c - 尝试编写通过 WinAPI 录制和播放声音的函数

Question

我正在尝试在 C 中创建 2 个函数:

• 对麦克风进行 X 秒录音
• 获取录音并将其播放给用户

这是我写的:

#include <iostream>
#include <Windows.h>
using namespace std;

#pragma comment(lib, "winmm.lib")

WAVEHDR StartRecord(int seconds)
{
const int NUMPTS = 44100 * seconds;
int sampleRate = 44100;
short int *waveIn = new short int[NUMPTS];

HWAVEIN hWaveIn;
WAVEHDR WaveInHdr;
MMRESULT result;

WAVEFORMATEX pFormat;
pFormat.wFormatTag = WAVE_FORMAT_PCM;
pFormat.nChannels = 1;
pFormat.nSamplesPerSec = sampleRate;
pFormat.nAvgBytesPerSec = 2 * sampleRate;
pFormat.nBlockAlign = 2;
pFormat.wBitsPerSample = 16;
pFormat.cbSize = 0;

result = waveInOpen(&hWaveIn, WAVE_MAPPER, &pFormat, 0, 0, WAVE_FORMAT_DIRECT);

if(result)
{
    char fault[256];
    waveInGetErrorTextA(result, fault, 256);
    MessageBoxA(NULL, fault, "Failed to open waveform input device.", MB_OK | MB_ICONEXCLAMATION);
}

WaveInHdr.lpData = (LPSTR)waveIn;
WaveInHdr.dwBufferLength = 2 * NUMPTS;
WaveInHdr.dwBytesRecorded = 0;
WaveInHdr.dwUser = 0;
WaveInHdr.dwFlags = 0;
WaveInHdr.dwLoops = 0;
waveInPrepareHeader(hWaveIn, &WaveInHdr, sizeof(WAVEHDR));

result = waveInAddBuffer(hWaveIn, &WaveInHdr, sizeof(WAVEHDR));
if(result)
{
    MessageBoxA(NULL, "Failed to read block from device", NULL, MB_OK | MB_ICONEXCLAMATION);
}

result = waveInStart(hWaveIn);
if(result)
{
    MessageBoxA(NULL, "Failed to start recording", NULL, MB_OK | MB_ICONEXCLAMATION);
}

cout << "Recording..." << endl;
Sleep(seconds * 1000); //Sleep while recording

return WaveInHdr;

}

void PlayRecord(WAVEHDR WaveInHdr, int seconds)
{
WAVEFORMATEX pFormat;
pFormat.wFormatTag = WAVE_FORMAT_PCM;
pFormat.nChannels = 1;
pFormat.nSamplesPerSec = 44100;
pFormat.nAvgBytesPerSec = 2 * 44100;
pFormat.nBlockAlign = 2;
pFormat.wBitsPerSample = 16;
pFormat.cbSize = 0;

HWAVEOUT hWaveOut;

if(waveOutOpen(&hWaveOut, WAVE_MAPPER, &pFormat, 0, 0, WAVE_FORMAT_DIRECT))
{
    MessageBoxA(NULL, "Failed to replay", NULL, MB_OK | MB_ICONEXCLAMATION );
}

waveOutWrite(hWaveOut, &WaveInHdr, sizeof(WaveInHdr)); // Playing the data
Sleep(seconds * 1000); //Sleep for as long as there was recorded
 }

int main()
{
PlayRecord(StartRecord(3), 3);
return 0;
}

代码有什么问题？为什么它不起作用？我好像什么都听不见...

此外，是否有一个选项可以录制麦克风，而不是 X 秒，例如，直到没有来自麦克风的输入(例如 - 开始录制，我正在对着麦克风说一句话，当有一两秒钟的沉默时，它会停止录音或其他什么？)

谢谢!

Answer 1

回复:录音直到没有来自麦克风的输入。是的，准备几个缓冲区并在 WaveInStart 之前用每个缓冲区调用 waveInAddBuffer。 WaveIn 将连续并按顺序填充缓冲区，并在填充时将它们返回给您。您将需要使用 WaveIn 提供的通知之一来了解缓冲区何时已满。检查缓冲区数据以决定何时停止。如果您想继续前进，请将每个已填充的缓冲区返回给 WaveIn，只要您愿意，它就会继续填充它们。