[solved] need some help to solve dllcall crash

[brisesel]

Hi, I'm trying to use the ID3v2 Library :

http://www.3delite.hu/..../id3v2library.html

It's an id3v2 tag editing library that supports the stdcall calling convention. (I know there is an UDF able to tag mp3 without a dll, but a little more restricted).

I have little experience manipulating the DllCall function.

Here is the script :

local $dll=DllOpen ( "ID3v2Library.dll" )

;~ # ID3v1_Create(): Pointer; stdcall; 
$tagpointer=DllCall($dll,"ptr","ID3v2_Create") 
ConsoleWrite ("ID3v2_Create " &@error &@CR) ; returns 0

;~ # ID3v2_Load(Tag: Pointer; FileName: PChar): Integer; stdcall; 
DllCall($dll,"int","ID3v2_Load","ptr",$tagpointer,"str","input.mp3" ) ; <--- crash !
ConsoleWrite ("ID3v2_Load " &@error &@CR)

;~  Set Title ; ID3v2_SetAsciiText(Tag: Pointer; FrameName, Text: PChar): Boolean; stdcall;
DllCall($dld,"byte","ID3v2_SetAsciiText","ptr",$tagpointer,"str",'TIT2', "str","Some title")
ConsoleWrite ("ID3v2_SetAsciiText " &@error &@CR)

;~ # ID3v2_Free(Tag: Pointer): Boolean; stdcall; 
DllCall($dld,"byte","ID3v2_Free","ptr",DllStructGetData ($struct_fichier,1) )
MsgBox(0,"ID3v2_Free" ,@error &@CR)
 
DllClose($dll)

It crashs with the second call. Did I use "ptr" the right way ?

In comment, the Delphi function syntax.

Here is the library usage example. I didn't translate InitID3v2Library* because it just seems to load the dll (but I never learnt delphi...)

CODE

Uses ID3v2LibraryDefs;

//* Should be in FormCreate()

InitID3v2Library;

ID3v2Tag := ID3v2_Create;

ID3v2_Load(ID3v2Tag, FileName);

//* Do whatever you want here...

ID3v2_Save(ID3v2Tag, FileName);

ID3v2_Free(ID3v2Tag);

//* Should be in FormDestroy()

FreeID3v2Library;

Edited May 29, 2009 by brisesel

[brisesel]

ok... I'm on the good way, the second call crashs because I misunderstood the syntax, it needs absolute pathway...

local $dll=DllOpen ( "ID3v2Library.dll" )

;~ # ID3v1_Create(): Pointer; stdcall; 
$tagpointer=DllCall($dll,"ptr","ID3v2_Create") 
ConsoleWrite ("ID3v2_Create " &@error &@CR)

;~ # ID3v2_Load(Tag: Pointer; FileName: PChar): Integer; stdcall; 
DllCall($dll,"int","ID3v2_Load","ptr",$tagpointer,"str",'"'&@ScriptDir&'\input.mp3"' )
ConsoleWrite ("ID3v2_Load " &@error &@CR)

;~  Set Title ; ID3v2_SetAsciiText(Tag: Pointer; FrameName, Text: PChar): Boolean; stdcall;
$structchar=DllStructCreate("char[60]")
DllStructSetData($structchar,1,"Some title")
DllCall($dll,"byte","ID3v2_SetAsciiText","ptr",$tagpointer,"str","TIT2", "ptr",DllStructGetPtr($structchar,1)) ; crashs again..
ConsoleWrite ("ID3v2_SetAsciiText " &@error &@CR)

;~ # ID3v2_Free(Tag: Pointer): Boolean; stdcall; 
DllCall($dld,"byte","ID3v2_Free","ptr",DllStructGetData ($struct_fichier,1) )
MsgBox(0,"ID3v2_Free" ,@error &@CR)
 
DllClose($dll)

This time it the third call which crashes : Is anything incorrect in my autoit syntax ?

By the way, I don't kown in autoit dllcall, it's the same thing to use :

"str", "a string"

and to use DllStructCreate("char[60]"), then to pass a pointer using

"ptr", DllStructGetPtr ?

