Re: how to compress audio data - C / C++ / MFC Discussion Boards

vilmer14-Dec-04 21:55

14-Dec-04 21:55

Hi,
I have noticed a strange behaviour in my app.
I have 4 staic items:

static char* manuf[512];
static int link_man[512];
static char* comp[128];
static CDatasheet DS;

where CDatasheet is a class derived from CObject.

Filling in the manuf array, when I reach the 264th item, the app starts overwriting the memory space allocated for the DS object. So any assignment operation to that object produces an error.

Any suggestion?

Another question:

I tried to remove the DS object (commented out), but the compiler still build the app. I parsed all my files, but there are no other declaration for that object. What can it be happened?

Thanks

Dwarfpower

Re: Memory Overwrite

Cedric Moonen14-Dec-04 22:48

Cedric Moonen

14-Dec-04 22:48

vilmer wrote:
static char* manuf[512];

vilmer wrote:
Filling in the manuf array, when I reach the 264th item, the app starts overwriting the memory space allocated for the DS object. So any assignment operation to that object produces an error.

How are you filling the array ? You know that manuf is an array of pointers, and not a string ? You have an array of 512 'strings' that are undefined (that is all adresses are invalid at the begining).
Post the code, so maybe we can help you.

Re: Memory Overwrite

vilmer15-Dec-04 1:36

vilmer

15-Dec-04 1:36

Code is

manuf[i] = strdup("Hello");

the function provides to create a location of memory where it copies the string and writes the address of that location on the pointer manuf[i]

Why does reading a string cause errors?

tpndtbk14-Dec-04 21:35

tpndtbk

14-Dec-04 21:35

Hi all,
I have the following read/write program.

typedef struct
{
string s1;
string s2;
} Names;

int main
{
fstream fout("data.dat", ios::in | ios::out | ios::binary);
Names name;
name.s1.assign("abc");
name.s2.assign("xyz");
fout.write((char*)name, sizeof(Names));
fout.close
}

And then, I create another program to read this file
int main
{
fstream fin("data.dat", ios::in | ios::binary);
Names *name = new Names();
fin.read((char*)name, sizeof(Names));
// --> Till here, it's Ok. But if I want to access the struct. For example:
cout << name->s1.c_str() << endl;
fout.close
}

The strange thing is that, if I combine write and read file in one program, then no problem. But if I creat2 2 differenct programs, there's problems.
Can anyone help me out?
THank you in advance

Re: Why does reading a string cause errors?

Budric B.15-Dec-04 3:42

Budric B.

15-Dec-04 3:42

int main
{
fstream fout("data.dat", ios::in | ios::out | ios::binary);
Names name; <--- not a pointer
name.s1.assign("abc");
name.s2.assign("xyz");
fout.write((char*)name, sizeof(Names)); <--- never thought you can cast
fout.close a structure to a pointer to
} char.

Either this works for weird reasons, or you made a mistake copying (char *)&name.

how to compress audio data

yingkou14-Dec-04 21:32

yingkou

14-Dec-04 21:32

Recently I am writing a voice chatting program,I want to compress audio data before sending it to the other computer,could you help me?

Re: how to compress audio data

rikkemus14-Dec-04 22:55

rikkemus

14-Dec-04 22:55

When it is speech, you dont need as many bits to represent the sound. if its 16, use 8 instead, or even lower perhaps.

Re: how to compress audio data

yingkou14-Dec-04 23:47

yingkou

14-Dec-04 23:47

coulde you give me some details?thanks a lot

Re: how to compress audio data

rikkemus15-Dec-04 8:41

rikkemus

15-Dec-04 8:41

Usually speech doesnt need alot of bits to be audible.

If you record speech with 16 bit, try and reduce it.

Re: how to compress audio data

markkuk15-Dec-04 0:01

markkuk

15-Dec-04 0:01

Speex is a free voice codec, used e.g. in the BitWise Chat voice messaging program.

How to Use Dll in VC++

SivaramanDhamodharan14-Dec-04 19:12

SivaramanDhamodharan

14-Dec-04 19:12

Hi!
I had created an OLE Automation Server ( the out put is in the form of DLL). How can I use that dll in the Client Machines. Suspicious | :suss:

Thanks in Advance.

Re: How to Use Dll in VC++

vishalmore14-Dec-04 22:13

vishalmore

14-Dec-04 22:13

Hi ,

Exports the functions u want from DLL!

Regards,
Vishal

Re: How to Use Dll in VC++

SivaramanDhamodharan14-Dec-04 23:19

SivaramanDhamodharan

14-Dec-04 23:19

Thanks Vishal,
But I'm not using Pure DLL.

// by exporting DllRegisterServer, you can use regsvr.exe<br />
STDAPI DllRegisterServer(void)<br />
{<br />
<small>	AFX_MANAGE_STATE(AfxGetStaticModuleState());<br />
	COleObjectFactory::UpdateRegistryAll();<br />
	return S_OK;</small><br />
}

The above function is automatically implemented by the MFC class wizard.( During the add new class using class wizard, I had created a class which is derived from the CCmdTarget and also I added automation support for it)

But, I can't find any default code support for Dllunregister server. How do I implement code for DllunregisterServer. Smile | :)

Bad Dll calling convention

kk_vc14-Dec-04 17:49

kk_vc

14-Dec-04 17:49

i am getting this message "bad dll calling convention" when i am using openprocess from my vb code.
why?

