MPEG-2 DVD NTSC as a Back-up?

Mix_Garage wrote on 12/1/2002, 4:20 PM
My question has to do with working with mpeg's instead of avi's. When working with raw avi's (from my MiniDV Camera) a three minute video can be over a Gig of information. If you render this to the MPEG-2 DVD NTSC compression you squash it down to two or three hundred Mb's and the quality still looks great. How much does this impact your project if you work from the MPEG's instead of the AVI's? The MPEG's would be a lot easier to back up than the avi's, and could be viewed for reference on a DVD player. Does this make any sense or am I talking too much quality loss?
Thanks,
Mike

Comments

Aje wrote on 12/1/2002, 5:00 PM
I´ve just did that with a huge material 10 dvd´s full of mpeg2 rendered files of old films and videos (family stuff) - after editing and saved as data files.

I wouldn´t recommend editing work with mpeg 2 files as a base material. I´ve tried it but though quality is quite good after rerendering there can be black frames and it´s hard to edit details due to i- frames. I´m really not an expert but I think you will get other answers explaining why in technical terms.
But when editing work is done its perfect to back up in mpeg2 files for later use.
vonhosen wrote on 12/1/2002, 7:07 PM
As Aje has said,

Ok for storage but...

Editing in MPEG-2 is not easy because by it's nature not all the frames of video are complete frames. Some of the frames (B & P frames) carry less information, based instead only on the changes from the last or previous frame.
Therefore in editing you should be editing only on full frame (I frame) boundries or you will end up with balnk frames.
Paul_Holmes wrote on 12/1/2002, 9:45 PM
I've thought about this too. I'll always keep the DV tapes but it's nice to pull out an older mpg file, put it on the timeline, find scenes I want, and render it to avi. Then I can plop it anywhere I want. So, in my way of thinking, my mpgs are the ultimate backup if that neutron bomb ever goes off and destroys all magnetic data. When we get back online someday I'll still have my mpgs:>).
Spot|DSE wrote on 12/1/2002, 9:55 PM
Youa re far better off backing up to DVD DATA, or to hard drive and storing in a closet. MPEG 2 is NOT a good storage media. Media that has been compressed never comes out clean, and editing over MPEG 2's is a challenge at best. if you miss the I frame, you'll have blacking. Not to mention that the media is compressed, it's going to be soft, lacking color, lacking any clarity that was present in the beginning. Hard drives are just plain cheap these days. I think we've got close to 30 of the ADS data tanks full of client's material that is active, and maybe close to 50 hard drives of past projects. Works for us, and we've always got the veg, all associated media, and it's in one place that we can recall at any time.
If a neutron bomb hits, I sure hope I ain't around to be editing afterwards..
Mix_Garage wrote on 12/2/2002, 11:06 AM
I have the ADS Data Tanks also (after seeing you use them on the VAST tour in Boston), they are great. I also ordered an ADS AV-Link. I guess I am just going to have to be a man and stay with the large avi back ups. Thanks for all your opinions and ideas.
Mike