Having problem with SD (native and down-converted)
 

Hi everyone. My A1 has a fantastic image at HD, but i'm having major problems with progressive SD.
I started noticing some artifacts at bright parts of the image when there are straight lines present. So i tried to film in HDV and the lines where gone, but when i down-convert to SD (in the computer or in the camera) i get the lines again.
Here's a photo of the SD and HD version: http://www.pichotel.com/pic/2999dHTAP/140077.jpg

Any thoughts?

Thanks.

Hi Luis. I've seen something similar in the past, and it turned out that my workflow was causing a progressive image to be interpreted as interlaced, and the NLE was deinterlacing it and causing stairstepping artifacts. Can you give some more details of how you are doing the downconversion?

Richard

I export a QT file from Final Cut with "current settings". Next, i open that file in Compressor and export as DV or Mpeg2 PAL, 16:9 Progressive.
I'm sure it got to be some problem with wrong fields, because it only happens when i output to some form of PAL. If i resize it to the same 720x576 but in H264, i got no problems. Strange...

Made a quick test with interlaced footage and i don't get the same problem. The image is fine downconverting from 1080 50i.
So, it really must be some kind of fields problem.
What am i doing wrong??? I really need to use some 1080 25f footage.

Hi Luis, I have the exact same problem when converting to SD. I get those same lines and they move like a wave when the tape is rolling. I hate it, and I cannot seem to get rid of it either. I have tried 14 different workflows and all to no avail. It it is an interlaced problem, I would love to know how to solve it. I will be watching this thread and praying someone will look at your picture and be able to tell us how to solve it. J

I use the HV20 to import and use this workflow with Vegas.

Record 16:9 HDV at 24f/60i/30f
Pop the tape into the HV20 - set TV type to 16:9 - DV output to DV
Import as DV (Im using Vegas)
The avi file should be a full widescreen avi ( 1.2121)
Open a 4:3 timeline and pop it in.
Event/Crop to "match output" aspect for 4:3 or leave it for 16:9
Edit away.
Looks awesome.

Hi People,

I could be wrong..I need to confirm this, but I think you have to change the field order. When capturing HDV 1080i to your pc and then converting to SD. I believe the field order needs to be changed in the settings of the SD project. I use Premiere not FCP, in the same way and have a video tute from Total training where this was mentioned (it may be necessary to change field order).

My workflow.
1.Capture HDV 1080 50i (edit)
2.Bring footage into SD 720x576 (widescreen) project..Resize footage to fit screen. (change field order if necessary)
3.Export for DVD etc.

*I have never needed to change field order. I have seen many threads where people have had crap results when down converting from HDV to SD via camera.

Heres my video tute workflow with premiere (it may help)

http://www.esnips.com/web/Premiere-Pro-2-Video-Tutes

If you look at the HDV settings you might notice that HDV is "Upper field first" and in the SD project settings it is "Lower field first"

Like I said I could be wrong, but maybe something to try.

Thanks, but i only got the problem with progressive footage, not with interlaced...

I made another quick test, and it seems i got better results if i resize first in quicktime, without changing codecs.
I open the HDV file, and under "movie properties" i change the size to 1024x575 and save changes. After that, i make the mpeg2 file with compressor, and i get far better results than letting compressor make the resizing.
Still testing...

Hi Luis, I have also been testing to solve this problem. I have discovered that adjusting bitrate while rendering to MPEG2 file to 8,000,000 for each of the three settings, use two pass, and then in DVD architect..select "reduce interlace flickering" seems to get rid of 90 Percent of the problem. I do not know why reducing interlace flickering would help since everything I have done is progressive, but it does help, tremendously. Keep posting your findings also. J

"reduce interlace flicker" softens and blurs the image.
You won't notice it too much on SD TV, but on a computer or HD
you may. Sometimes it's OK..sometimes not.

Hi Eric, I am looking for a solution for printing to DVD. If I stay on computer on over the net, I will use my HD rendering to WMV. Using a chromablur filter also helps. But if we could pinpoint the cause, we could come up with a real solution, not just blurring. J

Find a better downconvert. I find the incamera to be crappy and if your using the NLE its crappy too. Import and use MPEG streamclip to convert to SD or if your on a mac compressor....its so much better and it looks fantastic.

