARTUP_PIPELINE.md b/DOCS/STARTUP_PIPELINE.md
new file mode 100644
index 0000000000..b094c358c8
--- /dev/null
+++ b/DOCS/STARTUP_PIPELINE.md
@@ -0,0 +1,19 @@
+# Startup Pipeline
+
+```text
+session setup
+  -> mpv_create / mpv_initialize
+  -> load command
+  -> START_FILE
+  -> network open / first byte (network only)
+  -> FILE_LOADED (demux ready)
+  -> VIDEO_RECONFIG / AUDIO_RECONFIG
+  -> render context ready
+  -> first video frame available
+  -> first render begin/end
+  -> first EGL swap (startupTotalMs)
+```
+
+时间线在 core 内以 `clock_gettime(CLOCK_MONOTONIC)` 记录，所有阶段只写首次发生值。文件输入没有网络阶段时保持 -1；网络阶段只在真实 MPV log/event 证据出现时写入。`startupTotalMs` 在首个成功 `eglSwapBuffers` 写入，`firstFrameMs` 保留外壳兼容字段并与首 swap 对齐。
+
+音频 renderer start 和首 callback 由 OHAudio stats poll 观察；这两个字段可能晚于真实 callback，因此用于阶段诊断，不替代设备级 audio trace。
diff --git a/benchmark/.gitignore b/benchmark/.gitignore
new file mode 100644
index 0000000000..8b2e9983ea
--- /dev/null
+++ b/benchmark/.gitignore
@@ -0,0 +1,5 @@
+results/*.json
+reports/*.md
+runner/__pycache__/
+!results/.gitkeep
+!reports/.gitkeep
diff --git a/benchmark/reports/.gitkeep b/benchmark/reports/.gitkeep
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/benchmark/results/.gitkeep b/benchmark/results/.gitkeep
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/benchmark/runner/run_emulator.py b/benchmark/runner/run_emulator.py
new file mode 100755
index 0000000000..00b4c46855
--- /dev/null
+++ b/benchmark/runner/run_emulator.py
@@ -0,0 +1,385 @@
+#!/usr/bin/env python3
+"""Repeatable Playback Lab emulator benchmark runner.
+
+Only uses the standard library and the OpenHarmony hdc/uitest command line.
+Metrics unavailable from the emulator are emitted as null, never inferred.
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import math
+import os
+import re
+import shlex
+import subprocess
+import tempfile
+import time
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any, Iterable
+
+
+ROOT = Path(__file__).resolve().parents[2]
+PACKAGE = "com.velix.playbacklab"
+DEFAULT_SERIAL = "127.0.0.1:5555"
+DEFAULT_HDC = "/Applications/DevEco-Studio.app/Contents/sdk/default/openharmony/toolchains/hdc"
+
+
+def command(argv: list[str], timeout: float = 30.0) -> str:
+    result = subprocess.run(argv, check=False, capture_output=True, text=True, timeout=timeout)
+    if result.returncode != 0:
+        raise RuntimeError(f"command failed ({result.returncode}): {shlex.join(argv)}\n{result.stderr.strip()}")
+    return result.stdout.strip()
+
+
+class Emulator:
+    def __init__(self, serial: str, hdc: str) -> None:
+        self.serial = serial
+        self.hdc = hdc
+        self.layout_counter = 0
+
+    def hdc_shell(self, text: str, timeout: float = 30.0) -> str:
+        return command([self.hdc, "-t", self.serial, "shell", text], timeout)
+
+    def click(self, x: int, y: int) -> None:
+        self.hdc_shell(f"uitest uiInput click {x} {y}", timeout=10)
+
+    def layout(self) -> dict[str, Any]:
+        self.layout_counter += 1
+        marker = self.hdc_shell(f"uitest dumpLayout -b {PACKAGE} -m true -d 0", timeout=10)
+        match = re.search(r"saved to:(\S+)", marker)
+        if not match:
+            raise RuntimeError(f"layout dump did not return a path: {marker}")
+        remote = match.group(1)
+        local = Path(tempfile.gettempdir()) / f"velix-layout-{os.getpid()}-{self.layout_counter}.json"
+        command([self.hdc, "-t", self.serial, "file", "recv", remote, str(local)], timeout=10)
+        with local.open(encoding="utf-8") as stream:
+            return json.load(stream)
+
+    def pid(self) -> int | None:
+        output = self.hdc_shell(f"pidof {PACKAGE}", timeout=10)
+        match = re.search(r"\b(\d+)\b", output)
+        return int(match.group(1)) if match else None
+
+    def process_sample(self) -> dict[str, Any]:
+        pid = self.pid()
+        sample: dict[str, Any] = {"pid": pid, "rssKb": None, "pssKb": None, "heapKb": None,
+                                  "virtualMemoryKb": None,
+                                  "threadCount": None, "fdCount": None, "cpuPermille": None,
+                                  "cpuSupported": False}
+        if pid is None:
+            return sample
+        status = self.hdc_shell(f"cat /proc/{pid}/status", timeout=10)
+        for key, field in (("rssKb", "VmRSS"), ("virtualMemoryKb", "VmSize"), ("threadCount", "Threads")):
+            match = re.search(rf"^{field}:\s+(\d+)", status, re.MULTILINE)
+            if match:
+                sample[key] = int(match.group(1))
+        fd_output = self.hdc_shell(f"ls /proc/{pid}/fd 2>&1 | wc -l", timeout=10)
+        if fd_output.isdigit() and fd_output != "0":
+            sample["fdCount"] = int(fd_output)
+        stat = self.hdc_shell(f"cat /proc/{pid}/stat", timeout=10)
+        match = re.match(r"^\d+ \(.+\) (.*)$", stat)
+        if match:
+            fields = match.group(1).split()
+            if len(fields) > 12:
+                sample["cpuJiffies"] = int(fields[11]) + int(fields[12])
+        return sample
+
+    def product_version(self) -> str | None:
+        try:
+            value = self.hdc_shell("param get const.product.software.version", timeout=10)
+        except RuntimeError:
+            return None
+        return value or None
+
+
+def walk_nodes(node: dict[str, Any]) -> Iterable[dict[str, Any]]:
+    yield node
+    for child in node.get("children", []):
+        if isinstance(child, dict):
+            yield from walk_nodes(child)
+
+
+def node_text(node: dict[str, Any]) -> str:
+    attrs = node.get("attributes", {})
+    return str(attrs.get("text") or attrs.get("originalText") or "")
+
+
+def find_node(layout: dict[str, Any], text: str) -> dict[str, Any] | None:
+    for node in walk_nodes(layout):
+        if node_text(node) == text:
+            return node
+    return None
+
+
+def center(bounds: str) -> tuple[int, int]:
+    values = [int(value) for value in re.findall(r"\d+", bounds)]
+    if len(values) != 4:
+        raise ValueError(f"invalid bounds: {bounds}")
+    return (values[0] + values[2]) // 2, (values[1] + values[3]) // 2
+
+
+def click_text(emulator: Emulator, text: str) -> None:
+    node = find_node(emulator.layout(), text)
+    if node is None:
+        raise RuntimeError(f"UI node not found: {text}")
+    emulator.click(*center(node["attributes"]["bounds"]))
+
+
+def all_texts(layout: dict[str, Any]) -> list[str]:
+    return [node_text(node) for node in walk_nodes(layout) if node_text(node)]
+
+
+def text_matching(layout: dict[str, Any], prefix: str) -> str | None:
+    for value in all_texts(layout):
+        if value.startswith(prefix):
+            return value
+    return None
+
+
+def parse_int(text: str | None, pattern: str) -> int | None:
+    if not text:
+        return None
+    match = re.search(pattern, text)
+    return int(match.group(1)) if match else None
+
+
+def parse_state(layout: dict[str, Any]) -> str | None:
+    value = text_matching(layout, "state: ")
+    return value.split(": ", 1)[1] if value and ": " in value else None
+
+
+def parse_run(layout: dict[str, Any]) -> dict[str, Any]:
+    startup = text_matching(layout, "startup=") or ""
+    buffer_line = text_matching(layout, "buffer enter=") or ""
+    napi_line = text_matching(layout, "napi calls=") or ""
+    render_line = text_matching(layout, "render updates=") or napi_line
+    error = text_matching(layout, "error=") or ""
+    timeline: dict[str, Any] = {}
+    for key, value in re.findall(r"(startup|firstSwap|seekRecovery|audioStart|audioCallback)=(-?\d+)", startup):
+        timeline[{"startup": "startupTotalMs", "firstSwap": "firstSwapMs", "seekRecovery": "seekRecoveryMs",
+                  "audioStart": "audioRendererStartMs", "audioCallback": "firstAudioCallbackMs"}[key]] = int(value)
+    first_frame = parse_int(text_matching(layout, "dropped="), r"firstFrameMs=(-?\d+)")
+    if first_frame is None or first_frame < 0:
+        first_frame = timeline.get("firstSwapMs")
+    if first_frame is not None and first_frame < 0:
+        first_frame = None
+    startup_ms = timeline.get("startupTotalMs")
+    first_swap_ms = timeline.get("firstSwapMs")
+    seek_recovery_ms = timeline.get("seekRecoveryMs")
+    audio_start_ms = timeline.get("audioRendererStartMs")
+    audio_callback_ms = timeline.get("firstAudioCallbackMs")
+    if startup_ms is not None and startup_ms < 0:
+        startup_ms = None
+    if first_swap_ms is not None and first_swap_ms < 0:
+        first_swap_ms = None
+    if seek_recovery_ms is not None and seek_recovery_ms < 0:
+        seek_recovery_ms = None
+    if audio_start_ms is not None and audio_start_ms < 0:
+        audio_start_ms = None
+    if audio_callback_ms is not None and audio_callback_ms < 0:
+        audio_callback_ms = None
+    return {
+        "state": parse_state(layout),
+        "firstFrameMs": first_frame,
+        "renderCount": parse_int(text_matching(layout, "dropped="), r"renderCount=(-?\d+)"),
+        "startupTotalMs": startup_ms,
+        "firstSwapMs": first_swap_ms,
+        "seekRecoveryMs": seek_recovery_ms,
+        "audioRendererStartMs": audio_start_ms,
+        "firstAudioCallbackMs": audio_callback_ms,
+        "bufferingEnterCount": parse_int(buffer_line, r"buffer enter=(-?\d+)"),
+        "bufferingExitCount": parse_int(buffer_line, r"exit=(-?\d+)"),
+        "napiCalls": parse_int(napi_line, r"napi calls=(-?\d+)"),
+        "renderUpdateCalls": parse_int(render_line, r"updates=(-?\d+)/"),
+        "renderFrameUpdates": parse_int(render_line, r"updates=-?\d+/(-?\d+)"),
+        "coreSyncCalls": parse_int(render_line, r"sync=(-?\d+)/"),
+        "coreSyncSkipped": parse_int(render_line, r"sync=-?\d+/(-?\d+)"),
+        "error": error,
+    }
+
+
+def wait_for_first_frame(emulator: Emulator, timeout: float = 10.0) -> tuple[dict[str, Any], list[dict[str, Any]]]:
+    deadline = time.monotonic() + timeout
+    samples: list[dict[str, Any]] = []
+    latest: dict[str, Any] = {}
+    next_sample = 0.0
+    while time.monotonic() < deadline:
+        latest = emulator.layout()
+        now = time.monotonic()
+        if now >= next_sample:
+            samples.append({"atMs": int((timeout - max(0.0, deadline - now)) * 1000),
+                            **emulator.process_sample()})
+            next_sample = now + 1.0
+        run = parse_run(latest)
+        if run.get("startupTotalMs") is not None or run.get("state") == "ERROR":
+            return latest, samples
+        time.sleep(0.15)
+    raise TimeoutError(f"playback did not expose first-frame timeline: {parse_run(latest)}")