Re: Bad Dll calling convention

Ryan Binns14-Dec-04 17:51

Ryan Binns

14-Dec-04 17:51

Probably because functions exported from your DLL were not written in VB

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

write to a text file

dex_ter1114-Dec-04 17:47

dex_ter11

14-Dec-04 17:47

Hi all,

Im new to VC++, so i would like to ask how to write a data i store to a text file?

below are part of my code:

FILE *fp1;
Boolean Stats

if(Stats)
{
printf("number of my phone is %.2x:%.2x:%.2x:%.2x:%.2x:%.2x\n",
(PCHAR)(Phone->Data)[0],
(PCHAR)(Phone->Data)[1],
(PCHAR)(Phone->Data)[2],
/* how do i write the Data into My text file*/
fp1 = fopen("Phone.txt","w");
}

Thanx for the advance help.

thanx

Re: write to a text file

vishalmore14-Dec-04 17:56

vishalmore

14-Dec-04 17:56

Hi,

char str[1024];
wsprintf(str,"number of my phone is %.2x:%.2x:%.2x:%.2x:%.2x:%.2x\n",
(PCHAR)(Phone->Data)[0],
(PCHAR)(Phone->Data)[1],
(PCHAR)(Phone->Data)[2],.....);

fp1 = fopen("Phone.txt","w");
fwrite(str,...,fp);

Wink | ;)

is this you wanted ?

Regards,
Vishal

Re: write to a text file

dex_ter1114-Dec-04 19:01

dex_ter11

14-Dec-04 19:01

yes... Something like that....
fwrite(str,(PCHAR)(Phone->Data)[0],,fp);

there are some syntax problem...

thanx

Re: write to a text file

vishalmore14-Dec-04 19:10

vishalmore

14-Dec-04 19:10

Hi,

see the following example whhich writes 25 chars to (FILE*)stream
/* Write 25 characters to stream */
char list[25] = "a...z"
numwritten = fwrite(list, sizeof( char ), 25, stream );

in your case it should be
fwrite(str,sizeof(char),strlen(str),fp);

For more info. plz refer to MSDN documentation of fwrite, wsprintf etc.

Enjoy !

Blush | :O

Regards,
Vishal

Re: write to a text file

eli1502197914-Dec-04 21:32

eli15021979

14-Dec-04 21:32

Hi,
Try this:

FILE *fp1;
char output[1024];

sprintf(output,"the number of my phone is %.2x:%.2x:%.2x:%.2x:%.2x:%.2x\n",
(PCHAR)(Phone->Data)[0],(PCHAR)(Phone->Data)[1],
(PCHAR)(Phone->Data)[2],.....);
fputs(output,fp1);

Eli.

Re: write to a text file

David Crow15-Dec-04 4:20

David Crow

15-Dec-04 4:20

dex_ter11 wrote:
/* how do i write the Data into My text file*/

How about using fprintf()?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Active X for other browsers or something similiar

Jsmooth14-Dec-04 17:10

Jsmooth

14-Dec-04 17:10

How can you do this for other browsers like Netscape or Opera? Can this be done for other browsers?

http://www.codeproject.com/useritems/iemozilla.asp[^]

If it has been done can you tell where I can learn more about this or other good resource sites like the link above.

Thanks,

How to reroute connection

Member 38774714-Dec-04 16:17

Member 387747

14-Dec-04 16:17

Hi,
I wrote the proxy app (WinSock) forwarding data from one socket to another. I listen for the client connection on the first socket, when the connection is established I create second socket and connect to the destination. Than I only forwarding data using these 2 sockets (client & destination).

My question: is it possible (after accept client connection) to bind client & destination sides without creating 2 sockets ? I mean, how to reroute connection only, without using my proxy to forward the data.

Thanks

------------------
PeterP

Re: How to reroute connection

Ryan Binns14-Dec-04 18:07

Ryan Binns

14-Dec-04 18:07

PeterP2004 wrote:
is it possible (after accept client connection) to bind client & destination sides without creating 2 sockets ? I mean, how to reroute connection only, without using my proxy to forward the data.

No, it's not possible. Once a socket is connected, it cannot be reconnected without being disconnected first, and the reconnection can only be initiated by the client.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Windows Lex/Yacc (and Bumblebee)

maxmaven14-Dec-04 15:01

maxmaven

14-Dec-04 15:01

I'm trying to get Bumbleebee Software's lex and yacc generator up and running. I'm pretty experienced with lex and yacc, but only on unix systems. The problem is, if I use Bumblebee's ParserWizard, I get a good grammar and can compile, but the resulting application (I'm building into a windows console application) always crashes. I've tried "empty" grammars. I've also tried a grammar that can only produce a single non-terminal, i.e., it should be able to match an input of "binky", and nothing else. No matter what I try, the resulting application always crashes. I've tried reading from stdin and from a file, with no luck. I wish I could copy and paste some of the examples provided with bumblebee (like the calculator grammar), but it seems that most of them are the grammar without an accompanying lexer. I had hoped that there would be a complete example that I could compile in ParserGenerator and then compile in Visual C++ and have a working application (no matter how simple). But, apparently, no luck there.

I would be immensely grateful for any of the following:
1. Any simple grammar (and lexer if needed) that I can compile in Bumblebee and then MSVC and run the resulting console app without a crash.
2. Advice, tips, suggestions on what is needed to get a working Bumblebee generated grammar and lexer. I obviously don't know why my parsers and lexers are not working. Could it be because under unix, anything not parsed gets dumped to stdout, and this is not acceptable in windows? Is it something else that I have not done properly?

Thanks for any help you can offer!

maxmaven

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