Anime Checker is a tool that calculates the CRC32 of your files.

The CRC is a 8 hexadecimal characters that most fanssubers include at the end of their releases filename (like my_video_[A3B6DF52].avi).

To check the file integrity, Anime Checker will compute the CRC value of the file and compare it with the given CRC value. If it's the same, there are nothing wrong with the file. If it's not the same, the file is probably corrupted or incomplete.