AnyDVD is an app that runs in the background to remove DVD video protections on the fly. This is a nice feature when playing or ripping protected DVD movies but it causes problems when ripping Xbox 360 games because the video data (and possibly game data) will be altered in a way that is detectable on Xbox Live. Altered video will be easily detected and fixed because abgx360 knows which video partition (and matching PFI) your game should have based on the timestamp of authoring in the SS, and it knows what the CRC of that data should be. However, AnyDVD has also been observed to cause corruption in the game partition. If corruption occurs in an actual file in the game data, it could result in the game crashing or reporting an error when playing that backup. If it occurs in the random padding in between files, the corruption will not affect gameplay but could be detectable on Xbox Live. abgx360 looks for AnyDVD style corruption in the game data whenever the game CRC is checked by simply searching for "DVDVIDEO-" at the start of every sector (it was observed that video files inserted by AnyDVD always begin with either "DVDVIDEO-VTS" or "DVDVIDEO-VMG"). abgx360 is unable to fix game data corruption because it has no way to know what the data should be; it only knows what the resulting CRC should be (assuming a verified ini was found for that game) and the only way to fix bad game data is with a PPF. Other forms of game data corruption unrelated to AnyDVD (for example: single bit errors commonly caused by unstable CPU/RAM) will only be detected if abgx360 can find a verified ini and your game CRC doesn't match.
