Shooting DV footage w/ "saw tooth" output issues

[vhelp]

Hi DV fans..

I thought I would start this topic w/ respect to these issues that I've
ben wrestling with for a while now. I brought this over from another
topic that I was participating in, and I didn't want to taint the
spirit of that topic. So, here I am. Anyways.. below is a snip that
I MOVED from another tread.

...
I've ben wrestling w/ the "saw tooth" along horizontals when shooting
in 16x9 mode. When at 4:3 mode, all edges age clear and perfect, but
as soon as I switch to 16x9, all is saw tooth.

what's with this 4:2:2 and 411 helper (not to vear too far from orig.
topic) ?? ..and, if that might help w/ my 16x9 "saw tooth" situation.
was going to start another topic on this.. perhaps I should

I was wondering if anyoneelse here was suffering from this same phenomina
and have they learned how to compensate for it ??

If there is no rememdy for this (as I'm starting to believe) then the
only alternative is to look into an opitonal 16x9 Widescreen Adapter
which is what I've ben doing this past week.. w/ $319 being the cheapest price.
These promise NO video issues during 16x9 because of the way they preject
the video onto the CCD. I've even seen some sample pics, and I must
say, I def. appreciated the look.

I believe that all DV CAMs suffer this 16x9 saw tooth issue.. my Canon ZR-10
and my Sony TRV22 suffer this.. so it's pretty safe to assume that all
DV CAMs share this.

Anyways.. as I was saying.

I also found one other anamily too. There are some slight color artifats
in certain pixels (ie, green) Only a pic can describe, but since we
can't post pics, where we can see inside this thread, I won't bother.

I'm wondering what any of you DV fans out there have to say on this
issue. All comments are welcomed :)

Thanks for any response,
-vhelp

[FredThompson]

I'll help as best I can but need to see screenshots. If you don't have webspace, get some free hosting at geocities or something similar.

[vhelp]

Hi Fred..

I didn't want to inlcude pics becuase for some reason, this forum
decided NOT to allow users to post pics, in the "live" view, and
instead, you have to click the links.. and that just plain bothers
me, as it helps to illustrate what I'm talking about. If you or I
have to resort to D/L'ing pics, its a pain sometimes to follow the
discussion.. sigh. Anyways..

I did some surfing at your website today, and I got to the point of
D/L'ing those two Star Wars .avi test clips of yours, but after
that, my system froze and bombed out. I often run too low on resources
under Windows 98. Anyways..

Other than DV "saw tooth" issues, I'm using the Matrox DV codec. I
believe this is a great codec.. w/ pretty good output quality, but I
still may have some issues that I don't funnly understand or see as
of yet. Maybe I just havent noticed them yet. But, for the most part,
my DV source files from my TRV22 seem to be great quality :rolleyes:

-vhelp

[FredThompson]

They probably don't want to host images because of the overhead.

I don't know what to say other than without seeing what you are trying to describe, it's unlikely anyone can help.

All you really need to see on that page is the combined image comparing FlyVideo and Canopus ADVC-100 raw captures. There's alsoa version on Xesdeeni's website.

Is Win98 the only version you have? DV is 13G/hour. FAT32 can only handle files of 2G or less. You're looking at a lot of trouble trying to edit DV in Win98.

Here's a site you might find helpful: Ross McLennan's Firewire SVCD'S and DVD pages http://www.geocities.com/aussie01au

[Mug Funky]

this problem is a combination of a cheap DV cam, and bad firmware in the camera.

it's resizing each field seperately (which is good in principle, as you wouldn't want blurred fields), but doing so in a stupid way that leads to the 2 fields no lining up properly.

when a 4:3 frame is shot, the fields are "displaced" 1 scanline. when the fields are resized seperately, this changes to a displacement of 4/3, but it is written to tape as if it were 1.

this isn't noticeable on REALLY cheap cameras, as they don't have sufficient vertical resolution to make it obvious.

but note that no camera under about $10,000 will be able to shoot the full 576 lines of PAL. most of the time there are internal sharpeners that will actually make your problem worse.

all i can recommend (well, the anamorphic lens is a good one. if i had the money i'd get that) is to "shoot and protect", that is to shoot in 4:3, but compose your shots for 16:9. you could even put little lines on the camera's screen to help with this.

that way, there's not as much nasty internal resizing going on, and you can use avisynth to do it later in a much nice way (i recommend bicubicresize(w,h,1,0) for enlarging).

hope this is all correct... if there's anything erroneous here, i'm sure a DV boffin will correct me.

