.avi to SVCD using DVD2SVCD

[Diver]

Hi folks

I´m using DVD2SVCD with AVI2SVCD 1.1.2 build1 and I have the folowing avi-formats (extracted from G-Spot):
704x432 (1.630:1) [~13:8]
720x480 (1.500:1) [~3:2]
352x288 (1.222:1) [~11:9]
352x280 (1.257:1) [~5:4]
640x368 (1.739:1) [~7:4]
720x432 (1.667:1) [~15:9]

The question now is: do I have to edit the Avisynth-script file any more (as mentioned in Q62 in Q&A), or does the latest version of DVD2SVCD everything for me?


Another question is: Whitch aspect ratio do I have to select in DVD2SVCD, or should I better choose VCD?


I have another question: Is it recommendable to "enlarge" an 384x288 (1.333:1) [=16:12] movie to 480x576?
And should I put the 2hour film (715MB) on one SVCD or on two? Or better choose VCD?


Thanks a lot
diver

[DJRumpy]

The question now is: do I have to edit the Avisynth-script file any more (as mentioned in Q62 in Q&A), or does the latest version of DVD2SVCD everything for me?

No idea here. You should post the info in Q62 here so we know what your refering to.

Another question is: Whitch aspect ratio do I have to select in DVD2SVCD, or should I better choose VCD?

This is something you will have to decide. You would typically choose the aspect ratio closest to one of the standard ratios (1.33, 1.77, 1.85, 2.21, 2.35). I usually only use 1.33, 1.85, or 2.35. Your first AVI is closest to 1.85:1, so that would be the one to choose. I assume of course that none of these AVI's have letterboxing?

I have another question: Is it recommendable to "enlarge" an 384x288 (1.333:1) [=16:12] movie to 480x576?

This one falls back to the quality of your source. If the source is good, you may be able to get away with bumping it up to the next format (VCD to CVD, or VCD to SVCD for example). If your source is dirty, or just poor quality, then stick with reducing the size. A small encoded test clip will usually tell the tale pretty quickly.

And should I put the 2hour film (715MB) on one SVCD or on two? Or better choose VCD?

A 2 hour movie on 1 svcd would probably look like total crap due to the very low bitrate required to get it to fit. Definately look at 2, or even 3 discs for a movie that length. You can always use CVD (352x480) resolutions instead of SVCD. It will look better at the lower bitrates (lower bitrate = more video on a disc) required to make it fit on a disc.

[Diver]

Hi
First of all thanks for the replie.


Sorry I forgot to post the text. Here is what Q62 (from the doom9.org forum) days:

Q62: My converted DivX/AVI files show up wrong (stretched/squeezed) on TV. What's wrong with the AVI2SVCD feature?
A: The resizing with the AVI2SVCD feature may sometimes be not correct when converting DivX/AVI files due to the huge amount of AVI codecs around. Here is a way to correctly resize those AVIs manually in case DVD2SVCD fails in doing so.

A common DivX/AVI display size for example is 640x272 pixels. To resize this DivX/AVI correctly to SVCD you have to resize it to 480 x 576 pixels for PAL and 480 x 480 pixels for NTSC but you have to take into consideration the different pixel aspect ratios of a PC monitor and a PAL/NTSC TV. Monitor pixels have a pixel aspect ratio of 1:1 (y) but TV pixels are not square! The TV pixel aspect ratio for PAL is 54:59 and 11:10 for NTSC.

To keep it simple use the following formulas to calculate the correct resizing parameters for your DivX/AVI to show up correctly on your TV and to keep the correct aspect ratio.

For example your DivX/AVI has a display size of 640 x 272 pixels (Pixels_X x Pixels_Y).

1) For NTSC TV sets:
[....]

2) For PAL TV sets:

Calculated height = ((720 / Pixels_X) x Pixels_Y) / (54 / 59)
e.g. ((720 / 640) x 272) / (54 / 59) = 334,33
So the correct "Resize" statement in the AviSynth script would be for example:
...
SimpleResize(480,334)
...

