Since there's been a non-zero interest in evaluating my encoder, here's a short guide on how to build and invoke the encoder.

• Building nihav-encoder
• Input limitations
• Using nihav-encoder to encode into AVI
• Using nihav-encoder to encode into EA format

Building nihav-encoder

Since distributing binaries in modern Internet is considered dangerous, here are build instructions instead:

1. get Rust version 1.69 or later
2. clone NihAV git repository from git://git.nihav.org/nihav.git
3. clone nihav-encoder git repository from git://git.nihav.org/nihav-encoder.git into already existing nihav directory (or edit paths to it in Cargo.toml)
4. build it simply with cargo build --release (though I heard that RUSTFLAGS='-C target-cpu=native' cargo build improves performance significantly in this case)

Input limitations

NihAV is a research framework and thus it has support mostly for exotic formats and lacks on common ones. If you want to encode VP6 you need to feed nihav-encoder the format it understands, namely:

• AVI with raw RGB
• AVI with raw YUV (preferably raw YUV420, fourcc I420)
• AVI with MJPEG (huge AVI files with OpenDML extension should work)
• YUV4MPEG2 stream (recommended)

Additionally please remember that VP6 requires picture dimensions to be multiple of 16.

Using nihav-encoder to encode into AVI

General command line looks like nihav-encoder --input input.y4m --output output.avi --ostream0 encoder=vp6,... You can additionally specify -an to drop audio streams if you do not want them to be present in output file.

Supported encoder options:

• bitrate — tells encoder to target this bitrate (in kilobits per second);
• quant — tells encoder to use fixed quantiser (in 0-63 range, the bigger the better);
• version — tells encoder to generate specific version of the bitstream. Version can be vp60, vp61 or vp62;
• huffman — tells encoder to code coefficients with Huffman codes instead of default bool coder.

E.g. if you want to encode VP 6.1 with Huffman coding and bitrate around 50kbps you should invoke nihav-encoder --input input.y4m --output output.avi --ostream0 encoder=vp6,version=vp61,huffman,bitrate=50000

You can also add --verbose option to see the encoding progress.

Using nihav-encoder to encode into EA format

This command line should produce compatible file but it has not been tested if the result works in the original games:

In theory it can also encode files with a separate alpha mask stream, for that you should provide encoder with an input file that has two video streams and invoke it like this:

Putting two streams can be done e.g. with avconv (or ffmpeg) like:

(or you can use -c:v rawvideo -pix_fmt yuv420p to make sure output file contains raw video streams).

Alternatively you can invoke encoder with two input files directly:

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