Progressive SD DVD

[David Jimerson]

Originally Posted by Jeff Harper

David, this post was about non-24p material. It was 720 60p. Completely different project. I mailed the progressive DVDs and hope they work for the customer!

OK. :)

Then it's a matter of motion -- do you want the movement to appear live, like the 60p footage? If so, then 60i (standard NTSC) is your only option.

If you want it to look like 30p, then you'll have to render it out as 30p BEFORE you render it as NTSC, else it will simply appear as 60Hz motion.

Or, if you want it to have 24p motion, you can render it out that way, too. However, footage shot at 60Hz will often not look so good when converted to 24p simply because whoever was shooting was probably moving the camera too quickly for 24p motion -- you really have to keep the conversion in mind while you're shooting to get a good conversion (and if you are keeping it mind, you're probably shooting 24p anyway).

You may also see similar motion problems if you convert it to 30p, but it's a bit less of a problem.

[Jeff Harper]

David, do you have knowledge of what will likely occur with a progressive dvd, without flags?

I'd like to be able to convert my 720 60p footage to 16:9 for DVD and keep it progressive, but from what has been recommended it seems to be a bad idea. Any thoughts?

[Jeff Harper]

Just saw your post. My intention was simply to avoid interlacing, not going for a look per se. I shoot four cameras with 720 60p.

Will the DVDs I mailed out work on the customers bluray player? I hope? I rendered out of Vegas using Widescreen DVDA template progressive. God they'll be pissed if it doesn't work.

Here's the thing on that project that I mailed already. I had three types of footage, FX1 HD footage was upper field first natively. Then another cam GH1 was 1080 60i (upper field first) then another was 1080 24p. BTW, this workflow will not have to be repeated, the camera situation was an anomaly, thank God.

When I converted it all with Cineform to interlaced it flickered badly, it was no good. So I re-converted it all to progressive 16:9 and it looked great.

I've got to go but will look for any feedback when I return.

[David Jimerson]

You really only have two options for standard DVD -- 24p and NTSC. (I'm not considering PAL at all here.)

24p can be on the disc native; it will have the flags. It can't be on the DVD without the flags, so DVD Architect will always encode it that way. But if you use the DVD Architect 24p template, flags will be in the file you render from Vegas.

NTSC doesn't need flags. It's just played straight out.

You cannot have 60p on a DVD; it must be NTSC. For all intents and purposes it will appear identical to the original 60p footage, just at SD resolution, but it will actually be 60i. But the motion will be the same.

30p will be encoded within a 60i stream. It will still appear to the eye as 30p. Flags are unnecessary. But there's no reason to do this unless you want the look of 30p.

[David Jimerson]

Originally Posted by Jeff Harper

Will the DVDs I mailed out work on the customers bluray player? I hope? I rendered out of Vegas using Widescreen DVDA template progressive. God they'll be pissed if it doesn't work.

Any DVD that you author with DVD Architect will play on a Blu-ray player (unless there's a media issue with burned DVD-Rs, which happens now and then -- but that's because of the physical disc, not the video).

[Dale Guthormsen]

Ahhh,

" You cannot have 60p on a DVD; it must be NTSC. For all intents and purposes it will appear identical to the original 60p footage, just at SD resolution, but it will actually be 60i. But the motion will be the same.

30p will be encoded within a 60i stream. It will still appear to the eye as 30p. Flags are unnecessary. But there's no reason to do this unless you want the look of 30p."

I wrote this many months ago and I was jumped on about it, I reckon you write much more clearly than I do!!!



thank you for clearifying this for others!!

[Peter Manojlovic]

David...

I don't want to drag this post any farther..
Jeff seems to have his questions answered...I just got confused by the statement "My original footage was progressive, and after interlacing it it just didn't look so hot, so I went with progressive".

I was trying to convey the message that shooting either progressive on interlaced is fine. As far playback is concerned, the DVD ouput is always in fields...

Interlaced downconverts, progressive outputs to the TV, and progressive encoding are all separate issues.
They have nothing to do with the native ouptut of a DVD disk..I was simply hoping that Jeff didn't pin his hopes on progressive scan DVD players.

DVD's can have progressive images on them (like 24P material), but the DVD players will always ouput them as fields..
Yes, Jeff is right. There are players that output progressively, and up-convert, but this is separate issue, in that the DVD player reassembles information to the display..It has nothing to do with the original progressive footage on the DVD itself..(since i've been away from the DVD community for a while, this could be an outdated statement).
The only reason you have the option to encode progressively on a stream, is to allow the encoder to do ZigZag scanning, rather than Alternate scanning.
Encoding progressive material allows for better allotment of bitrates to the image..

