24p vs. 60i workflow question for HV20 and Vegas 7

[Gerrit Schroder]

I’m going to the Yucatan next week to shoot some documentary footage with the Canon HV-20, but I haven’t learned enough about the Vegas 7 workflow to decide the format for my shoot: HDV 24p or regular HDV 60i. Whichever shooting format I choose, my end product will be distributed on DVD – but I would like to create a workflow that will enable me to output to HD-DVD or Blu-Ray down the road.

I shot last month down there with my HV-10, so I know that I can handle a small camera slowly and steadily enough to avoid the unwanted motion blur (except underwater – I’ll have to see what happens there). I’ll be using a tripod, Merlin or a pod for most of my shots. Even if I’m shooting in regular HDV 60i, I’ll still handle the camera as if I’m shooting in 24p – since I’ll probably be rendering to 24p in Vegas.

So here’s my question: If I shoot in 24p, will I be gaining quality but losing flexibility in the editing process – and in an eventual mastering to HD DVD? If I shoot in 60i, will the 24p I render in Vegas 7 be noticeable inferior to 24p created in the camera?

I know that 24p is compressed in the HV-20 in 60i with a 2:3 pulldown and I’m assuming that Vegas 7 can or will be able to handle that transition smoothly.

Any recommendations from Vegas 7 users or even HV-20 users??

Thanks
______________
Gerrit

[Ali Husain]

my recommendation is to run through your entire proposed workflow: from the type of capturing you'll do (maybe underwater, in caves, out in the sun with gND filters, etc.), to the ingestion, to the 3:2 pulldown removal (which vegas does NOT do currently: you need external tools like the ones made by cineform), to the edit projects, to the final DVD. some of these things you won't be able to duplicate, but you're better for it by coming as close as possible to the ACTUAL workflow you'll have out in the field and afterwards. this will really help you converge on a good process and work out the bugs in a way that theoretical planning can not easily do.

[Guy Bruner]

If you are going to DVD (standard definition), I don't see a need to shoot in 24p. I would leave everything in 1080i and downconvert to 480i. Vegas will not detect and remove pulldown on the HV20's 24p. You would need to use Cineform HDLink or some other software that detects 24p cadence in the absence of flags to remove pulldown. The conversion and editing hassle is not worth the gain, IMO.

Yes, I have an HV20 and use Vegas.

[Gerrit Schroder]

Thanks for the advice.

Ali - I guess this trip will be the one on which I run through all the possibilities. I have Vegas 7 and HDLink - but I'll play it safe and try to use 60i everywhere. If I'm forced to go to 24p for low-light in caves or underwater, I'll just have to work it into my 60i timeline. Your post helped convince me that I'm on the right track here.

Guy - I'll take that advice. I actually like the look of the HV-20's 60i video - and I'll have the camera in motion enough to worry about the 24p blur. I probably haven't seen what the HV-20 can really do with 24p, but I'll find that out on another project closer to home.

I haven't seen any underwater footage with the HV-20, so if I get some I'll post it here.

__________
Gerri

[Bill Porter]

Originally Posted by Guy Bruner

Vegas will not detect and remove pulldown on the HV20's 24p.

In this case, what format is the "un-pulled-down" 24p footage in? 60i?

I thought the camcorder records 24p across a 60i stream; therefore, footage without the pulldown removed, still appears to have the 24p cadence although the format is different, yes?

[Ian G. Thompson]

Originally Posted by Bill Porter

In this case, what format is the "un-pulled-down" 24p footage in? 60i?

I thought the camcorder records 24p across a 60i stream; therefore, footage without the pulldown removed, still appears to have the 24p cadence although the format is different, yes?

You are correct in all of your assumtions.

[Peter J Alessandria]

Originally Posted by Bill Porter

In this case, what format is the "un-pulled-down" 24p footage in? 60i?

I thought the camcorder records 24p across a 60i stream; therefore, footage without the pulldown removed, still appears to have the 24p cadence although the format is different, yes?

My thinking as well. I recall that when I first got my DVX100 none of the NLE's supported 24p DV pull down removal. So I just captured my 24p footage as 60i and edited it as 60i. Then I output to standard DVD's it looked fine. Maybe the DVD players I used did their own pulldown removal?

