1. Where's the movie cut? 2. Question about aspect ratio.

[Bernd]

Hi,

I'm new to this forum although I've read quite a lot of the threads here (and in cce forum and others).

I've got 2 questions about DVD2SVCD (and I've read the newbie-faq and the doom9-guide, honestly):

1. How does DVD2SVCD decide where to cut the movie and start the next SVCD? Is it at chapter points? Or maybe in the middle of the most important scene? OK, I can try it by myself but maybe someone can tell me how the "cut algorithm" works. This is important for me, and if the cut is just "somewhere" in the MPEG file, I'd rather cut it by hand to get a more "context compatible" cut.

2. The aspect ratio. I've read a lot of posts concerning this but what I still like to know is: how does DVD2SVCD know the thickness of the black borders of the film? When I do the DVD->SVCD conversion "by hand", I sometimes have to crop 16 pixels, sometimes 72 or 74 in DVD2AVI. Later I have to add borders using AVISynth depending on how much I cropped before. Furthermore, I crop left and right 24 pixels (which are in the 4:3 tv overscan area to save bitrate for more important areas of the picture).

The question (finally :) ): does DVD2SVCD do any cropping? At least in some example AVS scripts I didn't see any AddBorders line.

Thanks, and greetings

Bernd

[Mozart]

good questions;)

1) somewhare. The cut is at the setted filesize. Not time length.
2) No, it doesn't crop. If you know what to do, you can use "edit avisynth" to edit the avs file.

[Bernd]

OK, I see. Thanx for the prompt info.

Maybe it's worth considering some preview function to manually set the cut points at the beginning of the DVD2SVCD process.

:)

Bernd

[markrb]

If you read the txt file in the DVD2SVCD directory:

FUTURE:
- Preview settings
- Preview Video
- Bug Fixing
- AVI Support
- Movie database


It does not stick out like a soar thumb so no lashings for you. THIS TIME. :)

Mark

[markrb]

Cutting on a time basis is a feature that is always asked for, but it is so very difficult to implement if not impossible without knowing the final video size before the encoding starts.

VBR is tricky. You never know where the bits will be allocated. You could have the first half of the movie be half the file size of the second. You just never know until it's done encoding.
If this happened and you cut at 45 minutes of a 90 minute movie you could have the first video file be 500mb and the second 1000mb. Granted an exagerated example to make it more obvious, but I think you get the idea.
Now if there was an easy way to manually intervene after the video encode and set the cutpoints that would work, but it's probably beyond the goal of the program.

Mark

[machura]

May be, this can be way:

Try set in bitrate:

to 1th row lenght great than minuts of whole movie.
Set size of CD as suma for all CDs (1600-5(10)), what You need for movie => make only one mpg file and this cut in TMPGEnc manualy.

Is not so nice cut movie in "key scenes". Better is find near ch.

[Kedirekin]

To add to the responses for question #2:

DVD2SVCD only does two resize options.

For 4:3, it resizes to 480x480 and has no add borders command. If there were borders on the DVD, they'll be included in the resizing and you'll get the same borders on the SVCD. If there were no borders, it's full screen, and the SVCD shouldn't have any borders either.

For 16:9, it resized to 480x360 and adds top and bottom borders of 60. Again, if there were borders on the DVD, they're included in the resize and will combine with the borders added by AddBorders, so you'll end up with the correct aspect no matter what it was and you don't have to worry about it. If there were no borders, then the SVCD will have the 60 pixel borders only, which is what a 16:9 non-anamorphic SVCD should have.

So, you don't have to crop or do anything to the script. However, you can crop if you want to; it'll increase encoding speed a little bit, and ensures that in the end the borders you put in are absolutely black.

PS. cropping the side overscan does save some bits, but it may not be worth the hassle in some situations. For example, for a 2.35:1 non-anamorphic SVCD, cropping overscan from the sides eliminates only 34 macroblocks (40 macroblocks for PAL), which is fewer that 4% of the total (though the savings is over 6% of the movie portion). Overscan cropping is much more significant on full screen encodes (saves almost 13%).

[Bernd]

markrb:

It does not stick out like a soar thumb...

You're right with the thumb thing. Next is that I had first contact with DVD2SVCD 3 days ago and the first thing I did was not looking what the program will be able to manage in the future but what it can do for me now. ;)