[vhelp]

Hi fred,

Sorry for not responding sooner.

I have FAT32 and actually, it's 4gig limit. This works out fine for
me and my DV projects.

Thanks for the url link. I'll have a visit to see what's up, over their.

However, I still have a few other issues to resolve ie, the GREEN thing.
More on that later.


@ mug funky,

Thanks for you input too.
I actually considered the 4:3 idea, but I had reservation on the trueness
of the 16:9, and the proper AR setup if any, or resing etc that got me
:rolleyes: wondering :rolleyes: if it would pass for a true 16:9 view.
I use PDVD to view 16:9 encodes, as WDVD does not do this.

Basically, you're saying that I continue to shoot footage in 4:3 but
then crop off the top and bottom (calc the resize just right) and then
resize to 720 or 704 and basically output as 16:9 ??
And, as for the tape, I think I understand you. You mean to get an
perspective of a 16:9 during shooting of footage, this way, it makes
it easier to (in short) 16:9 it ??

@ fred,
I'll try and get a few sample pics for you to observe :)

OH, and please guys, don't get me wrong.. all my home footage is in
pretty good quality, and I can't complain too much, but I'd like to get
better quality, if I can.. if anything, to smooth out those easier
issues "green" hint hint.

All your helps are appreciated.

Thanks guys for the inputs,
-vhelp

[Longinus]

I found a workaround for this problem, but in post-processing.

I captured some footage with a really bad Panasonic camera (that was supposed to be good... "for professional use only", a sticker in the camera says)... But it turned out to be horrible..... Saw edges everywhere...

Since the video I'm doing is really short, about 4 minutes (a video-clip), I resorted to save the whole video to a sequence of images, and processing them with especial image processing softwares.

First, I used NeatImage (http://www.neatimage.com) to clean up the noise (A LOT). Then I used a strange software, called SAR Image Processor (http://www.general-cathexis.com/) to apply a filter called Isothope Smoothing... that smooths the saw edges... and make them really nice. First I did some kind of image super-sampling... Enlarged the image 2X with a Xin Lin filter.. then applied the Smoothing, and then recised back with Lancoz.. Of course, all in batch mode. The process takes quite some time, but it's easy to set up... you just have to wait. I could also do this with video software. Combustion gives a nice clean imagem, but I couldn't create a perfect edge smoothing like I did with this SAR software.

This creates a very clean and smooth image. That was what I was looking for. If you want to keep the noise or the scene is very complex, it will probably not work. This may appear strange to some, and even that there are another, simpler, methods...
But if you guys want to see some screen-shots, I think It'll all make sense.

[FredThompson]

Please post screenshots.

Also, are you shooting NTSC or PAL?

[Longinus]

I'm shooting in NTSC.

I created a little PSD file, with all the steps in the process in separeted layers. Just make them visible/invisible to see the changes. The size of the file is 2mb.. a little big.
If by any reason you can't open the psd, or want some simple jpeg, tell me.

http://www.carcasse.com/tmp/screenshot.zip

This frame in particulary is not very saw-edged. But since it was the one I used to check the color correction, I decided to do the rest of the steps in it. And it's important to notice that I have to deinterlace to do this right.

[FredThompson]

NTSC DV is 4:1:1 so that's why you have problems with straight edges. Doubling resolution, filtering, then shrinking can help but you can do all of that with AviSynth for free. Interpolet411 helps with chroma. I'll look into way to do the luma.

[vhelp]

Hi peoples.

@ Longinus,

I wouldn't mind seeing a sample clip, if you got one laying around..
to get an idea what you angle is like.

