MS7 and Horizontal Lines When Rendering HD to NTSC DVD

[woodti]

I've just recently purchased MS7 and the HD Plug-in for use with a Sony HD Camcorder. I'm following the workflow that Ulead publishes on the website for the HD Plug-in, but getting horizontal lines in the NTSC DVD MPEGs I'm producing.

I can capture just fine using the plug-in, but when I do Create Video in the Video Editor and save it to MPEG with NTSC DVD options, I get horizontal lines in the video. If I do a Convert, the lines are even worse. Or, if I pull the HDV/1080 mpeg into DVD Workshop 2 or MovieFactory 2, the lines are also worse than using Create Video.

Anybody know what I need to do using MS7 to produce DVDs from HDV without lines? (Microsoft's MovieMaker 2.1 does seem to convert HDV mpegs to DVD ok.)

Thanks in advance for any help.

[Devil]

Please give us details:
format of your footage (i or p)?
if i, which field first?
conversion to 480 or 576 i or p?
if i, which field first?
viewing on TV or computer monitor?

[woodti]

>> format of your footage (i or p)?
>> if i, which field first?
It's captured as 1080i, Upper Field first. The Ulead HD Plug-in gives no choice on the settings.

>> conversion to 480 or 576 i or p? if i, which field first?
480 and I have tried converting to both Upper and Lower first, and both exhibit the problem.

>> viewing on TV or computer monitor?
The lines appear when viewed on either a TV or a monitor, though my goal in putting it on DVD is to share the videos with family.

[Devil]

Can you please do a screen grab of what you are seeing and post it on a web site you can link us to? Personally, I've no practical experience of HD, but others here have and may be able to help you.

[woodti]

Here's a link that shows the original and the converted. You can easily see the lines on the boy's face in the "test_convert" image. http://pg.photos.yahoo.com/ph/woodti/album?.dir=/d9e2

[Grandpajack]

I joined this forum today looking for an answer to the same question.
Horizontal Lines show on burn DVD when viewed by playing on the computer and on the TV . They don't show on the computer when viewed as a finished file ready for burning. The lines seem to happen during vertical subject or vertical camera movement.
I'm a rookie. Have an FX-1 for 3 weeks and MSP 7 for 2 weeks and I need all the help I can get

[Devil]

OK, the lines on the kid's face are very typical of interlacing problems. The first thing you must realise is that, when viewed on a 'puter, either as a still image or as a video, you will always get these lines when the original is interlaced and there is horizontal movement of the subject. In that case, you must deinterlace the image to view it with the minimum of artefacts.

That having been said, on the HD image, the kid's head is blurred, also because of the movement, but it is less obvious because of the greater number of lines.

An interlaced image is best when viewing on an ordinary TV, which is designed for this purpose, and if you try to look at a deinterlaced image, you get the opposite effect, because alternate fields are not different, when they should be. This causes rapid movements to appear jerky and ill-formed.

Now, why should conversion from 1080i to 480i produce this? I cannot be sure, but it is not impossible that, because there isn't a direct mathematical relationship between 1080 and 480 (2.25:1), an effect akin to strobing may occur between the different positions in each field (my speculation). If this is so, I suggest you try a) deinterlacing the 1080 video and b) re-interlacing it (I don't think it will make any difference which field is first) when you convert to 480 and c) burn a DVD and view it on the TV, not on a computer. Note that my answer is theory and not practical experience, but please let us know how you get on.

[Gorf]

...Now, why should conversion from 1080i to 480i produce this? I cannot be sure, but it is not impossible that, because there isn't a direct mathematical relationship between 1080 and 480 (2.25:1)...

That's exactly the reason for the problem. If you just convert 1080i to 480i without some form of pre-processing, you're going to end up with an eggagerated interlacing problem.

(preamble)
Normally, TV-viewed footage which has its interlacing done incorrectly exhibits one of two properties. 1) It's blurred, because the editor has seen this as the best way to avoid number 2 - not realising that simply switching the field order will fix the problem. 2) Vertical details flicker during horizontal movement of the camera or subject.

There is a third - which is where the footage has been identified with the wrong field order, but so has the project. When this happens, vertical movement within the footage appears fine (two wrongs making a right) but the transitions, slow motion etc (anything requiring a field-order-dependent render) are wrong.

Finally, you have non-interlaced footage which displays without flickering (even on pause) irrespective of the prevailing field order. Each frame is more detailed, but movement is not as smooth because there are half as many apparent updates to the screen.

(Relevant bit)
So why the thick bands with this particular example?

You're starting off with 1080 lines - 1 is odd, 2 is even, 3 is odd etc. You're wanting 480 lines, so only four out of every nine will be used (Devil's 2.25:1 ratio) so you end up with the following (left side is 1080i source, right side is 480i or p result):

01 O Use = O 01
02 E
03 O
04 E Use = E 02
05 O
06 E Use = E 03
07 O
08 E Use = E 04
09 O
10 E Use = E 05
11 O
12 E
13 O Use = O 06
14 E
15 O Use = O 07
16 E
17 O Use = O 08
18 E
19 O Use = O 09
20 E
21 O
22 E Use = E 10
23 O
24 E Use = E 11
25 O
26 E Use = E 12
27 O
28 E Use = E 13
29 O
30 E
31 O Use = O 14

etc

1072 E Use = E 477
1073 O
1074 E
1075 O Use = O 478
1076 E
1077 O Use = O 479
1078 E
1079 O Use = O 480
1080 E

(If you bung this pattern into a spreadsheet, you'll see it comes out at 480 lines used from your 1080)

So you can see, in each frame you're ending up with four frames from one field, then four from the next, then back to the first field for the next four etc.

So how do you overcome it? Deinterlacing will get you 540 lines which will resize down to 480p because the source will all be from one field or the other. You might want 480i to maintain smoothness. To do this slow the 1080i footage to 50% so that each field becomes a half-resolution (540p) frame in its own right. Render that out at 720x480 (they will be progressive frames, but that doesn't matter) then speed it up to 200% to put distinct fields back in.

Both these methods (deinterlace the source, and slow down to yield distinct fields) will still generate some banding, because Ulead's video software does not resample, it just removes a line. When it resizes from 540 to 480 lines, it will just keep 8 out of every nine lines. The result is that on some diagonal surfaces you may see stepping.

The only way of overcoming this that I can think of (without buying a dedicated tool such as Canopus Procoder) is to output the 540 line slow footage to an image sequence, use something like IrfanView to batch-resize the images with resampling, then bring the image sequence back into MSP. It's a lot of arseing about though.

[Grandpajack]

Does anyone know if this is addressed in MSP 8.