jagged edges

[Marc Brak]

Those jagged edges are probably just interlacing lines – extra visible during movement.

I’ve noticed that Windows media player deinterlaces your footage in playback, that’s why you don’t see the jagged edges. Try watching it with a player like media player classic: the edges will probably be there.

It’s normal with dv. You won’t see it on a regular tv. If you’re going to play it on a digital screen, deinterlace.

[Jenny Himmelrick]

thanks!

[Jenny Himmelrick]

So, I was just going to take your response as is without even questioning why, but I then decided to look into interlacing and all that jazz to understand it and i think i just confused myself even more.

Computers use progressive scanning instead of interlacing, so thats why my video looks jagged b/c it can’t read the interlacing of my video? Is that what the problem is? But it will look okay on a tv b/c tvs use interlacing not progress scanning? This is confusing to me…

For HDV, PP2 gives the option of 1080i or 720p, would I want to capture my video at 720p and use progressive scan so as to avoid interlacing problems for posting my video on the internet?

But interlacing will give the best quility and is the standard over progressive and deinterlacing, correct?

I’m a television production student doing videos for an internship and i just want to understand all of this since it is what i’m going into and they don’t teach this kind of stuff in school, so if anyone can help that would be great. Thanks!

~Jenny

[Marc Brak]

Hi Jenny, let me try to answer this without getting too technical.

Small note before we start: in Europe the TV standard is PAL, which has 25 frames per second. In the US the standard is NTSC, which has 29,97 frames per second. Let’s go with PAL for now -it’s what i’m used to working with- but the same principles apply to NTSC.

Well then. The difference between progressive and interlaced footage is that with progressive footage you record 25 full pictures (frames) per second, whereas with interlaced you record fifty – but they show only half of the picture.

What do i mean, only half the picture? Ever noticed how a regular TV screen is made up of horizontal lines? Well actually , each of these lines consists of a lower half and an upper half, called fields.

So, progressive footage looks like this:

upper field – on
lower field – on

(25 full frames a second)

And interlaced looks like this

upper field – off
lower field – on

upper field – on
lower field – off

(50 “half” frames playing in turns)

Now, on a regular (old-school, not talkin about plasma or lcd) TV you won’t see this because the tv screen’s resolution is too low. But your computer screen WILL show it.

Wether you want to deinterlace your footage (this is something you do in post, not while capturing) depends on the target platform. Because deinterlacing basically means merging the lower field and upper field of each two consecutive frames into one full frame, and smoothing stuff out a bit, you will always lose some quality when you deinterlace. So if you’re creating a standard definition DVD, to be shown on a regular tv: don’t deinterlace.

If on the other hand you’re creating video for the web, or say a large plasma disply, then deinterlacing would be wise, especially if there’s a lot of action in the movie.

Of course, the best option would be to simply shoot progressive, if your camera allows it. And more and more camera’s do.

Hope this clears it up, if not, don’t hesitate to ask!

[Jenny Himmelrick]

Thank-you, that cleared up a lot actually. I’ve been working on an avid for a couple years now(on a different computer) and I had never seen these jagged edges before, and I had never heard of interlacing stuff, so I was afraid that I just didnt know how to work PP2, I’m glad to know thats not my problem!

I’m not sure if you could help me with this too, but when burning to a dvd, does PP2 compress your footage? I burned what I had on to DVD to see what it would look like without the jagged edges and I noticed that the resolution wasn’t the best. I’m recording on an HDV camera, shouldn’t I have great quaility vodeos on a normal(not LCD or plasa) tv?

[Marc Brak]

DVD is Mpeg2 format, so yes it is compressed. When you export to dvd there are many different presets you can choose from, ranging from low quality to high quality… you might want to experiment with those.

But still, regular dvd is SD (standard definition) and therefore has a much lower resolution than your original HD footage. The only way to get the most out of your HD footage would be to burn it to a HD-DVD – and most folks do not own one yet…

Anyway, this is all just theory as i have no actual experience with HD yet. So if i get it wrong i would very gladly stand corrected:-)

[Tenzin Dhonyoe]

you had make clear about interlaced and progressive. Thus will you clarify me about “I got a HDV camera that supports only interlaced, and I capture and edit my footage in PP CS4 with interlaced setting. Can I export the media or video in Progressive to get rid of the jagged edge. Is it the right procedure.

Tenzin