vcdhelp bitrate calculator..

[vhelp]

Hi guys.. Baldrick..

I've ben debuggin a bitrate calculator of mine for the past few weeks now.

I'm hoping to release it also on vcdhelp too.

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I've ben trying to duplicate your's on your webpage (below) and seem to
be running into trouble with the results:

* https://www.videohelp.com/calc.htm

1st Issue...
* CD [1] x [80] - - - Custom size: [797]

Correct me if I'm wrong, but an 80min. CDR is 700mb (or 700x1024)=719mb.
But, an 80 min. CDR should be ~700mb, not ~797mb.

2nd Issue...
* may not be an issue, but isn't 1 x [74] 74 minutes ?? or, ~640mb
but is showing as ~738mb <--- note, this sound more like an 80min CDR.

3rd Issue...
* And, the [1kbits = 1024]

This seems to be reversed. You have it as being 1000 as the default, but
when I try and match it w/ my calc, In my calc app, I have the option to
switch between 1024 or 1000 calcs. (I created it that way) And, after carefully
anylising and re-anylising my calc formula, I have concluded that your
calc is reversed maybe ??

Here are ALL the numbers I used in your calculator, for your testing:
[0]hr [90]mn [0]sec - - - Type: [CVD]
CD: [1] x [80] min - - - Custom size: [797]mb - - - Bps: [1024k]
Audio bits: [112] kbit/s - - - Custom aud bit: [112] kbit/s x [1] Tracks
Total video size = 781mb - - - Other ISO files: [0] mb
Calculated bitrate: [1073] kbit/s ([1099132]bps) CVD max bit: [2720] kbit/s

Note, if I make the setting, Bps: [1024k] your final result is: 1073 kbit/s
while my app says: 1101 kbit/s. If I switch my apps Bps toggle to 1000k,
it will then result with: 1073 kbit/s.

Thanks for any input on these issues,
-vhelp

[vitualis]

Read the data capacities of CDs: https://www.videohelp.com/forum/userguides/135642.php

You won't be able to get a workable calculator if you don't understand how data capacities work for S/VCDs.

As for units, kilobytes, megabytes, gigabytes all work from base 2 (i.e., 1024 bytes = 1 kilobyte).

However, when we are talking about kilobits per second from bitrates, the convention is almost always 1000 bits = 1 kilobit.

Regards.

[vhelp]

Thanks vitualis..

Reading up on link you provided now. I see now, that 1000k is what I
should have used as default, and now understand a little bit more. Now,
for more reading up

Note, there are some calculations that are based on 1024 though.
I'm wondering if they have anything to do w/ CDR or just conversion for
things like audio and video size

If you don't mind sheading some more light, based on some code snips I
have below ??

Some Examples:
--------------------------------

// Audio Size..
// C11=5400, D7=224 ...((5400 * 224) / 8 / 1024) = 147.66 Audio Size..
// Excel: =(C11*D7)/8/1024
rlAudioSize := (inLengthSecs * strToint(txt_audioSize.text)) / 8 / 1024;


Another one...

// our Actual CD Size.. ie, 700,000 is 711,680 in size or ~712 MB.. ??
// C7=700, C4=5, D4=1024k ... (711,680); // note, C4=overhead in MB's..
// Excel: =((C7-C4)*D4) ... 711,680
inActualCDSize := (strToint(txt_cdSize.text)-inOverHeadMB) * use_1024_1000(trackbar1.Position);

Thanks in advance,
-vhelp