periodic jagged edges, why?

[Shane Ross]

#2 Playback is blurry

Shane’s Stock Answer #2:

ONLY JUDGE THE QUALITY OF YOUR MATERIAL ON AN EXTERNAL NTSC MONITOR, OR AT LEAST A TV.

1. Disable overlays on the canvas
2. Make sure you’ve rendered everything (no green bars at the top of the timeline

https://docs.info.apple.com/article.html?artnum=24787

DV footage requires large amounts of data and many computations. In order to maintain frame rate and be viewable at a normal size, only about one-fourth of the DV data is used in displaying the movie to the screen. However, the DV footage is still at full quality, and is best viewed thru a TV or NTSC monitor routed thru your camera or deck.

Shane Ross
Alokut Productions
http://www.lfhd.net

[Todd Reid]

I have to admit, this is the type of answer I was hoping NOT to get.
The tone of “Stock answer #2” and ALL CAPS, immediately puts someone on the defensive.

I am looking for a discussion among professionals as to why this happens to some aspects of the example and not others
and not hey your an idiot you should know this.
I’ve been a professional editor for many years and I know about rendering and external monitoring.

Let’s play nice and share knowledge.

[Richard Boghosian]

I sometimes find the playback quality has been changed to less that “High” or “Dynamic”. Possible?

Richard Boghosian
Bogh AV Productions

[Shane Ross]

Sorry, but that is because that particular piece of info needs to be emphasized for a lot of people. You’ll be surprised how many people don’t know this. It is a cut and paste answer.

I didn’t mean to insinuate that you aren’t a professional. I thought that the other part of the answer might help…that the computer monitor doesn’t play back full res because of system resources. I guess I should have just stated it, but I hate having to type a lot, so when I can cut and paste my answers, I do.

Actually, that answer might not be appropriate anyway. What might actually be happening is that you created that graphic in another app in a nice high codec, like uncompressed 8-bit or Animation, and when you drop it into your DV timeline and render you now incur the DV 5:1 compression scheme and that softens the image. that is the nature of the DV codec, and why many people opt to take their DV timeline to 8-bit uncompressed, render, then add graphics and titling. But that only helps if you are outputting to a higher end format via a capture card, or going to DVD. If you are going back out to DV, then you are stuck with the DV compression.

Please accept my apologies for the pasted answer.

Shane

Alokut Productions

http://www.lfhd.net

[Todd Reid]

I’ve had 2 engineers in my suite for the last 30-45 mins.
What we seem to have come up with, basically boils down to dv25 interpolation.

We tried the same animated gfx in a dv50 timeline and it played fine with no jagged edges.
When FCP had to re-compress the dv50 quicktime to dv25 in order to play in realtime,
that’s when those jagged edges were introduced.

I’m getting closer to understanding this phenomenon.

My saga continues…

[Shane Ross]

Yes….DVCPRO 50 is a better codec. Far better than 25 or DV/NTSC. Less compression and a better colorspace.

That is why the image is better using that codec as opposed to the 25 or DV ones.

Shane

Alokut Productions

http://www.lfhd.net

[Todd Reid]

I think you’ve hit the nail on the head.

as my third post mentions, that’s very close to what the engineers had to say.
Of course they said it very “engineery”.

The sad fact is that where I work we deal with hundreds of hours of footage and use dv25
to maximize our server space.
We do promos in dv50, but choose to stay in the 25 realm for our programming.
Can be very frustrating, but is more cost effective.

Thanks for you valuable input.

[Blub06]

This might sound odd but as an experiment I would export the offending clip/composition and maybe try a few different settings then bring it back in. It wont necessarily answer what is wrong but it will get you closer to an understanding and maybe eliminate some issues that you otherwise might have included in your list of possible reasons.

Chris