gameframe-indeo

A decoder for Intel Indeo Video Interactive 4.1 (FourCC IV41), written in Rust. It decodes as Intel's own Video for Windows codec IR41_32.DLL (R4.11.15.91) does on its Pentium path, picture for picture: the same bytes in Intel's IF09 (YVU9) layout.

• No dependencies. Plain Rust: it builds for any host and for 32-bit Windows.
• Clean room. Every rule comes from Intel's own IR41_32.DLL, read in its code and run under GameFrame's emulator (tools/emu/pe32_emu.py). No other decoder's source, data or description of its internals was read. The work and its evidence are in the POD project (docs/formats/video.md, "The pictures"), where every rule names the address in Intel's DLL it comes from.
• Checked against Intel. On all 13,663 pictures of POD Gold's six videos, each picture is byte-identical to the one Intel's codec gives under the emulator (measured, 2026-10-24).
• Intel's tables are not in this crate. The codebooks, run/value maps, scan orders and quantiser matrices are Intel's data. Tables::from_dll reads them from the bytes of the player's own copy of Intel's DLL (it ships on many game discs, often in an INSTALL or INDEO folder). Tables::from_parts takes tables of one's own, for streams made with them.

Use it

let tables = indeo::Tables::from_dll(&std::fs::read("IR41_32.DLL")?)?;
let mut decoder = indeo::Decoder::new(tables);
for chunk in video_chunks {               // each video chunk of the AVI's movi list
    if let Some(frame) = decoder.decode(chunk)? {
        // frame.y, frame.v, frame.u: the planes; frame.rgba(): RGBA pixels
    }
    // None: no new picture for this chunk (a null or held-back one); the last one stays.
}

A chunk can hold two pictures (an intra picture and the predicted picture that follows it); decode returns the one Intel's codec shows for the chunk.

What it covers

Everything POD Gold's videos use: intra, predicted, bidirectional and droppable pictures, pictures held back for later display and null pictures; one luma band or four (the Haar recomposition); Slant 8 × 8 and 4 × 4, Haar 8 × 8, 1 × 8 and 8 × 1, and no transform; motion in whole and half samples, forward, backward and both. Not yet: custom scans and quantiser matrices sent in the stream, transparency, locked (keyed) pictures, the other transforms of Intel's table (each gives Error::Picture). Intel's MMX path recomposes four bands slightly differently; this crate follows the Pentium path.

Test

cd crates && cargo test -p gameframe-indeo

The tests decode streams made in the test with tables made in the test (tests/streams.rs): no Intel file is read.

Licence: Apache-2.0 (code), CC0-1.0 (this text).