bbcat

Dependency-free terminal viewer for CP437 ANSI and ansimation, DarkDraw DDW, DIZ, ADF, RIPscrip, and XBin art. It writes colored UTF-8 by default, with optional Kitty graphics plus PNG, APNG, and GIF output.

Browse and download BBS art packs at 16colo.rs.

Install

cargo install bbcat

To build from source, run cargo build --release.

Usage

bbcat [OPTIONS] [FILE]...

Pass one or more files, use - for standard input, or omit the filename to read standard input. Use -- before a filename that begins with -.

bbcat art.ans FILE_ID.DIZ
bbcat < art.ans
bbcat --kitty scene.xb
bbcat --output preview.png art.adf
bbcat --output - art.ans > preview.png
bbcat --apng animation.png animation.ans
bbcat --gif animation.gif animation.ans
bbcat --2x --kitty art.ans
bbcat --sauce art.ans
bbcat --baud 4x animation.ans
bbcat --asciimation ~/Downloads/starwars.txt

Output modes

Mode	Option	Behavior
UTF-8	default	Converts CP437 characters to Unicode and emits 24-bit ANSI colors.
Kitty	--kitty	Renders bitmap glyphs through Kitty graphics, cropping at the terminal's right edge.
PNG	-o FILE, --output FILE	Writes one indexed-color PNG; use - to write it to standard output.
APNG	--apng FILE	Writes a looping indexed-color animated PNG from an ANSI or DDW animation.
GIF	--gif FILE	Writes a looping 16-color animated GIF from an ANSI or DDW animation.

Kitty mode requires terminal stdout and a terminal that answers bbcat's Kitty graphics protocol probe. Kitty and Ghostty are supported on Linux and macOS, along with iTerm2 on macOS. Long images are emitted in strips so they remain available in terminal scrollback. Add --fit to scale the complete image to the terminal width instead of cropping. If that would make the image shorter than one terminal row, bbcat reports the minimum required terminal width.

PNG, APNG, and GIF modes require exactly one input file. Use - as their output path to write the image to standard output. Choose only one image output mode; none can be combined with --kitty, --slow, --delay, or --sauce. Static PNG output cannot use --baud; APNG and GIF use it for frame timing.

UTF-8 output is intended for character art using the standard CP437 glyph set. Use Kitty or PNG output for RIPscrip, XBin 512-character fonts, or artwork whose embedded bitmap font must be reproduced exactly.

Animation

bbcat recognizes ansimation from repeated ANSI screen rewrites and DarkDraw DDW animation frames, then plays them automatically when standard output is a terminal. Playback defaults to 1X. Use --baud RATE to choose an animation frame rate or set the row-reveal speed for static ANSI and text:

bbcat --baud 2400 animation.ans
bbcat --baud 57600 animation.ans
bbcat --baud 2x animation.ans
bbcat --baud 4x animation.ans

2400, 9600, 14400, 28800, 38400, 57600, 115200 (1X), 2X (230400), and 4X (460800) are suggested familiar rates; run bbcat --baud to print the list. Any positive numeric rate is accepted, as is an Nx multiplier of 115200 (for example, 3X is 345600). Animated playback uses each frame's source byte count to determine how long it remains visible. DDW uses its source-defined per-frame duration at 1X, scaled proportionally by the selected rate. Static art uses the same smooth row reveal as --slow: 1X is 25 milliseconds per row, with lower rates slower and higher rates faster. Terminals with synchronized-output support reveal each redraw atomically to avoid visible row-by-row tearing. Animation playback preserves CP437 text and source-defined 16-color, 256-color, and true-color SGR sequences. An animation that explicitly homes to the terminal's top-left clears the canvas before playback; relative animations leave the terminal intact. Both retain their final frame and return the shell prompt below it.

Redirected UTF-8 output and Kitty or PNG output render the last visible state instead of replaying the animation. --apng and --gif retain every detected frame and loop forever. Their frame delays use the same source-byte timing as terminal ansimation, or DDW's native durations, with --baud scaling either one. Supplying --baud explicitly replays an animation or uses the static row reveal even when UTF-8 output is redirected. --baud cannot be combined with Kitty, static PNG, --slow, or --delay.

ASCIImation text streams

The plain-text streams published by asciimation.co.nz do not contain terminal control sequences, so bbcat does not try to detect them automatically. Use --asciimation to play one explicitly:

bbcat --asciimation ~/Downloads/starwars.txt

The format stores a duration in 100 ms ticks followed by thirteen complete ASCII rows per frame. Playback requires terminal stdout and redraws each frame atomically; it cannot be combined with graphics, output, width, or speed flags.

Slow mode

bbcat --slow art.ans
bbcat --delay 50 art.ans
bbcat --kitty --slow art.ans

--slow reveals one character row at a time with a 25 millisecond delay. --delay MS enables slow mode with a custom delay from 1 through 10,000 milliseconds. Both UTF-8 and Kitty modes flush each row before waiting; Kitty mode automatically uses one image strip per character row.

Slow mode is not supported with ANSI animation, image output, or RIPscrip raster graphics. Use --baud for baud-paced ANSI/text output. In Kitty slow mode, --chunk-lines has no effect.

