.length to minutes and seconds format


I making a program using the mpegdll.dll, it has a .length property, to display the time, but it is in milliseconds. I tried converting it to Minutes and seconds but had no luck, can anyone show me how to do it. Currently I have this

T := ((MPEG1.Length div 1000) div 60);
I := IntToStr(T);
Label3.Caption := I

Now the time I get is rounded like say 4 minutes, how do I get the seconds too, and how to format the label so it is displayed like this 0:00 (Minutes:Seconds). I'm not even sure my calculation is correct so please show the full procedure.
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Hi Hellfire,

If you use div you will always get an integer; It rounds everything so you can assign the result to an integer.

Use / and you get a float or double ---> if you need numbers after comma, just take this float minus the integer part of it and you got it!

Regards ZiF.

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hellfire052497Author Commented:
Ok, but how do I format the Label. Can you show me
Well, I assume we can't use TimeToStr --> this uses the numbers behind the comma as time...

We could do it like this :

T := ((MPEG1.Length / 1000) / 60);

label3.Caption := IntToStr(Trunc(T)) + ':'+IntToStr(Frac(T));

Regards, Zif.
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hellfire052497Author Commented:
I got the double, but I cannot convert it to Integer, I always get "invalid typecast) when using S := (Integer(T));
A sample would help.
hellfire052497Author Commented:
Added the last question before your second answer, will try that first.
hellfire052497Author Commented:
nope, double and string are no go. Still no luck with the Double to Integer part.
Hi hellfire,

T is double? Correct?
S is String? Correct?

To translate T to string you must use FloatToStr....

OR to get minutes ... You need :

 IntToStr(Trunc(T)) ---> Trunc gets the integer value of T;

to get minutes :
 Frac(T) ---> gets the fractional part of T....

So if you got 2 values after comma --->

var seconds : string;
 seconds :=  Trunc(Frac(T)*100);

 Label3.Caption := IntToStr(Trunc(T)) + ':'+IntToStr(Trunc(Frac(T)*100));
hellfire052497Author Commented:
I must be missing something here,

ok here is the full code

T : Double;
T := ((MPEG1.length /1000) /60);
Label3.Caption := IntToStr(Trunc(T))+':'+ IntToStr(Frac(T)*100); =>> here I get Incompatible types Integer and Real.
Any ideas
Yep ... Sorry... I corrected this in my last comment .... Forgot to tell you about this...

See Frac returns a real value.... So, we do this :

 If frac(T) is 0.32 ---> * 100 --> 32 ---> change to integer ---> Trunc(32)

This is the code --> IntToStr(Trunc(Frac(T)*100));

Regards, Zif.
Hi guys,
maybe this is all you need. Drop a TButton, a TLabel and a TEdit on a blank form and put this in the buttons OnClick handler. Now you can test the format of milliseconds to HH:MM:SS:FF.

procedure TForm1.Button1Click(Sender: TObject);
// frames in 25 fps (PAL), can also be 30 (NTSC)
const FPS = 30;
var H, M, S, F, MS : Integer;
  MS := StrToInt(Edit1.Text);
  H := (((MS div 1000) div 60) div 60) mod 60;
  M := ((MS div 1000) div 60) mod 60;
  S := (MS div 1000) mod 60;
  F := ((MS mod 1000) * FPS) div 1000;
  Label1.Caption := Format('%.2d:%.2d:%.2d-%.2d', [H, M, S, F]);

This function outputs *very* fast.

hellfire052497Author Commented:
it all works now, thanks for the answer
he he... quite some time later (I got here through hellfire's profile and couldn't resist checking if the answer was the one I'd give...)

When reading this thread, I just wanted to say that IntToStr is rather slow and using and rounding lots of floats doesn't help either...

I guess the fastest/shortest way of doing this is:
Label1.Caption:=Format('%d:%.2d', [MPEG1.Length DIV 60000, MPEG1.Length DIV 1000 MOD 60]);
This doesn't display hours, but I think that's ok... few Mpegs will last more than one hour and even then, something like "87 minutes" is quite normal for movies...

P.S.: d003303, what does H := (((MS div 1000) div 60) div 60) mod 60; do? Are you a workaholic and your day "only" has 60 hours? *bg*
hellfire052497Author Commented:
Thanks i'll try it out.
hehe, workaholic might be... maybe E-E-holic ;-)
Oh, btw (just to keep this thread alive *lol*):
ZifNab's a workaholic as well... his minute has 100 seconds!
hellfire: If you used ZifNab's code, you should change IntToStr(Trunc(Frac(T)*100)); to IntToStr(Trunc(Frac(T)*60));... but that code is kinda weird/slow anyway!
hellfire052497Author Commented:
I noticed then, and I did changed it to 60.
my, my am I under fire in this thread. Sorry for my mistakes people... As I said earlier, I'm not god and I just try to help as much as I can. See my state too, i'm not a programmer like some good people around here.
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