c++ divx calculator programming problem

[xviddivxoggmp3]

I'm trying to write a C++ program for shit and giggles.
It only calculates DivX calculations for my first formula.
If you know any C++ help out a newbie and tell me what is wrong. This is generic without a gui.
It does compile, but I'm not sure what is wrong.
The only thing I see that my text book says is wrong is the nested if statement, but in other languages I can write the if statement this way. I would like idea's on how to fix.

************************************************
see attached .txt file for code
************************************************

[khp]

It runs fine when I compile with MS VC6.

But I would suggest using a switch instead of the nested if.

like this

 
//divx 
//program 1

#include <iostream>

using namespace std;

int main()

{
	int     calc;
	double	MovieLength,
			kbps,
			count;
	
	float	sum;

	do
		{
			cout << "Enter (1) for DivX 3 or (2) for DivX 4/5: ";
			cin >> calc;
			
			switch (calc)
				{
			case 1:
				cout << "Input Movie Length in Minutes: ";
				cin >> MovieLength;

				cout << "Input kbps: ";
				cin >> kbps;
				
				sum = ((MovieLength * 60) * kbps) / 8192;
							
				cout << "Size of Movie: " << sum << "MB ";
				cout << "\nInput (1) to calculate another Movie: ";
				cin >> count;
				break;
			case 2:
				cout << "Input Movie Length in Minutes: ";
				cin >> MovieLength;

				cout << "Input kbps: ";
				cin >> kbps;

				sum = (((MovieLength * 60) * kbps) / 8192) * (float (1000) / float (1024));
										
				cout << "Size of Movie: " << sum << "MB ";
				cout << "\nInput (1) to calculate another Movie: ";
				cin >> count;
				break;
			default:
				cout << "Input valid calculation request ";
				cout << "\nInput (1) to calculate another Movie: ";
				cin	>> count;
			}
		}
	while (count == 1);

return 0;
}

And of course I'am not a fan of do { } while loops. There is never any need for such a structure and it makes the code harder to read. Just use while {} insead.

EDIT: the above code has been futher modified to fix the problems mentioned below

[khp]

And I suppose it should be

while (count == 1);

instead of

while (count = 1);

unless you really want to loop forever.

[khp]

And I suppose this line might also be giving you problems in the divx4/5 calculation

sum = ((MovieLength * 60) * kbps) / (8192 * (1000 / 1024));

When you divide two integers you get an integer division, which means that (1000/1024) = 0 because it's rounded down. This, then causes a division by zero. At least in my compilation

And shouldn't it have been (8192 * (1024 / 1000) or maybe (8192 / (1000/1024))

I think this line will give you the correct result.

sum = (((MovieLength * 60) * kbps) / 8192) * (float (1000)/float (1024));

[khp]

If you are interrested, here is a bitrate calculator I wrote, it's written in perl.

package bitrate;  # ahhhh the bitrate calculator.
                  # just about the simpelst code in the script
sub calc {        
    my $invocant = shift;  
    my $self = bless({}, ref $invocant || $invocant);
    ($size,$conversionpath,$ripped) = @_;  # formal arguments
    $logfile = $ripped->logfile;
    print $logfile "Calculating video bitrate for" . $size . " MB, length: " . $ripped->framecount . " frames\n"; 
    $size = $size * 1024 * 1024;              # we'll calculate this in bytes
    $videosize = $size - (63 * $framecount);  # avi overhead, not very precise, I know.
    use File::stat;
    print $logfile "looking for first audio track: " . $ripped->audio1 . "\n";
    if ($filestat = stat $conversionpath . $ripped->moviename . "\\" . $ripped->audio1) { #looking for audio1
	$videosize = $videosize - $filestat->size;
	print $logfile "Found audio1 file size: " . $filestat->size . "\n";
    }
    print $logfile "looking for second audio track: " . $ripped->audio2 . "\n";
    if ($filestat = stat $conversionpath . $ripped->moviename . "\\" . $ripped->audio2) { #looking for audio2
	$videosize = $videosize - $filestat->size; 
	print $logfile "Found audio2 file size: " . $filestat->size . "\n";
    }
    opendir converted, $conversionpath . $ripped->moviename or die "can't open conversion dir";
    @allfiles = readdir converted;      # search through all file in the conversion dir
    foreach (@allfiles) {
	if (m/\.sub/) {
	    $filestat = stat $conversionpath . $ripped->moviename . "\\" . $_;
	    print $logfile "Found subs file: " . $_ . "\nsize: " . $filestat->size . "\n"; 
	    $videosize = $videosize - $filestat->size;
	}
	if (m/endcredits\.avi/) {     # subtract size of endcredits
	    $filestat = stat $conversionpath . $ripped->moviename . "\\" . $_;
	    print $logfile "Found endcredits file: " . $_ . "\nsize: " . $filestat->size . "\n";
	    $videosize = $videosize - $filestat->size;
	}
	if (m/begincredits\.avi/) {     # subtract size of endcredits
	    $filestat = stat $conversionpath . $ripped->moviename . "\\" . $_;
	    print $logfile "Found endcredits file: " . $_ . "\nsize: " . $filestat->size . "\n";
	    $videosize = $videosize - $filestat->size;
	}
    }
    $videosize = $videosize * 8;      # calculate video size in bits
    $bitrate = ($videosize / $ripped->framecount) * 25;  # calculate videobitrate in bits persecond
    print $logfile "Calculated video size: " . $videosize . "  bitrate: " . $bitrate . "\n";
    return $bitrate;
}

return 1;

It's part of a collection of scripts, for automatic DVD->divx conversion. So you can't run it as is.

This is turning into a monologue, am I saying anything usefull, or have I just gone mad.

[xviddivxoggmp3]

thanks for the info.
I didn't know you could put float in the equation. when i try to compile it with float in the equation it gives me the fallowing error

Debug/divx calculator.exe : fatal error LNK1169: one or more multiply defined symbols found


*************************************************

sum = (((MovieLength * 60) * kbps) / 8192) * (float (1000)/float (1024));

*************************************************
I'm reading on the switch now. I'm used to case statements, but did not know they where called switch in c++

will post my results later this evening after I recode it all.
thanks again khp you rule.

sorry I'm a newbie and clueless to perl

[khp]

Originally posted by xviddivxoggmp3

Debug/divx calculator.exe : fatal error LNK1169: one or more multiply defined symbols found

OK, so your compiler doesn't like c-style casts. I guess I should have known better, but I've always been a c programmer at heart .
Anyway it would probably be the best to keep to integer calculations as much as possible. As I try to do in my perl script, although perl happily converts to float at every chance it get.

In your case this should also work.

sum = ((((MovieLength * 60) * kbps) / 8192) * 1000 ) / 1024;