Build an image sample before an annotated dataset
VideoFrame Extractor can help prepare still images for a computer-vision workflow. Choose a local recording, select a meaningful range and sample at a controlled interval. Download the resulting images with timestamped names, then label them in your annotation tool. This workspace does not export YOLO bounding boxes, COCO JSON, class labels or segmentation masks. Those require a separate labeling and validation step.
Sampling decisions affect what the model sees
A one-second interval reduces near-duplicate frames but can miss short events. A smaller interval can show transitions while overrepresenting one scene. Start with a short trial, inspect the images, then decide whether the interval matches the task. Exclude unreadable frames and verify that lighting, backgrounds and object sizes are represented appropriately. Do not assume that a larger number of similar pictures creates a more diverse training set.
Split by source, not only by image name
Adjacent frames from the same recording are strongly related. Randomly placing them across training and evaluation sets can produce an overly optimistic assessment. Track the original recording and requested timestamps outside this tool, and plan splits by an appropriate independent source or scene. Browser timestamp seeking is approximate; use a dedicated decoder if exact frame identity matters. Process short batches within the 120-frame and 96 MB gallery limits, and retain permission to use the footage.
Questions for this workflow
Can I download YOLO or COCO labels?
No. The ZIP contains images and, if enabled, frames.json with filenames, dimensions and player timestamps. It has no bounding boxes or class annotations. Add and validate those separately.
Does the tool automatically remove duplicate frames?
No. Choose an interval and inspect the output. Dataset deduplication and split validation remain separate steps.
Continue your workflow
Read practical guides · Enlarge an image · Report a reproducible problem
Capture uses the shared frame-extractor limits: 2 GiB source, 8,294,400 decoded pixels, 120 pictures and 96 MiB retained images. Start with a short playable sample; codec support and device memory vary.
Preserve the optional ZIP record
Enable the metadata checkbox before Download ZIP to include frames.json. It records source filename, picture names, dimensions, format, player time and capture role. Keep it with your annotation project; it is not COCO JSON and does not prove an exact source-frame identity. Group related recordings before splitting training and evaluation sets.