DVDs - Interlaced Image

[LordVader]

I'm capturing my videos at 720x480 (AVI), of course i get an interlaced image at 480 lines.

Using "de-interlace" filter in tmpgenc will reduce sharpness and image quality , so i'm compressing my videos to DVD format with the INTERLACE option enable , but the video doesn't move smoothly in my DVD player. why is that ?

wich compression method i should use to compress interlaced videos ?

i mean, original dvds has the image interlaced and plays smootly. Then , what's wrong with my videos ?

[TaranScorp]

Are you encoding top field or bottom field first?

[LordVader]

"bottom field first"

[TaranScorp]

Try top field first, that is what I use with VirtualVCR but CCE likes bottom field first for VHS interlaced material.

[BJ_M]

top field or bottom field or field 1 /2 is dependent on the source material - and not on the encoder ..

DV is aways bottom field ... anything else can be either .. get it wrong and it is bad ...


interlaced pictures on a pc look bad unless your playback software auto de-interlaces it .. but just making it look "good" on a pc will have the oppisite effect on a tv where it is interlaced anyway (unless you have a progressive scan tv) .. de-interlacing will cause the 2 fields to be blended and time skewed - which will caue the picture to look jumpy on a tv ..

only time you deinterlace is when it is going to be only used on a pc .. or there are some time you have to use a decomb filter -- but best not to de-interlace if your going to play back on a tv ..

and get the field order correct .

[JPHenry]

But what if you're trying to make a DVD that will look great on both? I'm making a reel of my work for potential employers and some will use a standalone DVD player and others will use computer - can't I just encode Non-Interlaced to be safe either way?

[BJ_M]

if you want both -- try a decomb filter in v-dub .. or deinterlace filter merge fields in tmpgenc ,, but encode it as interlace


if you want it to look good ona pc also tell your clients to use windvd or powerdvd or such to view as they will play interlaced material proper on a pc and also display aspect ratio corrrect which media player will not always .

[JPHenry]

By "deinterlace filter merge fields" in TMPGenc - is that Double Deinterlace?

So to get a video that looks great on PC and standalone player I should deinterlace with the filter and then encode it as interlace?

How will that be better than encoding it interlace when the original source is already interlaced? (Captured VHS)

[LordVader]

like i said, original DVDs are interlaced and look great on PC and TV

my videos are not DV , so i don't know if they are "bottom field"

my videos are just 720x480 normal RGB format.

has to be a way to compress this videos like the original DVDs , because using a de-interlace filter will just reduce image quality & sharpness.

[DJRumpy]

I've asked this one before. Is there a definitive way to tell which field is first? Is there a program out there that can say with any certainty that Upper Field, or Lower Field is first?

[LordVader]

does the "field" matter ?

i mean, i have tried both methods compressing interlaced videos.

Top field & bottom field , and both doesn't play smooth on my DVD player.

-------------------

if i have a VCD file and i want to convert it to DV format & recompress to DVD. i should use a method.

What i want to know is :

the prob is on the AVI file o tmpgenc just don't recompress interlaced videos in the exact same way like original DVDs ?

[DJRumpy]

Actually, I have since found a method to identify which field is first in an AVI. You can use AVISynth, and a script to identify which field should be first.

It looks like this:

# Modify the line below to reflect the actual path and file name of your video.

AVISource("capture.avi")


AssumeFrameBased

# To begin, leave the '#' before the 'ComplementParity' function.
# If the video plays smoothly with the '#' in place,
# the video is bottom (even) field dominant.
# If the motion in the video is jerky,
# remove the '#' before 'ComplementParity'.
# If the video plays smoothly now,
# it means your video is top (odd) field dominant.

#ComplementParity


SeparateFields

# Don't forget to save this file after making changes.

[LordVader]

this method doesn't apply for re-encoding of mpeg-2

if i have a VOB(Mpeg-2) file & i recompress to mpeg-2 just to reduce the bitrate, and i do it on interlaced mode, the video doesn't play smooth, on the DVD player.

So what's happening then ?

i mean, if i just decide to recompress an original "DVD Interlaced Video" to an "DVD Interlaced Video" it will not work......

why not ?

[DJRumpy]

MPEG is much eaiser. Use Bitrate Viewer. It will tell you which field is first.

I'm wondering if you could post more info on your source material. You say it's from a DVD, but it's interlaced? Have you also verified it's not telecined material?

[LordVader]

Just imagine that you're rripping an entire dvd to your machine.

Now you have the entire Movie in VOB material

(Original DVD Material Interlaced, right ? )

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Now you want to recompressthe mvie to a lower bitrate, but you don't wanna de-interlace, because the original source material, is not interlaced.
right ?

what you want to do is to recompress the movie or a music video or anything else, to a lower bitrate without touching this specs, inte way Re-MPEG do.

you know what i mean ?

[BJ_M]

many dvds are both top field and bottom field mixed together .. along with 24p source with pulldown .. as well as progressive source 30 (for menu's and title cards)

i mix all 4 all the time on comercial dvd's just to screw up everyone ..