Why archive AVCHD as disk images, versus .MOV or .MP4?

[Drew Wallner]

Originally Posted by Ron Evans

I understand the advantage of Clipwrap for a MAC user and if it just wraps the AVCHD to make it easier for the MAC to read then you are not likely saving any space just formatting. Not needed for a PC though and I misunderstood that you were reducing the resolution to save space at the same time.

MAC = a networking term, referring to hardware ethernet addressing
Mac = most computers made by Apple after 1984

That aside, the purpose isn't "to make it easier for a Mac to read" really, though certain Mac users might use ClipWrap or a similar tool for that reason (both the native video playback tools in Windows and Mac OS X are pretty crappy with AVCHD if you have an older/weaker GPU).

No, rather my primary annoyance with AVCHD is the tendency toward maintaining complete disk images of the AVCHD filesystem, which especially in the early days of the format was necessary out of paranoia because the few tools that did deal well with the content did so in very picky ways (not true today).

AVCHD is a random access affair, and the storage space it takes up is multipurpose. I agree that it's wise to keep whole tapes of old projects around, because with most tape workflows it would be damn near impossible to easily rebuild a project if all the clips weren't exactly in the position on the tape that they started out at. With random access, that's different. There's no sensible reason to keep an entire capture session, SD card, etc. in tact if there's a large portion of it that's pure junk. Think of it this way, if you bought a box of tapes, and you shot one of them, would you want to have to put the entire box on a shelf and never touch the unused portions? That's what a disk image forces you to do, if there are a lot of junk shots inside of it.

Originally Posted by Ron Evans

AVCHD doesn't take up a lot of space for the quality so personally I keep everything !!!

I definitely don't want to keep everything. I'd want to keep everything that I used in a project, everything that might have even the most remote value someday. But do I want to keep around shots of the floor, shots of my feet, shots in which the camera was set up wrong or some other error occurred? Nope. That's why I'm breaking my disk images up, not just to make the clips more usable...but also to allow me to delete individual clips that have no value to me. I'm not saying everyone should do this, I was just checking to make sure I hadn't overlooked some benefit of keeping the whole disk image.

The one good point that was made was AVCHD metadata...if you maintain it actively and need it for anything then yes, one would want to keep the complete archive in tact. I've not come up with any use for it personally though, so that's not a big deal for me. The only details that are important to me are the timestamp on each clip and the lossless preservation of the audio and video streams inside. This process meets both those requirements (ClipWrap optionally sets the filesystem timestamp on each file of output to exactly match the AVCHD media that was used as input).

[Ron Evans]

All my cameras are Sony and I transfer with the Sony utility so only the file itself and the metadata are transferred to the PC. With the utility keeping track of most of the metadata anyway. All my projects are multicam events so keeping all the camera data is the only sensible way as if I want to re-edit at some time I need all the data since all the camera are in sync and of course only the equivalent of 1 of the 4 cameras is used. The only single camera files are family and yes I throw away stuff as I transfer that !!! I back up everything to LTO3 tape.

Ron Evans