Read strings...need help!
Michael Eriksson
I need help with reading strings out of files, this is the story...The files
are karaokefiles in format .kar (regular midi with lyrics). First I need to
find the characters @T in the file and then go back to the byte before @T
for reading the length of the string and then display the string in an
editbox without the first two characters @T. Then I need to find the next @T
in the file and do the same as above for another editbox. I'm trying to make
a databaseprogram for all my karaokefiles, then I need to read artist and
title from the files. The first @T<title> string contains title and the
second artist. There can be a lot of meta events in a .kar file...
The KAR text meta events start with an @ followed by a character indicating
the type of KAR text meta event, then followed by text for that event. The
following text meta events occur embedded in regular MIDI text events:
FileType: @KMIDI KARAOKE FILE
Version: @V0100
Information: @I<text>
Language: @LENGL
Title 1: @T<title>
Title 2: @T<author>
Title 3: @T<copyright>
So if you can make a Delphiscript that can do this I'll be very happy
because the script I use now dont read the first byte of string (length),
and I dont know how to do it because I,m just a beginner, see the code
below...
procedure TForm1.Button1Click(Sender: TObject);
var fil: TFileStream;
c: Char;
i,j: Byte;
s: String;
done: Boolean;
title: array[1..2] of String;
tempstr: array[1..4] of char;
begin
i:=0;
done:=False;
title[1]:='';
title[2]:='';
if opendialog1.execute then begin
fil:=TFileStream.Create(opendialog1.FileName,fmOpenRead or
fmShareDenyNone);
if(AnsiUpperCase(ExtractFileExt(opendialog1.filename))
=AnsiUpperCase('.kar')) then begin
fil.Read(tempstr,4);
if(tempstr='MThd') then begin
radiobutton1.checked:=true;
while(not(done)) do begin
fil.Read(c,1);
if(fil.Position >= fil.size) then done:=true;
if(c='@') then begin
fil.read(c,1);
if(c='T') then begin
inc(i);
if(i=2) then done:=true;
j:=0;
while((ord(c)<>0) and (j<50)) do begin
fil.read(c,1);
title[i]:=title[i]+c;
inc(j);
end;
end;
end;
end;
end;
if(not(radiobutton1.checked)) then begin
MessageDlg('This is not a .kar file',mtError,[mbOk],0);
end else begin
Edit1.Text:=title[1];
Edit2.Text:=title[2];
Edit3.Text:=ExtractFileName(opendialog1.filename);
s:=edit3.text;
Delete(s,length(edit3.text)+1-length(extractfileext
(edit3.text)),length(extractfileext(edit3.text)));
edit3.text:=s;
end;
end;
fil.Free;
end;
end;
end.
Please, please, please help me ;)
Michael
micke_...@hotmail.com
Ekkehard Domning
I think You want somebody to do Your job. But I assume nobody has the Time for
doing it for nothing :-(
Michael Eriksson schrieb:
>
> Hi all and Merry Christmas
>
> I need help with reading strings out of files, this is the story...The files
> are karaokefiles in format .kar (regular midi with lyrics). First I need to
> find the characters @T in the file and then go back to the byte before @T
> for reading the length of the string and then display the string in an
> editbox without the first two characters @T.
Some hints anyway.
First, what do You want to do with the result. If You need this stuff only
once for information, it might be clever to build a perl script because You
can use there "regular expressions" wich makes lufe sometimes eayier.
If You want to place the result into a Database, ok, do it in a
Delphi-Program.
I dont know how the file works in detail so this must be cleared before
starting.
File analysing is a tricky job because a lot of errors are possible. My way to
do so is a "State-Engine". This State-Engine jumps from one step to the next
depending from the actually state.
Example
// Define all States Your Engine runs thru
const
karStart = 0;
karAT = 1;
karTitle = 2;
...
karDone = 99;
//define a State variable
var State : Integer;
...
// lets go
State := karStart;
while State <> karDone do
begin
case State of
//here comes the State definitions
karStart :
begin
fil.Read(c,1); // read a single Char
if c = '@' then // is it the @
State := karAT; // yes, in the next cycle do something different
end;
karAT :
begin
fil.Read(c,1); // read a single Char
case c of // Test to defined Types
'K': State := karFile;
'V': State := karVersion;
'I': State := karInfo;
'L': State := karLang;
'T': State := karTitle;
...
else
State := karError; //Unknown Tag, report Error, or Abort
end;
end;
karTitle :
begin
while((ord(c)<>0) and (j<50)) do
begin
fil.read(c,1);
title[i]:=title[i]+c;
// Save the Title to someplace
end;
State := karStart;
end;
// kar... // More states here
end;
end;
At first it looks a bit strange, but on the second view You will see that this
will lead You clear through the file.
> Please, please, please help me ;)
> Michael
> micke_...@hotmail.com
Good luck
Ekkehard
--
DomIS Internet Solution - Ekkehard Domning
Im "mCC": Industriestr. 17 - 49740 Haselünne
Mail: e...@domis.de Internet: http://www.domis.de