+
+
+def stats(values: list[float | int]) -> dict[str, float | int | None]:
+    numbers = sorted(float(value) for value in values if value is not None and math.isfinite(float(value)))
+    if not numbers:
+        return {"count": 0, "min": None, "max": None, "avg": None, "median": None, "p90": None, "p95": None}
+    def percentile(fraction: float) -> float:
+        return numbers[max(0, min(len(numbers) - 1, math.ceil(fraction * len(numbers)) - 1))]
+    return {"count": len(numbers), "min": numbers[0], "max": numbers[-1],
+            "avg": sum(numbers) / len(numbers), "median": percentile(0.5),
+            "p90": percentile(0.9), "p95": percentile(0.95)}
+
+
+def git_revision(path: Path) -> str | None:
+    try:
+        return command(["git", "-C", str(path), "rev-parse", "HEAD"], timeout=10)
+    except RuntimeError:
+        return None
+
+
+def load_local(emulator: Emulator) -> tuple[dict[str, Any], list[dict[str, Any]]]:
+    click_text(emulator, "Load Local Test")
+    return wait_for_first_frame(emulator)
+
+
+def startup_local(emulator: Emulator, repeat: int) -> list[dict[str, Any]]:
+    runs: list[dict[str, Any]] = []
+    for index in range(repeat):
+        began = time.monotonic()
+        click_text(emulator, "Load Local Test")
+        layout, samples = wait_for_first_frame(emulator)
+        run = parse_run(layout)
+        run.update({"runIndex": index + 1, "cacheClass": "cold-ish" if index == 0 else "warm",
+                    "hostFirstFrameMs": int((time.monotonic() - began) * 1000),
+                    "processSamples": samples})
+        runs.append(run)
+    return runs
+
+
+def wait_for_seek_recovery(emulator: Emulator, timeout: float = 5.0) -> tuple[dict[str, Any], list[dict[str, Any]]]:
+    deadline = time.monotonic() + timeout
+    samples: list[dict[str, Any]] = []
+    latest: dict[str, Any] = {}
+    next_sample = 0.0
+    while time.monotonic() < deadline:
+        latest = emulator.layout()
+        now = time.monotonic()
+        if now >= next_sample:
+            samples.append({"atMs": int((timeout - max(0.0, deadline - now)) * 1000),
+                            **emulator.process_sample()})
+            next_sample = now + 1.0
+        run = parse_run(latest)
+        if run.get("seekRecoveryMs") is not None and run.get("seekRecoveryMs") >= 0:
+            return latest, samples
+        if run.get("state") == "ERROR":
+            return latest, samples
+        time.sleep(0.1)
+    raise TimeoutError(f"seek did not expose recovery timeline: {parse_run(latest)}")
+
+
+def seek_local(emulator: Emulator, repeat: int) -> list[dict[str, Any]]:
+    runs: list[dict[str, Any]] = []
+    for index in range(repeat):
+        click_text(emulator, "Load Local Test")
+        # The bundled clip is intentionally short and may finish before a
+        # multi-command text-input interaction completes.  The native +/-10s
+        # action exercises the same seek API without that race.
+        time.sleep(0.05)
+        click_text(emulator, "+10s")
+        latest, samples = wait_for_seek_recovery(emulator)
+        run = parse_run(latest)
+        run.update({"runIndex": index + 1, "mode": "relative", "offsetSeconds": 10,
+                    "processSamples": samples})
+        runs.append(run)
+    return runs
+
+
+def stress_lifecycle(emulator: Emulator, repeat: int) -> list[dict[str, Any]]:
+    initial = emulator.layout()
+    load_center = center(find_node(initial, "Load Local Test")["attributes"]["bounds"])
+    stop_center = center(find_node(initial, "Stop")["attributes"]["bounds"])
+    runs: list[dict[str, Any]] = []
+    for index in range(repeat):
+        emulator.click(*load_center)
+        time.sleep(0.08)
+        emulator.click(*stop_center)
+        time.sleep(0.08)
+        layout = emulator.layout()
+        run = parse_run(layout)
+        run.update({"runIndex": index + 1, "processSample": emulator.process_sample()})
+        runs.append(run)
+    return runs
+
+
+def play_pause(emulator: Emulator, repeat: int) -> list[dict[str, Any]]:
+    load_local(emulator)
+    initial = emulator.layout()
+    play_center = center(find_node(initial, "Play")["attributes"]["bounds"])
+    pause_center = center(find_node(initial, "Pause")["attributes"]["bounds"])
+    runs: list[dict[str, Any]] = []
+    for index in range(repeat):
+        emulator.click(*play_center)
+        emulator.click(*pause_center)
+        if index % 10 == 0:
+            time.sleep(0.05)
+        run = {"runIndex": index + 1, "processSample": emulator.process_sample()}
+        if index % 10 == 0 or index + 1 == repeat:
+            run.update(parse_run(emulator.layout()))
+        runs.append(run)
+    return runs
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("scenario", choices=["startup_local", "seek_local", "stress_lifecycle", "play_pause"])
+    parser.add_argument("--repeat", type=int, default=None)
+    parser.add_argument("--serial", default=os.environ.get("DEVECO_DEVICE", DEFAULT_SERIAL))
+    parser.add_argument("--hdc", default=os.environ.get("HDC", DEFAULT_HDC))
+    parser.add_argument("--output", type=Path)
+    args = parser.parse_args()
+    defaults = {"startup_local": 20, "seek_local": 50, "stress_lifecycle": 100, "play_pause": 200}
+    repeat = args.repeat if args.repeat is not None else defaults[args.scenario]
+    emulator = Emulator(args.serial, args.hdc)
+    if args.scenario == "startup_local":
+        runs = startup_local(emulator, repeat)
+    elif args.scenario == "seek_local":
+        runs = seek_local(emulator, repeat)
+    elif args.scenario == "stress_lifecycle":
+        runs = stress_lifecycle(emulator, repeat)
+    else:
+        runs = play_pause(emulator, repeat)
+    metric_names = ["firstFrameMs", "startupTotalMs", "firstSwapMs", "seekRecoveryMs", "audioRendererStartMs",
+                    "firstAudioCallbackMs", "bufferingEnterCount", "bufferingExitCount", "hostFirstFrameMs", "hostTerminalMs"]
+    output = {
+        "timestamp": datetime.now(timezone.utc).isoformat(),
+        "gitCommit": git_revision(ROOT),
+        "mpvCommit": git_revision(ROOT),
+        "ffmpegCommit": git_revision(ROOT.parent / "Velix-FFmpeg-Harmony"),
+        "deviceType": "emulator",
+        "deviceSerial": args.serial,
+        "harmonyVersion": emulator.product_version(),
+        "testScenario": args.scenario,
+        "mediaId": "sample.mp4",
+        "protocol": "file",
+        "codec": "H.264/AAC",
+        "resolution": None,
+        "audio": "ao_harmony",
+        "subtitle": "none",
+        "hwdec": "software",
+        "repeat": repeat,
+        "metrics": {name: stats([run.get(name) for run in runs]) for name in metric_names},
+        "runs": runs,
+        "errors": [run.get("error") for run in runs if run.get("error") and "error=NONE" not in run.get("error", "")],
+        "sampling": {"pss": "unsupported unless exposed by device", "cpu": "raw /proc stat only when available"},
+    }
+    output_path = args.output or ROOT / "benchmark" / "results" / f"{args.scenario}-{int(time.time())}.json"
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+    output_path.write_text(json.dumps(output, ensure_ascii=False, indent=2) + "\n", encoding="utf-8")
+    print(output_path)
+    print(json.dumps(output["metrics"], ensure_ascii=False, indent=2))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/benchmark/scenarios/audio_on_off.json b/benchmark/scenarios/audio_on_off.json
new file mode 100644
index 0000000000..ab7bc6a96f
--- /dev/null
+++ b/benchmark/scenarios/audio_on_off.json
@@ -0,0 +1,7 @@
+{
+  "name": "audio_on_off",
+  "media": "sample.mp4",
+  "repeat": 10,
+  "variants": ["audio_on", "audio_off"],
+  "notes": "Compare firstAudioCallbackMs and startupTotalMs without changing decode quality."
+}
diff --git a/benchmark/scenarios/http_range.json b/benchmark/scenarios/http_range.json
new file mode 100644
index 0000000000..7cb5627f96
--- /dev/null
+++ b/benchmark/scenarios/http_range.json
@@ -0,0 +1,7 @@
+{
+  "name": "http_range",
+  "media": "controlled-http-mp4",
+  "repeat": 10,
+  "requiredServerEvidence": ["Range bytes=0-", "206 response", "seekResult"],
+  "notes": "HTTPS/HLS are separate controlled-network scenarios and remain pending without a reliable source."
+}
diff --git a/benchmark/scenarios/seek_local.json b/benchmark/scenarios/seek_local.json
new file mode 100644
index 0000000000..5dc71467d0
--- /dev/null
+++ b/benchmark/scenarios/seek_local.json
@@ -0,0 +1,7 @@
+{
+  "name": "seek_local",
+  "media": "sample.mp4",
+  "positionsPercent": [10, 25, 50, 75, 90],
+  "repeatPerPosition": 10,
+  "modes": ["fast", "exact"]
+}
diff --git a/benchmark/scenarios/startup_local.json b/benchmark/scenarios/startup_local.json
new file mode 100644
index 0000000000..bd286c87e3
--- /dev/null
+++ b/benchmark/scenarios/startup_local.json
@@ -0,0 +1,8 @@
+{
+  "name": "startup_local",
+  "media": "sample.mp4",
+  "repeat": 20,
+  "coldIsh": true,
+  "warm": true,
+  "notes": "OS page cache is not controlled; firstFrame/startup timeline comes from the Playback Lab."
+}
diff --git a/benchmark/scenarios/stress_lifecycle.json b/benchmark/scenarios/stress_lifecycle.json
new file mode 100644
index 0000000000..47b45b7434
--- /dev/null
+++ b/benchmark/scenarios/stress_lifecycle.json
@@ -0,0 +1,6 @@
+{
+  "name": "stress_lifecycle",
+  "loadStopCycles": 100,
+  "playPauseCycles": 200,
+  "notes": "Release/recreate requires a fresh XComponent surface and is kept separate from load/stop stress."
+}
diff --git a/benchmark/scenarios/subtitle_ass.json b/benchmark/scenarios/subtitle_ass.json
new file mode 100644
index 0000000000..f2fd6d384b
--- /dev/null
+++ b/benchmark/scenarios/subtitle_ass.json
@@ -0,0 +1,7 @@
+{
+  "name": "subtitle_ass",
+  "media": "sample.mp4",
+  "repeat": 10,
+  "variants": ["none", "embedded_srt", "embedded_ass", "external_ass"],
+  "notes": "Run only when the corresponding controlled fixture is installed on the emulator."
+}
diff --git a/include/mpv/harmony_playback.h b/include/mpv/harmony_playback.h
index df19f4daa7..7e2e25cacd 100644
--- a/include/mpv/harmony_playback.h
+++ b/include/mpv/harmony_playback.h
@@ -173,6 +173,14 @@ typedef struct mp_harmony_playback_metrics {
     double cache_duration;
     int64_t cache_bytes;
     int64_t current_bitrate;
+    int64_t buffering_enter_count;
+    int64_t buffering_exit_count;
+    int64_t buffering_total_ms;
+    int64_t buffering_max_single_ms;
+    int64_t network_wait_ms;
+    int64_t late_frames;
+    int64_t mistimed_frames;
+    int64_t decoder_frames;
 } mp_harmony_playback_metrics;
 
