dv -> dvd: deinterlace or not?

[dvbert]

I'm about to transfer my personal video from miniDV tapes to DVD.
I'm pondering whether or not to deinterlace the video.
When I search this forum & web I mostly find recommendations
to leave the video interlaced so that it looks good on a tv screen.
But I'd like the DVDs to be a bit future proof. Ten years
from now, a lot of CRT TVs will have been replaced with progressive
displays. It would be great if I don't have to start all over again then and
deinterlace everything. (I have 30 tapes of 60min now, and counting)

So I have a couple of questions:

1. Doesn't interlaced video look awful on a progressive display?
(I don't have a living room model at hand, but on my PC it doesn't look good)

2. If so, is there a deinterlace method in TMPGEnc where the output
looks good on both interlaced and progressive displays?

3. As I understand it, the "even field" and "odd field" methods reduce the vertical
resolution by 50%. Is that correct?

4. The "double" and "double (adaptation) methods seem to replace the "comb" zone with a blurred zone. Is this really an improvement in real world (living room) viewing conditions?

5. Is the quality improvement for progressive displays big enough for a deinterlace step to be worth the trouble?

TIA!
Kind regards,
Bert

[edDV]

I'm about to transfer my personal video from miniDV tapes to DVD.
I'm pondering whether or not to deinterlace the video.
When I search this forum & web I mostly find recommendations
to leave the video interlaced so that it looks good on a tv screen.
But I'd like the DVDs to be a bit future proof. Ten years
from now, a lot of CRT TVs will have been replaced with progressive
displays. It would be great if I don't have to start all over again then and
deinterlace everything. (I have 30 tapes of 60min now, and counting)

TIA!
Kind regards,
Bert

You can deinterlace if you want for today but if you value the material for the future you will maintain the interlaced DV format as an archive. Future encoders will want to see the full resolution of native DV.

[dvbert]

Quoting from this post in another thread:

A progressive TV will have technology built-in to either perform an IVTC or to deinterlace the video so that it appears normal.

So it looks that my interlaced video has a long future ahead and deinterlacing it now is not worth the trouble?

[edDV]

So I have a couple of questions:

1. Doesn't interlaced video look awful on a progressive display?
(I don't have a living room model at hand, but on my PC it doesn't look good)

Not if you use a quality deinterlacing player.

2. If so, is there a deinterlace method in TMPGEnc where the output
looks good on both interlaced and progressive displays?

NO. You can optimize for low processing 29.97 progressive or for 59.94 fps interlace. High processing players will support 59.94 frame per second progressive (from NTSC) or 100 frame per second (from PAL) to minimize flicker.

3. As I understand it, the "even field" and "odd field" methods reduce the vertical
resolution by 50%. Is that correct?

YES/NO Do you mean tossing a field. If you toss a field you get half vertical resolution AND half motion resolution (29.97p) which is a guarantee for flicker on a good display (unless the display is smart and repeats frames).

4. The "double" and "double (adaptation) methods seem to replace the "comb" zone with a blurred zone. Is this really an improvement in real world (living room) viewing conditions?

What software is this? Comb usually refers to comb filter on NTSC or PAL. "Double" usually refers to "line double" AKA "bob". High quality deinterlacers will use a motion adaptive mixture of bob, weave and drop field on a pixel block basis. Much of what you get on TV has been processed this way on very expensive equipment. This technology will soon make it down into consumer HDTV.

5. Is the quality improvement for progressive displays big enough for a deinterlace step to be worth the trouble?

Moderately expensive progressive displays come with a deinterlacing engine (often dubbed "cinema" or "wega") that search for interlace or telecine patterns and apply increasingly sophisticated image processing to optimize display. These will get better and better in the near furure as you replace your TV. HDTV technology is in a period of rapid improvement. Spend only what you need now. Next year's set will be much better. Look for a transiton set that will be in the bedroom in 3 years.

If you use software deinterlace today, you are locking that clip to today's software technology. It can't be reversed. That is why you want to save the interlace DV master for the good stuff in the future.

Note: I'm not talking about film telecine. That can be IVTC'd with today's technology.

[dvbert]

3. As I understand it, the "even field" and "odd field" methods reduce the vertical
resolution by 50%. Is that correct?

YES/NO Do you mean tossing a field. If you toss a field you get half vertical resolution AND half motion resolution (29.97p) which is a guarantee for flicker on a good display (unless the display is smart and repeats frames).

Yes I mean tossing a field. Losing half of the resolution is not an attractive option.

4. The "double" and "double (adaptation) methods seem to replace the "comb" zone with a blurred zone. Is this really an improvement in real world (living room) viewing conditions?

What software is this? Comb usually refers to comb filter on NTSC or PAL.

With the "comb zone" I mean the jagged edges of horizontally moving objects.

5. Is the quality improvement for progressive displays big enough for a deinterlace step to be worth the trouble?

Moderately expensive progressive displays come with a deinterlacing engine (often dubbed "cinema" or "wega") that search for interlace or telecine patterns and apply increasingly sophisticated image processing to optimize display. These will get better and better in the near furure as you replace your TV.

OK, I think I'll make my DVDs with interlaced video.

If you use software deinterlace today, you are locking that clip to today's software technology. It can't be reversed. That is why you want to save the interlace DV master for the good stuff in the future.

Any ideas on how to store the DV master? The AVI files take 13 GB per hour of video on my HD. I tried zipping them, but they still take 90% of the original size. Should I burn close to 100 DVD-ROMs of 4.7 GB to store my 30 hrs of master video?

[guns1inger]

Keep on the tape if you can.

[dvbert]

Keep on the tape if you can.

I won't throw away the tapes, that's for sure.
And their switch stays on "read-only"
I was only thinking of a more randomly accessible medium, like DVD-ROM.

[guns1inger]

If it really needs to be that accessible, you could consider either and external drive or caddy drive bay and a good sized drive.

[edDV]

I edit out the crap on my camcorder tapes (lossless) and on average save about two thirds of the original takes. Then, I also keep an edit master in DV format on tape plus the DVD master for copies.

When the Blu-Ray 25GB/side DVD writers get reasonable in price, I'll dub the data to DVD @ ~115 min per side or ~460 min per 4 layer DVD.