Progress event value

**Describe the bug**

listening to the progress event, the progress value is a very big negative number, but it should be between 0 and 1 ?

```
ffmpeg.on("progress", ({ progress, time }) =>
{
console.log( (progress * 100)+"%, time: "+(time / 1000000)+" s");
});
```

```
0%, time: 0 s
-3406300%, time: 0.034063 s
-7306300%, time: 0.073063 s
-11406300%, time: 0.114063 s
-12706300%, time: 0.127063 s
-15406300%, time: 0.154063 s
-19206300%, time: 0.192063 s
```

**To Reproduce**

check out the git repository, run the example - the examples also give this wrong number

**Expected behavior**

should be a number between 0 and 1

Any idea how to fix this ?