 typedef struct mp_harmony_playback_error {
@@ -180,6 +188,43 @@ typedef struct mp_harmony_playback_error {
     char raw_message[MP_HARMONY_TEXT];
 } mp_harmony_playback_error;
 
+/* Elapsed milliseconds from the current load request; -1 means unavailable. */
+typedef struct mp_harmony_playback_timeline {
+    int64_t session_setup_ms;
+    int64_t mpv_create_ms;
+    int64_t mpv_initialize_ms;
+    int64_t load_command_ms;
+    int64_t start_file_ms;
+    int64_t network_open_begin_ms;
+    int64_t network_open_end_ms;
+    int64_t first_byte_ms;
+    int64_t demux_ready_ms;
+    int64_t file_loaded_ms;
+    int64_t video_decoder_ready_ms;
+    int64_t audio_decoder_ready_ms;
+    int64_t video_reconfig_ms;
+    int64_t audio_reconfig_ms;
+    int64_t render_context_ready_ms;
+    int64_t first_video_frame_available_ms;
+    int64_t first_render_begin_ms;
+    int64_t first_render_end_ms;
+    int64_t first_swap_ms;
+    int64_t startup_total_ms;
+    int64_t audio_renderer_start_ms;
+    int64_t first_audio_callback_ms;
+    int64_t playback_restart_ms;
+    int64_t seek_request_ms;
+    int64_t seek_command_ms;
+    int64_t seek_demux_ms;
+    int64_t seek_video_reconfig_ms;
+    int64_t seek_playback_restart_ms;
+    int64_t seek_first_frame_ms;
+    int64_t seek_first_swap_ms;
+    int64_t seek_command_latency_ms;
+    int64_t seek_recovery_ms;
+    int64_t seek_first_visible_frame_ms;
+} mp_harmony_playback_timeline;
+
 typedef struct mp_harmony_playback_snapshot {
     uint64_t session_id;
     mp_harmony_state state;
@@ -202,6 +247,7 @@ typedef struct mp_harmony_playback_snapshot {
     mp_harmony_playback_metrics metrics;
     mp_harmony_media_info media;
     mp_harmony_network_info network;
+    mp_harmony_playback_timeline timeline;
 } mp_harmony_playback_snapshot;
 
 /* Stable model aliases for language bindings. */
diff --git a/memory/2026-08-29.md b/memory/2026-08-29.md
index 1353965c61..f4bf436def 100644
--- a/memory/2026-08-29.md
+++ b/memory/2026-08-29.md
@@ -38,3 +38,9 @@
 文件变更: player/harmony_playback.c, include/mpv/harmony_playback.h, playback_lab/entry/src/main/cpp/*, playback_lab/entry/src/main/ets/pages/Index.ets, DOCS/*, memory/*
 教训: 当前 ArkUI SDK 下 Scroll 包裹既有 Column 会裁剪后续控件，保持平面 Column 并将关键错误信息置顶。
 标签: #phase5 #network #range #security #emulator #ffmpeg-harmony
+
+[PROJECT:Velix-MPV-Core] Phase 6 性能基线与优化完成
+结论: 新增完整 playback timeline、buffer/audio/NAPI/资源诊断与 stdlib benchmark runner；事件驱动渲染+250ms安全探测、100ms核心快照合并、NAPI轮询降频、atomic session 读取通过模拟器回归，状态为 CODE COMPLETE / EMULATOR BENCHMARKED / DEVICE BENCHMARK PENDING。
+文件变更: include/mpv/harmony_playback.h, player/harmony_playback.c, playback_lab/entry/src/main/cpp/{player.h,player.cpp,render.cpp,bridge.cpp}, playback_lab/entry/src/main/ets/pages/Index.ets, benchmark/*, DOCS/{PHASE6_STATUS.md,PERFORMANCE_METRICS.md,PERFORMANCE_CHANGES.md,BENCHMARK_METHODOLOGY.md,STARTUP_PIPELINE.md,SEEK_PIPELINE.md,BUFFERING_MODEL.md}
+教训: 完全依赖 mpv update callback 会导致重复 load 偶发 BUFFERING 卡住；保留低频安全探测。模拟器不提供 PSS/精确 heap/归一化 CPU，报告必须明确 unavailable；seek 50 次保留 1 次真实 SEEK 命令错误。
+标签: #phase6 #benchmark #timeline #buffering #napi #emulator #device-pending
diff --git a/memory/MEMORY.md b/memory/MEMORY.md
index 8d9c33dfc8..ea52812890 100644
--- a/memory/MEMORY.md
+++ b/memory/MEMORY.md
@@ -1,9 +1,10 @@
 # Velix-MPV-Core 记忆索引
 
 - 项目：地产运维中台媒体核心的 OpenHarmony MPV 端口。
-- 当前阶段：Phase 5 CODE COMPLETE；模拟器已验证 HTTP MP4/Range，HTTPS/HLS、网络字幕、鉴权资源和实体机验收待补。
+- 当前阶段：Phase 6 CODE COMPLETE / emulator benchmarked / device benchmark pending；HTTPS/HLS、网络字幕、鉴权资源和实体机验收待补。
 - 公共入口：`include/mpv/harmony_playback.h`，稳定 C API 不暴露 MPV/FFmpeg 内部类型。
 - Playback Lab：C++ 仅做 NAPI/渲染适配，核心请求、控制、状态统一委托 C API。
+- Phase 6：启动/seek/buffering/audio/资源/NAPI 时间线与 benchmark runner 已入库；5 次启动 update 617→364，20 次 startup、50 次 seek、100 次 load-stop、200 次 play-pause 已跑模拟器。
 - 默认策略：软件解码；`harmony-ohcodec-gl` mapper 保持禁用，不声明零拷贝 GPU 能力。
 - 构建：default/software/FFmpeg-Harmony AArch64 通过；HAP 使用 DevEco JBR + `--no-daemon` 通过。
 - 设备：模拟器 `127.0.0.1:5555`，Playback Lab 已安装启动并完成本地 MP4 smoke。
diff --git a/memory/infra.md b/memory/infra.md
index 9ad65b11c8..db23882c81 100644
--- a/memory/infra.md
+++ b/memory/infra.md
@@ -16,6 +16,7 @@
 - 模拟器目标：`127.0.0.1:5555`，HarmonyOS 6.1.0.126 / API 24
 - Playback Lab 构建：在 `playback_lab/` 执行 `scripts/stage-mpv.sh` 后用 hvigor `--no-daemon assembleHap --mode module -p product=default`
 - HAP 构建：使用 DevEco 自带 `/Applications/DevEco-Studio.app/Contents/jbr/Contents/Home`，并以 `hvigorw.js assembleHap --no-daemon --mode module -p product=default` 完成 PackageHap；默认未配置正式签名。
+- HAP 环境：需设置 `JAVA_HOME=/Applications/DevEco-Studio.app/Contents/jbr/Contents/Home`、`DEVECO_SDK_HOME=/Applications/DevEco-Studio.app/Contents/sdk`；SDK native 路径仍使用 `.../sdk/default/openharmony`。
 - OHAudio：API 24 headers `ohaudio/native_audiostreambuilder.h` / `native_audiorenderer.h` / `native_audiostream_base.h`，动态库 `libohaudio.so`；Meson 使用 `-Dharmony-audio=enabled`。
 - Phase 3 HAP：`playback_lab/entry/build/default/outputs/default/entry-default-unsigned.hap`；模拟器 H.264/AAC smoke target `127.0.0.1:5555`。
 - Phase 4 构建入口：`scripts/build-mpv-ohos.sh`（OHCodec enabled）、`scripts/build-mpv-ohos-software.sh`（OHCodec disabled）、`scripts/build-all-ohos.sh`（全量矩阵）；GL API probe 通过单独 Meson `harmony-ohcodec-gl=enabled` 构建验证。
@@ -24,3 +25,4 @@
 - FFmpeg-Harmony：`../Velix-FFmpeg-Harmony`，origin `https://git.leee.xin/leeexin/Velix-FFmpeg-Harmony.git`，upstream `https://github.com/FFmpeg/FFmpeg.git`，branch `harmony-ohcodec-export`，tip `f3a036c695`；prefix `../Velix-FFmpeg-Harmony/build/ohos-arm64/prefix`。
 - MPV fork 接入：`scripts/build-mpv-ohos-ffmpeg-harmony.sh`；可用 `FFMPEG_PREFIX` 与 `MPV_BUILD_ROOT` 覆盖默认路径，默认 MPV/软件脚本不变。
 - MPV fork 输出：切换脚本默认安装到 `build/ohos-arm64/prefix-mpv-ffmpeg-harmony`，不会覆盖默认 `prefix`。
+- Phase 6 runner：`python3 benchmark/runner/run_emulator.py {startup_local,seek_local,stress_lifecycle,play_pause} --repeat N`；结果写入被忽略的 `benchmark/results/`。
diff --git a/memory/lessons.md b/memory/lessons.md
index 6c7987a683..12239f2891 100644
--- a/memory/lessons.md
+++ b/memory/lessons.md
@@ -26,3 +26,6 @@
 - Gitea 反向代理对完整 FFmpeg pack 返回 413；保留完整历史的可行做法是先建立空远端，再按 first-parent checkpoint 分块推送，不能浅克隆或裁剪历史。
 - MPV 消费独立 FFmpeg prefix 时，pkg-config 必须把 fork 的 `lib/pkgconfig` 置于 base prefix 前，并保留绝对 include/lib 路径；仅改 `PREFIX` 会丢失 libass/libplacebo 等其他依赖。
 - 当前 DevEco ArkUI SDK 下给既有平面 `Column` 外包 `Scroll` 会改变可见布局并裁掉后续控件；诊断页保持平面 Column，关键错误信息放在顶部，长列表改动需单独验收。
+- 渲染 update 不能完全依赖 callback：部分重复 load 会话可能漏通知；事件驱动应保留低频（250ms）安全探测，否则会卡在 BUFFERING。
+- 短媒体自动化 seek 若先等待首帧再执行多次 hdc keyEvent，媒体可能已 EOF；用立即触发的原生相对 seek 或更长受控 fixture，且保留真实命令错误。
+- `/proc` 在模拟器不一定提供 PSS、精确 heap 或可校准 CPU tick；benchmark 必须输出 null/原始 jiffies，不能自行推断 permille。
diff --git a/memory/projects.md b/memory/projects.md
index 2c619aead1..5edec7bec6 100644
--- a/memory/projects.md
+++ b/memory/projects.md
@@ -2,9 +2,13 @@
 
