Question for Barry about downconversion

J

John Trent

Well-known member
Barry,

I'd like to hear your views on downconverting HDV to SD DVD. I don't know anyone that has a HDV cam so I can't see for myself. My problem is every tv show I see that is shot on HDV and downconverted to my sd tv (ICONOCLASTS, LOVESPRING INTERNATIONAL, SOUTH OF NOWHERE) looks like it was shot through a strong Tiffen Soft/FX filter. It's the same with HDV downloads I've burned to DVD. Everything looks soft and lacks detail. If I buy a HDV cam will this be what my DVD's will look like?

Most say downconverted HDV looks better than footage originated on a SD only cam. But when I ask the above question, I'm told it looks fine to them and it's just DirectTV's broadcasting. But why do the DVX and VX/PD shot shows look sharper? Is it that the HDV GOP and compression can't handle being broadcast or put over the web without the image becoming mushy?

I saw MASTER'S OF HORROR: THE SCREWFLY SOLUTION (shot on the HVX) over the weekend. It showed none of the softening of the HDV shows I've mentioned.

I've read what you've said before, something like, 'downconverting is like fitting 3 pegs into one hole' and the 'rounding off of corners' explanation in this thread and on this page:

http://www.dvxuser.com/V6/showthread.php?t=22316&highlight=downconversion

http://www.dvxuser.com/V6/showthread.php?t=22316&page=8&highlight=downconversion

Do you still feel this way? Is there anything new you've come across? I've heard AfterEffects does the best job downconverting. Have you tried it? What do you use?

I liked what I saw when I plugged a HDV cam into a HDTV at a store, but if my SD DVD's are going to look like the tv shows listed and download burns I've done, I guess I'll stay with SD and buy a DVX, as I can't afford the HVX solution. Help.

Thank you.
 
I used Vegas to downconvert my finished HDV edit to SD and it looks fabulous. Way better than anything originating in SD and waaayyyy better than Premiere does it.
 
I don't agree with his comments at all. It has not been my experience. HDV downconverted looks way better and more detailed than anything shot in SD.
 
My downconverted SD footage from the A1 looks better than any SD-original clip I've seen on the web, other than that 2/3" short entered in horror-fest that had the girl in the bikini.
 
The simple fact is, you will never get more detail from HD-downconverted-to-SD than the SD frame will hold. I don't care if you source it from a RED at 4k, you cannot get more than 720x480 out of a DVD. It's just not possible.

So a top-performing SD camera, like an SDX900, is going to produce a DVD that fills the frame with detail, and no downconverted HD or HDV or 4K image is likely going to exceed what a top-performing SD camera can do.

Now, with that said, an inexpensive SD camera is unlikely to produce a full-saturated frame of detail, and there is potential that you could get a fully-saturated frame out of downconverted HDV, assuming the downconversion is done properly. Vegas does a great job, and I would expect that the new FCP5.1 would do a good job, but prior versions of FCP were pretty lousy in their scaling, and I don't know how Premiere performs. Old versions of Premiere (like 6.0) were horrific in their scaling.

So I would expect that what Vincent saw was the result of a lousy downconvert. Plus the fact that a DVD is not going to hold 1/4 the detail that proper HD could show (when shown on HD). So if he was saying that the HD version was all super-sharp, and the DVD version wasn't, well, duh. Even with the best possible conversion the DVD is still going to deliver no more than 720x480. HD can have much more detail than that, so of course it looked better on the timeline and on the high-def monitor.

But once you downconvert it to DVD, you're going to get 720x480. That's immutable.

And, in my tests, you don't really get any more detail downrezzing HDV to DVD than a good comparable SD camera would deliver. Some people have tried to say "well, yeah, but you have to add a touch of sharpening and whatnot, and it just looks so good." To which I'd say: then you're not testing actual resolution, you're testing the sharpening filter. And that same sharpening filter could be applied to the SD footage, and it'd have the same effect.

If just downconverting to look at it in PhotoShop, downrezzed HDV can look great. It's when you strip the color information in half again and re-compress it to MPEG-2 that you end up with about the same results (as a good quality SD original).

And besides, all these cameras probably work the same way anyway, which is that they do all internal processing at the full 1920x1080 (or, in the JVC's case, 1280x720) matrix, and then downconvert to DV anyway when you record DV. So you really shouldn't be able to get any additional detail out of downconverting in post, because all you're doing is adding an additional step of scaling & compression when you record HD and then downconvert to DV, vs. the straight in-camera downconvert. But DV is limited in that it's 4:1:1, which doesn't transfer to DVD all that well. In PAL territories it's a different story though.

