CF video kiosk playback best settings MPEG2

[Kevin Camp]

dv is not the first choice for keying, but you can do it. the most important thing for getting a good key is really the lighting, not the encoding… search the forum and the tutorials for some tips for keying dv, it has been discused a lot… if you can shoot dv50, it will make your keying better, but dv25 will work.

as far as the banding issue, it may be due the recompression of already highly compressed dv25 to mpeg2. adding a little noise over the footage may help. also, if you can, try rendering out of ae to a lossless or uncompressed codec or image sequence, then take that to a compression application to create the mpeg2. i almost always get better quality compression from a external compression utility like compressor (mac only, but there are many others)

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Paul]

Kevin,

Thanks for the response. As always I learn something when talking to COWS. So am I to understand that “normal” or consumer level DV is DV 25? The standard DV handycam? Then my next question is what is the 25 or 50 designation but I could google that.

When you say adding a little noise to you mean with an AE filter.

As for compressor.. I have that. So render out of AE in the Animation (Lossless codec) and then compress with compressor?

Any quick settings ideas that will give the best possible results for a non pro?

Thanks for your help 🙂

[Kevin Camp]

yep, dv and dv25 are the same… the number following the dv basicly identifies the the data rate… dv25 has a data rate of 25 megabits/sec, dv50 is 50mbps. the higher the data rate the more information is contained in the stream. in dv50 the extra information is extra color data, it has twice the amount of chroma and saturation. and, of couse, chroma and saturation are important for chroma keying, making dv50 a better choice, if you have it.

as far as settings for compressor for mpeg2, it should be pretty straight forward. if you are rendering as progressive, make sure that compressor is set to keep it progressive, that may only apply to 24p to avoid compressor from putting in a pulldown… but check for that.

one other thing, since the destination is 16:9, is your camera capable of shooting 16:9 sd? if so you would like to shoot that way, and mpeg2 supports 16:9 sd with the correct resolution and pixel aspect ratio, so on a widescreen tv it will fill the screen without having to do a zoom or stretch the picture.

for the record widescreen (16:9) sd is 720×480 with a pixel aspect ratio of 1.33.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Kevin Camp]

oh, and in response to the noise effect question, yes the noise effect in ae… i’ve often use a setting of about 3-5, mono chromatic noise, when i’ve started to see banding due to limitations of 8 bit/channel color blending… a little different then what you’re getting, but it might be a place to start.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Kevin Camp]

actually, if all your footage is keyed, you wouldn’t need to shoot widescreen, as long as the sides of the shot were keyed out. then the keyed video cound be taken to a widescreen comp for compositing, making that fill the 16:9 hd set…. i forgot you were keying…

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Paul]

Thanks for all your help. I’ve got a couple more questions and I still hope that you’re getting posted on this.

We shot the greenscreen and pulled a pretty good key. I noticed..(how couldn’t I) that the DV footage almost looks de-interlaced when previewing back on the computer. If the person doesn’t move then it looks pretty good but movement shows lines every other line…much like de-interlacing.

I read a little about this and am trying Chroma smoothing using an adjustment layer but just wanted to hear what you had to say on this.

Also, any advice when capturing the DV25 into a NLE (Final Cut or Premiere – have both) and then export settings?

Definitely learning a lot on this one.

sincerely,
Paul

[Kevin Camp]

when you key you would like to de-interlace the footage (remove the field lines). ae usually does this on its own, when it knows the footage is interlaced, but sometimes you need to tell it the footage is interlaced. if you can see the interlace lines in ae’s preview window, select the footage in the project window and choos file>interpret footage>main. from the interpret footage settings, select separate fields and the propper field dominance (lower for dv) and hit ok.

now, the footage should not show the interlace lines. if you want to get the interlacing back at render time, from the render settings (click where it says ‘lossless’), choose render fields, setting it back the correct dominance.

a little chroma smoothing can often help, there is also a effect preset that can make it easy, called ‘remove dv blockiness.’ you can apply on the footage prior to the keying effects. in the effects palette entry field, just type ‘dv block’… it should show up.

if you can export to lossless or uncompressed, ae will work a little better than with dv footage, plus you’ll avoid any recompression of the footage prior to keying. if you can’t afford the disk space for lossless/ucompressed files, try pulling the dv straight from the capture scratch folder (fcp, but ppro should have a similar folder) to avoid any further compression.

rendering out of ae, i would render to lossless animation or uncompressed and let the nle convert it to dv… i think ae (or maybe it’s quicktime) does a lousy dv compression. if disk space is really tight and you don’t need to export an alpha channel (your keyed footage is already composited on a background in ae), photojpeg is a good option, it would be a selection from the render queue in the output module, click format options and select photojpg from the pulldown.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Paul]

I’m using CS2 apps so I will go in and see if that filter you mentioned is in there.

My workflow is:

1. capture best green screen possible ( camera on manual, manual exposure, aperature 2.0f, manual focus, tons of lights, big screen good audio)

2. unfortunately caught on DV25 cam.

3. Capture infor FCP or Premiere as a SD comp.

4. Edit on timeline

5. export as Microsoft DV AVI uncompressed. When I just play this back in Media Player or Quicktime here’s where I see the fields. IS THIS BECAUSE I’M VIEWING ON THE COMPTUER AND NOT A NTSC TV? The Uncompressed option without that Microsoft descriptor don’t play back.

6. Open that uncompressed footage in AE 7.0. Use Keylight and adjustment layers, garbage mask.

7. Render out of AE using the Animation(lossless) codec to a video file.

8. Slap that baby into Compressor and give it the best MPEG2 settings that I can.

Does that sound about right?

By the way.. space isn’t really a consideration as I have at least 100GB of space on my 10K hard drives.

Thanks for your tutelage on this.

[Paul]

One last question and I’ll leave you alone. By the way, you’ve really helped out.

Ultimately I’m headed to 16:9 or landscape. Is that going to cause headaches when I take the 4:3 footage into it and stretch it too much?

Anyway, there’s so much to learn.

Thanks again.

[Kevin Camp]

hi paul, sorry i haven’t had time to update posts….

but in regards to seeing fields on the computer playout… yes, you will notice them more on a computer monitor. this is because a computer’s screen does not refresh using alternating fields.

and you will be headed for some problems taking 4:3 sd to 16:9 sd if you need to scale the 4:3 to fill the 16:9 screen. if you footage is keyed out on both sides of the screen, then you shouldn’t have much of a problem, you will just take the keyed comp/footage into a 16:9 comp to composite on 16:9 footage/comps/layers etc.

but if you have to scale up the 4:3 to fit 16:9, then you will need to make sure that the 4:3 interpret footage settings are set to separate fields (lower) and it would probably be best to choose smooth edges. if you are going to render out progressive, then you may also want to try enabling frame blending. if you are going to render back to fields, you probably don’t need to try the frame blending trick.

by the way, ae defaults to progressive, if you need fields back in, set that in the render settings.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW