Fix Windows NuGet pack: FFmpeg DLL path moved to vc18

[shimat]

Problem

The Windows CI build job fails at the Pack NuGet packages step:

error : Could not find a part of the path '...\opencv_artifacts\x64\vc17\bin'.
[nuget/OpenCvSharp4.runtime.win.csproj]

Cause

windows.yml was updated to the Visual Studio 18 2026 generator (commits dc77c4d9, bb2da29c). OpenCV's install layout is toolset-versioned, so it now installs under opencv_artifacts/x64/**vc18**/ instead of vc17/. Confirmed from the CI build log:

-- Installing: .../opencv_artifacts/x64/vc18/bin/opencv_videoio_ffmpeg4130_64.dll

OpenCvSharp4.runtime.win.csproj still referenced the stale vc17 path for the FFmpeg DLL, so pack failed.

Fix

Update the FFmpeg DLL path in OpenCvSharp4.runtime.win.csproj from vc17 → vc18 to match the new install layout.

Scope notes:

• UWP packages and ReleaseMaker keep vc17 — those use a separately distributed prebuilt OpenCV (opencv_world490, built with VS 2022), unrelated to this from-source build.
• The Windows ARM64 job keeps the VS 2022 generator (a3fb3bf7) and already passes.
• The slim package disables videoio, so it does not ship the FFmpeg DLL.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Updated the Windows x64 runtime package to include the correct FFmpeg DLL from the newer runtime artifact path, helping ensure smoother video I/O support on Windows.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 905d0af2-2b68-4296-8959-83e83c6e151e

📥 Commits

Reviewing files that changed from the base of the PR and between 6c10282 and 767e484.

📒 Files selected for processing (1)

• nuget/OpenCvSharp4.runtime.win.csproj

---

📝 Walkthrough

Walkthrough

Updates the Windows runtime NuGet package entry for opencv_videoio_ffmpeg4130_64.dll to source the DLL from the vc18 artifacts path while keeping the same packed destination.

Changes

Windows runtime package path update

Layer / File(s)	Summary
NuGet DLL source path update nuget/OpenCvSharp4.runtime.win.csproj	The packaged opencv_videoio_ffmpeg4130_64.dll reference now points to opencv_artifacts/x64/vc18/... instead of opencv_artifacts/x64/vc17/..., with the same runtimes/win-x64/native output path.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

Possibly related PRs

• shimat/opencvsharp#1883: Updates the same NuGet project and DLL packaging path for opencv_videoio_ffmpeg4130_64.dll, making it a direct prior change to compare against.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: updating the Windows NuGet pack path for the FFmpeg DLL to vc18.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/windows-pack-ffmpeg-vc18

---

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

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

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