- Kyle

Kyle, are you saying after editing in the NLE, then export to MPEG streamclip? Thanks.J

Hi Luis. Sorry for the delay in getting back to you on this. I've just tried a render from a Vegas 25p HDV timeline using 25F footage from the A1. If I select the Quicktime DV codec I see stairstepping on diagonal lines, but if I use the Vegas DV codec (AVI) there is no problem. The AVI colours are much richer as well. Seems to me that QT7 must have some problems rendering progressive footage to certain output formats. DV is not really supposed to be progressive, so maybe that's part of the problem.

Richard

Thanks everybody.
So, Richard, it seems i'm in trouble, since i'm on a mac and it's all done around QT...

Hi Luis. Well you could choose a different codec for the output. It doesn't have to be DV, does it? What happens if you render as MPEG2 and burn it to DVD?

Richard

OK! Problem solved!
And the solution it's a very strange one...
Even with progressive footage, i must export it as interlaced to DV.
After that, the DV and the mpeg2 files were fine.
I'm happy because i solved the problem, but it doesn't make any sense.

Hi Luis. That's good news, glad you got it working.

Richard

OK, i think i opened my mouth too early.
Everything is fine 'till i make the DVD. The DVD got the strange lines and some flickering again.
I'm going to try to post this in the Mac forum to see if i can get some more help, because it seems to me some kind of problem with QT.

Hi Luis, I have been fighting the same thing although I am Using PC with Vegas and Architect. I finally got rid of the lines completely, I ended up rendering my project to a .wmv file in HD. Then let Architect rerender the file for DVD and I clicked "reduce interlace flicker" before the rerender. It came out beautiful, No problems at all. I was able to get the same result rendering directly to SD by upping my bitrates and then making sure I clicked "reduce interlace flicker". Silly since its all progressive, but whatever works.

Hi Luis. How are you watching the DVD? Is it on a computer, TV or what? Also, when you make the MPEG2 file for the DVD, does it follow the standard, i.e. interlaced, Upper Field First, or is it progressive?

Richard

I'm watching on both computer and TV.
Right now i'm getting better results if i bypass the DV conversion and go directly to mpeg2, but it's not perfect yet. And i'm also having better results with "upper field".

Such a shame I didn't see this thread before!
I needed an XH-A1 for a job in Moscow I'll have next week. I bought one thinking it was on a pair with my DVX in SD (I'm not mentioning the nice and sharp hdv image).
I am stupid, since I din't test it personally BEFORE buying!!

I can't believe how many people don't see and don't mind for this horrible aliasing in SD. It turns out I'll sell it the day after I come back from Moscow, because (unfortunately) I'll need HD/HDV only when clients will ask for it.

From a professional point of view, this camera is unusable in SD

Cheers

Same problem
 

Anyone use New Tek's VT4? I have the lines problem in SD and I think a little in HD. Anyone know how to get rid of them in MY editing system. I use DVD Workshop to create the DVD.

No, it's not unusable for SD production. Down-conversion from the camera is viable in some cases, but the quality is generally reckoned to be better when done in software. I shoot and edit HDV then do the conversion on my PC at the end of the edit. As mentioned above, some NLEs do a good job of the down-conversion (I use Avid Liquid 7.2 which creates very good-looking PAL DVDs from 1080/50i footage), but if you have problems you can try MPEG Stream Clip or Canopus ProCoder on a PC or Compressor on a Mac - again, as recommended above. Progressive seems to be more fussy than interlaced, but there are workflows that work.

At the end of the day, you may still prefer your old DVX for SD production and there will be other people that share your view. The work flow is certainly simpler. However, many other professionals (and amateurs like myself) find the XH-A1 a very usable, versatile camera that gives remarkably good results. You will even find experienced producers who prefer the XH-A1 to a 2/3" Sony DSR DVcam for SD DVD production.

I finally managed to make good down-conversions in fcp.
Tried many ways and many codecs and i found out the problem.
Try this: Edit 1080f and at the end put the final result in a square pixel SD uncompressed or prores sequence (rendering set to best). Export using "current settings" as a self contained movie.
Make your new beautiful DVD...

One problem was down-converting directly to anamorphic SD. Converting first to square-pixel SD solved the problem.
The other was the DV codec. I don't know if this is correct, but the DV codec seems always interlaced. Even with progressive footage the signal is interlaced (but with the progressive cadence). So avoid it at any cost.

The results are perfect, at least for me.

L.R.

Hi Lous
 

Luis, I have a question what did you do after you exported as SD square pixels from FCP before burning your DVD? Did you go directly to DVD Studio Pro?

Thanks,
Pavel