Videos exported from the replay editor played two to three times too
fast unless the frame rate was capped, or the export was slow enough to
hold it down by itself (4K, WebM). The fault is in the game's own export
path.
Replay export (Extension/Rendering/replay_export.*)
- While exporting, the game steps the replay by one frame of video
(speed / fps) for every frame it renders. The engine's movie encoder
takes a frame only while a permit byte is set; a world update sets it
once, and a frame submitted without it is dropped. Rendering two or
three frames per update, most of a clip never reached the file, and an
MP4 is exactly as long as its frame count. One clip came out as 181
frames at 30 fps and 297 at 60, 6.0 s and 5.0 s.
- The encoder's frame submit is detoured and the permit set before the
original runs, for the replay editor's encoder only (matched by its
vtable). The frame is encoded on the render thread before the call
returns, so the renderer is held to the pace the encoder keeps and no
frame is lost. The replay still runs fast on screen during an export:
that is the encoder's speed, not the file's.
- The same clip afterwards, frame rate uncapped, MP4 1080p: 505 frames
at 30 fps and 1008 at 60, 16.8 s both, audio as long as the video.
WebM and 4K take the same path and were not run again.
- Addresses are in Engine/Game/Build/20260929/replay_export.h. The hook
starts with the others in runtime_init.cpp.
AyeZeeBB