Keyboard
| Space | play / pause | ← → | one frame |
| Shift+←/→ | ±1 s | Alt+←/→ | ±10 s |
| , . | ±5 s | [ ] | slower / faster |
| M | mark contact at the current frame | ↑ ↓ | nudge the mark ±1 frame |
| Enter | register event at the mark | E | extract clip for the last registered event |
| G | go to time | J | jump to mark |
| T | target-player click on the centre frame, on / off | N | notes |
| ? | this help | | |
Verify frames
Frames rendered by FFmpeg from the source at the marked time ±1 frame. The centre frame is what the clip pipeline will treat as the contact. Click a side frame to move the mark there. Click the target player on the centre frame to set the target (T turns this on or off). The corner button on a frame opens it full size.
Precision
The browser seeks to the frame it can decode nearest the requested time; the readout shows the presented frame's media time. Before registering, check the three FFmpeg frames under the timeline: the centre one is exactly what the pipeline will use.