Having problem with SD (native and down-converted)

[Luis Rolo]

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.

[Richard Hunter]

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

[Luis Rolo]

Originally Posted by Richard Hunter

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...

[Luis Rolo]

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.

[John L. Miller]

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

[Eric Weiss]

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.

[Ivan Barbarich]

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.

[Luis Rolo]

Originally Posted by Ivan Barbarich

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...

[Luis Rolo]

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...

[John L. Miller]

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

[Eric Weiss]

"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.

[John L. Miller]

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

[Kyle Prohaska]

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

[John L. Miller]

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

[Richard Hunter]

Originally Posted by Luis Rolo

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. 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