Video frame extractor

Why extract frames in the browser?

The usual answer to "I need a still from this video" is a screenshot or an ffmpeg command. A screenshot caps you at screen resolution and catches player overlays. ffmpeg you have to install, then remember the syntax for.

Browsers already ship a complete, hardware-accelerated video decoder. floi points that decoder at your file, draws the decoded frame to a canvas at its full size, and encodes it. The result is pixel-identical to what ffmpeg would give you, with no install and no upload.

Frame-accurate, not approximately accurate

Most browser-based tools nudge currentTime by a hard-coded 1/30th of a second and hope. That drifts on 24 fps film, 25 fps PAL, 50 fps and 60 fps footage alike.

floi instead derives the real rate from the decoder itself, and drops it into a picker you can override. It measures the interval between presented frames, falling back to the decoder's frame counter when the compositor is idle. Stepping then moves exactly one frame. Captures wait for the decoder to actually present the new frame before reading pixels, so you never get the previous frame by accident.

Batch extraction

For contact sheets, thumbnails, dataset frames or scene breakdowns, set an interval and let it run. floi seeks to each mark in turn, captures, and reports progress. When it is done you can download all of them in one ZIP, named by timecode so they sort correctly:

my-video-00h00m00s000ms.png
my-video-00h00m05s000ms.png
my-video-00h00m10s000ms.png

Runs are capped at 300 frames. Each captured frame is held in memory as an encoded blob, and a few hundred 4K PNGs is already a serious amount of RAM. The cap keeps the tab responsive. For longer jobs, run several passes with different start points.

Keyboard shortcuts

Using the frame extractor

Opening and replacing a video

Drop your video on the empty player, or click it to Choose a video file. The file name and size appear above the player. The video stays in your browser.

Your browser must support the video's codec, not just its file extension. If it cannot play the file, convert it to a supported format first. Choose another closes the video and clears its captured frames. Then pick or drop a replacement.

Finding the frame

The frame counter depends on the detected or selected rate. Variable frame rate footage may not line up with a single fixed interval. If detection cannot find a rate, choose one manually.

Choosing the output

Format offers PNG, JPG and WebP where supported. PNG is lossless. JPG and WebP expose the Quality slider from 40% to 100%, initially 92%. Lower values usually make smaller files with more compression artefacts.

Capture frame adds the current picture to Captured frames at the video's native dimensions. The preview's on-screen size does not change the export resolution. A capture keeps its format and quality even if you change those settings later.

Extracting a series

Every selects an interval of 0.5, 1, 2, 5, 10, 30 or 60 seconds. Extract series starts at the beginning of the video, not your current position. It adds frames to the existing tray and shows progress.

A run is capped at 300 frames to limit memory use. If your interval would produce more, the confirmation offers the first 300. Choose a longer interval to cover more of the video. Playback stays paused after extraction.

Previewing and downloading frames

Full screen and keyboard controls

Full screen expands the workspace. Width offers Narrow, Wide and Full. Done, Escape or browser Back returns to the document.

While the workspace has focus, Space or K toggles playback. Left and Right Arrow step one frame; hold Shift to move one second. C or Enter captures a frame. Shortcuts leave input fields and dropdowns alone.