But that's why I say if you want the best-looking DVDs from an HVX, just shoot DV50 in the first place.
 
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bballplaya283 said:
other than that 2/3" short entered in horror-fest that had the girl in the bikini.
Click to expand...
Which was shot on a 2/3" camera through a lens that probably resolves over 800 lines. Which means that it was fully saturating the frame with all the detail it could muster. Which kind of goes to prove the point.

I mean, if I had access to the cams, I'd love to test a VariCam downconverted against an SDX900 shooting DV50. I bet the DV50 would look better on DVD than the downconverted HD.
 
Barry_Green said:
So you really shouldn't be able to get any additional detail out of downconverting in post, because all you're doing is adding an additional step of scaling & compression when you record HD and then downconvert to DV, vs. the straight in-camera downconvert.
Click to expand...

Barry - But surely it depends on the scaling algorithm used. I've seen examples from people who've got better scaling from virtualdub than Vegas, purely because they can pick the algorithm used (Although it's a nightmare workflow). Using the photoshop example, I know that photoshop's scaling algorithms are bad compared to other pieces of software.

Therefore, I guess I'm saying that some cameras will be better than others at scaling and so will the software people use in post. So you can't say 'it's better done in camera', because it might not be.

In the end people have to be careful downscaling HDV footage and shouldn't assume that it will be better than SD - that's just not the case.
 
this is all subjective and I stand by my opinion that downsampled HDV looks better than SD-originated material.
 
MPEG Streamclip does a fantastic job of downscaling. I can easily take an HDV edit, and then tell it to give me an SD 16x9 PhotoJPEG QT output @ 100% quality (RGB 4:4:4 setting) and it is actually giving me more chroma info in the SD frame than I could even achieve in DV50 4:2:2 SD. And it's razor sharp too.

An oversampled image with a good scaling algorithm can go a long ways.
 
As long as it doesn't look worse than a SD camera to DVD would look, I'm good.

But Barry, why do these shows look so soft? Have you seen them? Are they all doing their downconversions wrong? Is that what bad downconversions look like? Or will broadcast just strain HDV too much and turn it into mush? Someone else has to be noticing this. There has to be a reason. These shows make you think you need new glasses. Backgrounds are the worse. With these small chip cameras everything in the background should be in focus (unless you're really working hard to not have it be) but instead it all looks completely out of focus - and not in a good way - in a really bad strong diffusion filter way, like a Cokin Diffusion 3 way.

Anybody here have their HDV footage broadcast without this sort of softening? Something is going on. I'd like to know what it is so I never ever make the same mistake.

Elton, MPEG Streamclip - have you compared it to AfterEffects? And how long does a downconvert take? BTW those pictures you posted today in the DVX/A1 thread looked great.
 
John Trent said:
Elton, MPEG Streamclip - have you compared it to AfterEffects? And how long does a downconvert take? BTW those pictures you posted today in the DVX/A1 thread looked great.
Click to expand...

Haven't directly compared them, as I like to use MPEG Streamclip for it's simplicity and efficiency with the task.

Those grabs were all actually exported from a FCP HDV 24F timeline.
 
Haven't seen any of those, so I can't answer.

There's nothing inherent in HDV that would make for a bad downconversion! Broadcast TV standards aren't all that high, and camera-original footage will always look better than broadcast. I guess it's possible that they're all doing lousy downconverts, or maybe you're getting the stations through cable and the cable channel operator is starving them of bandwidth or something?

What networks are these shows on?
 
Yeah, Sundance ch. for ICONOCLASTS. For awhile they ran it on the Travel ch. I don't know it they still do.

LOVESPRING INTERNATIONAL was on Lifetime but they're not running it currently.

SOUTH OF NOWHERE is on Nog (ch. 298) on DirectTV (weekend nights). On cable it might be called the N. This was shot with the Canon H1 and IMO looks extremely soft. I hope you can see this, Barry, and tell me what you think the problem is. Various MTV shows and IT'S ALWAYS SUNNY IN PHILADELPHIA shot with the DVX look much sharper and I don't understand why.

Elton, did you color correct those grabs? From what I've seen so far I like the Canon color better than the Sony's...but I still prefer Panasonic's color most of all.
 
Very interesting discussion go'n on here guys... which only leads to one question.
Which is it... what camera to go for here when the ultimate output is SD DVD.
The Canon XH-A1 or the DVX100b? Down converted 16x9 HD (24f) or the 16x9
squeeze of the DVX100b (24p)? What about the 60i's of either Camera with the
same ultimate SD DVD as final destination. I ask this not based on specs... rather
the look. We all know what is reasonably good looking material vs. the unacceptable.
Subjectivity aside... just give us the plain hard and cold truth. It's ok to be as undiplomatic as need be... Panasonic and Canon and this forum can handle it.
o.k. ya got me... more than 1 question- I know.
 
