How it works
Reading the file
The report is read from the container, not guessed from the extension: format, duration, overall bitrate, and for every video, audio and subtitle stream its codec, frame size, frame rate, rotation and colour description when present.
Play the file in the preview and scrub the timeline to see the same frames the sheet will use.
The contact sheet
Pick 8, 12, 16 or 24 frames. They are taken at the middle of equal slices of the video, drawn 320 pixels wide, four to a row, each with its timecode in a corner, and saved as one PNG.
time of frame i = duration × (i + 0.5) ÷ count
