Thanks so much for the insights - This move to HDV has brought with it a whole new learning curve ;-)

Cliff Etzel - Solo Video Journalist
bluprojekt

Interpolate drops a field, best for fast motion, but looses information.
Blend can cause issues with fast motion.

It does depend on what your delivery method will be. I actually had good success converting fast motion 1080-30i to 720-60p in vegas. Just experiment a bit with your own footage to see what you like the best.

I don't de-interlace any HDV from my Sony HC3 for playback on HDTV's.
If converting to other formats that don't support interlacing then yes. If your seeing actual zaggies on a HDTV that's interlacing 1080 lines I would suspect the problem to be elsewhere.
Some of the internal settings for these new LCD's HDTV's (setup menu) have so many options.
I think Plasma's playback interlaced video the best, I have a Sony LCD Projection HDTV & HDTV CRT Monitor, both of them playback interlaced video without any problems.

Interlacing was originally conceived to give television higher temporal resolution. Even though TV is said to be running at 29.97 frames per second (in NTSC land. It's 25 fps in PAL) each frame is divided into two fields. There are actually 59.94 individual images per second (50 in PAL), this makes motion much smoother. If you deinterlace, then you have reduced the temporal resolution by half, down to 29.97 frames per second and there will be a stuttering effect on quick movements. (24 fps is even worse.) Somewhere around 40 images per second is generally considered to be the minimum image rate to fool the eye into seeing completely smooth motion. (720p HD video is 59.94 progressive images per second.)

If your interlaced SD or HDV footage is destined for viewing on a TV, then leave the interlacing intact. If it is destined for streaming or progressive download off the Internet, then you could deinterlace in Vegas using a "smart deinterlacer" like this one from Mike Crash:

http://www.mikecrash.com/modules.php?name=Content&pa=showpage&pid=6

John

Im sorry, but you shoudl be shooting in the format to which you are delivering, save for deliberate shots whcih will be processed for slowmotion.

Interlace and Progressive footage have a VERY different look and feel, and i fyou want your video to look like home video, then by all means stick to interlace.
One thing that strikes me, is how 24/25p is streamed into a panel, which obviously requires no deinterlacing, then to have that panel ATTEMPT to deinterlace based on the stream it recieves.
THIS is a major issue as you may have filmed 25p, but as its within a 50i stream, the panel is attempting to deinteralce said footage, when for one, it doesnt have to, and 2 degrades the image and may compromise the way the work is supposed to be seen.

Persoanlly i shoot progressive until i need to shoot something in interlaced for slowmotion output. Id prefer a HVX or EX for this, but alas, the budget doesnt allow..

Frankly, irrespective of the subject matter, to my eye, progressive may not move as smoothly as interlaced, but it sure as hell beats the home video look... THIS is what i sell and how i sell. th fact that my stuff is different to uncle bobs

1080i however is perfectly acceptable for a plasma or LCD display as these diaplays are in fact progressive on their own accord. The home video feel doesnt exist on thsee units. Deinterlacing will not occur and in some cases, may look better than 720p or even 1080p (depending on teh screen)

"it sure as hell beats the home video look...

What exactly constitutes the "home video look"? High temporal resolution? If 24p doesn't have the home video look, then why not shoot at 12p or even 6p, wouldn't that "feel" even better?

Years ago :) , I was taught everything in the studio worked good at 30fps hardwired.
When they had to transmit the signal over the airwaves (line of sight), there wasn't enough bandwidth so they broke the picture into 2 parts, hence creating 2 fields along with doubling the vertical oscillator in TV's to 60fps.
Then when they added color 29.97/59.94 came into effect. They had to use these frequencies so the sound would be correct. Gets technical, it's interesting to know the the video uses AM (amplitude Modulation) and the sound is FM (Frequency Modulation).

Back to the original post any Home Grown HDV Videos I make always retain their correct fielding.

I routinely shoot long-form HDV on a Sony Z1 for subsequent deinterlacing before pan&scan.

Having surveyed the area and experimented with various deinterlacing algorithms, the best ones are based on motion compensation. These give noticeably higher resolution results than dropping, blending or interpolating or smart deinterlacing etc.

Until recently, the best mo-comp application I knew was the commercial AlparySoft DeInterlacer but now after numerous experiments on real footage I prefer the free TDeint, available for AviSynth, though that involves quite a bit of a learning curve and fiddling for getting HDV into AviSynth and subsequently interfacing it to Vegas (say). The AviSynth route also gives the possibility of doubling the frame rate to 50p, giving the best of both worlds. Of course it's done by estimation but it looks pretty good in practice.

