I write my own programs/tools if the problem is small enough to justify it or if the thing you want to do is so specific/niche that no other tools exist. Sometimes it's faster to simply write a new program than to search for and toying around with existing tools.
The actual algorithm for conversion was: create a 16-bit lookup table with 256 entries where the index into the table is the input signal. Each table entry represents a 1/256th piece of an exponential curve with a power of 8 which is scaled to the range of -32678 to 32767. You read a byte, use this as index into the lookup table und the value you find there is the output sample.
To be honest, I don't how to do that :D Sorry again. Can you please for another favor about 'same' problem..? PC files for same game have a little different structure. I wrote python script with chatgpt help to extract viv files and the convert to wav. But I am not satisfied with result, because of loudness, and noise. As I understand, that are a vox adpcm files, and need to convert to wav. But.... Maybe that is the same think. Can you take look on files? PC Example
The actual data in the VOX files seem to start at offset 92, not 0. Standard VOX files usually have no header so you need to skip it. And the Endianess is wrong. Each byte needs the upper and lower group of 4 bits swapped before decoding.