Edited May 28, 2009 by brisesel

[martin]

ok... I'm on the good way, the second call crashs because I misunderstood the syntax, it needs absolute pathway...

local $dll=DllOpen ( "ID3v2Library.dll" )

;~ # ID3v1_Create(): Pointer; stdcall; 
$tagpointer=DllCall($dll,"ptr","ID3v2_Create") 
ConsoleWrite ("ID3v2_Create " &@error &@CR)

;~ # ID3v2_Load(Tag: Pointer; FileName: PChar): Integer; stdcall; 
DllCall($dll,"int","ID3v2_Load","ptr",$tagpointer,"str",'"'&@ScriptDir&'\input.mp3"' )
ConsoleWrite ("ID3v2_Load " &@error &@CR)

;~  Set Title ; ID3v2_SetAsciiText(Tag: Pointer; FrameName, Text: PChar): Boolean; stdcall;
$structchar=DllStructCreate("char[60]")
DllStructSetData($structchar,1,"Some title")
DllCall($dll,"byte","ID3v2_SetAsciiText","ptr",$tagpointer,"str","TIT2", "ptr",DllStructGetPtr($structchar,1)) ; crashs again..
ConsoleWrite ("ID3v2_SetAsciiText " &@error &@CR)

;~ # ID3v2_Free(Tag: Pointer): Boolean; stdcall; 
DllCall($dld,"byte","ID3v2_Free","ptr",DllStructGetData ($struct_fichier,1) )
MsgBox(0,"ID3v2_Free" ,@error &@CR)
 
DllClose($dll)

This time it the third call which crashes : Is anything incorrect in my autoit syntax ?

By the way, I don't kown in autoit dllcall, it's the same thing to use :

"str", "a string"

and to use DllStructCreate("char[60]"), then to pass a pointer using

"ptr", DllStructGetPtr ?

Using "str","some string" should be ok, but I think the way you passed it here is wrong

DllCall($dll,"int","ID3v2_Load","ptr",$tagpointer,"str",'"'&@ScriptDir&'\input.mp3"' )

I think it should be

DllCall($dll,"int","ID3v2_Load","ptr",$tagpointer,"str",@ScriptDir & '\input.mp3' )

I can't comment on the way you've made the dllcalls otherwise because I have no knowledge of the dll you are calling or where to find the information for it.

EDIT:spelling

Edited May 28, 2009 by martin

[brisesel]

reading the delphi source, your modification is right...

But it makes ID3v2_Load crashing again.

I think i will forget this dll.

Anyway, thanks you.

[picaxe]

Maybe this udf (no dll required)

[trancexx]

DllCall() returns an array. You need to do this:

$tagpointer=DllCall($dll,"ptr","ID3v2_Create") 
; check errors...

$tagpointer = $tagpointer[0]
...

[brisesel]

>>>picaxe

Thanks, but in last ressort... this is a fight between me an this dll (and by the way this dll offers much more implementation)

>>>trancexx

In fact, dllcall crashes before returning anything, so...

In fact, the main trouble is probably the type conversion from delphi :

ID3v2_Load(ID3v2Tag, PChar(Edit1.Text));

in this delphi code, ID3v2Tag is a pointer (the void pointer in c, "ptr" in autoit)

PChar() returns a pointer to the string in argument (like char *p in c)

(there is an explanation of delphi types there at the page bottom)

I tried to translate this in autoit like this :

local $dll=DllOpen ( "ID3v2Library.dll" )

$struc_ptr=DllStructCreate("ptr")
DllStructSetData($struc_ptr,1,DllCall($dll,"ptr","ID3v2_Create") )
ConsoleWrite ("ID3v2_Create " &@error &@CR)

;~ # ID3v2_Load(Tag: Pointer; FileName: PChar): Integer; stdcall; 
DllCall($dll,"int","ID3v2_Load","ptr",DllStructGetData($struc_ptr,1),"str","input.mp3" ) ; <--- crash (yeah, in fact relative path should also works)
ConsoleWrite ("ID3v2_Load " &@error &@CR) ;< ---never arrives thereoÝ÷ Ø9e   ©ejëh×6"str", "some string"

works (passes a pointer to the first char of the string), because only when I change "input.mp3" to something that don't exist, there is no execution error (all @error set to 0)(and no result of course...) (and the dll is not buggy because there is an delphi compiled exe working in example...)

So, I actually think that something may be wrong in the way I tried to implement the delphi pointer, or the way I pass the pointer to ID3v2_Load. If you find what it is....

