Audio & video / Local FFmpeg tool
Extract PNG frames at a chosen time interval, with a hard maximum of 60 images.
The first run loads an approximately 31 MB FFmpeg WebAssembly core from this site. It does not use a CDN or upload your files.
Files are limited to 200 MB total and 20 minutes; mobile devices use an 80 MB limit. Reverse, GIF and boomerang tools have lower duration caps.
At most 60 download files are generated.
Validated downloads will appear here after processing.
Method, example & boundaries
Extract PNG still frames from a local video at a chosen time interval, with an explicit output-width cap and a hard maximum of sixty images. The workflow is designed for review boards, thumbnail selection, and shot sampling where predictable spacing matters more than decoding every source frame.
Up to 12 sequential PNG files named 321kit-frame-001.png onward, each no wider than 1280 pixels and retaining the source aspect ratio.One sample is selected for each ten-second interval. Scaling only reduces oversized frames, so a smaller source is not enlarged.
The browser-local FFmpeg runtime applies an fps filter of one frame per selected interval, scales the video proportionally to the chosen maximum width, and writes numbered PNG outputs. Before processing, the duration and interval are checked so the planned result cannot exceed sixty files.
Local AI / Speech to text
Open-source Whisper Tiny runs in your browser. The file, audio and result are never uploaded.
Choose an audio or video file in the workbench above first.
◎ The model loads only from 321Kit; MiniMax is not called and no transcript history is stored.
How it works
One frame is selected for every interval using FFmpeg’s fps filter.
One frame is selected for every interval using FFmpeg’s fps filter. Processing uses single-thread FFmpeg.wasm. The page does not upload, store or inspect file content outside this device. Cancel, error and page close terminate the worker and revoke temporary object URLs.
Increase the interval for long videos; frame extraction has no audio output. Files are limited to 200 MB total and 20 minutes; mobile devices use an 80 MB limit. Reverse, GIF and boomerang tools have lower duration caps.
Anonymous feedback
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