AVCDH to Mpeg2 (DVD) - final output too soft

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farss wrote on 12/15/2009, 9:27 PM
Vegas will render interlaced at the same resolution as progressive. That's technically a problem but one Vegas has in common with everything else.
What people need to go back to is the camera. You need more than res charts too. You'll noticein the BBC's tests of cameras they use zone plate test charts. I believe what they're interested is not just the resolution but what happens as the reolution limit is approached. The cheap cameras fare very badly, they've been tricked up to look good in HD but the aliasing bites you when the image is downscaled. That seems to be why cameras such as the EX passes muster (just) but the Z5 doesn't (just not quite good enough).

I've seen this daily. The SD composite directly from the Z1 looks OK when I feed to into our 720 Bravia. About as good as the PD170. The cheaper HDV and AVCHD cameras look pretty bad, the latter really bad. Admittedly the upscaler in the old Bravia is really dodgy but it's kind of useful for these tests. Feed Planet Earth off DB into the same input, same horrid composite signal etc and it still looks a million dollars.
Yet feed the HD signal from the Z1 or any of the HD cameras into the component input of the same TV and hey it looks better than the SD from the BBC. The problem I think is we get blown away by the sheer number of pixels and don't look hard enough for the artifacts. I make this mistake all the time myself.

Bob.

[edit] I just realised that you may have been talking about something different. If you're tlaking about scaling interlaced HD to SD with Vegas then yes indeed, if you don't know what you're doing then you can run into problems. On the other hand the OP did say he'd read all the posts and tried everything.
We don't have much hard evidence to work from in terms of what he's actually tried and I've put my hand up to see if I can see specifically what his problem are but so far that's an offer that's not been taken up.

ECB wrote on 12/16/2009, 11:44 AM
I just got Lost Season 5 SD version and it is amazing. I have a looong way to go. :)

-ed
ECB wrote on 1/9/2010, 2:56 PM
I can down convert HDV to SD DVD and the results are excellent. When I down convert AVCHD to SD DVD the results do not come close to HDV down convert quality. I have tried all the preferred/suggested processes and some results are better than others but not are as good as the HDV down convert. The problem with the AVCHD down convert is primarly noise. Is this a camera issie or an AVCHD issue?

Ed
farss wrote on 1/9/2010, 4:34 PM
" Is this a camera issie or an AVCHD issue?"

It would seem to be the combination of the cheap camera front end and AVCHD. I doubt there's any great difference in the front end between Sony's HDV and AVCHD cameras. I can encode good quality video from the EX1 to AVCHD at quite low bitrates and it looks very impressive. Even video from the old HC5 holds up quite well but I make some effort to manage the noise issue.

Bob.
ECB wrote on 1/9/2010, 4:48 PM
The AVCHD looks excellent with no noise. WHen I downconvert, using any of the recommended methods, is when the noise appears.

" Even video from the old HC5 holds up quite well but I make some effort to manage the noise issue."

How do you manage the noise?

Ed
musicvid10 wrote on 1/9/2010, 5:39 PM
HDV is MPEG-2. So is DVD.
AVCHD is h.264.

Ducks and ducks make better baby ducks than do chickens and ducks.

John Meyer's technique is the best I have tested sofar.
farss wrote on 1/9/2010, 6:07 PM
"How do you manage the noise?"

This only applies to shooting events on stage and they've mostly got a lot of black in them.

1) Setup the HC5 to Spotlight and Autoexposure EV shift to -1.
2) Before encoding use a Color Curve to every so slightly crush the blacks a bit more. I do this while watching the waveform monitor and the preview monitor.

You need to be very careful doing this as it's quite easy to make a mess. You need separation between the blackout cloth and clothing. In my case shooting mostly very dark skinned people I also need separation between their skin and the background. Mostly I get lucky but I have to admit to making a mess of it more than once myself and having to go back, adjust the settings of the curve and do the encode again.

If it's really bad noise then Mike Crash's free dynamic noise reduction plugin is very easy to use. It's a bit of a render hog. I believe it uses the best of the noise reduction tools from the open source guys simply packaged to run in Vegas.

Bob.
ECB wrote on 1/9/2010, 8:38 PM
I should clarify that the noise I see in the downconverted image looks like artifacts . If I filter with a 0.001 X & Y Gaussian blur prior to downconvert the artifacts are gone but the image is soft.

Bob, I appreciate your suggestions in dealing with dark field noise.

Ed
farss wrote on 1/10/2010, 1:27 AM
"If I filter with a 0.001 X & Y Gaussian blur prior to downconvert the artifacts are gone but the image is soft."

Are you certain you're doing it before downconversion.

Bob.
ECB wrote on 1/10/2010, 9:32 AM
"Are you certain you're doing it before downconversion."

I tried applying the blur before and after the downconvert (not simultaneously). The results in both cases were about the same.

Since I don't have a crt display connected to the computer, I evaluate the final results using Sony DVD Player and Sony Wega. What I had forgotten was the DVD player throws away every 4th horizontal scan line to produce the 16:9 aspect ratio pix. 25% of the vertical resolution thrown away. Wega has the option to set a 16:9 enhanced mode which reduces the size of the verticle scan and increases the resolution to match 16:9. I set the DVD player to 16:9 TV and the player no longer throws away every 4th line. The picture now looks good. The majority of what I was interpreting as artifacts/noise in the down convert was due interlacing effects by throwing away 25% of the horizontal scan lines.

Ed