The header in every Mpeg stream has information on how to output these fields. BFF and TFF.

The only native progressive scan coming off of a disc, is 1280x720P...

As far as downconverting goes, and this should be a sticky...
HD interlaced material, unless properly Bob deinterlaced, resized, and rewoven back, will never produce a sharp enough image IMHO.
HD progressive material always look good resized, since it's just a simple bicubic resize.

And this is why progressive HD material always looks better donwconverted.
Not because the DVD player supports a progressive scan...

[Eric Olson]

Some authoring software can force 720p60 into an otherwise standard DVD structure. The resulting disk will not play on a regular DVD player; however, it will play on Toshiba HD-DVD players and with VLC on a computer.

For a standards complaint DVD transcode 720p60 to 480p30 with 2:2 pulldown flags. The advantage of 30p with flags as opposed to 60i is better encoding efficiency and higher spatial resolution on fully progressive systems such as LCD monitors. You can verify what actually went on the DVD by checking the VOB files with mediainfo. Mediainfo will detect progressive files flagged for 60i compatibility with the seemingly contradictory lines:

Scan type                        : Progressive
Scan order                       : Top Field First

Note that Bottom Field First would also be okay.

[David Jimerson]

Peter, if you meant that whole pictures are not output all at once, then yes . . . they are "scanned" line-by-line. Just wanted to clarify whether you meant output is always interlaced.

[David Jimerson]

Originally Posted by Eric Olson

The advantage of 30p with flags as opposed to 60i is better encoding efficiency and higher spatial resolution on fully progressive systems such as LCD monitors.

There's no option to do that from Vegas, though.

In any case, if you have software with the option, do keep in mind that the conversion to 30p *will* change the motion signature of the footage and it will no longer look "live." If that's what you want, then fine, but if you want to keep the "live" look, you shouldn't do 30p.

So, make the choice based on what you want the footage to look like.

[Jeff Harper]

Peter, I am not done with this issue, yet, unfortunately.

Eric, I am running 4 cameras, sometime 5. So I must encode my 720 60p footage for editing purposes, if for no other reason. Besides that, it's going to DVD so at some point it must be made DVD compliant at some stage in this process.

HD Link, which I have, can convert it to 1280 X 720 60p AVI or 480 60p, or 480 60i, but not 30i or 30p. It doesn't offer a way to change the frame rate.

When I choose 480 60i the footage flickers. It sucks. It's happening on my timline right now.

But if I choose 480p in Cineform (HD Link) for my conversion there is no way, that I can see, to add pulldown flags in Vegas when it's time to render later.

So what to do with 480 60p footage in Vegas? Can anyone spell it out for me? If I'm missing something I do apologize, but this is driving me nuts.

[David Jimerson]

There's no standard for 480/60p. It technically doesn't exist. In 480, there's only 60i, 24p, and 30p.

You can create an uncompressed 480/60p AVI, but there's no delivery format (MPEG, DV, etc.) which carries it as a standard, so you can't make a playable DVD with 60p. Any authoring sofware will convert it to 60i.

It probably flickers because the detail is too high. Try a slight vertical blur, like 0.002 or around there.

[Jeff Harper]

David, so when I rendered out 480p in my last project and put it into DVDA, you're saying it probably it converted it to 480i?

Thing is, there was no re-encoding at all in DVDA, it seemed to be compliant as it was.

My DVD and Bluray players are all dead and I'm going to buy a new Bluray player today or tomorrow. I need to buy a DVD player though to test these discs. That's what I really need to do.

[Jeff Harper]

Here are the steps I've been told will work for anyone else who needs to edit 720 60p for SD 16:9 DVD delivery.

1. Start a new project using 16:9 DVD and 30p settings. Be sure to change interlaced to progressive. In other works field order should be "none", not upper or lower field first.

2. Bring footage into edting program, and if you want to, then crop the footage to fill the screen. When you first bring it in it will have black bars on the sides, cropping will fix that. This is optional and up to you.

3. Edit footage

4. Render out to 16:9 for DVD, settings should be 30p and progressive just as the project settings are. Make sure to render progressive not interlaced, to match your project settings.

Done. If this sound wrong to anyone, please offer feedback. No pulldown flags needed for 16:9 SD 30p right?

[Peter Manojlovic]

Yes. You are correct.
Pulldown flags are only needed if you're encoding 24F footage. Unless you're shooting and editing film framerates, it's a no go..

Good luck!!!