HD, DV and stills theory

cheroxy wrote on 12/30/2003, 7:12 PM

I asked this question a few months ago in another forum, but didn't get a real satisfactory answer. I have also seen this topic touched upon here a few times, but never really answered completely. So...

I know garbage in - garbage out, but given two scenarios:
1-video shot in HD and rendered at a CBR of 6.5
2-same video shot in mini-DV and rendered at a CBR of 6.5

Question 1=
With these two scenarios how much of a difference will there be?

I am asking this question for a couple of reasons. First off, when I see my videos on my home 27” TV monitor they look perfect clarity wise, and then when I see them on my father’s 55 inch, they look terrible. Secondly, I have heard that higher megapixel still shots are psuedo-HD.

Question 2=
If I rendered my video and stills as HD would the quality improve for either or both?

Question 3=
If so, how? Why would the same bit rate be better with HD? I know that HD has a higher resolution when filmed, but…Even mini-DV loses quality when rendered to mpeg2 for DVD playback. For whatever reason HD is better, why can’t some of that be incorporated into the render for a better quality? I hope this isn’t too confusing. I just don’t understand how rendering mini-DV to mpeg-2 loses quality, but when you render from HD to mpeg-2 you can have a better image. I imagine I am missing some basics here so please fill me in.

My anticipated answer will simply be, “Carson, don’t worry, just render your mini-DV video to HD and it will look better on the big screen tv’s.” :)
Thanks,
Carson Calderwood

Comments

Spot|DSE wrote on 12/30/2003, 8:12 PM

#1. Big difference, simply because of acquisition formatting. You can see this VERY easily by taking an original still of larger size, and the same still, reduced in size and compressed to JPEG for instance, and rendering them both out from the timeline as MPEGs. HD, depending on the cam, is also a lower compression formula, therefore there is more information to work with/see.
#2. No. Because it was never there to begin with. You CAN make fake HD, and pull off some saturation differences, etc. But it still won't be as rich and deep as a properly lit and shot HD image will be.
#3. #1 sort of answers this, there is more for the encoder to look at and process, so the colors, etc will be richer regardless of bitrate. Look at it this way....
Aside from encoding differences, why do Hollywood films look so much better than your encodes, when Hollywood's stuff is done at, or even lower bitrates than you are doing? Because there is more information/cleaner image/saturation, and a dozen other reasons, existing in the originating media. Remember, DV is 4:1:1 media, and a lot of Hollywood stuff at WORST is 4:2:2, which is what some HD stuff is, some is 4:4:4 (uncompressed) and some is other compression schemes, all of which are designed for a richer, highly informed image.
You *could* experiment with going from DV unprocessed to uncompressed HD (heaven forbid) doing all your color correction, filters, transitions, etc, and there *might* be a slightly better image when you render the uncompressed to MPEG, but I'd doubt it. That's one I've not looked at.
For a good test, create a project using generated test media and some DV, stills, render directly to uncompressed, and then render that to MPEG. Make it short, waste a disk, put on your bigscreen, and see. I'd be interested. Occasionally for giggles, I'll monitor on our cinema screen for scoring, where it's a 10' screen/projection system. You can see a huge diff when going from HD to DV, but I've not tried doing the DV to HD to MPEG cycle on the bigscreen.
Let us know what you get!

cheroxy wrote on 12/30/2003, 9:00 PM

I have been thinking for a while to do a project like that. Use DV and high res stills to render out in the various formats and see how each turns out. I'll do that after I get back to my computer after the holidays and post it.
Thanks for the reply.

farss wrote on 12/31/2003, 5:29 AM

I've done some very HiRes stills straight to mpeg-2 and they look fantastic, mind you they were damn fine stills to start with. About 10 of them on the TL and Vegas just about stopped dead,I ended up converting them from tiff to png at half the res and Vegas was still having trouble but it got there in the end.

