smk

A pure Rust library for decoding Smacker Video (.smk) files.

This is a faithful port of libsmacker 1.2.0. The Rust implementation produces pixel-perfect, bit-identical output compared to the original C library.

Features

• Open .smk files from disk (streaming or fully buffered) or from memory
• Decode video frames (8-bit indexed, all 6 block types including SMKv4 extensions)
• Decode audio tracks (raw PCM and DPCM compression, mono/stereo, 8/16-bit)
• Decode palettes (delta-encoded with skip, copy, and direct-set operations)
• Frame navigation: first, next, seek to keyframe

Usage

use smk::{Smk, FrameStatus};

let mut s = Smk::open_file("video.smk", true)?;

let info = s.info();
let video = s.info_video();

s.enable_all(0xFF); // enable video + all audio tracks

let mut status = s.first_frame()?;
loop {
    let pixels = s.video_data();   // &[u8], w*h indexed pixels
    let palette = s.palette();      // &[[u8; 3]; 256], RGB

    // do something with the frame...

    if status == FrameStatus::Done || status == FrameStatus::Last {
        break;
    }
    status = s.next_frame()?;
}

Testing

Run the unit tests (no test files needed):

cargo test

To test with a real .smk file, place it at testdata/test.smk and run:

cargo test

The integration tests will automatically pick it up and verify that all frames decode without errors. If the file is not present, those tests are skipped.

Extracting frames and audio

An example program extracts BMP frames, WAV audio, and an uncompressed AVI from an .smk file:

cargo run --example extract

This reads testdata/test.smk and writes output to testdata/. You can also specify paths:

cargo run --example extract -- path/to/video.smk output_dir/

Output files:

• frame_NNNN.bmp - every 10th frame as 8-bit indexed BMP
• audio_N.wav - PCM audio for each track
• output.avi - uncompressed 24-bit AVI with audio

License

LGPL-2.1-or-later (same as the original libsmacker).