Sakura Taisen: Atsuki Chishio Ni .MOV files

Codecs, formats, encoding/decoding of game audio, video and music
Genoard
Posts: 4
Joined: Tue Oct 08, 2019 7:50 pm

Sakura Taisen: Atsuki Chishio Ni .MOV files

Post by Genoard »

I need help extracting videos from Sakura Taisen: Atsuki Chishio Ni for PlayStation 2. I processed the .CVM file found in game's .ISO image with cvm_tool as described here. That got me an .ISO which apparently contains all the game files and among them there are 77 .MOV files which i presume to be videos. However, none of them plays back correctly- the image is greatly distorted/has a lot of artifacts and there is no sound. Am i missing something or is it just my game .ISO being corrupted?
Roak
Posts: 2
Joined: Sun Dec 19, 2021 1:04 am

Re: Sakura Taisen: Atsuki Chishio Ni .MOV files

Post by Roak »

apologies for the necro, but after some desperate adventuring on my part, someone finally managed to solve this. a discord user named doop graciously offered his time to help crack this and he both found the encryption ciphers *and* created a python script to decrypt it all. the MOV files have the header MVE3, and they seem to have some sort of encryption that only encrypts the first 512 bytes of a given 8192-byte section. i dont quite know the details, but after disassembling some of the code, he managed to find out how they were encrypted. you can probably look at the python code to know more, but here it is. im extremely extremely glad to have helped finally solved this lol, though doop honestly did all of the actual work.

rename mve3.txt to mve3.py, keep magic.bin and mve3.py in the same folder, and just drag and drop the extracted .MOVs onto mve3.py.

EDIT: it's important to note that the mov files actually seem to not have any audio, despite what ffprobe will tell you—the files post-decryption are almost exactly the same size yet there are still no audio tracks. theyre probably strung about the CVM somewhere.
DKDave
Posts: 136
Joined: Mon Nov 23, 2020 6:01 pm

Re: Sakura Taisen: Atsuki Chishio Ni .MOV files

Post by DKDave »

Well done to doop! Just a note: the audio is in the video file as Playstation ADPCM. You can demux it using VGMToolbox if you set the video type to PSS. For some reason, a lot of players don't recognise the audio in these files.
Roak
Posts: 2
Joined: Sun Dec 19, 2021 1:04 am

Re: Sakura Taisen: Atsuki Chishio Ni .MOV files

Post by Roak »

DKDave wrote:Well done to doop! Just a note: the audio is in the video file as Playstation ADPCM. You can demux it using VGMToolbox if you set the video type to PSS. For some reason, a lot of players don't recognise the audio in these files.

oh that's rather interesting lol, i use mpv as my video player and i assumed there was nothing because it didnt play in there. the later ps2 sakura taisen games use sega adpcm (since they're sofdec files) and they play inside mpv perfectly fine, so i thought they werent in there at all lol. my poor hubris!