SAUCE metadata

Use --sauce to show an artwork's available SAUCE title, author, group, and creation date as a compact gallery-style caption below the rendered art. Files without descriptive SAUCE metadata render without a caption. The option works with UTF-8 and Kitty output, including multiple input files, but cannot be combined with image output.

2x scaling

bbcat --2x --kitty scene.xb
bbcat --kitty --fit wide.ans
bbcat --2x --output large.png drawing.rip
bbcat --2x --apng large.png animation.ans
bbcat --2x --kitty --slow art.ans

--2x doubles both graphical output dimensions. Kitty mode crops the doubled bitmap at the terminal width unless --fit is present; image output writes an image with twice the width and height. It works with every supported input format and can be combined with Kitty slow mode. Slow-mode delays remain per original artwork row.

Scaling is intentionally unavailable in UTF-8 mode: repeating text characters would change strings and distort line art. Use --kitty, --output FILE, --apng FILE, or --gif FILE with --2x.

When UTF-8 output goes directly to a terminal, rows wider than the terminal are cropped to its current column count. Redirected or piped UTF-8 output preserves the full artwork width. Kitty crops at terminal width by default; --fit scales the complete image down when at least one terminal row remains. Image output always retains its full dimensions.

Formats

• ANSI and plain CP437 text, including .ANS, .DIZ, .ASC, .NFO, .MEM, and .TXT. ANSI cursor movement, erasing, standard and bright colors, inverse video, blink/iCE colors, wrapping, SAUCE dimensions, and baud-paced ansimation are handled. Ansimation playback also preserves 256-color and true-color SGR sequences.
• DarkDraw (.DDW) UTF-8 JSON Lines text art and animation. Base and frame-specific objects are painted in source order; reusable group references are expanded recursively at their positioned frame. Each DDW frame uses its declared duration. A Dimensions metadata record is used when present; otherwise bbcat infers the canvas from the positioned text. Terminal playback preserves Unicode glyphs and 16- and 256-color styles; graphical output uses a CP437/VGA approximation where necessary. APNG and GIF retain every frame.
• XBin (.XB) with embedded palettes, 8- or 16-color backgrounds, embedded fonts up to 32 pixels high, 256- and 512-character modes, and XBin RLE.
• ArtWorx Data Format (.ADF) version 1 with its embedded palette and 8x16 font. ADF is fixed at 80 columns.
• RIPscrip (.RIP) level-one vector graphics, including its bitmap and proportional BGI stroke fonts. RIPscrip is rendered to a 640x350 canvas and requires Kitty or PNG output.

SAUCE metadata is used for content length, canvas dimensions, iCE color mode, 8- or 9-pixel VGA letter spacing, and named IBM VGA50, Amiga MicroKnight, Amiga Topaz 2+, and Empathy bitmap fonts when present. Kitty and image output reproduce their exact glyph shapes; UTF-8 output remains a terminal-font approximation. A 9-pixel Kitty raster reserves its full pixel width, so it may occupy more terminal columns than the source character grid. A DOS EOF marker terminates plain ANSI/text input.

Common raster image inputs such as PNG, GIF, JPEG, WebP, TIFF, ICO, BMP, and QOI are rejected by content with an explanatory error instead of being parsed as character art. Malformed, truncated, oversized, or unsupported BBS inputs also produce a non-zero exit status and a filename-scoped error. With multiple inputs, bbcat reports a rejected file and continues with the remaining files.

Options

Option	Description
-w COLS, --width COLS	Override text width. ANSI/text accepts declared widths through 10,000 columns; untagged plain text is inferred through 1,000. DDW and XBin must match their declared width; an untagged DDW may be widened but not narrowed. ADF must be 80, and RIPscrip must be 640.
--chunk-lines ROWS	Set the number of character rows in each Kitty image strip, from 1 through 256. The default is $LINES - 1, clamped to 1 through 64, or 24 when $LINES is unavailable.
--kitty	Use Kitty graphics instead of colored UTF-8.
--fit	Scale complete Kitty output to terminal width instead of cropping. Errors if the result would be shorter than one terminal row.
--slow	Reveal one character row at a time using a 25 ms delay.
--delay MS	Enable slow mode with a delay from 1 through 10,000 ms per row.
--baud RATE	Play ANSI animation by source-byte timing or DDW animation by native frame timing, set static ANSI/text row-reveal speed, or control APNG/GIF frame timing. 1X is the same 25 ms/row as --slow; rates scale it proportionally. Run --baud alone for familiar suggested values.
--2x	Double Kitty or image output width and height. Requires --kitty, --output FILE, --apng FILE, or --gif FILE.
--sauce	Show the available SAUCE title, author, group, and creation date below the artwork.
-o FILE, --output FILE	Write an indexed-color PNG. Use - for standard output; requires exactly one input.
--apng FILE	Write a looping indexed-color animated PNG from ANSI or DDW animation frames. Use - for standard output; requires exactly one input. --baud controls timing.
--gif FILE	Write a looping 16-color animated GIF from ANSI or DDW animation frames. Use - for standard output; requires exactly one input. --baud controls timing.
--asciimation	Play one explicit asciimation.co.nz-style text stream: a duration plus thirteen ASCII rows per frame. Requires terminal stdout and cannot be combined with rendering or output options.
-h, --help	Print command help.
-V, --version	Print the bbcat version.

bbcat has no runtime dependencies and does not require a particular Rust version beyond what is needed to compile the current Rust edition.