Memory error

**Describe the bug**

The file memory is doubled in Chrome, if the file occupies 400mb, the memory increases by 800mb.
**To Play**
-> use ffmpeg.writeFile(fileName, array400mb);
**Expected behavior**
I imagine the problem is:
Browser -> worker (file 400mb) -> webasembly (file 400mb)

Wasm does not use the file system, only memory, could you give me some clue to see where this copy is made to see if we can pass the file to webasembly by ranges while the worker file is deleted and when the file is formed in webassembly send them by range to the worker and finally pass it to the browser.

I think it would be optimal, let's see if I wanted to replicate the file system with ffmpeg when wasm does not use the file system, I think it was a mistake.