EDIT : misspelling

Edited May 28, 2009 by brisesel

[ProgAndy]

For me, this works:

local $dll=DllOpen ( "ID3v2Library.dll" )

;~ # ID3v1_Create(): Pointer; stdcall;
$tagpointer=DllCall($dll,"ptr","ID3v2_Create")
$tagpointer = $tagpointer[0]
MsgBox(0, '', $tagpointer)

;# ID3v2_Load(Tag: Pointer; FileName: PChar): Integer; stdcall;
DllCall($dll,"int","ID3v2_Load","ptr",$tagpointer,"str", "D:\Music\A_File.mp3" )
;~ ConsoleWrite ("ID3v2_Load " &@error &@CR)

 ;Set Title ; ID3v2_SetAsciiText(Tag: Pointer; FrameName, Text: PChar): Boolean; stdcall;
DllCall($dll,"int","ID3v2_SetAsciiText","ptr",$tagpointer,"str","TIT2", "str","This is a Testtitle")
ConsoleWrite ("ID3v2_SetAsciiText " &@error &@CR)

; ID3v2_Save(Tag: Pointer; FileName: PANSIChar): Integer; stdcall;
DllCall($dll,"int","ID3v2_Save","ptr",$tagpointer,"str", "D:\Music\A_File.mp3"  )

;~ # ID3v2_Free(Tag: Pointer): Boolean; stdcall;
DllCall($dll,"int","ID3v2_Free","ptr",$tagpointer )

Edited May 28, 2009 by ProgAndy

[martin]

>>>picaxe

Thanks, but in last ressort... this is a fight between me an this dll (and by the way this dll offers much more implementation)

>>>trancexx

In fact, dllcall crashes before returning anything, so...

In fact, the main trouble is probably the type conversion from delphi :

in this delphi code, ID3v2Tag is a pointer (the void pointer in c, "ptr" in autoit)

PChar() returns a pointer to the string in argument (like char *p in c)

(there is an explanation of delphi types there at the page bottom)

I tried to translate this in autoit like this :

local $dll=DllOpen ( "ID3v2Library.dll" )

$struc_ptr=DllStructCreate("ptr")
DllStructSetData($struc_ptr,1,DllCall($dll,"ptr","ID3v2_Create") )
ConsoleWrite ("ID3v2_Create " &@error &@CR)

;~ # ID3v2_Load(Tag: Pointer; FileName: PChar): Integer; stdcall; 
DllCall($dll,"int","ID3v2_Load","ptr",DllStructGetData($struc_ptr,1),"str","input.mp3" ) ; <--- crash (yeah, in fact relative path should also works)
ConsoleWrite ("ID3v2_Load " &@error &@CR) ;< ---never arrives thereoÝ÷ Ø9e    ©ejëh×6"str", "some string"

works (passes a pointer to the first char of the string), because only when I change "input.mp3" to something that don't exist, there is no execution error (all @error set to 0)(and no result of course...) (and the dll is not buggy because there is an delphi compiled exe working in example...)

So, I actually think that something may be wrong in the way I tried to implement the delphi pointer, or the way I pass the pointer to ID3v2_Load. If you find what it is....

EDIT : misspelling

I'm a bit confused by now and I'm not sure what version you have tried etc. Trancexx's note bout the dll returns looks like the main step forward to me but I don't see that you've applied that. What happens if you run this, and if there is a crash where does it occur?

local $dll=DllOpen ( "ID3v2Library.dll" )
 
;~ # ID3v1_Create(): Pointer; stdcall;
 $tagpointer=DllCall($dll,"ptr","ID3v2_Create")
 $tagpointer = $tagpointer[0]
 ConsoleWrite ("ID3v2_Create " &@error &@CR); returns 0
 
;~ # ID3v2_Load(Tag: Pointer; FileName: PChar): Integer; stdcall;
 DllCall($dll,"int","ID3v2_Load","ptr",$tagpointer,"str",@ScriptDir & "\input.mp3" ); <--- crash??? !
 ConsoleWrite ("ID3v2_Load " &@error &@CR)
 
;~  Set Title; ID3v2_SetAsciiText(Tag: Pointer; FrameName, Text: PChar): Boolean; stdcall;
 DllCall($dld,"byte","ID3v2_SetAsciiText","ptr",$tagpointer,"str",'TIT2', "str","Some title")
 ConsoleWrite ("ID3v2_SetAsciiText " &@error &@CR)
 
;~ # ID3v2_Free(Tag: Pointer): Boolean; stdcall;
 DllCall($dld,"byte","ID3v2_Free","ptr",$tagpointer)
 MsgBox(0,"ID3v2_Free" ,@error &@CR)
  
 DllClose($dll)

EDIT: probably a redundant post since Prog@ndy got in first.

Edited May 28, 2009 by martin

[brisesel]

$tagpointer = $tagpointer[0]

Thanks you all, there is the error !

I was tired and misunderstood DllCall return type (thought it returned directly the called function return value...)

[ProgAndy]

trancexx already stated in post #6 that DLLCall returns an array

[Paixao]

Interesting Functions of this dll. Somebody knows how to get the tags.

Is it :

DllCall($dll,"int","ID3v2_GetAsciiText","ptr",$tagpointer,"str","TIT2")

???