SD DVD from HDV, best practice?

farss wrote on 2/12/2005, 8:57 PM
If I can find the time tomorrow I'm going to have another go at this, so far the results are a tad confusing. For the least amount of grief just using the Z1 to downconvert and capture as DV25 and then normal workflow seems to give results about as good as any, certainly other paths I've tried might be a little better but some seem to be worse.
Apart from using the camera to downconvert I've tried coming from the CF DI and the original m2t file, from these I've then gone either to DV25, Sony 4:2:2 YUV or straight to mpeg-2. From what I can see so far going straight from either master to mpeg-2 seems to give pretty much the same result. I do recall a comment from BJ_M that there was an issue going from the CF DI to mpeg-2 but he didn't elaborate.
The odd one out here was going from the CF DI to the YUV codec, results looke pretty bad, worse than going to DV25, that really threw me.
As part of the ongoing saga tomorrow I'll be trying some more 'normal' footage so I can a better handle on how it looks.
Just wondering if anyones has any other ideas or suggestions, where I'm working at the moment it's a bit hard to get to this forum.

Bob.

Comments

Spot|DSE wrote on 2/12/2005, 9:00 PM
Farss, there is a color issue for the DI in Vegas, hence the preset download we've got on the VASST site. But there's no problem that I've seen going from the DI to MPEG if you're going from the HD to SD, only because Vegas is already in the 601 colorspace vs the 709 colorspace of HD.
For me, I've had good results with the DI to HD using either MC in Vegas or Procoder. I've not rendered from the DI to the 4:2:2 and then to MPEG, what are you seeing?
FWIW, for testing I've been using the Serious Magic focus chart and a standard Kodak chip chart for color, then looking at renders from there.
farss wrote on 2/12/2005, 9:19 PM
Going from the DI to 4:2:2 YUV the field order was reversed, minor issue but it looked soft even in the static areas. That's just on the 4:2:2 avi. Need better footage though to be certain, maybe there's something else going on in there. The actual colors being shot are so abnormal and under typical theatrical lighting it's really hard to know.
I know about the issue going back from Vegas to the DI, don't need to do that at this time anyway.
We have a focus and chip chart, should have thought to test on that first. Been a hell of a week, new computer, first plunge into HDV and the 'boss' wanting to see something pronto to impress his client.
I think I'm just going to give his project a miss for week or two and concentrate on some normal footage to get my sealegs with this stuff. I should also invest some time and get the monitors calibrated as well.
Oh and I forgot to mention while I'm trying to do this I have a Macolite making snide remarks about noisy fans. After all that and me not killing anyone I think I'm in line for a sainthood :)
Bob.
Spot|DSE wrote on 2/12/2005, 9:28 PM
Saint Bob works for me.
Seriously, anyone who would like to know what Bob looks like, just imagine Santa Claus in his "adolescence." No white in the hair or beard, but everything is pretty close.
When you render to the 4:2:2, I can imagine a field order problem really showing up when you go to MPEG from that. I've done the MPEGS and WMV files straight from the DI...I'll experiment some tomorrow, I've got a little free time.
farss wrote on 2/12/2005, 11:29 PM
Geez SPOT, now you've got me blushing.
Here's an even funnier story about me, my parents christened me Robert Roy Grant without even thinking about it. You might need Grazie to explain that one.
Bob.
Spot|DSE wrote on 2/13/2005, 8:16 AM
Well...if you're referring to Rob the Red....I think that's a compliment. But remembering world history, some might not think so. IMO, he was a standup guy that didn't take crap from nobody, but was kind of a "Robin Hood" in his land.
Isn't your beard kinda red? :-)
farss wrote on 2/13/2005, 1:45 PM
I was referring to "Rob Roy", a rather well known Scottish hero and also a brand of scotch as is "Grants". Sadly both are a fairly ho hum blend.
Bob.
winrockpost wrote on 2/13/2005, 2:01 PM
farss wrote on 2/13/2005, 2:29 PM
I shoot very little, most of my work is in post. Good position to be in, get to bag everyone else's work :)
I do work two days per week for a hire company who are pretty well exclusively Sony. Big attraction for them and Sony cameras is the quality of service. They have JVC 500 MiniDV camera with serious glass on it, blows away our Sony cameras in terms of picture quality but it's been back for repair more times than I've had hot dinners. I hear JVC have a new model with native 16:9 and D5 DV tape transport, should be awesome.
We're just getting into DV Rack for setups but again we (they) shoot mostly opera, you just got to shoot what you're given and it's mostly a nightmare.
Bob.
Spot|DSE wrote on 2/13/2005, 4:18 PM
Bob,
FWIW, Rob Roy and Rob the Red are the same guy. :-)
farss wrote on 2/13/2005, 8:42 PM
OK,
now down to the serious stuff.
Got some more HDV footage out of our Z1 to play with today. Normal stuff shot on a nice sunny Sydney day down by the beach. Capture fine and converted to CF DI at medium file size. DI plays back OK in Vegas.
Converts to WMV 9 720p using default templates and look just like all the other demo footage around the place. Obviously we need more time with the camera to get the best out of it and at 50i pans are a bit of a worry but thats the camera.

