commit 4eaf80f562748a26dce91bcfa7d6cb17985bf47f
author Sunggook Chue <sunggch@microsoft.com> Fri May 09 23:07:46 2025
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon May 12 19:57:07 2025
tree 53ac3fbcb35cd45cb88133f7032cbbce1989b896
parent 1e71d089aa63e0f82451d1983863a06110e694a7

Desktop Capture Performance Improvement via HMONITOR Caching

The GetHmonitorFromDeviceIndex API previously made
repeated calls to the EnumDisplayDevicesW OS API,
which is an expensive kernel operation.
Specifically, EnumDisplayDevicesW was invoked twice—once in
IsScreenValid and again in GetScreenRect.

GetHmonitorFromDeviceIndex alone cost is 1000 counts meanwhile
its parent ProcessFrame() itself is around 4000 counts, which
includes memcpy (2000 counts) and other d3d11 operation (1000).

This change removes the redundant call to IsScreenValid, no
calling the expensive EnumDisplayDevicesW, as GetScreenRect
already performs the necessary validation.

Additionally, the HMONITOR value is now cached for each
WgcCaptureSession used in screen capture.

After this CL, GetHmonitorFromDeviceIndex cost is almost 0
as it isn't shown on the traces anymore.

Bug: chromium:416088620
Change-Id: I1a9076ac9c797c3cb12f420dc60c73f174fe4f9f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/390180
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Alexander Cooper <alcooper@chromium.org>
Commit-Queue: Sunggook Chue <sunggch@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#44599}