Help with HD @ 29.97fps to DVD at 25fps

[Killer3737]

Ok I convert a lot of HD to DVD without issue, always keeping the framerate the same as the input. However, I'm making a compilation DVD of something, and whereas most of my source material is PAL (from UK TV), I have one video in HD at 29.97fps, as it was shown in the US. Now since converting all of the already standard def material to NTSC wouldn't make much sense, i'd like to downscale the HD to PAL DVD, so 25fps, 720x576, to fit on the DVD with the rest of the video.

I'd just like to know the most efficient way to do this basically. For straight conversions i generally use DGIndex and then an AVISynth script into my encode, so a similar script for what I'd like to do would be great. Here are the details of the video from mediainfo:

Video
ID : 224 (0xE0)
Menu ID : 1 (0x1)
Format : MPEG Video
Format version : Version 2
Format profile : Main@High
Format settings, Matrix : Default
Duration : 26mn 9s
Bit rate mode : Variable
Bit rate : 13.5 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Colorimetry : 4:2:0
Scan type : Interlaced
Scan order : Top Field First
Bits/(Pixel*Frame) : 0.217
Stream size : 2.47 GiB (92%)

So basically I'd like to know the best way of converting that to PAL 720x576i.

Thanks.

[manono]

If it's from film, then you either "Force Film" in DGIndex to make it 23.976fps, or you use "Honor Pulldown Flags" in DGIndex and IVTC back to 23.976fps in the script. Which you do depends on how it was encoded. Is this film? If you don't know, provide a short sample, one with movement.

Then perhaps the easiest way is to do a straight resize to 720x576 (if progressive already). Encode at 23.976fps followed by DGpulldown set for 23.976->25.000fps. That avoids having to stretch the audio. Any templates or compliant DVD settings in your encoder might have to be disabled or turned off to allow you to encode 23.976fps at 720x576.

If the source is pure interlace (shot on video and not on film), then there are other ways to convert to PAL, none of them optimal.

[Killer3737]

It's a TV music show from 2002 and 2005, so i'd assume it's video, but i'll make a sample shortly for you to check.

I do have another source the video in pure PAL, but it's analogue TV > VHS sourced, so i'm pretty sure this HD source should look much better, even once converted to PAL. I also think it's actually an upscale, doesn't look true HD to my eyes anyway, but still, better than the VHS.

Anyway, i'll get that sample sorted shortly.

Thanks

[Killer3737]

Sample:
http://www.mediafire.com/?wzz2ynzkw0n

Thanks.

[manono]

I admit to being baffled with this thing. It's not film, though. Damn music videos! There's clear evidence of field blending and I think it started life as an interlaced PAL video. But I'm not positive. I have 2 solutions. For both make the D2V using Honor Pulldown Flags. If you want to keep it interlaced when converting to PAL, with no attempt to unblend it:

AssumeTFF() #if TFF
Yadif(Order=1,Mode=1)#or your favorite bobber
LanczosResize(720,576)
ChangeFPS(50.00)
AssumeTFF()
SeparateFields()
SelectEvery(4,0,3)
Weave()
ConvertToYUY2(Interlaced=True)#if needed for your encoder

That'll give you an interlaced PAL 25fps video ready to encode at 16:9. My other way, and the one I prefer, at least partly because you get progressive video out of it, is an attempt to unblend it to 25fps:

Yadif(Order=1,Mode=1)#or your favorite bobber
LanczosResize(720,Height)
SRestore()
LanczosResize(Width,576)

Both ways keep it the same length so the audio doesn't have to be stretched. The second way does seem to drop unique frames every now and again, but with all the movement it's not really noticeable when being played. Perhaps someone else will come along with a better idea.

http://avisynth.org/mediawiki/Srestore

[Killer3737]

Thanks, i'll try both tommorow and see how I get on.

[Killer3737]

I'm just getting around to doing this today, and I have one quick question that i've always wondered. I use Cinema Craft Encoder as my MPEG2 encoder, and feed the AVS file straight into it. Now my question is, do I need to adjust the settings inside CCE to correspond to what I want the output to be, or will the AVISynth script do that for me? So In otherwords, how should I set this screen, like this:




Thanks.

[manono]

As long as you don't have that "For DVD" box checked (and you don't), you can do about anything you want in the script. Over on the left, I also have Top Field First, but for the Offset Line I have 0 instead of your 1. Which it is, though, depends on how you're encoding interlaced material. If you leave it the way it is now, and if you encode following the interlaced script and the result plays real jerky in the standalone, then that's the reason why. And if encoding the progressive script, add a:

ConvertToYUY2()

to the bottom of the script. You have Multipass CBR checked and I would never use that and, in my opinion, neither should you. You're using a different CCE than I have, and mine doesn't have a "Rate Conversion" box, but since you're feeding it a 25fps script, and since you have the 25fps box checked, you're not doing a rate conversion. The rate conversion already took place in the script, before being fed to CCE. But maybe it doesn't make any difference whether or not the box is checked. I don't know. Always test your scripts in VDub(Mod) before sending them to the encoder, to make sure they're OK.

[Killer3737]

Thanks. Any specific reason i shouldn't use multi-pass CBR? That's just how i've always done it to be honest.

[manono]

VBR encoding results in better bit distribution. A case can be made for using CBR encoding for short length DVDs (an hour or less), but for full length stuff (like movies or a large compilation DVD) VBR is the way to go.