DVD-player-type and interlace encoding

[MJH]

Not sure where to post this, cause it's both a newbie question and a non-newbie TMPGenc advanced-setting question. I've read the doom9 guides on interlacing, but this issue is a bit off that and not directly answered by the guides I've seen.

Right now I have a regular TV (not a 1080i one) and a non-progressive scan dvd player that plays dvd-r's w/o any problems.

However I've run into an interesting difference between my TV/DVD set-up and my computer/DVD when I play a dvd-r made from interlaced video sources that are first edited in VideoDubMod, encoded with the(supposedly) lossless Huffy codec (to limit file size) and then MPEG-2 encoded by TMPGenc.

The video on the TV/DVD setup looks best if the originally interlaced video is encoded as non-interlaced but w/o running the TMPG deinterlacer. In this case the image is much sharper than the version that is run through the deinterlacer (the TMPGenc one set at setting 'Double') and just as smooth.

However if I play the DVD-R on my computer, the version that was not subject to de-interlacing ends up with pronounced horizontal 'lines' when there's a lot of motion, while the deinterlaced version looks better.

BTW, I tried to use the interlaced encoding-setting (which TMPGenc tried to default to with the interlaced video source) but the results looked awful; lots of blurry motion no matter how I tried to compensate with the motion-search settings.

So I'm wondering if I'm forced to make a choice between making one encoding for my current TV/DVD set-up on one hand, and then another for my computer plus future 1080i TV/progressive scan DVD player. If such a choice isn't one that people are forced to make normally, I can then go back to tweaking my encoding procedures, fairly confident that I don't have to produce 2 versions of each disk.

Thanks in advance!

MJH

[ammck55]

MJH:

I can't help you with this one, but I can send it over to the TMPG forum. The last question you submitted over there was well received and commented on, let's hope for the same results this time around. Good luck!:)

ammck55

[MJH]

I think I found a partial answer to my question on http://www.100fps.com/.

That means that when you deinterlace a movie for your computer or your projector or your TFT monitor, and you want to play it on a standard TV set, your software (or your hardware) have to interlace it again.

Example: There are 2 kinds of DVDs: Some have an interlaced format (like the examples above) and some are transferred from film to DVD directly, thus have 25 progressive frames encoded. This is purely a decision of the DVD company. Since TV sets expect you to feed them with 50 images per seconds (whether it's from your old analog VHS recorder or from your antenna or from your DVD player) you need to convert those 25 progressive frames to 50 images and send them to the TV set. That means you have to interlace them artificially (well, it's not interlacing in its original sense, but you are making 50 images out of 25 images) instead of letting the TV simply display those original 25 fps.



MJH

[MJH]

Ah - I found the answer I was looking for:

[quote]So, the question becomes : Do you need to de-interlace? The general consensus is yes, if you're driving a HDTV (from a progressive DVD player) or computer monitor. Otherwise, it's more debatable(sp).[quote]

This makes sense to me now. The computer is able to read all the frames without interlacing them again (like the TV does), and thus the TV smoothes the horizontal jaggedness out while the computer does not; hence the difference in quality.

MJH

[wongck5]

MHJ,

I hope my opinion will give you some help.

Personally I preferred interlace encoding, as the author in 100fps.com says, interlaced movie looks much more fluid on both TV as well as on computer monitor, especially when the source is truly interlaced like TV shows. Film (most are progressive but the DVD player give interlaced signal to TV sets) is different and I agreed that film should be deinterlaced by IVTC or decomb....etc.

However, I found that TMPG cannot give you good quality if you perform interlace encoding (no matter how high you set the bitrate), though this encoder give you excellent result for non-interlace encoding. Try LSX MPEG encoder or bbMPEG. You need to use higher bitrate, something like 7000 kbit/s.

To play interlaced Mpeg2 movie on computer, you need to use PowerDVD or WinDVD. They have good realtime deinterlacer (newer version preferred) and you wont see any horizontal line during playback.

Hope it helps. Try LSX MPEG encoder and it wont disappoint you.

[wongck5]

Add one point, the quality of non-interlace encoding of LSX mpeg encoder is much inferior when compared with TMPG.