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From: Larry on 23 Dec 2009 18:09

"ScottMcP [MVP]" <scottmcp(a)mvps.org> ha scritto nel messaggio
news:90e0fd36-f591-411e-a020-80c5a0ea4180(a)v7g2000vbd.googlegroups.com...

> If you are going to reuse the buffer do not call waveInUnprepareHeader
> and do not delete the buffer!

By the way, I have just found this chunk of code:
http://home.elka.pw.edu.pl/~mroj/h323/homepage/works/mroj/html/audio/waveform.htm

It shows the regular way to open an input device and create some buffers.
Yet, it has a different way to allocate buffers with the use of malloc:

pwf.wBitsPerSample= 16;
pwf.wf.nChannels = 1;
pwf.wf.nSamplesPerSec = 8000;

pwf.wf.wFormatTag = WAVE_FORMAT_PCM;
pwf.wf.nBlockAlign =
pwf.wf.nChannels * pwf.wBitsPerSample / 8;
pwf.wf.nAvgBytesPerSec =
pwf.wf.nSamplesPerSec * pwf.wf.nBlockAlign;

if (waveInOpen(&rip->hwi,
/*WAVE_MAPPER*/ 0, (LPWAVEFORMATEX)&pwf,
(DWORD) rip->eventh, 0, CALLBACK_EVENT )) {
printf("Couldn't open sound device. Leaving..\n");
goto problem;
}

/* Preparing system buffers */

sb = (WAVEHDR**) malloc(sizeof(WAVEHDR**) * system_buf_num);
if(!sb)
goto problem;

for (i = 0; i < system_buf_num; i++)
sb[i] = NULL;

for (i = 0; i < system_buf_num; i++) {

count = i;
sb[i] = (WAVEHDR*) malloc(sizeof(WAVEHDR));

if (sb[i] == NULL) {
put_debug_message("malloc() error!\n");
goto problem;
}

sb[i]->lpData = (LPBYTE) malloc(system_buf_len);
sb[i]->dwBufferLength = system_buf_len;
sb[i]->dwBytesRecorded = 0;
sb[i]->dwUser = 0;
sb[i]->dwFlags = 0;
sb[i]->dwLoops = 0;

if(!sb[i]->lpData)
goto problem;

if (waveInPrepareHeader(rip->hwi, sb[i], sizeof(WAVEHDR))) {
put_debug_message("waveInPrepareHeader problem!\n");
goto problem;
}
if (waveInAddBuffer(rip->hwi, sb[i], sizeof(WAVEHDR))) {
put_debug_message("waveInAddBuffer problem!\n");
goto problem;
}
}

Do you think there much difference between this code and mine? can this be
more smooth?

thanks

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