[Guy Bruner]

Once 24P is telecined, it will play on interlaced playback and display devices as interlaced footage. The progressive footage is 'encoded' (as an analogy) into the interlaced stream. However, Vegas and DVD players need to have flags embedded in the metadata in order to know the 60i has pulldown in it so they can remove it. The HV20 doesn't put the flags in the metadata so it all looks like interlaced to Vegas. Some software like Cineform can read the 60i stream and force removal of the pulldown without the flags. You have to tell Cineform to do this before capturing.

[Peter J Alessandria]

Originally Posted by Guy Bruner

Once 24P is telecined, it will play on interlaced playback and display devices as interlaced footage. The progressive footage is 'encoded' (as an analogy) into the interlaced stream. However, Vegas and DVD players need to have flags embedded in the metadata in order to know the 60i has pulldown in it so they can remove it. The HV20 doesn't put the flags in the metadata so it all looks like interlaced to Vegas. Some software like Cineform can read the 60i stream and force removal of the pulldown without the flags. You have to tell Cineform to do this before capturing.

Guy - you know a lot more about this than I do but as an example I captured some in-camera downrezzed (HV20 output DV lock) from the camera to my Memorex stand alone DVD recorder (the recorder couldn't record HDV/DV out footage from the HV20). The resulting DVD looked just like 24p footage from my DVX100 recorded to DVD. I definitely wasn't watching 60i video. I'm going to get around to trying it myself very soon, but again just wondering if any has tried editing 24p footage as 60i and outputting it to their favorite format (for me SD DVD).

[David Jimerson]

Something recorded as 24p but in a 60i stream will retain all of the aesthetic of 24p. So, if you're playing a DVD made from it on a standard TV, you wouldn't really see a difference between it and an actual 24p DVD.

But you'll see interlacing artifacts if you play it on a progressive TV, whereas you wouldn't with a true 24p DVD played on a progressive-scan DVD player.

Maybe the DVD players I used did their own pulldown removal?

No, this doesn't happen. In fact, quite the opposite -- when a true 24p DVD is played to a standard 60i TV, DVD players actually ADD pulldown in order to play it. This has been true since the beginning -- all Hollywood movies are on DVD in 24p, and any DVD player can do it.

[Peter J Alessandria]

Originally Posted by David Jimerson

But you'll see interlacing artifacts if you play it on a progressive TV, whereas you wouldn't with a true 24p DVD played on a progressive-scan DVD player.

Hmmm... Both my TV's are progressive (plasma and LCD HDTV's) and both my DVD players are progressive and I didn't see any interlacing artifacts. Again, I think progressive DVD players (and most progressive scan TV's) do their own pulldown removal. I never said anything about DVD players ADDING pulldown to 60i files and I am aware all Hollywood DVD's are 24p. My point was perhaps my DVD players were REMOVING pulldown from 60i files which was why the DVD burned from the HV20 DV lock output has no interlacing artifacts. Maybe we're saying the same thing here :-)

The point of my initial post was, do I really need to edit my HV20 24p footage as 24p footage (in Vegas or elsewhere) to get the same look. Or perhaps, as with the DVX100 when it first came out, I can just edit 60i and not worry about the pulldown issue. I realize my DVD's from that timeline won't be true 24p but does that matter?

[David Jimerson]

No, DVD players don't remove pulldown. It's just not how they work, and it's not how video is encoded to disk. There would be no info for the player for where to start the pulldown removal.

Now, some players and/or TVs may deinterlace, but that's not the same thing. You might be seeing the footage bumped up to 60p. But you're also probably losing some of the resolution from the encoded file when you do.

As for whether or not it matters, it's partially up to whether or not you're happy with what you see.

There are disadvantages to editing 24p material as 60i -- differences in the motion cadence between the footage and any movement you may add -- moving text or graphics (including fades on those items), track motion, possible problems with short transitions -- because the timebase of the footage doesn't match the timeline. If you have 24p material, it's better to edit in 24p.

As for DVD, you can fit up to 20% more video on a disc if you encode as 24p, leaving room for more video, or higher-quality video, or more room for a more robust audio track, or special features, etc.. And, you preserve the full 480p resolution when it's played.

But, like I said, in many ways it's about being happy with what you see.

[Gerrit Schroder]

While on my trip to Quintana Roo, I've captured and converted my underwater 24p footage with Connect HD, removed the pulldown and viewed on my laptop's progressive display.

Most of my doubts have been removed. The resolution and playback are incredible. If Vegas can carry this quality through to standard DVD (and in future, HD DVD) export, I'll be happy with this camera until the next thousand dollar progressive camera from a company on par with Canon comes along.

Kudos to Cineform, Canon and I hope to Sony (Vegas) as well.