mpeg2

[dalelpaq]

There is actually a number of mpeg2 codecs available which use differing inter-frame coding algorithms. The differences include whether intermediate (between key frames) are decoded by looking back at the previous key frame, looking ahead to the next key frame, of some combination of these.

Does anyone know: which codec is used? can additional codecs be added? Thanks, Dale

[Steve Grisetti]

It depends on the purpose of your output, Dale.

Is this an MPEG for DVD or for viewing on a computer, for instance?

[Chuck Engels]

I think Premiere Elements only uses the Main Concept codec for MPEG.

[Bob]

DVD Architect Studio also uses Main Concept. I wouldn't be surprised if most of the commercial NLEs used it. It's a very good codec. And, yes, it uses both types of intermediate frames.

[dalelpaq]

My passion is visual effects and I am learning after effects the hard way - books and on-line tutorials. Creative Cow has numerous posts concerning use of mpeg2 for visual effects in AE (all bad) and often refers to NLEs as having the same problems as well (because you can do visual effects in PE4, for example), because of the inter-frame compression. Unfortunately, I don't know what I don't know so I have trouble expressing some of my questions. The Creative Cow consensus seems to be that to maintain quality throughout the work flow (never make it worse that the HDV source footage), it is important to convert it to an uncompressed file thus eliminating the inter-frame issue but resulting in larger (much larger) files. Thus, there is an issue of file size vs. rendering time. Rendering time is important to me as many effects can only be appreciated in real-time. Re-compressing the files back to mpeg2 should be done only once - at the very end of the process.

My ultimate purpose is to demonstrate high quality, near-professional visual effects on BD to amaze my family and friends. Dale

[Steve Grisetti]

Is this an MPEG for DVD, a BluRay disc, for online viewing or for viewing on a computer?

Naturally, you want the highest possible quality -- but in what form and on what delivery system? That makes all of the difference.

[Bill Hunt]

Dale,

When working on the NLE, and especially if I'm going to/from AE, I keep things as uncompressed as I can, for as long as I can. I find the Lagarith Lossless CODEC to be a good intermediate one for this. It's free, fairly fast, and will be used by both PrPro and AE, if directed, and installed.

I try to stay as far away from anything MPEG (obviously if I was shooting HD, that would change), until I need it to author to DVD. Then, I use MainConcept, which is very good and the choice of both PrPro and Encore (my authoring app of choice).

Like I mentioned, with HD work, things are not quite so easy, but I have not crossed that bridge yet.

Good luck,

Hunt

[dalelpaq]

Thanks, had the grand kids visiting for a couple of weeks so video was left to filming only. Anyway, for the time being, my videos are limited to watching on the PC and ALSO watching on TV by means of a WD TV HD Media Player (BDs are still too expensive for anything but my next full length feature!). What I need is to see what my work will look like on a big LCD flat panel as I go along. I don't have the ability to direct connect my PC to it. Burning a new BD for each 10-30 second clip is not cot-effective. As I understand the WD HD Player, it'll work with several formats but since some day it'll be BD, then MPEG2 is what I'm using. Hence the questions about which MPEG codec is employed. (Frankly, I don't even know which one I'd use if I had options!)

I start with HDV mpeg2 which is a quality hit from the git go. Thus, working with a lossless intermediate will at least let me not lose any more! I have a choice to import the clips into PE4 (there they are decoded via this "unknown" codec) and then outputting them through the intermediate lossless codec until all transforms, effects, and compositing is done before I recode for viewing. Another option I've read about in "DV Rebel" is to output as a TIFF image sequence. Moving to After Effects which is what I play with mostly, I can import an image sequence as footage. Of course, I can start with AE, output through a lossless intermediate, and then import to PE for editing. Likewise, I can work with image sequences.

There are two problems!! First, there's so many opinions about what is the "preferred" ways to do this kind of stuff and so little detailed info from Adobe as to make a personal decision hard. Second, I really don't know if, even if I found the perfect way, anyone could tell the difference when watching it on TV. Perhaps if I were going to film for theatre presentation, differences might be obvious, but I'm not.

As always, your collective input is welcome and appreciated.