I filmed some random footages with my digital camera, then installed a program called 1st Audio Extractor. After installation and extracting the mp3 from the .avi files, I discovered that the video is now upside-down with BSPlayer (note, key: only bsplayer, other players work fine). So I looked through my older dig-cam videos, and they are all inverted if I try to open them with BSPlayer, but other avi files work fine with BSPlayer, strangely. And I'm 100% certain that those files worked normally before.
I looked through the codec, it tells me that I already have it installed (obviously, or else it wouldn't play at all), the codec for the files I'm referring to is mjpg (motion jpeg) and file format is .avi.
Any suggestions?