Divx encode from A DVD..Is this OK to do..Using 2-pass

[hardwork12]

From The DVD RIP I did the following. I am not sure I used the 2 pass correctly for Divx this was my first try that seemed to work.

I used DVD2AVI and VFAPI convert so I could use Vdub for the resize and Divx encoding in 2-pass bit rate at 850.

Now I wanted to do two things;

1)Inverse Telecine (Film content was around 92%) First I tried force film but had too much interlaceing artifacts when playbacking back so I re-ran DVD2AVI without forcefilm.

2) Resize from 720X480 to 512x288 (I found for my liking this was a good resolution to not use too much CPU on playback and also gave me a video that seemed quite good.)

Now my question about 2-pass encoding.

Using virtualdub I set up the first pass and the second pass both with the filters for Inverse Telecine (adaptive) and resize set. Is this OK or does it try to do both filters 2 times. What I mean is once on pass 1 and once on pass 2.

Just want to make sure that down the line If I want to convert to another format that what I did here is OK the video looks and runs very well without the interlace lines I had when I used the force film in DVD2AVI. I also did not crop as I read somewhere that some other formats can not deal with this. Also In reading I think I read that the SIze must be such that they are divisible by 32 just can't remember why.

[crahak]

Well, the easy way to do it all, without too much hassle, there's a nice all in one package (a must) to do it: Gordian Knot. (Takes all the math out of it, and all you really need is there)

Oh. for the interlacing, you can try greedyhma in avisynth by hand...

2 pass encoding? you're encoding the exact same thing twice, both passes, it will ivtc and resize on the fly. 2 Pass is a good thing

Good luck

[hardwork12]

Thanks for the info I was not sure that is what the 2 pass meant.

I have gordian knot to try and will do that. I am just trying to understand these tools first since I was sucessful with them finally. Now when I use gordian Knot I think I will understand it better.

[banjazzer]

1)Inverse Telecine (Film content was around 92%) First I tried force film but had too much interlaceing artifacts when playbacking back so I re-ran DVD2AVI without forcefilm.]

Did you try swapping the field order in DVD2AVI with the forcefilm option?

I would also agree that Gordian Knot is preferable. You can visually crop and resize, and can also play around with the de-interlacing if necessary, before it gets to Virtualdub.

[hardwork12]

Will try "swapping the field order" so I can see what that does. The IVTC Divx looks great but there may be times when that does not work but methods like the "swapping field order" would. Thanks

I am going to try Gordian Knot seems like many use it so it must be good.

I am not cropping right now based on the following article I read. I do not know if it is correct or not . If anyone knows please advise on this cropping. Is this article correct?

http://nickyguides.digital-digest.com/quality.htm

From the article in the link above.

Warning on Cropping

It is only fair to warn you that, athough in my opinion cropping improves the image quality of the DivX rip by a lot, before you decide that cropping is the best way to go, you must consider these four facts:
1. A cropped movie is sometimes harder to convert into another format. This is because you may need to re-add the black bars to the top and bottom of the movie first or the movie may be stretched out of shape.
2. A cropped DivX movie will play at the wrong aspect ratio in PowerDVD and some other Video players. On the other hand, Media Player, MicroDVD and many other players will play back a cropped movie perfectly.
3. VCD's and SVCD's cannot be cropped if they are to be played in a standalone DVD player because it will not accept them.
4. Finally, Mpeg-4 files (and DVD files for that matter) have problems playing back on some hardware if they are not encoded in sizes that can be divided by 32. This means the Matrox G400 or the Nvidia GeForce would probably have problems outputing it to TV. This TV out problem is associated with the Mpeg-4 codec and does not apply to most other codecs.

As an example:
A 528 pixels wide size divided by 32 = 16.5. This is not a multiple of 32 and so may have trouble.
But a 576 pixel wide size divided by 32 = 18. This is a multiple of 32 and will play back perfectly.

[banjazzer]

Cropping should generally never be done without resizing. If you use Gordian Knot (which basically creates an Avisynth script) then you can crop to your heart's content visually, and know that you can maintain correct aspect ratio. Not only will it let you conform to recognised DivX standards, but you can also use it as a stage to creating fully compliant VCD or SVCD. Also, letting GK do the cropping/resizing seems to be a fair bit quicker than allowing Virtualdub to do it.

Basically, although the article you quoted is correct, none of this applies if you use Gordian Knot. I use it wherever possible. Always when creating DivX, and as much as possible when creating SVCD. And all DivX so created are very easily converted to other formats.

One final point, most DVDs have black borders - often on all 4 sides. With DivX you want maximum bits to encode the picture, especially if creating a one-disc DivX. It makes sense that you don't waste bits encoding the black surround, even though this uses far less bits than the equivalent area of picture.

[hardwork12]

Thanks Great information it explains why I have read that the cropping is not an issue if handled corretly.

Really appreciate the guidance.

Next up Gordian Knot

[banjazzer]

You will find much information at www.doom9.net about Gordian Knot, including an active forum. The guide is quite detailed, but bear in mind you can use Gordian Knot for as much or as little as fits your requirements. 8)