BBC (UK) View on Z1 and HDV

[Ruslan Odintsov]

Thanks everyone for replies.

Douglas, I completely understand that you're a busy man. It's just that I wanted a little more explanation as why you thought my downconversion results were not valid. When you're back in July, I'd still like you to try that 60i M2T clip you have on your site with a surfer walking on the beach, convert it through Z1 to DV (or better through component Z1's 480i downconversion to lossless, if you can capture that way). Then convert the same M2T in Vegas to 480i, and pay attention to fields rendition. Let's try to put all the theory aside and just see what downconverst more naturally.

Yes, I absolutely dislike the way the bright colors, especially reds, look from a DV codec. They look particularly bad and stairy when viewed through component outputs on LCD or plasma TV's. That's where software downconversion to lossless codec wins 100%. However, I'm sorry, but the interlaced downscaling in Z1 (put colors aside) is far superior to any software I've tried. Software wasn't bad, it was quite good doing downconversion, but Z1's version wasn't just good, it was transparent, it didn't look like something was scaled. It looked as it was shot in 576i/480i.

So this is my quest now: How to achieve the interlaced downconversion rendering quality of Z1, combined with color rendition of a software lossless codec? Any ideas? Is the analog component input capture card the only answer? Z1's component downconversion to 576p or 480p from HDV is simply stunning.

As for deinterlacing (SD for now). I don't know why people say that software is always best at it. Even highly praised Magic Bullet, with whatever possible tweaks, could not give me as good deinterlacing as a $2k Panasonic EDTV plasma that deinterlaces in real time. This plasma retains the most resolution and least artifacts, while Magic Bullet was struggling on many horizontal lines. Therefore I disagree, I think that dedicated hardware is still for the most part the best for whatever it's designed to do. Software is still lagging behind. Software gives you great flexibility, but not always the best result.

Please anybody, try that surfer clip and see it for yourself..... First of course you'll have to upload that M2T clip back to your Z1/FX1. Also I'm not really sure if Z1 and FX1 use the same downscaling technique, so Z1 test would be preferred.

Thanks.

Ruslan.

[Kurth Bousman]

...so the question for mac users now is - 1) if fcp 5 has the capability and/or - 2) what then is the best codec to use as intermediate ? i've got a studio upgrade already coming but should I also invest in Lumiere ? This question aside - all I've done is edit downconverted footage thru my Z1 and then run it thru Graemes' filter and I am very pleased . Yes it's dv but it looks way better. I've compared equal footage from my dsr-pd100a next to the z1 downconverted .I've looked at it on my hd 17" lcd and projected at 1024x768. There's no comparison . I haven't yet burned a dvd so maybe that's where the kicker is - otherwise , for whatever their reasons , BBC will be using a great camera .

[John Poore]

Ok so, if HDV 4:2:0 is converted via lossless software SD 4:2:2, there's actually no real difference in picture quality. That's what I thought.

And I don't mean 'it just looks better' statements from the BBC or others, this is just being subjective. Hype. People going gaga over new tech. etc. No offence intended to anyone, of course, merely my humble opinion, and I am open to being corrected on this.

There's no techinical or scientific basis for downconverted HDV becoming superior SD, right? Or am being to controversial here, but's that's what I seem to be reading as the bottom line.

Anyway I'll take a bet in ten years time - FCP 12, or Premier 20 - will have software that will make DV or its progenitor look just like high end film colour. Laughing? just remember what things were like ten years ago, could you imagine editing high end stuff on your laptop-?

[Radek Svoboda]

Does BBC use only PD150/170, or they use also DVX and XL2?

Radek

[Steve Crisdale]

Originally Posted by John Poore

There's no techinical or scientific basis for downconverted HDV becoming superior SD, right? Or am being to controversial here, but's that's what I seem to be reading as the bottom line.

Have we been reading the same thread? I know English is a beautifully intricate language with nuances that can beguile a novice into erroneous assumptions...

There's also no technical or scientific basis for ignoring the logic that a higher rez source (HD/HDV) should provide a result of at least equal quality to a native SD original. That's assuming the processes to achieve that result are understood by the operator carrying out the downconversion...

[Robert Young]

Originally Posted by John Poore

There's no techinical or scientific basis for downconverted HDV becoming superior SD, right? Or am being to controversial here, but's that's what I seem to be reading as the bottom line.

I have followed this topic on several different forums for a while now trying to figure out the answer to this. There are quite a few production pros and super techie posters who are really digging into all angles of HDV. These people are like Lewis & Clark, hacking thru the underbrush, trying to get the map drawn. Me, I'm like a tourist. I just want to know where it's safe to drink the water. The few clues I've gotten are as follows:
1) If you want the best SD DV possible, don't use a $5,000 camera. Use a 2/3"chip pro camera with pro lenses.
2) If you are exploring what the Z1 is capable of in SD final output, shoot in HDV, capture m2t, convert to 4:2:2 IC, or capture component output as high level codec, or uncompressed. These images, when downrez to 720x480, are pretty uniformly reported as being of noticably higher quality than DV shot on the Z1.
3) If your projects are for delivery on NTSC SD DVD, as mine are, it makes theoretical sense, and is apparently true in the event, that by avoiding color downsampling to 4:1:1 between the HDV acquisition and the final 4:2:0 DVD output, you will end up with better looking DVD video than you would have obtained from shooting DV in camera. I haven't heard how that works in PAL. There my not be as much difference.
4) I think that the ultimate purpose of the Z1 is to make HD products for people to watch, not SD on steroids. Unfortunately, for the moment, it seems like the camera has arrived before the delivery system. When HD DVD is finally up and running the Z1 HDV will produce video that is head and shoulders above standard DV format.

For me, the question is whether or not to jump in to this now, thinking that I may only get a marginal improvement in my end product, or wait for the technology to mature a bit, and to see what options we'll have for delivery.
Bob

[John Poore]

Fair enough. And I do understand the concept of downconverting HD in a simple way. But as a keep saying, what does 'noticable better quality' mean? More chroma or luma, for example, like dvpro50.

It's just when I view HDV, it looks like ordinary DV.

If anyone has the time, can they post comparisons for judgement...just a thought.

[John Jay]

interesting thread....

if you downsample to 720*540 you will get 4:4:4 from a HDV source, provided you save in a lossless c*dec

more info here:

http://www.canopushdv.com/conversion/index.html

see page bottom

[Dylan Pank]

Originally Posted by John Poore

ps. I think independent producers do 25% percent of BBC output, not the other way around as you mentioned.

John. sorry, guess I got my numbers backwards.

[John Poore]

No problems, I guess I'm pretty backward myself at times :)

John, thanks for that link. That does put the discussion it in a better light. Though frame grabs and moving vid do tend to be very different things. The HDV downsamples do look sharper, certainly compared to the dsr250 SD, as they have there. I think DSR uses the PD 150 chip, and I think most agree the FX chip does produce cleaner images than the old PD/DSR insides.

It would be more interesting if they were actually comparing FX video shot in normal SD, not in-camera downconvert via HDV for a truer comparison???

[Steven White]

Hey John, interesting link.

Does anyone besides me find it funny that while Canopus mentions the possibility of down-converting to 4:4:4 SD, their codec only goes to 4:2:2 SD? They're throwing away more information than they have to. While they quote that they do it in "the best possible quality", this is completely incorrect.

-Steve

[Ruslan Odintsov]

Originally Posted by John Jay

http://www.canopushdv.com/conversion/index.html

OK guys, I looked at those M2V clips. And guess what, if you think I'm doing something wrong with my software downconversion to SD, well Canopus must be doing something wrong as well, because those horizontal lines look awful!

I mean yes there's less mosquito noise and slightly better color rendition in Canopus version of downconversion, but come on, one must be blind not to see that FX1/Z1's downconversion produces more natural looking lines without softening the overall image. Simply try viewing this on interlaced PAL monitor (yes it's in PAL). I viewed it through RealMagic Hollywood+ MPEG2 card and in-camera downconversion looks way better on the eye than Canopus' version.

Try to compare sony_tram.m2v to edius_tram.m2v and look for the nasty horizontal artifacts on those long steps in the lower part of the frame, especially when zooming out. In-camera version looks almost completely natural, while Edius' does not. And this is the kind of artifact that no filtering will be able to remove. It seems like FX1/Z1 does some really good motion estimation technique when downconverting, while software doesn't do it at all or does it really poorly.

The difference is very obvious in favor of in-camera downconversion. So I'd say, if you want to bypass DV codec, you have to capture SD from component FX1/Z1's output into lossless codec for best results. But the in-software downconversion looks plain bad on those detailed shots. If you think that it's Canopus' issue, well, I was getting the same exact results with Vegas. That certainly is not an acceptable result for me.

So, can anybody at all see what I'm talking about? Anybody???

P.S.: You could also burn those clips to a PAL DVD. However, you'll have to reduce the bitrate first, as those clips are beyond the allowed bitrate specifications for DVD-Video. You can either recompress with MPEG2 encoder or transcode using some free transcoding application such as DVDShrink.