Process a folder of javelin throws

Coaches can do this entirely in the browser. There is no script to install or command to type.

1. Open Process a folder from the javelin app in desktop Chrome or Edge.
2. Choose a folder of strict side-view throw videos, one throw per video, and allow the browser to read and write it.
3. Confirm the capture FPS, throwing arm and pose model. Override the FPS for individual videos if needed.
4. Choose the highlight layout, then press Process videos and keep this tab open.
5. Find the MP4 highlight, PDF report and Markdown text beside each original. Review each row for warnings or failures.

What gets saved

For throw.mp4, the app creates results_throw.mp4, results_throw.pdf and results_throw.md. A results_throw.json receipt records the settings, actual frame rates, analyzed range and output sizes. The MP4 is a metric highlight reel, with 30 FPS output.

Originals are not changed. Existing result files are skipped, including incomplete sets. Move old or partial results before retrying. Videos with the same base name, such as throw.mp4 and throw.mov, must be renamed first. Files beginning results_ or reslts_ are excluded. Subfolders are not processed.

Recording settings that matter

• Camera: a strict side view of the run-up, plant and release. The whole clip is analyzed, so trim each video to one throw.
• Capture FPS: Auto reads the encoded file rate. Slow motion filmed at 120 FPS may be saved at 30 FPS; enter 120 in that case. Auto fails if the file rate cannot be read, so you can choose a rate explicitly. Every frame of the file is analyzed.
• Throwing arm: right- or left-handed. Use separate batches for throwers with different arms.
• Pose model: MoveNet Thunder is the default; BlazePose Heavy and the YOLO26 sizes are the same choices as Advanced mode.
• Events and release angle: the block and release frames are detected automatically, as in Basic mode. The release angle needs the guide lined up with the javelin by hand, so batch results list it as “Not scored yet”. To score it, open the video in the single-video app’s Advanced mode.

Local processing and recovery

Video analysis and export happen in your browser. Static app code and model files may download from the internet. Folder permissions are granted by you in the browser, and you may need to grant them again after reopening the page.

One video runs at a time. A failure does not stop the rest. Stop batch cancels the active analysis/export; a save already in progress finishes before the queue stops. Closing the browser can leave partial results. Move these before retrying. Avoid concurrent programs writing to the same folder.

If the folder picker is unavailable, use a supported desktop browser such as Chrome or Edge, or return to the single-video app. MP4 export requires H.264 WebCodecs support; an unsupported encoder produces an error. Results are the same estimates and coaching guidance offered by the javelin app’s individual-video workflow.

const api = window.apoptAutomation;
api.capabilities();   // app "javelin", options, defaults, outputs (no view option)
const id = api.start({
  captureFps: 240, throwingSide: "left", model: "movenet_thunder"
});
api.getJob(id);       // state: running → succeeded / failed / cancelled
// After state === "succeeded":
await api.markdown(id);   // the text results
api.download(id, "mp4");  // also "pdf" and "md"
api.cancel(id);           // stops a running job