.length to minutes and seconds format

hi,

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.
Thanks
hellfire052497Asked:
Who is Participating?
 
ZifNabConnect With a Mentor Commented:
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
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ZifNabCommented:
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.
Thanks
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hellfire052497Author Commented:
Added the last question before your second answer, will try that first.
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hellfire052497Author Commented:
nope, double and string are no go. Still no luck with the Double to Integer part.
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ZifNabCommented:
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));
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hellfire052497Author Commented:
I must be missing something here,

ok here is the full code

Var
T : Double;
Begin
T := ((MPEG1.length /1000) /60);
Label3.Caption := IntToStr(Trunc(T))+':'+ IntToStr(Frac(T)*100); =>> here I get Incompatible types Integer and Real.
Any ideas
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ZifNabCommented:
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.
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d003303Commented:
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;
begin
  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]);
end;

This function outputs *very* fast.

Slash/d003303
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hellfire052497Author Commented:
it all works now, thanks for the answer
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Holger101497Commented:
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*
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hellfire052497Author Commented:
Thanks i'll try it out.
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d003303Commented:
Holger,
hehe, workaholic might be... maybe E-E-holic ;-)
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Holger101497Commented:
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!
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hellfire052497Author Commented:
I noticed then, and I did changed it to 60.
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ZifNabCommented:
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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