The simplest approach to plain simple mo-comp deint from 50i to 25p is the free VirtualDubMod, with the free Canvas Resizer filter and the commercial AlparySoft Deinterlacer filter. The Canvas Resizer is needed to temporarily increase from 1440x1080 to 1440x1088 which is divisible by 16 as required by AlparySoft Deint, and to restore to 1440x1080 afterwards. It doesn't resize the original image, it just adds 8 (black) lines to the frame (to be removed again afterwards).

In the case of HDV, it is convenient to save the result to the effective but commercial and pricey Cineform format, though of course other options exist. Remember to check that whatever codec you choose recognises that the resulting footage is progressive (you may have to tell it manually) and likewise check (don't assume) that the media properties in Vegas recognize the end-result as progressive.

As I type this, I am running VirtualDubMod in low priority with the described filter chain of CanvasResizer(1440x1088) > AlparySoft Deinterlacer > CanvasResizer(1440x1080) > Deshaker, then saving to Cineform. I first did a test output of a small section and imported it to Vegas to ensure that no silly mistakes had been made, prior to running the main job overnight.

John_Cline, why so angry? 24p has the feeling of something of higher quality as all movies are shot like that. Likevise some TVs that take the 24p footage and play it as 60p make some expensive movies look a bit like "home movies" as there is simply too much information. Don't hate something u can't change.

Cliff, if you decide to deinterlace, I have had good results using the "edge-directed interpolate" method in the Smart Deinterlacer Filter for VirtualDub. I don't think that advanced option was available when Mike Crash adapted the filter for Vegas.

I like to frameserve to VirtualDub from Vegas.

This stuff is within my guide on preparing Xvid videos from Vegas.

Hey Nick - visited your page - nice tutorial :-)

Thanks from one Vegas user to another...

Cliff Etzel - Solo Video Journalist
bluprojekt

if shooting in interlaced HDV, DO NOT deinterlace the same res HDV... it really does look like rubbish.
If however you start with 1080i then scaling down for DVD, deinterlacing is fine and looks very nice indeed.

I was experimenting with this just the other day.
The res loss is REALLY noticable unless your scaling down to 720p or 576p

preferably if u wnt teh 24/5p cadence, shoot with it in the first place.. makes a whopping difference with these resolutions..

DJPadre, What kind of deinterlacing do you use when you get that kind of bad result? Prior to editing in Vegas, I regularly deinterlace HDV PAL1080x1440 50i to similar 25p using one or other kind of motion-compensated deinterlacer (in VirtualDub or AviSynth), and the results look fine. The deinterlacing built into most NLEs, Vegas included, is more primitive and tends to lose detail and create ghost edges. Motion compensated deinterlacers tend not to.

"John_Cline, why so angry? 24p has the feeling of something of higher quality as all movies are shot like that.

I'm not angry. The 24fps rate was determined a LONG time ago because film was/is expensive and 24fps was the lowest possible rate that could still impart some semblance of motion without being a totally stuttering mess. 24 isn't some magic number, it was dictated purely by economics. I have always been bothered by the stutttering pans and other temporal artifacts of 24fps.

It's strange to me that everyone is clamoring for more spatial resolution. Ooooo, 1920x1080. No wait, 2k! Oh wow, 4k! 8k is just around the corner! But let's not increase the temporal resolution, let's keep to that good old 24 frame rate because that's the way they did it back in the stone age.

"Don't hate something u can't change."

But it can be changed, the Red can do 4520 X 2540 at 60p. Sounds good to me.

A lot of people didn't like photography when it first showed up because it didn't look like a painting. To me, the "film look" is all about the lighting, not the 24 frame per second rate.

Death to 24p! :)

John

fact remains is that 24/5p DOES offer higher resolution on acquisition.

This in itself is one argument for it. The second argument is the actual motion cadence.
Aside from the cost of film back in the day, the fact remains that 24/5p is now a standard for motion picture output to DVD. This is what the punters are used to. This is what they want.
If they were exposed to 50 or 60p then im sure theyd eventually adapt, but its hard enough getting ppl to adapt to HD, let alone bandwidth requriements which effectively double what were seeing today.. it just wont happen..

