More than a year back, I bought my first HD camcorder. At the time I bought it, I didn’t have enough knowledge about the various HD file formats, bitrates, what kind of software is there to edit the software and so on. I started taking the video and every now and then when the sd card is half full, I get a warning by the camcorder to save the files and I used to take a backup, erase the sd card and start fresh. The SD card used to have one folder for photos and another for video. The Video folder looks like
The actual video files used to be in AVCHD/BDMV/STREAM/ as 00000.MTS, 00001.MTS and so on. I could play these .MTS files using VLC and so thought why do I need all the rest of the folders, unnecessary navigation steps. So, a couple of times when I took the backups, each time I used to create a new directory and copy only the .MTS files into it.
This year, I got my iMac. One of the reason I bought it is to do video editing of the HD video (my Windows Vista based HP laptop with 4GB RAM used to heat up and so wanted to try out more powerful hardware). Along with iMac comes iLife which contains iMovie, Apple’s video editing software. I like the various apps that come within iLife.
Once I got used to iMovie, a couple of times when I directly inserted the SD card, it used to recognize and I could edit the .MTS files (raw HD video I believe) without any problem. Then, one day I wanted to get back to my earlier videos which are sitting in my external harddisk. So, I opened iMovie and tries to open an .MTS file and it doesn’t open it! After a bit of research I found out that iMovie can’t open the .MTS files directly but can open what is called a camera archive which is all the contents starting from AVCHD directory.
Hence forth, every time I needed to backup the videos, I copy the entire AVCHD directory. I create a brand new directory each time, like Video1, Video2 and so on and dump the entire AVCHD directory.
The main information that one would lose not having the other files in AVCHD is the time the video was taken, though the timestamp on the files should give this info, unless your file timestamp gets modified. This information gets stored in the CLIPINF directory. I don’t think PLAYLIST directory is really useful, it’s just the playlist you create on your camera (I don’t bother to do that). I have not seen any files in BACKUP, I don’t know when that get’s used by the camcorder. Also, don’t know about INDEX.BDM and MOVIEOBJ.BDM. Finally, the CANON directory contains a .MPL file and an INDEX.BDM file. Again, not sure what these are for.