I tried to extract the .usm files in StreamingAssets\VideoAssets by using vgmtoolbox, but none of the extracted .m2v and .hca files are playable.These files seem to be encrypted and there are some .auth files which totally don't know what to do with.
I just want the original video without the subtitle and uid watermark.
I've uploaded one of the usm+auth files.Any help is very appreciated.https://mega.nz/file/CGpDCaoB#6JpIeg4AhXajIbQ5bIpz148ggUjYv5ivhb375CqzM-c
OK, so, update:
You can convert the HCA to WAV and they will play. They are not encrypted audio files.
However, the M2V is a different story and I'm still working on it.