Take a still

A still shot (kind = "still") renders one moment, 150 ms after its tape’s last step, as a 16-bit sRGB master PNG and 8-bit PNG deliveries. With the sample app:

prec still demo palette --app-dir examples/demo --size 1080p --derive 720p --web 800

recording demo palette in a 60x16 pty…
recorded 1.30s shown, 237 events → tmp/prec/run/demo-still-palette-cast-234771/demo-still-palette.cast
replaying demo palette to 2.35s at 1920x1080…
archive: skipped (unconfigured)
tmp/renders/demo/still/demo-still-palette-1920x1080.json

tmp/renders/demo/still/
  demo-still-palette-1920x1080.master.png       56,418 bytes   16-bit sRGB, lossless
  demo-still-palette-1920x1080.png              38,395 bytes   8-bit delivery at the master's size
  demo-still-palette-1280x720.png               50,332 bytes   8-bit, from --derive 720p
  demo-still-palette-1920x1080-web-800.png      31,202 bytes   800x450, from --web 800
  demo-still-palette-1920x1080-web-800@2x.png   65,620 bytes   1600x900, its @2x copy
  demo-still-palette-1920x1080.cast             15,287 bytes
  demo-still-palette-1920x1080.json              4,768 bytes

Sizes

--size is the master’s size: 720p, 1080p, 1440p, 2160p, WxH, or a single N for a square. The default is 1080p, or the shot’s own size.
--derive adds more delivery sizes from the same master, each no larger than it: --derive 720p or --derive 1280x720,640x360.
--web adds web copies at the given widths, each also at @2x, keeping the master’s aspect.

The master is drawn at its own size, never scaled; every derived size and web copy is resampled from it with Lanczos3 in linear light, so edges and colours hold up when they shrink.

Native pixels

The grid is fixed by the recipe and the font is fitted to the render size, so a 4K still shows exactly what a 720p still shows, each drawn at its own pixels. Top: a crop of a 1280x720 still, enlarged three times; bottom: the same crop of the 3840x2160 still from the same tape.

Two crops of the same box: the upper one, from the 720p still and enlarged three times, shows blocky pixels on the CJK character, the text and the arrow; the lower one, from the 4K still at its own pixels, shows the same glyphs smooth.

For the sharpest small image, render that size with --size instead of deriving it.

Colour

The master is a 16-bit sRGB PNG, and every delivery an 8-bit PNG with an sRGB chunk. The terminal draws 24-bit truecolor, painted by xterm.js in Chromium with its colour profile forced to sRGB, so the same cast gives the same pixels on any machine.

Several themes at once

--themes renders one recording in each theme, with the theme’s slug in each file name; see Choose a theme.