Yesterday I started wrapping the LZO algorithm inside libavutil into a Node.js library. I'm still working on the C code, but let's have a look at how to test if it's actually working. I needed to generate some LZO-compressed date, so I installed the lzop tool using sudo apt install lzop. Then I generated a compressed file using:

echo "The quick quick quick brown fox" | lzop > y.lzo

I opened the resulting file in a hex editor and found the compressed bit, which looked like this: The quick q)�brown fox. Based on this, I figured that if I skip the first 50 bytes of the file, I get to the actual compressed data. So I wrote the following JS code to test if the decompression algorithm works:

const binding = require('node-gyp-build')(__dirname);
const fs = require('fs');

fs.readFile('y.lzo', (err, data) => {
  if (err) throw err;
  const skip = 50;
  const ret = binding.decompress(data.slice(skip), data.length - skip);
  console.log(ret.toString());
});

module.exports = binding;

So far I can see that the data decompresses successfully, but I'm still having a bit of trouble passing back the data into a Node.js Buffer object.