Either can do a fine job for standard-def DVD. The Canon can make a sharper image, the Panasonic delivers the cinegamma and richer color palette.

In a lot of ways it's the same argument as the XL2 vs. DVX was. No doubt the XL2 was sharper, but a lot of us just preferred the overall look of the DVX. And some doggedly preferred the XL2 no matter what. So if you're of the persuasion that you liked the XL2 more than the DVX, then you'll probably find that you'd like the XHA1 over the DVX (for DVD). If you liked the DVX instead of the XL2, you'll probably find that you prefer the DVX's image (on DVD) over the XHA1's as well. (HD being another matter entirely, but you didn't ask about HD, you asked about DVD).

But you're asking for a subjective opinion, and in cases like that the only opinion that matters is your own.
 
ok... yes I know it is a very difficult question especially when dealing with individual tastes. I guess we have all experienced the casual observer and clients that really does not see the differences, however subtle or stark. It does boil down to simply a matter of preference. I'm just concerned that even though HDV is the latest "bleeding edge" for the do it yourselfers, the DVD delivery format has to factor in when making such a tough buying decision. I know the HDV is sharper in it's raw form... but after post processing, more compression to format DVD, is it really that much better? Typically at most camera stores there is only the evaluation of the in camera material... no DVD'd material of demo'd camera for final evaluation. So you basically have to wait til you get home to see what it will really look like when you complete your masterpiece and prepare it for distribution.
I'm leaning toward the Canon XHA1 but.. that DVX100b is going toe to toe with it
for the full 15 rounds. Even though it's SD only... a tribute to the strength of that
camera I suppose. Continuing with this terrible metaphor... I believe the A1 will be
there to challenge the next contender with fewer bruises and more prepared for the
next onlsaught of technology. The DVX will be still in the arena but not in the ring.
Who does'nt like the crowd favorite...(DVX) now relegated to the role of underdog.
It's just tough to let go and see the Champ sorta fade... ok enough of that. I'll just
have to make that decision DVX100B or XHA1 on my own. Thanks for the insight Barry. Your opinions are much respected.
 
John Trent said:
Elton, did you color correct those grabs? From what I've seen so far I like the Canon color better than the Sony's...but I still prefer Panasonic's color most of all.
Click to expand...

Uncorrected raw grabs from the FCP timeline and simply resized via QT player and exported as individual JPEG's.

The "Your Move" clip was a raw m2t camera original captured via DVHSCap on the Mac. It wasn't pushed too much in camera in order to have more flexibility in post.
 
Anyone watch SOUTH OF NOWHERE over the weekend?

I had some friends over and flipped between BREAKING BONADUCE & S.O.N. and asked them which show was shot on HDV. They all picked BONADUCE (DVX lensed) and were surprised to find S.O.N. was shot on HDV. "It looks worse. / It's blurry. / How can that be? / Why's it blurry? / Are you sure you didn't get them mixed up?", went the various responses. One girl still doesn't believe me. Then I showed them some VX2000 footage, that they all agreed looked sharper. Then, and here's the real kicker, I showed them VX stuff shot with 1/30 shutter speed (poor man's frame mode, it was once called, what is it - 300 some lines?) and asked them if they felt it was sharper then S.O.N.? This was tripod mounted, wide angle stuff and I asked them which backgrounds looked sharper? Some said they looked the same, some said the VX footage looked better. I think they both looked bad - each had their own brand of softness. But I still want to know why a $9,000 modern hi-tech HDV cam (Canon H1) looks as bad as lo res field-doubled footage from an "ancient" ($2,000) VX2000 on a SD tv?

This shouldn't be. I've seen a HDV cam plugged directly into a HDTV and I know it looks better than a SD cam could. On SD tv it should look as good as the DVX but it clearly doesn't. There has to be a reason. As I've said before, this "softness" is seen on other HDV shows and from Sony cams as well. Are all the professionals turning the sharpness OFF and/or doing bad downconverts? Is broadcasting HDV just too much for HDV's compression and/or GOP? DVD's I've made from HDV web downloads also have this blurry fuzzy look. There HAS to be a reason for this. I'm more convinced of this than ever.

I don't believe I'm the only one whose noticed this. Why aren't others asking questions? I would think the possibility of having your footage shown on tv and having it look this bad would concern more people here. Is this the dirty secret of HDV?

Thanks.
 
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