Bitrate Calculator for Scale Settings for TMPGEnc

[Maine]

Hi, I am trying to figure out what to set the scale percentage at for TMPGEnc, but can not make sense out of the directions given in the Doom9 Instructions The directions are in parentheses below.
My questions are: How do you find out how big the movies extras are?
How do you know how much of the size of the VOBs is Video and how much Audio?
Can someone simply translate these particular instructions to Dummy it down a little?

I am new to this so please forgive me if this is explained somewhere else. I have looked without much success. I would just like to get the best possible bitrate and I until I figure this out I will just be guessing.
Thank You,
-Rob

This is what the instrauctions say:
"We want to have 4.37 GB (4.7 billion bytes) to fit the whole movie onto a DVD-5. Subtract the size of the VOBs for the movie's extras, menus and ifo files from that size. In the example of bait the extras only take 7.5MB which leaves us with 4'692'135'680 bytes for the main movie.

The size of the main movie VOBs is 5'141'125'120 bytes at the moment, whereof the actual video stream takes 4'706'988'750 bytes (multiply the length as shown in ReMPEG2 by the avg.bitrate and divide by 8 to get from bits to bytes). So we have 434'136'370 bytes for the audio stream, subtitle stream and navigational packets in the VOBs. If you subtract this from our remaining free space (4.37GB - 7.5MB) we get 4'257'999'310 bytes for the new video stream. Divide this number by the size of the current stream to get the bitrate reduction factor. In this case we have 0.904 which means the new video stream must have a bitrate that's 90.4% of the original bitrate to still fit onto our DVD disc. Now go to the Options screen in ReMPEG2.

Use the scale factor slider to set the correct bitrate scale factor (90% in our case). You'll also be shown the resulting average bitrate for the selected scale factor.There's no need to limit the max bitrate."

[rpa]

Ok. Let's do this. First we need an example so let's say that you have the following files in your VIDEO_TS folder ready to be transcoded. Let's assume (or must assume) that you have work on these files stripping unwanted languages and subtitle streams. These is important and must be done before transcoding the movie. It is advisable that you try viewing the DVD (using IFOEDIT) to make sure that all is working. For simplicity, let's just round the numbers to the nearest tenths and thousands.

VIDEO_TS.IFO 20 KB
VIDEO_TS.BUP 20 KB
VIDEO_TS.VOB 15,000 KB
VTS_01_0.IFO 50 KB
VTS_01_0.BUP 50 KB
VTS_01_0.VOB 110,000 KB
VTS_01_1.VOB 1,000,000 KB
VTS_01_2.VOB 1,000,000 KB
VTS_01_3.VOB 1,000,000 KB
VTS_01_4.VOB 1,000,000 KB
VTS_01_5.VOB 1,000,000 KB
VTS_01_6.VOB 500,000 KB

Now, the important thing here is to determine which one is the movie and which are the extras. The main movie in this case is VTS_01_1.VOB
up to VTS_01_6.VOB (Remember that VTS_01_0.VOB is not part of the movie but the menu). Now for the extras, just add up ALL the remaining files in the folder (easy ha..) . Since we need BYTES in our calculations, multiply KB by 1024 to get the equivalent. Here are the numbers.

(A) Size of the movie = 5,500,000 KB X 1024 = 5,632,000,000 BYTES
(B) Size of the extras = 125,140 KB X 1024 = 128,143,360 BYTES

Next, determine the LENGTH and the AVERAGE BITRATE of the movie. We can do a lot of complicated calculations here but the easiest way is just use REMPEG to do that. I assume you already know how to do it otherwise just follow doom9's guide. For the sake of example, let's just say you have these numbers.

LENGTH OF MOVIE = 5988.2
AVE. BITRATE = 5,810,000

Multiply the length of movie by the ave. bitrate and divide by 8 to get ACTUAL VIDEO STREAM.

(C) ACTUAL VIDEO stream = 5988.2 X 5810000 / 8 = 4,349,075,500

Next thing is to determine what size of the movie is the audio and navigational packets. Here we simply subtract ACTUAL VIDEO STREAM from the ACTUAL MOVIE SIZE as follows.

CURRENT MOVIE SIZE = 5,632,000,000
LESS: ACTUAL VIDEO STREAM SIZE = 4,349,075,500
-------------
(D) AUDIO & NAV PACKET SIZE 1,282,924,500

Finally and this is constant, we find the disk capacity in BYTES. Here, I use 4.33 GB as the available size of the disk (other guides suggest 4.37 but I wanted to be on the safe side so I use 4.33) To get the equivalent BYTES, simply multiply 4.33 by 1024 three times which is

(E) DISK CAPACITY = 4.33 X 1024 X 1024 X 1024 = 4,649,302,098 BYTES.

From here on its just a matter of doing the math and following the calculations below. Just note the letters I've put alongside data.

---------------------------------

DISK CAPACITY (E) = 4,649,302,098 BYTES
LESS: SIZE OF EXTRAS (B) = 128,143,360
-------------
FREE DISK BEFORE AUDIO/NAVS 4,521,158,738
LESS: AUDIO & NAV PACKET SIZE(D) 1,282,924,500
-------------
TARGET VIDEO STREAM SIZE 3,238,234,238
DIVIDE: ACTUAL VIDEO STREAM SIZE (C) 4,349,075,500
-------------
REMPEG SCALE FACTOR (x 100) 74.45%

To get the the AVERAGE and MAX BITRATE for TMPG, just follow these formulas:

NEW AVE. BITRATE = Size of new video stream x 8 /length of movie /1000

MAX. BITRATE = 10000 - (Size of audio stream x 8 / length of movie / 1000)

THAT'S IT. Now the thing is you can use DVD-R Calculator to get rid of the above computations. You just need the input data (size of movie, extra, lenght, ave. bitrate) as describe above.

Hope this helps.
:)

[Maine]

I forgot to say Thank You.
So Thank you very much for your in-depth, very helpful reply, I greatly appreciated it.