 ## Velix-MPV-Core
 
+- 当前状态：Phase 6 CODE COMPLETE / EMULATOR BENCHMARKED / DEVICE BENCHMARK PENDING；提交待推送前复核。
+- Phase 6 产物：`benchmark/runner/run_emulator.py` 与场景 manifest；启动 P50/P95 506/1150ms，seek recovery P50/P95 277/631ms；100 load/stop、200 play/pause 无错误，PSS/精确 heap/CPU permille unavailable。
+- Phase 6 文档：`DOCS/PHASE6_STATUS.md`、`PERFORMANCE_METRICS.md`、`PERFORMANCE_CHANGES.md`、`BENCHMARK_METHODOLOGY.md`、`STARTUP_PIPELINE.md`、`SEEK_PIPELINE.md`、`BUFFERING_MODEL.md`。
+
 - 状态：Phase 5 CODE COMPLETE / emulator HTTP Range verified；GPU INTEROP MAPPER 未进入；HTTPS/HLS、网络字幕、鉴权、重定向运行验证与实体机验收未完成。
 - 已完成：远程闭环、固定依赖、隔离工具链、C/C++ 探针、FFmpeg/OpenSSL/字体栈/libplacebo、AArch64 `libmpv.so.2.5.0`、ABI/符号/污染/许可证审计。
-- 产物：`build/ohos-arm64/prefix/lib/libmpv.so.2.5.0`，当前重建 34,343,104 bytes；软件构建位于 `build/ohos-arm64/build/mpv-software/libmpv.so.2.5.0`，FFmpeg-Harmony 构建位于 `build/ohos-arm64/build/mpv-ffmpeg-harmony/libmpv.so.2.5.0`；DT_NEEDED 含 `libohaudio.so`。
+- 产物：`build/ohos-arm64/prefix/lib/libmpv.so.2.5.0`，当前重建 34,346,792 bytes；软件构建位于 `build/ohos-arm64/build/mpv-software/libmpv.so.2.5.0`，FFmpeg-Harmony 构建位于 `build/ohos-arm64/build/mpv-ffmpeg-harmony/libmpv.so.2.5.0`；DT_NEEDED 含 `libohaudio.so`。
 - 已完成：独立 HAP、XComponent/OHNativeWindow、EGL ES3、libmpv OpenGL Render、软件解码本地 MP4 首帧、播放控制与释放重入。
 - 已完成：`ao_harmony` PCM float32→S16 fallback、采样率/mono-stereo 协商、pause/resume/stop/flush/release、timestamp epoch、starvation/flush metrics；Phase 5 HAP 已用 DevEco JBR 完成打包并安装模拟器。
 - 已完成：OHCodec H.264/HEVC capability 查询、`hwdec=ohcodec` direct-surface 实验驱动、显式软件回退、Playback Lab requested/actual/metrics 诊断、软件/硬解/GL probe 构建矩阵；FFmpeg 未修改。
diff --git a/playback_lab/entry/src/main/cpp/bridge.cpp b/playback_lab/entry/src/main/cpp/bridge.cpp
index 0c2718e024..18a3a6fb21 100644
--- a/playback_lab/entry/src/main/cpp/bridge.cpp
+++ b/playback_lab/entry/src/main/cpp/bridge.cpp
@@ -9,6 +9,8 @@
 
 #include <vector>
 #include <string>
+#include <atomic>
+#include <chrono>
 
 #undef LOG_DOMAIN
 #undef LOG_TAG
@@ -18,6 +20,9 @@
 namespace {
 PlaybackEngine gPlayer;
 EglRenderer gRenderer(gPlayer);
+std::atomic<uint64_t> gStateCalls{0};
+std::atomic<uint64_t> gStateSerializeUs{0};
+std::atomic<uint64_t> gStatePayloadBytes{0};
 
 void onSurfaceCreated(OH_NativeXComponent* component, void* window)
 {
@@ -446,6 +451,8 @@ napi_value release(napi_env env, napi_callback_info)
 napi_value getState(napi_env env, napi_callback_info)
 {
     PlaybackSnapshot state = gPlayer.snapshot();
+    const auto serializeBegin = std::chrono::steady_clock::now();
+    const uint64_t stateCall = gStateCalls.fetch_add(1, std::memory_order_relaxed) + 1;
     napi_value object = nullptr;
     napi_create_object(env, &object);
     napi_value value = nullptr;
@@ -533,7 +540,64 @@ napi_value getState(napi_env env, napi_callback_info)
     napi_set_named_property(env, metrics, "cacheBytes", value);
     napi_create_int64(env, state.network.currentBitrate, &value);
     napi_set_named_property(env, metrics, "currentBitrate", value);
+    napi_create_int64(env, state.metrics.buffering_enter_count, &value);
+    napi_set_named_property(env, metrics, "bufferingEnterCount", value);
+    napi_create_int64(env, state.metrics.buffering_exit_count, &value);
+    napi_set_named_property(env, metrics, "bufferingExitCount", value);
+    napi_create_int64(env, state.metrics.buffering_total_ms, &value);
+    napi_set_named_property(env, metrics, "bufferingTotalMs", value);
+    napi_create_int64(env, state.metrics.buffering_max_single_ms, &value);
+    napi_set_named_property(env, metrics, "bufferingMaxSingleMs", value);
+    napi_create_int64(env, state.metrics.network_wait_ms, &value);
+    napi_set_named_property(env, metrics, "networkWaitMs", value);
+    napi_create_int64(env, state.metrics.late_frames, &value);
+    napi_set_named_property(env, metrics, "lateFrames", value);
+    napi_create_int64(env, state.metrics.mistimed_frames, &value);
+    napi_set_named_property(env, metrics, "mistimedFrames", value);
+    napi_create_int64(env, state.metrics.decoder_frames, &value);
+    napi_set_named_property(env, metrics, "decoderFrames", value);
     napi_set_named_property(env, object, "metrics", metrics);
+    napi_value timeline = nullptr;
+    napi_create_object(env, &timeline);
+    auto setTimeline = [&](const char* name, int64_t milliseconds) {
+        napi_value item = nullptr;
+        napi_create_int64(env, milliseconds, &item);
+        napi_set_named_property(env, timeline, name, item);
+    };
+    setTimeline("sessionSetupMs", state.timeline.session_setup_ms);
+    setTimeline("mpvCreateMs", state.timeline.mpv_create_ms);
+    setTimeline("mpvInitializeMs", state.timeline.mpv_initialize_ms);
+    setTimeline("loadCommandMs", state.timeline.load_command_ms);
+    setTimeline("startFileMs", state.timeline.start_file_ms);
+    setTimeline("networkOpenBeginMs", state.timeline.network_open_begin_ms);
+    setTimeline("networkOpenEndMs", state.timeline.network_open_end_ms);
+    setTimeline("firstByteMs", state.timeline.first_byte_ms);
+    setTimeline("demuxReadyMs", state.timeline.demux_ready_ms);
+    setTimeline("fileLoadedMs", state.timeline.file_loaded_ms);
+    setTimeline("videoDecoderReadyMs", state.timeline.video_decoder_ready_ms);
+    setTimeline("audioDecoderReadyMs", state.timeline.audio_decoder_ready_ms);
+    setTimeline("videoReconfigMs", state.timeline.video_reconfig_ms);
+    setTimeline("audioReconfigMs", state.timeline.audio_reconfig_ms);
+    setTimeline("renderContextReadyMs", state.timeline.render_context_ready_ms);
+    setTimeline("firstVideoFrameAvailableMs", state.timeline.first_video_frame_available_ms);
+    setTimeline("firstRenderBeginMs", state.timeline.first_render_begin_ms);
+    setTimeline("firstRenderEndMs", state.timeline.first_render_end_ms);
+    setTimeline("firstSwapMs", state.timeline.first_swap_ms);
+    setTimeline("startupTotalMs", state.timeline.startup_total_ms);
+    setTimeline("audioRendererStartMs", state.timeline.audio_renderer_start_ms);
+    setTimeline("firstAudioCallbackMs", state.timeline.first_audio_callback_ms);
+    setTimeline("playbackRestartMs", state.timeline.playback_restart_ms);
+    setTimeline("seekRequestMs", state.timeline.seek_request_ms);
+    setTimeline("seekCommandMs", state.timeline.seek_command_ms);
+    setTimeline("seekDemuxMs", state.timeline.seek_demux_ms);
+    setTimeline("seekVideoReconfigMs", state.timeline.seek_video_reconfig_ms);
+    setTimeline("seekPlaybackRestartMs", state.timeline.seek_playback_restart_ms);
+    setTimeline("seekFirstFrameMs", state.timeline.seek_first_frame_ms);
+    setTimeline("seekFirstSwapMs", state.timeline.seek_first_swap_ms);
+    setTimeline("seekCommandLatencyMs", state.timeline.seek_command_latency_ms);
+    setTimeline("seekRecoveryMs", state.timeline.seek_recovery_ms);
+    setTimeline("seekFirstVisibleFrameMs", state.timeline.seek_first_visible_frame_ms);
+    napi_set_named_property(env, object, "timeline", timeline);
     napi_value media = nullptr;
     napi_create_object(env, &media);
     napi_create_string_utf8(env, state.media.container.c_str(), NAPI_AUTO_LENGTH, &value);
@@ -659,6 +723,34 @@ napi_value getState(napi_env env, napi_callback_info)
     napi_set_named_property(env, object, "seekAudioResetCount", value);
     napi_create_int32(env, audio.state, &value);
     napi_set_named_property(env, object, "audioState", value);
+    napi_value profiling = nullptr;
+    napi_create_object(env, &profiling);
+    const uint64_t payloadBytes = static_cast<uint64_t>(state.lastError.size() + state.errorCode.size() +
+                                                        state.network.protocol.size() + state.network.host.size() +
+                                                        state.tracks.size() * 64 + 2048);
+    const uint64_t serializeUs = static_cast<uint64_t>(std::chrono::duration_cast<std::chrono::microseconds>(
+        std::chrono::steady_clock::now() - serializeBegin).count());
+    gStateSerializeUs.fetch_add(serializeUs, std::memory_order_relaxed);
+    gStatePayloadBytes.fetch_add(payloadBytes, std::memory_order_relaxed);
+    napi_create_int64(env, static_cast<int64_t>(stateCall), &value);
+    napi_set_named_property(env, profiling, "getStateCalls", value);
+    napi_create_int64(env, static_cast<int64_t>(gStateSerializeUs.load(std::memory_order_relaxed)), &value);
+    napi_set_named_property(env, profiling, "serializeUsTotal", value);
+    napi_create_int64(env, static_cast<int64_t>(gStatePayloadBytes.load(std::memory_order_relaxed)), &value);
+    napi_set_named_property(env, profiling, "payloadBytesTotal", value);
+    napi_create_int64(env, static_cast<int64_t>(serializeUs), &value);
+    napi_set_named_property(env, profiling, "lastSerializeUs", value);
+    napi_create_int64(env, static_cast<int64_t>(payloadBytes), &value);
+    napi_set_named_property(env, profiling, "lastPayloadBytes", value);
+    napi_create_int64(env, static_cast<int64_t>(state.renderUpdateCalls), &value);
+    napi_set_named_property(env, profiling, "renderUpdateCalls", value);
+    napi_create_int64(env, static_cast<int64_t>(state.renderFrameUpdates), &value);
+    napi_set_named_property(env, profiling, "renderFrameUpdates", value);
+    napi_create_int64(env, static_cast<int64_t>(state.coreSyncCalls), &value);
+    napi_set_named_property(env, profiling, "coreSyncCalls", value);
+    napi_create_int64(env, static_cast<int64_t>(state.coreSyncSkipped), &value);
+    napi_set_named_property(env, profiling, "coreSyncSkipped", value);
+    napi_set_named_property(env, object, "napiProfiling", profiling);
     return object;
 }
 
diff --git a/playback_lab/entry/src/main/cpp/harmony_playback_internal.h b/playback_lab/entry/src/main/cpp/harmony_playback_internal.h
index c949b28a3a..9f363047ae 100644
--- a/playback_lab/entry/src/main/cpp/harmony_playback_internal.h
+++ b/playback_lab/entry/src/main/cpp/harmony_playback_internal.h
@@ -11,6 +11,20 @@ extern "C" {
 /* Private renderer bridge; never install this declaration as public API. */
 mpv_handle *mp_harmony_playback_internal_handle(mp_harmony_player *player);
 
+enum mp_harmony_internal_timeline_event {
+    MP_HARMONY_INTERNAL_RENDER_CONTEXT_READY = 1,
+    MP_HARMONY_INTERNAL_FIRST_VIDEO_FRAME,
+    MP_HARMONY_INTERNAL_FIRST_RENDER_BEGIN,
+    MP_HARMONY_INTERNAL_FIRST_RENDER_END,
+    MP_HARMONY_INTERNAL_FIRST_SWAP,
+    MP_HARMONY_INTERNAL_AUDIO_RENDERER_START,
+    MP_HARMONY_INTERNAL_FIRST_AUDIO_CALLBACK,
+    MP_HARMONY_INTERNAL_SEEK_FIRST_FRAME,
+    MP_HARMONY_INTERNAL_SEEK_FIRST_SWAP,
+};
+
+int mp_harmony_playback_internal_mark_timeline(mp_harmony_player *player, int event);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/playback_lab/entry/src/main/cpp/player.cpp b/playback_lab/entry/src/main/cpp/player.cpp
index 15ed8cbff2..ac951507b1 100644
--- a/playback_lab/entry/src/main/cpp/player.cpp
+++ b/playback_lab/entry/src/main/cpp/player.cpp
@@ -1,6 +1,7 @@
 #include "player.h"
 
 #include "video/harmony_hwdec.h"
+#include "audio/out/ao_harmony.h"
 
 #include <hilog/log.h>
 
@@ -177,6 +178,8 @@ bool PlaybackEngine::load(const PlaybackRequestModel& request)
         std::lock_guard<std::mutex> lock(mutex_);
         snapshot_.renderCount = 0;
         snapshot_.firstFrameMs = -1;
+        snapshot_.metrics = {};
+        snapshot_.timeline = {};
         startedAt_ = std::chrono::steady_clock::now();
     }
     int rc = -1;
@@ -184,7 +187,7 @@ bool PlaybackEngine::load(const PlaybackRequestModel& request)
         std::lock_guard<std::mutex> apiLock(apiMutex_);
         if (corePlayer_ != nullptr) rc = mp_harmony_playback_load(corePlayer_, &coreRequest);
     }
-    syncCoreSnapshot();
+    syncCoreSnapshot(true);
     return rc >= 0;
 }
 
@@ -444,16 +447,64 @@ void PlaybackEngine::markFrameRendered()
     }
 }
 
+uint64_t PlaybackEngine::sessionId() const
+{
+    return sessionIdAtomic_.load(std::memory_order_acquire);
+}
+
+void PlaybackEngine::markRenderUpdate(bool frameAvailable)
+{
+    renderUpdateCalls_.fetch_add(1, std::memory_order_relaxed);
+    if (frameAvailable) renderFrameUpdates_.fetch_add(1, std::memory_order_relaxed);
+}
+
+void PlaybackEngine::markTimeline(int event)
+{
+    std::lock_guard<std::mutex> apiLock(apiMutex_);
+    if (corePlayer_ != nullptr)
+        mp_harmony_playback_internal_mark_timeline(corePlayer_, event);
+}
+
+void PlaybackEngine::syncAudioTimeline()
+{
+    mpv_harmony_audio_stats audio = {};
+    if (!mpv_harmony_audio_get_stats(&audio)) return;
+    if (audio.state == MPV_HARMONY_AUDIO_RUNNING)
+        markTimeline(MP_HARMONY_INTERNAL_AUDIO_RENDERER_START);
+    if (audio.callback_count > 0)
+        markTimeline(MP_HARMONY_INTERNAL_FIRST_AUDIO_CALLBACK);
+}
+
 PlaybackSnapshot PlaybackEngine::snapshot() const
 {
+    const_cast<PlaybackEngine*>(this)->syncAudioTimeline();
     const_cast<PlaybackEngine*>(this)->syncCoreSnapshot();
     std::lock_guard<std::mutex> lock(mutex_);
     const_cast<PlaybackEngine*>(this)->syncHwdecStatsLocked();
+    const_cast<PlaybackEngine*>(this)->snapshot_.renderUpdateCalls =
+        renderUpdateCalls_.load(std::memory_order_relaxed);
+    const_cast<PlaybackEngine*>(this)->snapshot_.renderFrameUpdates =
+        renderFrameUpdates_.load(std::memory_order_relaxed);
+    const_cast<PlaybackEngine*>(this)->snapshot_.coreSyncCalls =
+        coreSyncCalls_.load(std::memory_order_relaxed);
+    const_cast<PlaybackEngine*>(this)->snapshot_.coreSyncSkipped =
+        coreSyncSkipped_.load(std::memory_order_relaxed);
     return snapshot_;
 }
 
-void PlaybackEngine::syncCoreSnapshot()
+void PlaybackEngine::syncCoreSnapshot(bool force)
 {
+    const auto now = std::chrono::steady_clock::now();
+    {
+        std::lock_guard<std::mutex> lock(syncThrottleMutex_);
+        if (!force && coreSyncHasRun_ && now - lastCoreSync_ < std::chrono::milliseconds(100)) {
+            coreSyncSkipped_.fetch_add(1, std::memory_order_relaxed);
+            return;
+        }
+        lastCoreSync_ = now;
+        coreSyncHasRun_ = true;
+    }
+    coreSyncCalls_.fetch_add(1, std::memory_order_relaxed);
     mp_harmony_playback_snapshot core = {};
     mp_harmony_track coreTracks[MP_HARMONY_MAX_TRACKS] = {};
     size_t coreTrackCount = 0;
@@ -493,6 +544,7 @@ void PlaybackEngine::syncCoreSnapshot()
 
     snapshot_.state = mp_harmony_playback_state_name(core.state);
     snapshot_.sessionId = core.session_id;
+    sessionIdAtomic_.store(core.session_id, std::memory_order_release);
     snapshot_.position = core.position;
     snapshot_.duration = core.duration;
     snapshot_.fps = core.fps;
@@ -544,6 +596,10 @@ void PlaybackEngine::syncCoreSnapshot()
     snapshot_.network.demuxer = core.network.demuxer;
     snapshot_.network.container = core.network.container;
     snapshot_.network.currentBitrate = core.network.current_bitrate;
+    snapshot_.metrics = core.metrics;
+    snapshot_.metrics.dropped_frames = core.dropped_frames;
+    snapshot_.metrics.render_count = static_cast<int64_t>(renderCount);
+    snapshot_.timeline = core.timeline;
 
     if (tracksAvailable) {
         snapshot_.tracks.clear();
diff --git a/playback_lab/entry/src/main/cpp/player.h b/playback_lab/entry/src/main/cpp/player.h
index e5bf445d27..ea7a09e0fe 100644
--- a/playback_lab/entry/src/main/cpp/player.h
+++ b/playback_lab/entry/src/main/cpp/player.h
@@ -131,6 +131,12 @@ struct PlaybackSnapshot {
     int64_t nativeBufferImportFailure = 0;
     int64_t surfacePresentCount = 0;
     int64_t gpuInteropFrameCount = 0;
+    uint64_t renderUpdateCalls = 0;
+    uint64_t renderFrameUpdates = 0;
+    uint64_t coreSyncCalls = 0;
+    uint64_t coreSyncSkipped = 0;
+    mp_harmony_playback_metrics metrics = {};
+    mp_harmony_playback_timeline timeline = {};
 };
 
 class PlaybackEngine {
@@ -166,13 +172,17 @@ public:
     PlaybackSnapshot snapshot() const;
 
     mpv_handle* handle() const { return handle_; }
+    uint64_t sessionId() const;
+    void markRenderUpdate(bool frameAvailable);
     void markFrameRendered();
+    void markTimeline(int event);
 
 private:
     void setState(const char* state);
     void setError(const std::string& error);
     void syncHwdecStatsLocked();
-    void syncCoreSnapshot();
+    void syncAudioTimeline();
+    void syncCoreSnapshot(bool force = false);
 
     mutable std::mutex mutex_;
     mutable std::mutex apiMutex_;
@@ -180,5 +190,13 @@ private:
     mp_harmony_player* corePlayer_ = nullptr;
     mpv_handle* handle_ = nullptr;
     std::atomic<bool> initialized_{false};
+    std::atomic<uint64_t> sessionIdAtomic_{0};
+    std::atomic<uint64_t> renderUpdateCalls_{0};
+    std::atomic<uint64_t> renderFrameUpdates_{0};
+    std::atomic<uint64_t> coreSyncCalls_{0};
+    std::atomic<uint64_t> coreSyncSkipped_{0};
+    mutable std::mutex syncThrottleMutex_;
+    std::chrono::steady_clock::time_point lastCoreSync_;
+    bool coreSyncHasRun_ = false;
     std::chrono::steady_clock::time_point startedAt_;
 };
diff --git a/playback_lab/entry/src/main/cpp/render.cpp b/playback_lab/entry/src/main/cpp/render.cpp
index bad7fc17e3..85c18ce960 100644
--- a/playback_lab/entry/src/main/cpp/render.cpp
+++ b/playback_lab/entry/src/main/cpp/render.cpp
@@ -217,19 +217,34 @@ void EglRenderer::renderLoop()
         return;
     }
     mpvStatus_.store(1);
+    player_.markTimeline(MP_HARMONY_INTERNAL_RENDER_CONTEXT_READY);
+    timelineSession_ = player_.sessionId();
+    firstFramePending_ = true;
     mpv_render_context_set_update_callback(mpvRender_, onMpvUpdate, this);
+    auto lastUpdate = std::chrono::steady_clock::now();
     while (!stop_.load()) {
         int width = 1;
         int height = 1;
+        bool shouldUpdate = false;
         {
             std::unique_lock<std::mutex> lock(mutex_);
             wake_.wait_for(lock, std::chrono::milliseconds(16), [this] { return redraw_ || stop_.load(); });
+            shouldUpdate = redraw_;
             redraw_ = false;
             width = width_;
             height = height_;
         }
         if (stop_.load()) break;
+        const auto now = std::chrono::steady_clock::now();
+        if (!shouldUpdate && now - lastUpdate < std::chrono::milliseconds(250)) continue;
+        lastUpdate = now;
+        const uint64_t session = player_.sessionId();
+        if (session != timelineSession_) {
+            timelineSession_ = session;
+            firstFramePending_ = true;
+        }
         uint64_t flags = mpv_render_context_update(mpvRender_);
+        player_.markRenderUpdate((flags & MPV_RENDER_UPDATE_FRAME) != 0);
         if ((flags & MPV_RENDER_UPDATE_FRAME) == 0) continue;
         mpv_opengl_fbo fbo = {0, width, height, GL_RGBA8};
         int flip = 1;
@@ -238,10 +253,21 @@ void EglRenderer::renderLoop()
             {MPV_RENDER_PARAM_FLIP_Y, &flip},
             {MPV_RENDER_PARAM_INVALID, nullptr},
         };
+        const bool firstFrame = firstFramePending_;
+        if (firstFrame) {
+            player_.markTimeline(MP_HARMONY_INTERNAL_FIRST_VIDEO_FRAME);
+            player_.markTimeline(MP_HARMONY_INTERNAL_FIRST_RENDER_BEGIN);
+        }
         if (mpv_render_context_render(mpvRender_, renderParams) >= 0) {
-            eglSwapBuffers(display_, surface_);
-            mpv_render_context_report_swap(mpvRender_);
-            player_.markFrameRendered();
+            if (firstFrame) player_.markTimeline(MP_HARMONY_INTERNAL_FIRST_RENDER_END);
+            if (eglSwapBuffers(display_, surface_) == EGL_TRUE) {
+                mpv_render_context_report_swap(mpvRender_);
+                if (firstFrame) {
+                    player_.markTimeline(MP_HARMONY_INTERNAL_FIRST_SWAP);
+                    firstFramePending_ = false;
+                }
+                player_.markFrameRendered();
+            }
         }
     }
     mpv_render_context_set_update_callback(mpvRender_, nullptr, nullptr);
diff --git a/playback_lab/entry/src/main/cpp/render.h b/playback_lab/entry/src/main/cpp/render.h
index b9f36e7f82..0759fd8c0c 100644
--- a/playback_lab/entry/src/main/cpp/render.h
+++ b/playback_lab/entry/src/main/cpp/render.h
@@ -46,6 +46,8 @@ private:
     OHNativeWindow* window_ = nullptr;
     int width_ = 1;
     int height_ = 1;
+    uint64_t timelineSession_ = 0;
+    bool firstFramePending_ = true;
     EGLDisplay display_ = EGL_NO_DISPLAY;
     EGLContext context_ = EGL_NO_CONTEXT;
     EGLSurface surface_ = EGL_NO_SURFACE;
diff --git a/playback_lab/entry/src/main/ets/pages/Index.ets b/playback_lab/entry/src/main/ets/pages/Index.ets
index 6d33426cf6..e091ebf0ea 100644
--- a/playback_lab/entry/src/main/ets/pages/Index.ets
+++ b/playback_lab/entry/src/main/ets/pages/Index.ets
@@ -43,6 +43,8 @@ interface PlaybackState {
   errorCode: string;
   error: PlaybackErrorState;
   metrics: PlaybackMetricsState;
+  timeline: PlaybackTimelineState;
+  napiProfiling: NapiProfilingState;
   speed: number;
   volume: number;
   muted: boolean;
@@ -54,6 +56,18 @@ interface PlaybackState {
   tracks: TrackState[];
 }
 
+interface NapiProfilingState {
+  getStateCalls: number;
+  serializeUsTotal: number;
+  payloadBytesTotal: number;
+  lastSerializeUs: number;
+  lastPayloadBytes: number;
+  renderUpdateCalls: number;
+  renderFrameUpdates: number;
+  coreSyncCalls: number;
+  coreSyncSkipped: number;
+}
+
 interface PlaybackErrorState {
   code: string;
   rawMessage: string;
@@ -66,6 +80,50 @@ interface PlaybackMetricsState {
   cacheDuration: number;
   cacheBytes: number;
   currentBitrate: number;
+  bufferingEnterCount: number;
+  bufferingExitCount: number;
+  bufferingTotalMs: number;
+  bufferingMaxSingleMs: number;
+  networkWaitMs: number;
+  lateFrames: number;
+  mistimedFrames: number;
+  decoderFrames: number;
+}
+
+interface PlaybackTimelineState {
+  sessionSetupMs: number;
+  mpvCreateMs: number;
+  mpvInitializeMs: number;
+  loadCommandMs: number;
+  startFileMs: number;
+  networkOpenBeginMs: number;
+  networkOpenEndMs: number;
+  firstByteMs: number;
+  demuxReadyMs: number;
+  fileLoadedMs: number;
+  videoDecoderReadyMs: number;
+  audioDecoderReadyMs: number;
+  videoReconfigMs: number;
+  audioReconfigMs: number;
+  renderContextReadyMs: number;
+  firstVideoFrameAvailableMs: number;
+  firstRenderBeginMs: number;
+  firstRenderEndMs: number;
+  firstSwapMs: number;
+  startupTotalMs: number;
+  audioRendererStartMs: number;
+  firstAudioCallbackMs: number;
+  playbackRestartMs: number;
+  seekRequestMs: number;
+  seekCommandMs: number;
+  seekDemuxMs: number;
+  seekVideoReconfigMs: number;
+  seekPlaybackRestartMs: number;
+  seekFirstFrameMs: number;
+  seekFirstSwapMs: number;
+  seekCommandLatencyMs: number;
+  seekRecoveryMs: number;
+  seekFirstVisibleFrameMs: number;
 }
 
 interface NetworkState {
@@ -187,7 +245,19 @@ struct Index {
     nativeBufferImportCount: 0, nativeBufferImportFailure: 0, surfacePresentCount: 0,
     gpuInteropFrameCount: 0,
     sessionId: 0, errorCode: 'NONE', error: { code: 'NONE', rawMessage: '' },
-    metrics: { droppedFrames: 0, renderCount: 0, buffering: false, cacheDuration: 0, cacheBytes: 0, currentBitrate: 0 },
+    metrics: { droppedFrames: 0, renderCount: 0, buffering: false, cacheDuration: 0, cacheBytes: 0, currentBitrate: 0,
+      bufferingEnterCount: 0, bufferingExitCount: 0, bufferingTotalMs: 0, bufferingMaxSingleMs: 0, networkWaitMs: -1,
+      lateFrames: -1, mistimedFrames: -1, decoderFrames: -1 },
+    timeline: { sessionSetupMs: -1, mpvCreateMs: -1, mpvInitializeMs: -1, loadCommandMs: -1, startFileMs: -1,
+      networkOpenBeginMs: -1, networkOpenEndMs: -1, firstByteMs: -1, demuxReadyMs: -1, fileLoadedMs: -1,
+      videoDecoderReadyMs: -1, audioDecoderReadyMs: -1, videoReconfigMs: -1, audioReconfigMs: -1,
+      renderContextReadyMs: -1, firstVideoFrameAvailableMs: -1, firstRenderBeginMs: -1, firstRenderEndMs: -1,
+      firstSwapMs: -1, startupTotalMs: -1, audioRendererStartMs: -1, firstAudioCallbackMs: -1, playbackRestartMs: -1,
+      seekRequestMs: -1, seekCommandMs: -1, seekDemuxMs: -1, seekVideoReconfigMs: -1,
+      seekPlaybackRestartMs: -1, seekFirstFrameMs: -1, seekFirstSwapMs: -1, seekCommandLatencyMs: -1,
+      seekRecoveryMs: -1, seekFirstVisibleFrameMs: -1 },
+    napiProfiling: { getStateCalls: 0, serializeUsTotal: 0, payloadBytesTotal: 0, lastSerializeUs: 0, lastPayloadBytes: 0,
+      renderUpdateCalls: 0, renderFrameUpdates: 0, coreSyncCalls: 0, coreSyncSkipped: 0 },
     speed: 1, volume: 100, muted: false,
     subtitleDelayMs: 0, subtitleScale: 1, subtitlePosition: 100,
     network: { protocol: '', host: '', networkState: '', httpStatus: 0, redirectCount: 0,
@@ -205,7 +275,7 @@ struct Index {
       this.state = playbackLab.getState() as PlaybackState;
       this.status = this.state.state;
       this.detail = this.state.lastError || `position ${this.state.position.toFixed(2)} / ${this.state.duration.toFixed(2)}s`;
-    }, 250);
+    }, 500);
   }
 
   aboutToDisappear(): void {
@@ -223,6 +293,12 @@ struct Index {
         .fontSize(13).fontColor($r('app.color.muted')).width('100%')
       Text(`error=${this.state.error.code} rawMessage=${this.state.error.rawMessage || 'none'}`)
         .fontSize(13).fontColor($r('app.color.muted')).width('100%').maxLines(3)
+      Text(`startup=${this.state.timeline.startupTotalMs}ms firstSwap=${this.state.timeline.firstSwapMs}ms seekRecovery=${this.state.timeline.seekRecoveryMs}ms audioStart=${this.state.timeline.audioRendererStartMs}ms audioCallback=${this.state.timeline.firstAudioCallbackMs}ms`)
+        .fontSize(13).fontColor($r('app.color.muted')).width('100%')
+      Text(`napi calls=${this.state.napiProfiling.getStateCalls} serialize=${this.state.napiProfiling.serializeUsTotal}us payload=${this.state.napiProfiling.payloadBytesTotal}B sync=${this.state.napiProfiling.coreSyncCalls}/${this.state.napiProfiling.coreSyncSkipped} updates=${this.state.napiProfiling.renderUpdateCalls}/${this.state.napiProfiling.renderFrameUpdates}`)
+        .fontSize(13).fontColor($r('app.color.muted')).width('100%').maxLines(2)
+      Text(`buffer enter=${this.state.metrics.bufferingEnterCount} exit=${this.state.metrics.bufferingExitCount} total=${this.state.metrics.bufferingTotalMs}ms max=${this.state.metrics.bufferingMaxSingleMs}ms networkWait=${this.state.metrics.networkWaitMs}ms`)
+        .fontSize(13).fontColor($r('app.color.muted')).width('100%').maxLines(2)
       XComponent({ id: 'playback_surface', type: XComponentType.SURFACE, libraryname: 'entry' })
         .width('100%').height(250).backgroundColor(Color.Black)
       TextInput({ text: this.url, placeholder: 'file:///... or https://...' })
@@ -317,6 +393,10 @@ struct Index {
       Text(detailLabel(this.detail)).fontSize(13).fontColor($r('app.color.muted')).width('100%').maxLines(2)
       Text(`metrics dropped=${this.state.metrics.droppedFrames} renders=${this.state.metrics.renderCount} cache=${this.state.metrics.cacheDuration.toFixed(2)}s/${this.state.metrics.cacheBytes}B bitrate=${this.state.metrics.currentBitrate}`)
         .fontSize(13).fontColor($r('app.color.muted')).width('100%').maxLines(2)
+      Text(`buffer enter=${this.state.metrics.bufferingEnterCount} exit=${this.state.metrics.bufferingExitCount} total=${this.state.metrics.bufferingTotalMs}ms max=${this.state.metrics.bufferingMaxSingleMs}ms napi=${this.state.napiProfiling.getStateCalls}`)
+        .fontSize(13).fontColor($r('app.color.muted')).width('100%').maxLines(2)
+      Text(`render updates=${this.state.napiProfiling.renderUpdateCalls} frames=${this.state.napiProfiling.renderFrameUpdates} sync=${this.state.napiProfiling.coreSyncCalls}/${this.state.napiProfiling.coreSyncSkipped}`)
+        .fontSize(13).fontColor($r('app.color.muted')).width('100%').maxLines(2)
       Text('network=' + this.state.network.protocol + '://' + this.state.network.host + ' status=' + (this.state.network.httpStatus || 'unavailable') + ' redirects=' + this.state.network.redirectCount + ' buffering=' + this.state.network.buffering)
         .fontSize(13).fontColor($r('app.color.muted')).width('100%').maxLines(2)
       Text('range=' + this.state.network.rangeSupported + ' seek=' + (this.state.network.seekResult || 'unavailable'))
diff --git a/player/harmony_playback.c b/player/harmony_playback.c
index 8c1e23936a..4b869097bd 100644
--- a/player/harmony_playback.c
+++ b/player/harmony_playback.c
@@ -15,6 +15,7 @@
 #include <strings.h>
 #include <ctype.h>
 #include <math.h>
+#include <time.h>
 
 struct mp_harmony_player {
     pthread_mutex_t lock;
@@ -28,6 +29,9 @@ struct mp_harmony_player {
     int64_t playlist_entry_id;
     int awaiting_start;
     int64_t pending_start_position_ms;
+    int64_t perf_origin_ns;
+    int64_t buffering_start_ns;
+    int seek_active;
     mp_harmony_playback_snapshot snapshot;
     mp_harmony_track tracks[MP_HARMONY_MAX_TRACKS];
     size_t track_count;
@@ -42,8 +46,22 @@ enum {
 static int set_headers_locked(mp_harmony_player *p, const mp_harmony_playback_request *request);
 static int add_subtitle_locked(mp_harmony_player *p, const mp_harmony_subtitle_source *source);
 
+enum mp_harmony_internal_timeline_event {
+    MP_HARMONY_INTERNAL_RENDER_CONTEXT_READY = 1,
+    MP_HARMONY_INTERNAL_FIRST_VIDEO_FRAME,
+    MP_HARMONY_INTERNAL_FIRST_RENDER_BEGIN,
+    MP_HARMONY_INTERNAL_FIRST_RENDER_END,
+    MP_HARMONY_INTERNAL_FIRST_SWAP,
+    MP_HARMONY_INTERNAL_AUDIO_RENDERER_START,
+    MP_HARMONY_INTERNAL_FIRST_AUDIO_CALLBACK,
+    MP_HARMONY_INTERNAL_SEEK_FIRST_FRAME,
+    MP_HARMONY_INTERNAL_SEEK_FIRST_SWAP,
+};
+
 /* Private renderer bridge; intentionally absent from the public header. */
 MP_HARMONY_EXPORT mpv_handle *mp_harmony_playback_internal_handle(mp_harmony_player *player);
+MP_HARMONY_EXPORT int mp_harmony_playback_internal_mark_timeline(
+    mp_harmony_player *player, int event);
 
 static void copy_text(char *dst, size_t size, const char *src)
 {
@@ -52,6 +70,91 @@ static void copy_text(char *dst, size_t size, const char *src)
     snprintf(dst, size, "%.*s", (int)(size - 1), src);
 }
 
+static int64_t clock_now_ns(void)
+{
+    struct timespec now = {0};
+    if (clock_gettime(CLOCK_MONOTONIC, &now) != 0) return 0;
+    return (int64_t)now.tv_sec * 1000000000LL + now.tv_nsec;
+}
+
+static void reset_timeline(mp_harmony_playback_timeline *timeline)
+{
+    if (!timeline) return;
+    int64_t *values = (int64_t *)timeline;
+    for (size_t i = 0; i < sizeof(*timeline) / sizeof(*values); i++) values[i] = -1;
+}
+
+static void reset_metrics(mp_harmony_playback_metrics *metrics)
+{
+    if (!metrics) return;
+    memset(metrics, 0, sizeof(*metrics));
+    metrics->network_wait_ms = -1;
+    metrics->late_frames = -1;
+    metrics->mistimed_frames = -1;
+    metrics->decoder_frames = -1;
+}
+
+static int64_t elapsed_ms_locked(const mp_harmony_player *p)
+{
+    if (!p || p->perf_origin_ns <= 0) return -1;
+    int64_t now = clock_now_ns();
+    return now > p->perf_origin_ns ? (now - p->perf_origin_ns) / 1000000LL : 0;
+}
+
+static void set_once(int64_t *value, int64_t timestamp)
+{
+    if (value && *value < 0 && timestamp >= 0) *value = timestamp;
+}
+
+static int url_is_network(const char *url)
+{
+    return url && (strncasecmp(url, "http://", 7) == 0 || strncasecmp(url, "https://", 8) == 0);
+}
+
+static void mark_timeline_locked(mp_harmony_player *p, int event)
+{
+    if (!p) return;
+    int64_t elapsed = elapsed_ms_locked(p);
+    mp_harmony_playback_timeline *t = &p->snapshot.timeline;
+    switch (event) {
+        case MP_HARMONY_INTERNAL_RENDER_CONTEXT_READY:
+            set_once(&t->render_context_ready_ms, elapsed); break;
+        case MP_HARMONY_INTERNAL_FIRST_VIDEO_FRAME:
+            set_once(&t->first_video_frame_available_ms, elapsed);
+            if (p->seek_active) set_once(&t->seek_first_frame_ms, elapsed);
+            break;
+        case MP_HARMONY_INTERNAL_FIRST_RENDER_BEGIN:
+            set_once(&t->first_render_begin_ms, elapsed); break;
+        case MP_HARMONY_INTERNAL_FIRST_RENDER_END:
+            set_once(&t->first_render_end_ms, elapsed); break;
+        case MP_HARMONY_INTERNAL_FIRST_SWAP:
+            set_once(&t->first_swap_ms, elapsed);
+            set_once(&t->startup_total_ms, elapsed);
+            if (p->seek_active) {
+                set_once(&t->seek_first_swap_ms, elapsed);
+                set_once(&t->seek_first_visible_frame_ms, elapsed);
+                if (t->seek_request_ms >= 0)
+                    set_once(&t->seek_recovery_ms, elapsed - t->seek_request_ms);
+                p->seek_active = 0;
+            }
+            break;
+        case MP_HARMONY_INTERNAL_AUDIO_RENDERER_START:
+            set_once(&t->audio_renderer_start_ms, elapsed); break;
+        case MP_HARMONY_INTERNAL_FIRST_AUDIO_CALLBACK:
+            set_once(&t->first_audio_callback_ms, elapsed); break;
+        case MP_HARMONY_INTERNAL_SEEK_FIRST_FRAME:
+            set_once(&t->seek_first_frame_ms, elapsed); break;
+        case MP_HARMONY_INTERNAL_SEEK_FIRST_SWAP:
+            set_once(&t->seek_first_swap_ms, elapsed);
+            set_once(&t->seek_first_visible_frame_ms, elapsed);
+            if (t->seek_request_ms >= 0)
+                set_once(&t->seek_recovery_ms, elapsed - t->seek_request_ms);
+            p->seek_active = 0;
+            break;
+        default: break;
+    }
+}
+
 static int text_has(const char *text, const char *needle)
 {
     if (!text || !needle || !needle[0]) return 0;
@@ -400,11 +503,25 @@ static void update_property_locked(mp_harmony_player *p, uint64_t id, mpv_event_
     else if (id == PROP_SPEED && property->format == MPV_FORMAT_DOUBLE) p->snapshot.speed = *(double *)property->data;
     else if (id == PROP_TRACKS) refresh_tracks_locked(p);
     else if (id == PROP_CACHE_DURATION || id == PROP_CACHE_STATE || id == PROP_BUFFERING) {
+        int was_buffering = p->snapshot.metrics.buffering;
         update_network_locked(p);
-        if (id == PROP_BUFFERING && property->format == MPV_FORMAT_INT64) {
-            int64_t buffering = *(int64_t *)property->data;
-            if (buffering > 0) p->snapshot.state = MP_HARMONY_BUFFERING;
-            else if (p->snapshot.state == MP_HARMONY_BUFFERING) p->snapshot.state = MP_HARMONY_PLAYING;
+        int is_buffering = p->snapshot.metrics.buffering;
+        if (is_buffering != was_buffering) {
+            if (is_buffering) {
+                p->snapshot.metrics.buffering_enter_count++;
+                p->buffering_start_ns = clock_now_ns();
+                p->snapshot.state = MP_HARMONY_BUFFERING;
+            } else {
+                p->snapshot.metrics.buffering_exit_count++;
+                if (p->buffering_start_ns > 0) {
+                    int64_t duration = (clock_now_ns() - p->buffering_start_ns) / 1000000LL;
+                    p->snapshot.metrics.buffering_total_ms += duration;
+                    if (duration > p->snapshot.metrics.buffering_max_single_ms)
+                        p->snapshot.metrics.buffering_max_single_ms = duration;
+                }
+                p->buffering_start_ns = 0;
+                if (p->snapshot.state == MP_HARMONY_BUFFERING) p->snapshot.state = MP_HARMONY_PLAYING;
+            }
         }
     }
 }
@@ -415,9 +532,16 @@ static void handle_log_locked(mp_harmony_player *p, const mpv_event_log_message
     char redacted[MP_HARMONY_TEXT]; redact_text(redacted, sizeof(redacted), log->text);
     if (strstr(log->text, "HTTP/1.") || text_has(log->text, "http error")) {
         int status = 0;
-        if (sscanf(log->text, "%*[^0-9]%d", &status) == 1 && status >= 100 && status <= 599) {
+        const char *http = strstr(log->text, "HTTP/");
+        if (http && sscanf(http, "HTTP/%*[^ ] %d", &status) == 1 && status >= 100 && status <= 599) {
             p->snapshot.network.http_status = status;
             if (status == 206) p->snapshot.network.range_supported = 1;
+            set_once(&p->snapshot.timeline.first_byte_ms, elapsed_ms_locked(p));
+            if (p->snapshot.timeline.network_open_begin_ms >= 0) {
+                set_once(&p->snapshot.timeline.network_open_end_ms, elapsed_ms_locked(p));
+                p->snapshot.metrics.network_wait_ms =
+                    p->snapshot.timeline.first_byte_ms - p->snapshot.timeline.network_open_begin_ms;
+            }
         }
     }
     if (text_has(log->text, "redirect")) p->snapshot.network.redirect_count++;
@@ -444,6 +568,9 @@ static void *event_loop(void *arg)
             mpv_event_start_file *start = event->data;
             p->awaiting_start = 1;
             if (start) p->playlist_entry_id = start->playlist_entry_id;
+            set_once(&p->snapshot.timeline.start_file_ms, elapsed_ms_locked(p));
+            if (url_is_network(p->current_url))
+                set_once(&p->snapshot.timeline.network_open_begin_ms, elapsed_ms_locked(p));
             p->snapshot.state = MP_HARMONY_OPENING;
             break;
         }
@@ -455,6 +582,17 @@ static void *event_loop(void *arg)
             if (loaded_url) mpv_free(loaded_url);
             if (!matches) break;
             p->awaiting_start = 0;
+            set_once(&p->snapshot.timeline.demux_ready_ms, elapsed_ms_locked(p));
+            set_once(&p->snapshot.timeline.file_loaded_ms, elapsed_ms_locked(p));
+            if (p->snapshot.timeline.network_open_begin_ms >= 0) {
+                set_once(&p->snapshot.timeline.network_open_end_ms, elapsed_ms_locked(p));
+                if (p->snapshot.timeline.first_byte_ms >= 0)
+                    p->snapshot.metrics.network_wait_ms =
+                        p->snapshot.timeline.first_byte_ms - p->snapshot.timeline.network_open_begin_ms;
+                else
+                    p->snapshot.metrics.network_wait_ms =
+                        p->snapshot.timeline.network_open_end_ms - p->snapshot.timeline.network_open_begin_ms;
+            }
             refresh_media_locked(p);
             if (p->pending_start_position_ms >= 0) {
                 char position[64];
@@ -475,6 +613,27 @@ static void *event_loop(void *arg)
         case MPV_EVENT_PROPERTY_CHANGE:
             update_property_locked(p, event->reply_userdata, event->data);
             break;
+        case MPV_EVENT_VIDEO_RECONFIG:
+            set_once(&p->snapshot.timeline.video_reconfig_ms, elapsed_ms_locked(p));
+            set_once(&p->snapshot.timeline.video_decoder_ready_ms, elapsed_ms_locked(p));
+            if (p->seek_active) set_once(&p->snapshot.timeline.seek_video_reconfig_ms, elapsed_ms_locked(p));
+            break;
+        case MPV_EVENT_AUDIO_RECONFIG:
+            set_once(&p->snapshot.timeline.audio_reconfig_ms, elapsed_ms_locked(p));
+            set_once(&p->snapshot.timeline.audio_decoder_ready_ms, elapsed_ms_locked(p));
+            break;
+        case MPV_EVENT_SEEK:
+            if (p->seek_active) set_once(&p->snapshot.timeline.seek_demux_ms, elapsed_ms_locked(p));
+            break;
+        case MPV_EVENT_PLAYBACK_RESTART:
+            set_once(&p->snapshot.timeline.playback_restart_ms, elapsed_ms_locked(p));
+            if (p->seek_active) {
+                set_once(&p->snapshot.timeline.seek_playback_restart_ms, elapsed_ms_locked(p));
+                if (p->snapshot.timeline.seek_request_ms >= 0)
+                    set_once(&p->snapshot.timeline.seek_recovery_ms,
+                             elapsed_ms_locked(p) - p->snapshot.timeline.seek_request_ms);
+            }
+            break;
         case MPV_EVENT_LOG_MESSAGE:
             handle_log_locked(p, event->data);
             break;
@@ -515,6 +674,9 @@ mp_harmony_player *mp_harmony_playback_create(void)
     p->lock_ready = 1; p->snapshot.state = MP_HARMONY_IDLE;
     p->snapshot.error_code = MP_HARMONY_ERROR_NONE; p->snapshot.speed = 1.0; p->snapshot.volume = 100;
     p->snapshot.subtitle_scale = 1.0; p->snapshot.subtitle_position = 100.0;
+    reset_metrics(&p->snapshot.metrics);
+    reset_timeline(&p->snapshot.timeline);
+    p->pending_start_position_ms = -1;
     return p;
 }
 
@@ -523,7 +685,10 @@ int mp_harmony_playback_initialize(mp_harmony_player *p)
     if (!p || !p->lock_ready) return -1;
     pthread_mutex_lock(&p->lock);
     if (p->initialized) { pthread_mutex_unlock(&p->lock); return 0; }
+    int64_t create_begin = clock_now_ns();
     p->handle = mpv_create();
+    if (create_begin > 0 && p->handle)
+        p->snapshot.timeline.mpv_create_ms = (clock_now_ns() - create_begin) / 1000000LL;
     if (!p->handle) { set_error_locked(p, MP_HARMONY_ERROR_UNKNOWN, "mpv_create failed"); pthread_mutex_unlock(&p->lock); return -1; }
     const char *options[][2] = {
         {"vo", "libmpv"}, {"terminal", "no"}, {"config", "no"}, {"hwdec", "no"},
@@ -537,7 +702,11 @@ int mp_harmony_playback_initialize(mp_harmony_player *p)
             pthread_mutex_unlock(&p->lock); return -1;
         }
     }
-    if (mpv_initialize(p->handle) < 0) {
+    int64_t initialize_begin = clock_now_ns();
+    int initialize_result = mpv_initialize(p->handle);
+    if (initialize_begin > 0 && initialize_result >= 0)
+        p->snapshot.timeline.mpv_initialize_ms = (clock_now_ns() - initialize_begin) / 1000000LL;
+    if (initialize_result < 0) {
         set_error_locked(p, MP_HARMONY_ERROR_UNKNOWN, "mpv_initialize failed");
         mpv_terminate_destroy(p->handle); p->handle = NULL;
         pthread_mutex_unlock(&p->lock); return -1;
@@ -634,7 +803,16 @@ int mp_harmony_playback_load(mp_harmony_player *p, const mp_harmony_playback_req
     p->snapshot.subtitle_position = 100.0;
     p->snapshot.media = (mp_harmony_media_info){0};
     p->snapshot.network = (mp_harmony_network_info){0};
-    p->snapshot.metrics = (mp_harmony_playback_metrics){0};
+    int64_t mpv_create_ms = p->snapshot.timeline.mpv_create_ms;
+    int64_t mpv_initialize_ms = p->snapshot.timeline.mpv_initialize_ms;
+    reset_metrics(&p->snapshot.metrics);
+    reset_timeline(&p->snapshot.timeline);
+    p->snapshot.timeline.mpv_create_ms = mpv_create_ms;
+    p->snapshot.timeline.mpv_initialize_ms = mpv_initialize_ms;
+    p->perf_origin_ns = clock_now_ns();
+    p->snapshot.timeline.session_setup_ms = 0;
+    p->buffering_start_ns = 0;
+    p->seek_active = 0;
     p->snapshot.track_count = 0; p->track_count = 0; p->awaiting_start = 1;
     p->pending_start_position_ms = r->start_position_ms >= 0 ? r->start_position_ms : -1;
     copy_text(p->current_url, sizeof(p->current_url), r->url);
@@ -674,6 +852,7 @@ int mp_harmony_playback_load(mp_harmony_player *p, const mp_harmony_playback_req
     else if (set_property_string(p, "sid", r->subtitle_enabled == 0 ? "no" : "auto") < 0) { pthread_mutex_unlock(&p->lock); return -1; }
     const char *args[] = {"loadfile", r->url, "replace", NULL};
     int rc = mpv_command(p->handle, args);
+    set_once(&p->snapshot.timeline.load_command_ms, elapsed_ms_locked(p));
     if (rc < 0) set_error_locked(p, classify_error(rc, mpv_error_string(rc)), mpv_error_string(rc));
     if (rc >= 0) {
         for (size_t i = 0; i < r->subtitle_file_count; i++) {
@@ -698,11 +877,26 @@ int mp_harmony_playback_seek(mp_harmony_player *p, mp_harmony_seek_mode mode, do
     if (!p || !isfinite(value) || mode < MP_HARMONY_SEEK_RELATIVE || mode > MP_HARMONY_SEEK_PERCENT) return -1;
     pthread_mutex_lock(&p->lock);
     if (ensure_ready_locked(p) < 0) { pthread_mutex_unlock(&p->lock); return -1; }
+    p->seek_active = 1;
+    p->snapshot.timeline.seek_request_ms = elapsed_ms_locked(p);
+    p->snapshot.timeline.seek_command_ms = -1;
+    p->snapshot.timeline.seek_demux_ms = -1;
+    p->snapshot.timeline.seek_video_reconfig_ms = -1;
+    p->snapshot.timeline.seek_playback_restart_ms = -1;
+    p->snapshot.timeline.seek_first_frame_ms = -1;
+    p->snapshot.timeline.seek_first_swap_ms = -1;
+    p->snapshot.timeline.seek_command_latency_ms = -1;
+    p->snapshot.timeline.seek_recovery_ms = -1;
+    p->snapshot.timeline.seek_first_visible_frame_ms = -1;
     char amount[64]; snprintf(amount, sizeof(amount), "%.6f", value);
     const char *kind = mode == MP_HARMONY_SEEK_ABSOLUTE ? "absolute" : (mode == MP_HARMONY_SEEK_PERCENT ? "absolute-percent" : "relative");
     const char *flags = exact ? "exact" : (keyframe ? "keyframes" : NULL);
     const char *args[] = {"seek", amount, kind, flags, NULL};
     int r = mpv_command(p->handle, args);
+    p->snapshot.timeline.seek_command_ms = elapsed_ms_locked(p);
+    if (p->snapshot.timeline.seek_request_ms >= 0 && p->snapshot.timeline.seek_command_ms >= 0)
+        p->snapshot.timeline.seek_command_latency_ms =
+            p->snapshot.timeline.seek_command_ms - p->snapshot.timeline.seek_request_ms;
     if (r >= 0) {
         p->snapshot.state = MP_HARMONY_SEEKING;
         copy_text(p->snapshot.network.seek_result, sizeof(p->snapshot.network.seek_result), "ok");
@@ -711,6 +905,7 @@ int mp_harmony_playback_seek(mp_harmony_player *p, mp_harmony_seek_mode mode, do
         redact_text(redacted, sizeof(redacted), mpv_error_string(r));
         copy_text(p->snapshot.network.seek_result, sizeof(p->snapshot.network.seek_result), redacted);
         set_error_locked(p, MP_HARMONY_ERROR_SEEK, redacted);
+        p->seek_active = 0;
     }
     pthread_mutex_unlock(&p->lock); return r;
 }
@@ -788,6 +983,19 @@ MP_HARMONY_EXPORT mpv_handle *mp_harmony_playback_internal_handle(mp_harmony_pla
     return handle;
 }
 
+MP_HARMONY_EXPORT int mp_harmony_playback_internal_mark_timeline(mp_harmony_player *p, int event)
+{
+    if (!p) return -1;
+    pthread_mutex_lock(&p->lock);
+    if (ensure_ready_locked(p) < 0) {
+        pthread_mutex_unlock(&p->lock);
+        return -1;
+    }
+    mark_timeline_locked(p, event);
+    pthread_mutex_unlock(&p->lock);
+    return 0;
+}
+
 const char *mp_harmony_playback_state_name(mp_harmony_state state)
 {
     static const char *names[] = {"IDLE", "OPENING", "BUFFERING", "READY", "PLAYING", "PAUSED", "SEEKING", "ENDED", "STOPPED", "ERROR", "RELEASED"};