Letterbox to Anamorphic with as little quality degradation as possible?

[beatchef]

Hello everyone, I wonder if you can help me

I've got a 2.35:1 picture in a 4:3 format dvd as an m2v and I want to convert it to anamorphic 16:9 (still with black bars) still as an m2v for authoring it into a dvd.

In virtualdubmod, I can get it to load the m2v and to trim 60 off the top and bottom with Null Transform and then resize bicubically back to 720x576 with Resize, which should technically make it 16:9 anamorphic? HOWEVER, I can't get virtualdubmod to export in m2v, only various avi formats or mkv, which would need further converting, and loss of quality as it would be going from mpeg2 to severely compressed avi back to mpeg2 and I don't have enough space on one drive to do it uncompressed as it would come to 168 gig.

What is the best way to convert from Letterbox 2.35 in 4:3 to 2.35 in anamorphic 16:9? it seems that Vdubmod will do everything I want but not output in the same format.

Thank you for any help you can give!

[guns1inger]

60 and 60 is for NTSC. For PAL you have to crop 72 from the top and 72 from the bottom.

I wouldn't use virtualdub, simply because it is limited in it's resize filters. For upscaling, I would be using Lanczos in Virtualdub. However personally I believe avisynth is a better option, and there I would use either Lanczos4Resize, or perhaps one of the spline resize filters.

If you still want to use virtualdub, use the frameserving feater to pass uncompressed video via a sign-post file to your mpeg-2 encoder. No need to encode to an intermediate format. Search the guides for Frameserving to find Baldrick's guide on setting up and using this function in Virtualdub.

[beatchef]

Hello, thanks for your prompt and clear reply!
I have never used avisynth before and I immediately notice that it's not a program in it's own right and you have to frameserve to it, another thing i've never done. Are you recommending frameserving from virtualdub to avisynth? I don't know what to run avisynth with and as of yet what script I have to write for it or how to get something to read that script or find that Lanczos4resize to download (is it built into avisynth?)
Thanks

[guns1inger]

Virtualdub has it's own frameserver built-in, so if you use it, you generally frameserve directly to your encoder. You might go from avisynth to virtualdub when encoding however.

Go to your virtualdub folder and run auxsetup.exe. Click on Install Handler, then OK. You should now be set to go.

Open your video in virtualdub, crop, resize etc, then click on File -> Start Frameserver. You will be prompted for a session name, then a file name. You can use the default for both if you wish. The file created is a sign-post file. It will never get larger than a few kb in size. You load this file into your mpeg-2 encoder (while the frameserver is running - don't shut down virtualdub until you are finished) and it will receive uncompressed video and audio from virtualdub.

[beatchef]

In your example, I'm not using avisynth and lanczos4resize at all? I don't have an mpeg-2 encoder I'm afraid, I'm new to this and am usually used to loading a freeware program and just telling it what to do in a user friendly gui and then letting it get on with it. this seems very much indepth and user-unfriendly.

What I gather is that you write a script in Avisynth's programming language which is saved as an avs file. You load that file as a video in Virtualdubmod and it'll do everything. So what I really need to do is work out the script for loading a m2v into avisynth, cropping 72 off the top and bottom and then using something to resize it?

[beatchef]

Something like

# Created by AVSEdit
# User 02/02/2008
LoadPlugin("D:\MPEGdecoder.dll")
MPEGSource("D:\movie.m2v",0,"")
Crop(0,72,0,72)
Lanczos4Resize(720,576)

?

I can't actually get MPEGdecoder.dll because http://nic.dnsalias.com/MPEGDecoder.html doesn't work for me here. Then again neither does http://forum.doom9.org/showthread.php?s=2f07caf796d3194134c02456bb62bb0f&threadid=80641 at the moment so I suppose I'll wait a day or so to see if they come back up.

[guns1inger]

You don't need to use avisynth. It is just another option.

From my post (above), all you really need is

Open your video in virtualdub, crop, resize etc, then click on File -> Start Frameserver. You will be prompted for a session name, then a file name. You can use the default for both if you wish. The file created is a sign-post file. It will never get larger than a few kb in size. You load this file into your mpeg-2 encoder (while the frameserver is running - don't shut down virtualdub until you are finished) and it will receive uncompressed video and audio from virtualdub.

if you have a suitable encoder. If you don't, then the best free encoder is HCEnc, however it does require an avisynth script to load the video.

Where did the m2v come from ?

If you extracted it from an existing DVD then there is a much simpler option.

Rip the DVD to your HDD so you have a video_ts folder. Install the freeware version of DVD Rebuilder, and click on Options -> AVS Options -> Advanced (Expert) Options -> Convert LB 4:3 to 16:9 -> VTS_01. Choose the HCEnc encoder, and let Rebuilder crop, resize and encoder for you.

[beatchef]

Thanks for the tip on the program and how to use it
I used Imago MPEG Muxer to turn the m2v into a vob set then ifoedit to give it the ifos and bups etc then loaded it all into DVD Rebuilder and followed your instructions

[guns1inger]

Hope you added the audio back in, or you will have to demux again at the end of the process.

[beatchef]

It's very pixellated and flickery, is the user friendly way sacrificing a lot of quality?

[guns1inger]

I haven't had that problem from DVD Rebuilder before.

If this when you play back from the HDD or the burned disc ?

[beatchef]

From the HDD using PowerDVD, I'll burn it to disc and see how it looks on the television

[beatchef]

It's the same, the picture kind of shimmers and jiggles up and down a bit, making even static scenes 'vibrate' which makes the movie almost unwatchable...

[beatchef]

One thing, when HCenc is running, it says

"scan: ALTERNATE
interlaced: yes"

Should it be like that? I'm pretty sure the source is non interlaced PAL.

[guns1inger]

I don't have DVD RB on this machine, so I can't check it out until I hit home in a couple of hours. It sounds like it is analysing your video and concluding it is interlaced (which for PAL it is, even if both fields for a progressive frame) and somehow screwing up the field order. I'm not sure if there is an override for that.

Or it could simply be artifacts from resizing up. That is unfortunately always a risk.

Can you post some stills showing the problem ?

[manono]

One thing, when HCenc is running, it says

"scan: ALTERNATE
interlaced: yes"

Should it be like that? I'm pretty sure the source is non interlaced PAL.

DVD-RB just duplicates the source DVD encoding, and as guns1inger said it's common for PAL DVDs, sourced from progressive film, to be encoded as interlaced. My guess as to what's going wrong is that you took a widescreen 4:3 source and converted it to 16:9. There's not enough resolution there to begin with to make the resize any good at all. You'll always get shimmering/aliasing (as guns1inger also speculated), especially when fine lines are present. In my opinion you're wasting your time if you expect anything good to come out of the effort. Use the remote control of your player or TV set to zoom it, if you must.

[theewizard]

fitCD will createthe resize script for you

you save the script with one button click

then load the script to your encoder, henc, cce etc..

the encoder runs the script calls avisynth which servers the avi file to the encoder frame by frame,

virtual dub can also do this, except the process is a little more involved

both avisynth and virtualDub have their good points

but with vdub you load your file set up your sizing use the 'resize' command, start the frame server

save the myvideo.vdr file

then start your encoder and open the 'myvideo.vdr' file