Question

一段时间后，音频音调会变尖，然后只会发出声音这让我认为问题出在我填充缓冲区的方式上

int AudioThreadProc(AUDIOSTRUCT* audio) {
    SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST);
    HANDLE buffReady = CreateEvent(0, 0, 1, 0);
    audio->client->lpVtbl->SetEventHandle(audio->client, buffReady);

    unsigned int soundBuffSize;
    audio->client->lpVtbl->GetBufferSize(audio->client, &soundBuffSize);
    audio->client->lpVtbl->Start(audio.client);

    static float time = 0;
    float dtime = 1 / (float)44100;

    for (;;) {
        WaitForSingleObject(buffReady, INFINITE);

        unsigned int soundFrames;
        audio->client->lpVtbl->GetCurrentPadding(audio->client, &soundFrames);
        unsigned int FramesToFill = soundBuffSize - soundFrames;
        unsigned short int* soundBuff;
        audio->render->lpVtbl->GetBuffer(audio.render, FramesToFill, &soundBuff);

        for (unsigned int i = 0; i < FramesToFill; i++) {
            unsigned short int soundWave = audio->callback(time);
            time += dtime;
            *soundBuff++ = soundWave;
            *soundBuff++ = soundWave;
        }
        audio->render->lpVtbl->ReleaseBuffer(audio.render, FramesToFill, 0);

    }
    return 0;
}

回调函数仅是一个正弦波发生器

float callback(float time){
 returns sin(pitch * PI2 * time) * 0xFFFF;
}

//...
audio.callback = callback;

Answer 1

我认为这里的答案几乎等于几年前我给的this answer。随着time的增加，计算pitch*2π*time的浮点精度下降。调整代码，使time重置为零或为，并在完成一整波数据后从零开始偏移。

类似这样的东西：

time += dtime;
if (time > 1.0) {
    time -= 1.0;
}

此外，每个示例调用一个函数调用的总开销也可能是一个问题。将您的callback转换为宏。你不会后悔的。

使用wasapi渲染音频时出现问题

1 个答案: