{
  "added_at": "2026-10-19",
  "additional_evidence_urls": [
    "https://github.com/talkaboutdesign/elgato-hdr/blob/7799d3c53520bcc3dd049211244bfaf49b905cb0/tools/uvc_capture.c",
    "https://github.com/talkaboutdesign/elgato-hdr/blob/7799d3c53520bcc3dd049211244bfaf49b905cb0/tools/usb_desc_dump.c",
    "https://github.com/talkaboutdesign/elgato-hdr/blob/7799d3c53520bcc3dd049211244bfaf49b905cb0/tools/modetest.py",
    "https://github.com/talkaboutdesign/elgato-hdr/blob/7799d3c53520bcc3dd049211244bfaf49b905cb0/build.sh",
    "https://github.com/talkaboutdesign/elgato-hdr/blob/7799d3c53520bcc3dd049211244bfaf49b905cb0/LICENSE",
    "https://github.com/talkaboutdesign/elgato-hdr/pull/1",
    "https://x.com/talkaboutdesign/status/2109795113807630735"
  ],
  "category": "reconstruction-cases",
  "description_en": "A native macOS app that reaches the Elgato 4K X capture card’s 10-bit P010 video mode, which the project says Apple’s built-in webcam driver does not expose to apps. A root helper detaches that driver and runs the card’s USB Video Class streaming directly through libusb, feeding a Metal HDR viewer, an HDR10 recorder and an editor. Latency figures and device coverage remain author-reported.",
  "description_zh": "一款原生 macOS 应用，用于获取 Elgato 4K X 采集卡的 10 位 P010 视频模式；项目称苹果内置的摄像头驱动不会向应用开放该模式。一个 root 权限辅助程序卸下该驱动，通过 libusb 直接执行采集卡的 USB 视频类（UVC）串流，为 Metal HDR 预览、HDR10 录制和编辑器提供画面。延迟数据和设备覆盖范围仍为作者报告。",
  "entry_url": "https://awesomerea.org/resources/elgato-hdr-uvc-capture-case/",
  "entry_url_zh": "https://awesomerea.org/zh/resources/elgato-hdr-uvc-capture-case/",
  "evidence_url": "https://github.com/talkaboutdesign/elgato-hdr/blob/7799d3c53520bcc3dd049211244bfaf49b905cb0/README.md",
  "group": "cases",
  "id": "elgato-hdr-uvc-capture-case",
  "json_url": "https://awesomerea.org/resources/elgato-hdr-uvc-capture-case/record.json",
  "kind": "case-study",
  "markdown_url": "https://awesomerea.org/resources/elgato-hdr-uvc-capture-case/index.md",
  "markdown_url_zh": "https://awesomerea.org/zh/resources/elgato-hdr-uvc-capture-case/index.md",
  "name": "Elgato HDR: a userspace capture path for the Elgato 4K X’s 10-bit mode",
  "name_zh": "Elgato HDR：为 Elgato 4K X 的 10 位模式提供用户态采集通路",
  "record_type": "resource",
  "relationship": "independent-reconstruction",
  "requirement_facets": [
    "scope",
    "prerequisites",
    "scope",
    "testing",
    "license"
  ],
  "requirements": [
    "Reviewed at the 2026-10-13 head, after release 1.0.0 (2026-09-08). It targets an Elgato 4K X on macOS 14 or newer; the README reports building and testing on Apple Silicon only, and other Elgato cards with a P010 UVC format are untested. The HDR preview needs an HDR/EDR display. Among the 10-bit modes, 4K is limited to 30 fps by USB bandwidth.",
    "Building needs Xcode Command Line Tools and Homebrew’s libusb: build.sh compiles the C helper against libusb, bundles the library, compiles the Swift app and signs it ad hoc, and releases are not notarized. The helper needs one administrator prompt because detaching the macOS kernel driver requires root; it exits about 20 seconds after the app quits and hands the card back to macOS.",
    "The repository keeps the USB descriptor-dump tools used while reverse-engineering the card and a script that sweeps every capture mode; it contains no vendor firmware or driver binaries. Recordings carry fixed HDR10 mastering metadata because, per the README, the card does not pass the source’s HDMI HDR metadata over USB.",
    "The README and the Game-mode pull request report display delays of about 48, 22 and 5 ms for the Smooth, Game and Lowest Latency modes at 1440p60 on a 120 Hz MacBook Pro, measured from USB transfer completion to display as reported by macOS; the card’s own processing comes on top, and the PR notes that the test card sent silent audio. These are author measurements.",
    "MIT covers the project code; the bundled libusb library and captured content keep their own terms, and the project states it is not affiliated with Elgato or Corsair. An X post under the same handle credits REA with helping this latency work."
  ],
  "requirements_zh": [
    "审阅版本为 2026-10-13 的最新提交，晚于 1.0.0 版（2026-09-08）。目标设备为 macOS 14 及以上系统上的 Elgato 4K X；README 称仅在 Apple Silicon 上构建和测试，其他提供 P010 UVC 格式的 Elgato 采集卡未经测试。HDR 预览需要支持 HDR/EDR 的显示器。在各个 10 位模式中，4K 受 USB 带宽限制只能以 30 fps 采集。",
    "构建需要 Xcode Command Line Tools 和 Homebrew 的 libusb：build.sh 会将 C 辅助程序与 libusb 链接、打包该库、编译 Swift 应用并做临时签名，发布版本未经公证。由于卸下 macOS 内核驱动需要 root 权限，辅助程序需要一次管理员授权；应用退出约 20 秒后它会自行退出，并把采集卡交还给 macOS。",
    "仓库保留了逆向采集卡时使用的 USB 描述符转储工具，以及遍历全部采集模式的脚本；仓库不含厂商固件或驱动二进制文件。由于 README 称采集卡不会通过 USB 传递信号源的 HDMI HDR 元数据，录制文件写入的是固定的 HDR10 母版元数据。",
    "README 及 Game 模式拉取请求报告：在 120 Hz MacBook Pro 上以 1440p60 采集时，Smooth、Game 和 Lowest Latency 三种模式的显示延迟约为 48、22 和 5 毫秒，计时从 USB 传输完成到画面显示，以 macOS 报告为准；采集卡自身的处理时间另计，该 PR 还指出测试用采集卡输出的是静音音频。这些均为作者测量。",
    "MIT 许可覆盖项目代码；打包的 libusb 库和采集内容保留各自条款，项目声明与 Elgato 或 Corsair 无关联。同名 X 账号的帖子称 REA 协助了这项延迟工作。"
  ],
  "targets": [
    "app",
    "protocol"
  ],
  "url": "https://github.com/talkaboutdesign/elgato-hdr",
  "verification": "source-reviewed",
  "verified_at": "2026-10-18"
}