The other thing I've done is gone from SP via component into Miranda DV bridge into Vegas and encoded to mpeg-2. Now I'm still going DV to mpeg-2 right? Well it looked much, much better than anything I've done that was shot on DV and then to mpeg. The SP footage was straight from the studio, shot on boadcast cameras. Now the resulting DVD looked damn close to the original SP footage. I haven't any real explanation but I suspect that a lot of what's blamed on DV compression has more to do with the quality of the optics and the signal processing in the camera prior to DV compression. Also I'd bet lighting has a lot to do with it, harsh daylight seems to bring out the worst in DV, particularly in this country with dry air, little haze and high UV.

cheroxy wrote on 12/31/2003, 6:56 AM

When you say,

are you regularly transfering the DV to your computer via firewire? I can understand why you would get better quality if you usually are not. But, if you regularly are using 1394 then the improved quality from this other method is something very interesting.

Bill Ravens wrote on 12/31/2003, 7:08 AM

I'm routinely shooting stills with my Canon 10D and creating a slide show in Vegas that includes these stills(3000x2048 native) intermingled with DV video(720x480 native) and rendered out to either MPEG2(1080x720) or WMV9(1280x720), which I consider to be HD. The MPEG2 1080-30p format will burn onto a DVD and play fine in my DVD player. While the rendered product is "only" 1080x720, I do some pretty big zooms on the stills during editting, which takes advantage of the native 3000x2024 image . The zooms I do on the still images maintain clarity thru a pretty big zoom ratio. When all is said and done, I am continually amazed (aka awestruck) at the beauty of the 1080x720 still images on my 32" Sony TV. The native 720x480 video footage looks obviously fuzzy and of low rez compared to the stil limage footage. In fact, I'm having customers starting to complain about the poor quality of the DV footage when the previous image was an HD still image. Everything is relative and the still image footage shows up so well that it makes the video footage pale in comparison. I just can't say enough about the image quality of what you are calling "pseudo HD".

BD wrote on 12/31/2003, 7:52 AM

I've had similar experiences over the years: Quality in = quality out.

Yesterday I edited some 3000x2000 JPG scans of medium-format neg's, rendering them into an MPEG2 file in Vegas. The MPEG video looked very similar to the original scans, when compared on my 25" Sony TV set (via Vegas external DV preview). This MPEG had better color than any DV I've captured with my Sony VX-2000.

35 years ago, I demonstrated Phillips audio-cassette recorders (the very first model available in the US) at a department store, by connecting them to an average-quality stereo system to play and record music. Most customers couldn't hear the difference when compared to a $400 Sony reel-to-reel tape deck, although the Phillips recorder was designed for voice recording only..

Brandon's Dad

Spot|DSE wrote on 12/31/2003, 8:45 AM

Bill, your stills would be HD. So the 'psuedo' part of it is the DV scaled up to HD. It's got the pixels, but as you are finding, the DV just doesn't cut it compared to a highly defined image such as you are achieving with your digital still cam. You are actually down scaling the stills.....Just imagine that great resolution and color depth on everything, straight from the video cam....That's pretty cool.
Your experiments that you've mentioned on the DMN caused me to do some lengthy conversions using test media generated, printed and still-shot, and video shot. Just as you reported, whopping monster difference in final output regardless of the compression. It's all in the acquisition. Which has sort of always been the point.

Bill Ravens wrote on 12/31/2003, 10:30 AM

Douglas...

yeah, I never thought taking DV to HD would provide anything. As you've said many times, "you can't get something from nothing".

Indeed, my stunning still images are, most definitely, down converted for HD(3000x2024 to 1080x720).(you should see them in hard copy print!) Having seen what this looks like on HD, I'm absolutely chomping at the bit to get my hands around an HDCAM. I don't like the JVC offerings, so, I guess I'll have to wait for the next offering from Canon, aka XLs2? I was also looking at the Cineform Connct HD capture card and dreaming of the possibilities.

I shot an incredible piece at Canyon de Chelly with stills and DV. The shots of Spider Rock and the pans and zooms I did with Vegas just blew my mind. Everyone has been asking what film camera I used, LOL. There's a lot of celluloid die hards around here that can't beleive what I'm doing with DV. I think they're beginning to get the message that DV can be made to rival celluloid.

BTW, VERY nice article you wrote on 24fps conversion,thanx.

I can't wait..;o)
P.S. I've been shooting DV, exclusively, in the XL1s film mode. After reading your article, I think I'll go back to interlaced. I've been willing to accept the loss in rez that goes with film mode, but, maybe I'll try interlaced again.