canon frame mode, export for dvd

[Miguel Lombana]

ok i've searched this but for whatever reason am not finding a clear cut answer. currently there is a thread on the gl2 forum about exporting from premier or vegas, gl2 frame mode clips.

with that said, i've always setup my projects as default premier 4:3 or 16:9 projects and exported as default settings. in the new thread the person has mentioned that in the export phase the interlace setting should be changed to progressive.

is this correct or what? i'm still not 100% clear on this gl2 frame issue and have mucho video that i thought looked great the way i did it but could it be better if i did something different?

i'm ready to drop shooting in frame all together and go back to interlace due to all these little anooyances... oh wait, i just ordered a new sony hd fx1 and that shoots in true progressive, *(&$#^@, ok what do i do????

thanks in advance group!
Miguel

[Rob Lohman]

The rule is pretty simple:

" if you want to stay with the format you shot in, make SURE it is
SET to THAT SAME SETTING THROUGHOUT YOUR ENTIRE WORKFLOW "

So if you shot in frame mode (ie, (semi) progressive) and you want
it to stay that way you should make sure it is maintained throughout
the entire workflow, so this includes:

1. Vegas/Premiere project settings

2. Footage (import) settings if it needs to be set

3. output settings when doing an export to whatever format (DV AVI, uncompressed AVI, MPEG-2 for DVD etc.)

4. if you use an external MPEG-2 encoder make sure it is set to progressive (or 'none' for interlaced) as well

5. if needed, check your authoring application as well if you need to set progressive/interlaced there as well (you must if you do the MPEG-2 encoding there)

So yes, make sure everything is set to progressive in your case!

[Pete Bauer]

Rob's advice is unquestionably sound and is what I do. However, I'm not quite clear what the annoyances are that make you want to drop using progressive, since you said you thought your output looked good? I hardly ever shoot interlaced because I find THAT such a hassle -- in fact, the lack of a true progressive mode in HDV format in either the FX1 or the Z1 is one of the main reasons I'm not ready to jump into HDV quite yet.

Just to expand a little on the mechanics of what's happening:
Rather than frames composed of successive (slightly different) fields taken 1/60th of a second apart (interlaced video) to get 30fps, frame mode (or true progressive) is sending out frames composed of two fields taken at exactly the same time every 1/30th of a second. The two matching fields stay together as a frame in the timeline regardless of settings (though some processing or filters may behave differently for interlaced vs progressive settings), and then are either exported to be:
- a single progressive frame (which you'd normally want to do, since that's the point of shooting frame mode in the first place), or
- interlaced, in which the matching fields would be displayed sucessively at 1/60th of a second throughput the process. Since the fields are a matching pair (two halves of the same image), I think most people's eye wouldn't notice the difference in the timing of the display -- but I haven't actually tested that myself, so I'm guessing on that point.

Problems WOULD arise if you started with interlaced footage and then wanted 30p output...that would require deinterlacing. If you display interlaced video on a progressive scan monitor like a computer display, or encode interlaced video into progressive without using a deinterlace process, you'll see very annoying artifact that looks like comb teeth wherever there is motion in the image.There's a lot of ways to deinterlace, but all cause some degree of resolution loss in the attempt to blend two fields that are NOT an exact matched pair since they were shot 1/60th of a second apart.

Not sure if we are getting to the root of your concerns, but please clarify if we aren't.

[Rob Lohman]

We seem to be on the same page Pete! I can't stand interlaced
either (although I understand why you would still use it in a
broadcast environment!) and although I have no benefit for HD
at this point in time (no HD TV's etc. here etc.) I would definitely
not get a camera without (frame) progressive indeed either.