24p: Am I missing something?

kentwolf wrote on 4/10/2003, 8:04 AM
I tried the 24p format and quite honestly, I don't think it looks that good. Does this sound right?

I did it with a 90 second actual DV (not analog) test clip. I rendered the clip once with AVI/DV (and let DVD-A do the final render) and also rendered the same clip to 24p AVI, then re-rendered to the DVD-A mpg2 format.

I can now play either clip on my set-top DVD player and the normal, non 24p clip, looks much better.

Does this sound reasonably correct?

Did I create it correctly? The clip, when all was said and done did show as a 24p clip. I created it as follows, presumably as per the instructions.

1.) Took a AVI/DV clip and rendered it as 24p/AVI.
2.) Took the 24p/AVI clip into Vegas.
3.) Rendered the 24p/AVI clip as MPG2.
4.) Took the MPG2 clip into DVD-A. DVD-A did not do anything to the clip, so it took it straight in.
5.) Created and burned the DVD.

Both clips being the same, the regular 29.97 MPG2 clip looks better.

Have I done something wrong?

Thank you for any assistance anyone can offer.

Comments

zcus wrote on 4/10/2003, 8:12 AM
Your footage needs to be 24p - you don't convert interlaced 29.97 video to 24p
organism_seven wrote on 4/10/2003, 8:32 AM
If you want to do this, I think the Magic Bullet Suite software is designed to do the conversion. Visit: http://store.yahoo.com/redgiantsoftware/magbulsuit.html

Regards
Organism Seven
kentwolf wrote on 4/10/2003, 11:01 AM
I will check it out.

Note: According to the Vegas manual, you *can* convert to 24p, however, it apparently does not give the full effect, whatever that may be...

Thank you very much.
Arks wrote on 4/10/2003, 11:48 AM
from my understanding, you are taking a 29.97 fps, 60 interlaced fields and turning it into a 24 fps clip; these are not progressive scanned. The ag-dvx100 records in 24p, 24 progressive frames per second. Thats probably why the 29.97 captured video does not look close to what the original captured 24p would look like.... Am i right or wrong....help... lol

Brian
Chienworks wrote on 4/10/2003, 12:01 PM
Here's what's happening ... basically this is like seeing a gorgeous sunset and wanting to get a very high quality photograph of it, but you've forgotten your 6x7cm Hassleblad at home. So you take a picture of the sunset with your Kodak 110 Instamatic thinking that when you get the print back you can use your Hassleblad to take a high quality picture of the 110 print. To make matters even worse, the processing lab had an accident an all your pictures got stretched and folded. Don't worry though ... they gave you a special cheap plastic filter to put over your Hassleblad lens to correct for the stretching and hope you won't notice the creases from the folds.

So, what do you end up with? A very good photograph through a cheap plastic filter of a mutilated very poor photograph.

Yes, 24p is very good. But, it's only good if it's 24p all the way through from the beginning. Converting 29.97i over to 24p not only isn't going to look as good as 24p could, it's probably going to look worse than the original 29.97i did.
kentwolf wrote on 4/10/2003, 3:09 PM
Excellent analogy! :)

I figured it was something along the lines of taking a high quality picture of a low quality picture...or something like that.

Could I therefore conclude that Magic Bullet from

http://store.yahoo.com/redgiantsoftware/magbulsuit.html

Would not be truly effective?

Thank you.
rextilleon wrote on 4/10/2003, 3:11 PM
Magic Bullet would be very effective---truely---However be prepared for a steap purchase price----over 900 bucks and it is a plug-in for AE so you have to own that too---For fifteen hundred dollars more you can by the Panny 24fps.
yirm wrote on 4/10/2003, 4:50 PM
My question to Chienworks is whether the real-world end results are as poor as those of your analogy. My point is that if the results are worse, but not noticably so, or even acceptably noticably so, this may be desired when weighed against the reduced file size and compression time.

-Jeremy
Chienworks wrote on 4/10/2003, 7:59 PM
yirm, i'll admit my analogy was rather extreme. However, the conversion from 29.97i to 24p does involve both deinterlacing and resampling the frame rate. It's up to you and your clients as to whether the results of these conversions is still acceptable, but i wouldn't think the 20% savings in space is worth it the conversion losses or the time involved.
yirm wrote on 4/10/2003, 9:53 PM
Chienworks, my only question about your last comment is where you say "or the time involved." I have been seeing that it takes *less* time to render at 24p. Are you saying that this time savings is more than offset by another part of the process (e.g., the "preparing" part)?

As far as the visible end results, I'm about to find out. I'm almost done burning a DVD of the same clip rendered both ways.

BTW, there have been conflicting answers on these forums SoFo personnel. SonicDennis writes here: "If you shot in 60i, render to 60i. If you shot in 24p, edit and render to 24p, and use the 24p template when rendering for DVD Architect." While SonicSBD writes here: "The most logical use for this is when your source footage is shot in 24p. However, some may also employ this for compression advantages (at the loss of temporal resolution) or to achieve a certain look. (People may subconsciously associate this look with high budget productions.)" SonicSBD seems to leave room for a subjective view of which actually looks better.

-Jeremy
whothehell wrote on 4/11/2003, 7:21 AM
You're confused... Sometimes people expect some kind of magic out of computer.

Making 24p to 60i is not that difficult and the result is not bad. That's what usually happens when 35 mm film is telecined to NTSC video. But, to make 60i to 24p in good quality, you have to go through incredibly complex process. I mean, in "good quality".

Somebody mentioned earlier in the thread, "Magic Bullet". That's one of the such tools. Try it. They finally delivered Windows version recently. (For a long time, there was only Mac version.) I've seen many people shocked by the rendering time it requires. Yes, high quality deinteracing requires shocking-scale rendering time. That's awefully longer than what you might save in MPEG-2 encoding. The result can only come close to the originally progressive scan, not exactly the same. So, why not shoot progressive scan from the first? That's the ultimate solution.

Other than Magic Bullet, you can try ReelSmart FieldKit to perform high quality deinterlacing. It's much cheaper than Magic Bullet, but it only does deinteracing. Contrary to many people's hope, deinterlacers in not only Vegas Video, but also in some professional compositing tools such as Cumbustion, are not even come close to the sophistication of ReelSmart FieldKit or Magic Bullet.

No free lunch in physics... ;-)