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1080p 24 to NTSC DVD stutters because of improper pulldown or fields rendering?

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Dominic Lamontagne1080p 24 to NTSC DVD stutters because of improper pulldown or fields rendering?
by on Mar 4, 2013 at 9:08:01 pm

Hello all,

Though I worked a lot with field rendering in my "NTSC, 30 drop, VideoVision, 20th century" past, this is my first serious foray into square pixels, pulldown and 23.976 (24 drop?) territory.

At the moment, I am imitating rather then understanding...

Though Dave LaRonde's and Kevin Camp's insight have come close to putting me on the right track, I have to ask, what is wrong with my workflow here?

Here it is:

Using AfterEffects CS5 (Mac OS 10.7.4), I import Canon Rebel 3Ti footage shot in this DSLR's setting called "1920/24" (which many people refer to as 1080p 24)

On import, AfterEffects interprets the files, correctly I think, as 1920x1080, PAR 1.00 (Square pixels), 23.976 fps, fields off (since the footage is progressive and non-interlaced). From what I understand, I should leave this interpretation as it is, even if my end product will be an NTSC DVD which I understand is 720x480, 29.97 fps, Lower field first video.

I understand that HD broadcast 1080i / 60i is UPPER field first. But this is besides the point since my footage is 1080p and my delivery Lower field first on 720i / 60i NTSC DVDs, right?

So, I build my project as a 7 minutes long, 720x480 comp, with a 0.91 PAR (to get an accurate "play field") but kept the frame rate at 23.976.

Then, I rendered. Output module was set to Lossless (QT animation) with uncompressed AUDIO and render settings to
720x480, Lower Field First, WITH pulldown WSSWW.

Introducing this pulldown effectively changed my frame rate from 23.976 to 29.97 (what I used to call 30 drop).

This produced an 11 GB audio/video .mov file which I imported into Media Encoder CS5.
Encoder properly identified this source footage as 720x480 (0.9091), 29.97 fps, Lower
Then I chose MPEG2-DVD format and used the Match Source Attributes (Highest Quality) preset.

Consequently, the summary for the output was: NTSC, 720x480, 29.97fps, Quality 5.0, Lower / PCM, 48 kHz, 16 bit, STEREO / VBR, 2 Pass, Min 3.00, Target 6.00, Max 7.00 Mbps.

This, in my experience, will play fine on most, if not all, DVD players.

Encoder produced 2 files: MyDVD.m2v (315.6 MB) and MyDVD.wav (80.9MB)

I dropped these two in TOAST8, and burned a "DVD-Video" single layer DVD.

PROBLEM#1: Now, my problem is that the DVD, when viewed on SD TVs, though playing smoothly (with perfect sound), exhibits a slight stutter every second or so (maybe every 20 frames...). This is not a data rate issue.

Really looks like a pulldown/field rendering problem.

If this can help: stutter in motion is more noticeable on (AfterEffects) generated pans (slow crawls) where I slowly pan across a 1920x1080 footage item from "inside" my smaller 720x480 comp.

PROBLEM#2: On top of this, I'm trying to understand why sound plays distorted (too loud, clipped) when I play these DVDs in a Blu-ray player connected to an HD TV through HDMI cables... Sound is perfect on all DVD players connected through component or composite cables to SD TVs as well as on any computer with a DVD drive (which is all of them I guess). I gate the master audio at -4db...

Have these been answered over and over again in other threads?

If so, please point the way.

Thanks for your help and advise.


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