I want to add subtitles, but not work.

`
ffmpeg.run('-i', 'input.mp4', '-vf', 'subtitles=test.srt', 'output.mp4')
`

I use https://unpkg.com/@ffmpeg/core@0.11.0/dist/ffmpeg-core.wasm, but not work.

Isn't this problem solved in [#138](https://github.com/ffmpegwasm/ffmpeg.wasm/issues/138)??