However I again encoded to mpeg-2 from the CF DI, standard PAL template except changed max bitrate down to 7 MB/sec. Result is c**p, wierd macroblocking stuff happening and I mean wierd. Definately NOT related to motion etc. One shot following an overhead aircraft looks fine for a while and then the wings just go into blocks for a while and then it's fine again. The pans produce what looks like compounded interlace artifacts. Perhaps I should have had "Reduce Interlace Flicker" turned on.
I'd really like to know if anyone else has a handle on this, I can make good DVDs from the m2t files but NOT the CF DI!
Bob.
mdopp wrote on 2/13/2005, 10:43 PM
Bob,
here's my personal best practice for converting HDV-CFHD coded material to SD-DVD:
- apply ColorCorrector(ComputerRGBtoStudioRGB)
- switch ReduceInterlaceFlicker on
- add sharpness (amaount 0,03)
- reverse fieldorder (change media-properties of all clips to "lower field first")

I was very pleased with the results and never had any interlace artifacts. I like the sharpness-filter since the original HDV-material is rather soft. Give it a try.
Martin
farss wrote on 2/14/2005, 12:18 AM
Martin,
interesting results as that process would pretty much correct much of what I'm seeing. Now the odd part is how come it comes out pretty much 100% OK just going straight to WMV 9 720p, furthermore going from the m2t file (ie the camera tape) also doesn't require any of this fiddling around.

I suspect there's something wrong overall, if I render from the CFHD footage to DV25 first all is also OK.

Bob.
PeterWright wrote on 2/14/2005, 12:31 AM
> "at 50i pans are a bit of a worry but thats the camera."

Bob - could you describe this further? - I've read about pan artifact problems which were auto settings related - is this something else?
farss wrote on 2/14/2005, 3:06 AM
Camera was in factory settings, PP1, so I'd say it was nothing more than that.
I have seen pans with this camera on a BIG screen that looked a lot better so I'd say there is a way to avoid this problem. I didn't shoot this footage so there's not much more I can add. We are planning to run a series of tests, do as near identical pans as possible and use different shutter speeds to see how that affects things.
There also seems to be something wierd going on with the AE circuits in the Z1 in 'out of the box' mode. One shot of a shrub on a typical Sydney sandstone outcrop looks absolutely stunning, spot on everything. Yet shots of the beach from the headland look pretty blown out, the yellow and red beach umbrellas don't hold up too well either, scopes show it being pretty hot. This could even be the limitation of the optics as the camera was pointed in the same rough direction as the sun, whole lot of things to investigate and learn.
One thing for sure, I feel pretty vindicated in what I said even before Sony mooted at bringing out a consummer HD camera. Anything HiDef is whole new world, perhaps it is just DV with more pixels BUT you put it on decent monitor or big screen and what got hidden by the low res of DV isn't hidden anymore. Maybe there's a psychological component here too, we see a low def image and we don't expect much, you see a high res image and you notice everything about it. I guess it's a bit like listening to audio through a $10 car radio vs a $50K hifi system.
Bob.