"Irwin Feuerstein" <ebct@hotmail.com> wrote in message
news:542d2ca5.0312221131.40003d2d@posting.google.c om...
I hope I can help you with this.....
The aspect of 1:1, 4:3, and 16:9 are really what you intend it to be played
back on. The output should be 4:3, because that's all the VCD format
allows, even if you have a widescreen TV, 16:9. I always leave the input as
the same as the output. Generally, this is goign to be 4:3. 16:9 should
only be used for DVD production, and at that, anamorphic DVD production.
Since none of your AVI sources are anamorphic, I've never had to make a 16:9
DVD. I imagine though, if you had a 16:9 TV, you might have to do something
to it so that it plays correctly, but this may well just be a player issue
as well.
Anyways, since you are using VCD, you need to select the output as 4:3. The
input I also choose to be the same as the input, this prevents TMPGEnc from
resizing it, even if you think your aspect is 16:9.
This is how I do it, however:
For VCD, (I assume you are in the US like me), I need to use NTSC standards,
so I make a custom project, choose MPEG-1, and if the frame rate of the
video is 23.967, then I use that, if it is 29.97, then I use that, if it is
25 then it was originally PAL, and you need to choose 23.967, and then in
the advanced options "do not frame rate convert," this will make your video
play longer than it is really [for 100:00.00min, it is now 104:18.60, not
really noticeable]. I set the output as '4:3 display', and the input as
'4:3 display'. The size is 352x240. Rate control is CBR, 1150kbps.
For advanced, the Video Arrange Method is Center (Custom Size).
This is where the real part comes in. The input here is 544x288, and the
output is 352x240, but to not resize it the video needs to be something else
since the two aspects are different (1.888:1 vs. 1.466:1). So, I take some
basic math, ratios... 544/288 = 352/Y. Therefore, you cross multiply to
find that 544Y = (352x288), therefore Y = 186. So you want to make the
video arrange to be center (custom size) 352x186.
Here's another tip, TVs have overscan. To make your whole video play in the
TV screen, for the VIDEO ARRANGE CENTER (CUSTOM SIZE) use a 336xY value. To
find Y, here, we do like before, so 544/288 = 336/Y. Now we have Y = 177.
So to make the whole thing fit on your TV, use 336x177 for video arrange.
The good part about using the overscan idea is that you have more black
space. This means more of the 1150kbps can be allocated to the picture,
thus imporving the picture.
If you ever get the urge to make some SVCDs, though, you'll need to do
something similar. SVCD is different from VCD in that instead of MPEG-1,
you choose MPEG-2. If your source was 23.967, then you need to change
Encode Method to 3:2 on playback, and you'll notice the frame rate changed
to 23.967 (internally 29.97). If it is 29.97, fine, leave it, but on encode
method you should pick interlace, since TVs are interlaced. The output and
input aspects should be 4:3 (display). For rate control you can either do
Manual VBR, or 2-pass VBR. Manual VBR specifies a max bitrate, I use
2420kbps for max. It also has a minimum, some DVD players will get hung up
if there isn't enough data, so if you know that value, you can specify it,
or if you have a non-picky player, choose something, I use 750 for a
minimum. In 2-pass it is the same thing, except now you have an average
bitrate to specify. If you know how long your thing is and you want it to
be 1 cd, then you have to do some math to find that average.
The math for the average bitrate is pretty easy. You have an 80min CD-R,
and say, 60 minutes of video. It has audio, so you need to leave off
224kbps for audio from the final answer you get here. An 80 min CD-R holds
800MB of MPEG-1/2 VCD/SVCD data, it is special, so knowing this you take the
800MB, which is 6,553,600kb, and the length which is 60 minutes or 3600
seconds, and divide, so you get 6,553,600kb/3600s = 1,820kb/s. Now take off
224, so you have an average of 1596 for the video. That won't look too
good, but oh well...
Now, the SVCD has a size of 480x480, so put that in. For advanced, you
really only want the input to be "4:3 display" and to have the Video arrange
method center (custom size). Like before, I use ratios, so:
544/288 = 480/y **It is important to note here, that this "y" is 75% of
the actual Y you want**
y = (480x288)/544
y = 254
The Y you want though is 4/3 of this y, so multiply by 4/3 (this is because
of the way SVCD plays on TVs...due to their 4:3 aspect),
Y = 338.
Now, remember that overscan thing. Well, that 336/352 is 95.45% of the
horizontal, so we can multiply 480 x 95.45% = 460 (approx; actually about
459, but 460 works just as well).
So, now you have to find how big it is based on a 460px wide video.
544/288 = 460/y (again, it is 75% of the actual value)
y = (460x288)/544
y = 244
Y = 325
It is important to remind you of the difference between SVCD & CVD (not
really much of a standard, since it is SVCD but with 1 change). CVD is
352x480, while SVCD is 480x480. CVD's 480px height will use the SAME "Y" as
you derived from the above calculations, which is interesting to say the
least. So, basically, CVD is SVCD but instead of using a 480px video width
(on the main page), you use 352. The height for the video ARRANGE is the
same as it would be if it were 480px wide. If you want to do the overscan
thing, the ARRANGE width is 336, but the height is what it would be as if
there was a 460px width. Everything else is the same. CVD in theory can
have less blockiness and artifacts, but SVCD has more resolution, so it is a
balance of what you want.
