Technical details
These pages explain what happens between the motion data in your clip and the stabilized frame, and what each setting in the Stabilization and Motion data panels actually changes. You do not need them to get a good result with the defaults, but they help when a clip misbehaves: the horizon wanders, fast rolls look wobbly, or a jolt shows up that was never in the raw footage.
FPVFlow uses the Gyroflow stabilization engine: Gyroflow 1.6.3 plus later changes from Gyroflow’s development code, such as Glitch filtering, Automatic lock and Lock pitch angle for horizon lock. Most of what is described here also applies to Gyroflow itself, except where a page says a feature is FPVFlow only.
Glitch filtering, Automatic lock and Lock pitch angle are not in Gyroflow 1.6.3. To use them in Gyroflow or in the video editor plugins you need a newer Gyroflow build.
| Page | What it covers |
|---|---|
| Smoothing algorithms | The four smoothing methods, their parameters, horizon lock, zooming and field of view. |
| Rolling shutter correction | Frame readout time and direction, where the value comes from and how the correction works. |
| Gyro filtering | Low pass, median and glitch filters, and the DJI O4 Gyrogate repair. |
How the pieces fit together
- Motion data. FPVFlow reads the camera orientation over time, either straight from the orientation the camera recorded or by integrating raw gyro and accelerometer samples. The filters described in Gyro filtering clean this data before anything else uses it.
- Synchronization. The motion data is lined up with the video frames.
- Smoothing. A smoothing algorithm turns the real, shaky camera path into a calm virtual camera path. Horizon lock, if enabled, is applied here too.
- Frame correction. For every frame, the difference between the real and the virtual camera becomes a rotation that is applied to the image, together with lens undistortion and, if enabled, a per-row rolling shutter correction.
- Zooming. The rotated frame no longer covers the whole output, so the image is cropped (zoomed) to hide the empty borders.