Lets be realistic here

There is nothing wrong with going higher than this "standard", however the motion cadence above this frame rate/resolution is one major element to consider when running a small to medium sized production house.
Do you give thm really nice looking interlaced material which MOVES like a high end home video camera? Or do youshow them the differences between the two and the way each one represents the piece in its own motion "feel"

If you can offer 25p, why not? If you can offer 180p over 1080i or 720p, why wouldnt you?

If it puts more bread on the table, its only logical to go that way....

"If it puts more bread on the table, its only logical to go that way...."
That's so true. Hollywood has no commitment to 24fps, they're committed to their bottom line and that's all about bums on seats. At the moment their big thing is 3D because they need the wow factor to compete with home cinema. They're a bit light on for new content at the moment thanks to the writers strike, I've heard rumours of Citizen Kane being re-released in 3D.
As for familiarity, well there's a whole generation whose primary entertainment is at over 50fps, that's what they're used to, they'll even spend money to get more fps out of their video games. I'd bet good money that once the technical hurdles to shooting and projecting movies at 60fps or greater are solved Hollywood will be all over it if they feel that'll get the gen Xers back into the cinemas.

One of the reasons I bought the EX1 is it'll do 720p60, sure I would have preferred 1080p50/60 but if the res holds up at 720p I'll be pretty happy.

Bob.

wrong, wrong. it's almost as if you didn't ask yourself "what's that strange feeling i get when flip chanel and right away i know if it's a movie i'm watching or a small bit for evening news." Well that feeling (besids other equally important factor such as lighting) comes from the frame rate. It's as integral factor to the movie experience as locations, costumes, story, casting, lighting, framing.

...For that reason i'm not even sure why we are debating the issue. WHat's the point u r trying to prove?

"fact remains is that 24/5p DOES offer higher resolution on acquisition."

What?!?!?!

As a function of spatial and temporal resolution:

1920x1080 x 24 = 49,766,400 pixels per second.
1920x540 x 59.94 = 62,145,792 pixels per second.

At the moment their big thing is 3D because they need the wow factor to compete with home cinema.
3D should really benefit from higher frame rates... 24p motion doesn't look right in 3D.

fact remains is that 24/5p DOES offer higher resolution on acquisition
In practice, it generally does.

On the camera side, most cameras that shoot interlaced will do line-pair summation / combine two rows of pixels into one. For the next field, everything shifts down a row and they pair different sets of rows. On some cameras you can turn this off (e.g. DVX100) and vertical resolution will go up. It can introduce flicker problems.

This increases sensitivity, helps prevent problems with interlace flicker, and I believe it has less aliasing.

2-
On the display side, interlaced material might lose resolution when de-interlaced (more than progressive footage anyways). But I'm not 100% sure here as I haven't run tests myself.

3- Encoding 4:2:0 progressive with a 4:2:0 progressive chroma scheme will yield better looking chroma than 4:2:0 interlaced. Effective chroma resolution is higher when you shoot progressive and use a chroma scheme appropriate for progressive imagery.
This is subtle.

(If you take progressive material but treat it as if it were interlaced, then you don't get better chroma.)

Of course I've asked myself that question.

Doesn't mean I'm hanging my hat on just that answer though.

Probably we're not debating anything. Sure I can tell you how to shoot for TV so it looks like a movie and on a low budget, down here I'd suggest 25fps unless you're careful what lighting you use, I've noticed bad rolling banding shooting 24fps with some cameras.

Bob.

"3D should really benefit from higher frame rates... 24p motion doesn't look right in 3D."

Amen. There's many more tricks to 3D. I helped shoot and cut 3D years ago. Yes I cut it with Vegas when everyone else ducked for cover.
Watching it on a big screen in 3D it didn't jump out like the rest of the show which was real time generated 3D CGI. I've now learned why.
The cameras were set to an interocular of 65mm but there was nothing close to the camera so the natural 3D looked just like we'd see it, pretty damn flat, 2Dish. Knowing what I know now I would have advised them to increase the camera separation to get a hightened 3D image. Not something you want to do too much of but this was only a few minutes long so no risk of having the audience running for the rest rooms.
The other mistake was not having the camera shutters synced but they didn't have the budget for cameras that could and back then we didn't have cameras small enough with genlock to do it anyway and expensive 3D rigs were way out of the budget.

Bob.

Just for the record, I am all in favor of shooting progressive, I just want the temporal resolution to be higher than 24 or 25 fps.