If you want to make a anamorphic SVCD instead of a letterboxed SVCD then you have to correct your calculated height with the factor of (4 / 3) = 1.33
e.g. 334,33 x (4 / 3) = 445,77
So the correct "Resize" statement in the AviSynth script would be for example:
...
SimpleResize(480,446)
...

Note: You should always round up/down to even numbers - this might not be absolutely correct but this little aspect ratio error is usually not visible. And it is better if they can be divided by 4 or even better by 16 to let some MMX optimizations kick in.

Then you have to add borders on top and bottom to fill up to 576 pixels.

Correct borders = (576 - Calculated height) / 2
e.g. (576 - 334) / 2 = 121 when doing a letterboxed SVCD
So the correct "AddBorders" statement in the AviSynth script would be for example:
...
SimpleResize(480,334)
AddBorders(0,121,0,121)
...

So all you have to do is:
- to know the exact display size of your source DivX/AVI file (Mediaplayer/Properties/Details)
- calculate the correct height values for your destination TV standard
- tick the "Edit as part of Video encoding" option in "Frameserver" tab
- start the conversion and wait for the AviSynth script window to show up
- manually edit the AviSynth script like described above
- continue the conversion by hitting the "OK" button

This procedure does not apply to DV AVI sources - they will show up correctly with the AVI2SVCD option.

The rest is farely clear. The only question is how can I create an CVD with DVD2SVCD?


Thanks a lot
diver

[DJRumpy]

Ughh..what a mess. I would have to answer yes, you still need to do these things. Figuring out aspect ratios (width/height=aspect ratio), and resizing is simple once you know what your doing. If your NTSC, I can help you there. Make sure your source files have no letterboxing when getting the aspect ratio. If your PAL, then I don't know what they use for vertical values. You only have to remember these things for NTSC and a 4:3 aspect ratio on your MPEG.

When resizing to NTSC 1.33 video, it is always fullscreen 480x480 for SVCD with no letterboxing.

When resizing to NTSC 1.85 video, it is always 480x360, with the remaining 120 pixels filled with letterboxing.

When resizing to NTSC 2.35 video, it is always 480x276 with the remaining 204 pixels filled with letterboxing.

All you have to do from there if figure the aspect ratio of your source (divide the width by the height). If it's closest to 1.85, then you would resize it to 480x360, and add letterboxing for the remaing 120 pixels [120/2=60], or in AVISynth ( AddBorders(0,60,0,60) )

If you want to create a 16:9 video on an SVCD (for a widescreen TV for instance), you can place the 16:9 video into a 4:3 aspect ratio. To do this, you would resize as follows:

For 1.85:1 video, resize it to full 480x480 with no letterboxing.

For 2.35:1 video, resize it to 480x360, with 120 pixels of letterboxing.

For 4:3 video on PAL, I would guess that they would be something like this (hopefully someone can correct me):

for 1.33, again it would be fullscreen 480x576 with no letterboxing

for 1.85 it would be 432 with the remaining 144 pixels using letterboxing

for 2.35 it would be 328 with the remaining 248 pixels using letterboxing

Again these PAL values are just guesses, as I've never bothered to encode a PAL svcd.

[Diver]

Wow
This sounds really like hard stuff. I have to have a little workaround on the weekend.

I´ll give a report if I succeeded.


by
diver

[DJRumpy]

Not hard. I just tend to be a little to verbose in my replies

Just figure out what aspect ratio your AVI has. You can use GSpot in the TOOLS section if your squemish about math. It will report the aspect ratio of your AVI. Once you have that, just pick one of the options I listed for 4:3 video"

When resizing to NTSC 1.33 video, it is always fullscreen 480x480 for SVCD with no letterboxing.

When resizing to NTSC 1.85 video, it is always 480x360, with the remaining 120 pixels filled with letterboxing.

When resizing to NTSC 2.35 video, it is always 480x276 with the remaining 204 pixels filled with letterboxing.

Just look at the Resize command in your AVISynth script to ensure it matches, or is close to one of the above, depending on the aspect ratio.