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HD issue
Hi Cow members,
I am contacting this board in hopes that someone may be able to help me with an issue I am experiencing with outputting to HD cam using the Kona2 board.
Recently I have started to use the Kona for High Definition output. Up until this point I have been using the Kona in a NTSC capacity and have not experienced any problems.
However, when I output to HD, we are seeing what I would describe as stepping or stuttering in the video. The video was created using hi-resolution Jpegs in After Effects. I simply put a move on the Jpeg and rendered out an Uncompressed 10-bit Quicktime at 1920 x 1080 resolution, 29.97 fps. It appears that the greater the pan or move, the greater the stepping problem. I am using external reference (tri-level sync 59.94, 1920 x 1080) When I rendered the file, I used a lower field first setting and tried again using a prgressive render. To my suprise, the progressive render looked far better then the field render.
As a test, I took the rendered hi-def Quicktime file and re-rendered it as an anamorphic 720 x 486 29.97 NTSC quicktime. I then outputted that to digital beta to see if the problem was still present. I now see that there is no problem when I output to digital-beta. It only happens going to HD cam.
From my test, I have concluded that the problem lies somewhere in the path to the HD. The file itself seems to be fine, since I am not experiencing that stepping issue in NTSC.
If you have any info that could possibly help me, I would greatly appreciate it. Thanks in advance.
-Frank Ruggiero
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4 Replies
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I think it needs to be set to Upper Field.
Todd -
What HD cam framerate are you using?
What is the Timeline FramerateIs it 23.98 or 59.93?
I am assuming it is 23.98 because you are using a tri-level sync generator. If this is the case then you need to be sure that your sequence settings and KONA OP settings are all set to 23.98. I know it seems basic, but the stutter seems to sound framerate related.
David
Peace and Love 🙂
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Hey Guys,
Thanks for your help. A quick test is proving to me that you do need to render upper field first. I automatically assumed 1080i was lower field first since I have been using that for output to digital beta.
But rerendering on the upper field made the video pristine.
Thanks again.
FR
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Yes, this is something that caused me great confusion recently. There is definitely a sleight jitter if you change HDV (or HD ftg in general) to SD due to the fact that HD ftg is natively Upper Field and SD & DV footage is natively Lower Field.
Be sure to make sure your sequences match the field order of the captured footage!
To make matters more complicated, I had some footage from a Z1 I was editing and they used the Cineframe crap. Anyways, the only way to fix it was to bring it in After Effects, Interpret Footage to Upper Field Only, put it in the SD sequence and then render out lower field. Took a while and some help to get this workflow down, but it works like a charm and looks great.
Good luck.
KW
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