Also, you didn't say if you were shooting in 4:3 mode or 16:9 mode.

My whole issue w/ saw-tooth edges is due to the way my TRV22 records
and cruches the video images onto the CCD. Then, when a user goes and
firewire's it to hd, and views it, saw-tooth edges can be seen.

@ FredThompson,

Sorry I didn't get around to making a pic to U/L, but I've had some
problems w/ my separate provider account and using my FTP (wasn't allowing
me access or something)

Anyways, I'm comming to a conclusion that there is no way around fixing
this saw-tooth issue w/ I my source is shoot at 16:9 mode, and because
of the way the CAM orients the video etc. I think that its non-fixable :(

What I'm now doing (more experimenting) is shooting footage in 4:3 mode
and cutting off the tops/bottoms by 60 pixels and encoding to 16:9 output.
So far, I have found this to prove excellent in final output. But, my
only problem is the trueness of the 16:9 and all. Is it 16:9 enough,
or is it stretching it and I don't notice it. I don't know. I'll
continue to experiment in the mean time.

@ FredThompson,
I think that the GREEN (and BLUE) artifacts I saw in my DV .avi files
relates to the CAM's 16:9 issue above.

FWIW, I've tried the 4:1:1 Helper for vdub, since this is the
app I use major'wise for my frameserveing etc.
I don't seem to see any results when I use either of the options..
* Lume ..
* Interpolate ..

Video file is still the same.. z'far as I can tell. I'm not sure if
I'm suppose to use other filters in conjunciton to this filter, and/or
use both (above) modes for my DV source.

Any advice on this filter would be great :)
Also, any advice on the 4:3 to 16:9 (see above) that I'm using would
also be great, as far as proper resizing goes or whatever I might be
missing that I don't know about yet :rolleyes:

Thanks for listing guys,
-vhelp

[FredThompson]

Haven't you read Ross' site?

Even with extrapolating the chroma to 4:2:2, you're still going to have jaggies on straight edges with slight angles. You should choose extrapolate for 411Helper.

I suspect Longinus used what is, effectively, super resolution, processed, then resized down.

I'm toying with the idea of doing that type of operation on the luma. Super resolution has been kicked around on neuron2's site among other things. I suspect an intelligent resizing up, slight smoothing, then resizing down might help to remove some of the jaggies.

I don't have Photoshop loaded so can't see what he did. PNGs would be better. JPEGs are a poor choice as it smoothes.

[vhelp]

@ FredThompson,

I don't have Photoshop loaded so can't see what he did. PNGs would be better. JPEGs are a poor choice as it smoothes.

Actually, I've ben toying around w/ some resizing techniques. I did
notice that those GREEN artifacts I mentioned get hightened if I mess
too much w/ resizing. So, this may be a contributing factor as well,
if I'm not too careful :rolleyes: w/ this and other filters.

I've ben experimenting on trying to figure out how the DV cam does it's
resing squish/crunch or whatever its refered to as.. but I haven't
ben able to figure it out. I'm theorizing that if I can mimic the same
resizing algo, then I can undo it w/ a modified resize technique :rolleyes:
I don't know.. I'm trying, as I trial and error a fix (if possible)

-vhelp

[FredThompson]

What is that? Post-processed?

The green part of the hair over the left tear duct is 4 pixels wide. Remember what I said about 4:1:1? That chroma was chosen as the best fit.

[vhelp]

Hi all.

I just wanted to give you all an update on my saw-tooth issues.

So far, I've stopped shooting in 16:9 mode, and instead, am now shooting
footage in 4:3, and then cropping off the top and bottom 60 pixels ea.
then resizing to x480 (the squeeze) and then encoding to 16:9 output.

I must say, that with this new approach I have ben embarking on, has
shown me some great quality (w/out the saw-tooth)

I still have to iron out the final details of the 4:3 to 16:9 minipulation
and things, but I think things are comming along.

It's obvious that the BUG is inside the dv cam iteslf (in the way it
resizes and cruches/squeeze the video)

That's all the news for now..
So, be good everyone, and if anything new comes along i'll post back :)
-vhelp