> For the complete documentation index, see [llms.txt](https://flywith24.gitbook.io/flywith24-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://flywith24.gitbook.io/flywith24-docs/data-and-sync.md).

# Videos, ride data, and synchronization

### Supported inputs

FlyHUD accepts common MP4 and MOV videos, local **FIT, GPX, and CSV** activity files, and your own authorized **Strava** activities. TCX is not a supported import format. Container extensions alone do not guarantee that damaged files or special codecs can be decoded.

On iPhone, choose videos from Photos or Files. The Apple Watch activity entry reads cycling and running workouts from Health with your permission; available sensor and route data depend on what was recorded and authorized. FlyHUD does not write workouts to Health.

Available HUD metrics depend on the source. FlyHUD cannot reconstruct power, heart rate, cadence, GPS, or shifting events that were not recorded.

### Riders and data sources

Each activity can be linked to a rider. Weight and FTP enable W/kg, FTP percentage, and power-zone calculations. The Mac Follow HUD keeps separate camera-rider and followed-rider relationships.

Zwift and MyWhoosh can display a configured list of nearby riders, up to seven including yourself. These are imported activity records, not live online players. Mac stores the list in the project. iPhone stores bindings in each draft and keeps reusable rider profiles and FIT activities separately; deleting a draft does not delete those profile activities. Check each rider's time adjustment and matching status.

### Automatic matching

Shooting time is read first from a supported original filename, then from embedded video creation metadata. Filesystem creation dates are not used to infer shooting time. If metadata is missing or wrong, enter the shooting time manually; for a trimmed source, use the time of its new first frame.

FlyHUD compares the video time range with activity timestamps. Available time interpretations include standard UTC, a correction for local time written as UTC, and manual correction. Time overlap is a starting point, not proof that the picture and HUD are synchronized. Check a clear event such as starting, stopping, accelerating, or entering a climb near the start and middle.

### Manual time adjustment

Pause at a clear event and keep the video picture fixed while adjusting the corresponding activity time. Move the control a small amount and watch whether the HUD moves closer to the visible event; reverse the adjustment if it moves farther away. Repeat at another point in the clip before exporting. On iPhone, the calibration slider selects the activity time corresponding to the current picture.

Each video keeps its own fine adjustment. Mac batch synchronization leaves time calibration unchanged unless you explicitly include it.

### Missing or unmatched data

Professional templates hide metrics absent from the whole activity and reflow the available content. Some fixed cards, including Zwift and Race, keep stable slots and show a dash for local gaps; a genuine recorded zero remains zero. If the entire activity falls outside the video time range, FlyHUD reports an unmatched source rather than freezing the first or last value.

### Strava activities, laps, and network access

Strava supports recorded cycling and running activities, including supported virtual and indoor types. Manual activities without a time series cannot supply a HUD. FlyHUD uses the original elapsed timeline, including pauses, and reads laps through Strava's laps endpoint. If laps fail to load, other available telemetry remains usable and the app reports the failure; synchronize again to retry.

On Mac, activity telemetry is cached for up to **seven days**. A valid cache can restore previews and exports offline. FlyHUD checks the seven-day limit when reading the cache, removes expired data, and fetches it again; this does not guarantee background deletion while the app is closed. Queued exports retain their frozen data. On iPhone, Strava telemetry is not kept in a persistent draft cache: reopening a Strava draft and preparing an export requires a network fetch. Local-file activities do not have this Strava network requirement.

When an in-app Strava disconnect succeeds, it revokes authorization and clears related local tokens and activity associations/cache. In iOS 1.1.0, trial/access checks may restrict the in-app disconnect control. You can revoke FlyHUD directly in [Strava Settings → My Apps](https://www.strava.com/settings/apps) without purchasing Lifetime Unlock; see the Privacy Policy for revocation and deletion details. It does not delete original videos, local FIT/GPX files, or finished videos already saved by you. Changing accounts does not transfer the previous athlete's activities to the new account.

### Electronic shifting

Strava's public API does not provide electronic shifting events; its Gear field identifies equipment such as a bicycle or shoes. Import an original FIT containing standard front/rear gear-change events to use recorded shifting. FlyHUD displays recorded gear positions after you configure the drivetrain; it does not infer shifts from speed/cadence or provide live Bluetooth shifting control. MyWhoosh uses its own shifting card rather than a separate Gear overlay.