我目前正在研究 MSVAD 简单驱动程序。不幸的是，它没有按照我希望的方式工作。当一个新程序启动时，它在 C:\下创建为 STREAM_NN.WAV

不幸的是，这个文件只有 44 字节大小(只包含文件头)。我附加了调试器 View 并得到了这个输出:

MSVAD: [CMiniportWaveCyclic::NewStream]
MSVAD: [CMiniportWaveCyclicMSVAD::ValidateFormat]
MSVAD: [CMiniportWaveCyclic::NewStream]
MSVAD: [CMiniportWaveCyclicMSVAD::ValidateFormat]
MSVAD: CMiniportWaveCyclicMSVAD::ValidatePcm
MSVAD: [CSaveData::InitializeWorkItems]
MSVAD: [CMiniportWaveCyclicStreamMSVAD::Init]
MSVAD: SaveData 845A754C
MSVAD: [CSaveData::SetDataFormat]
MSVAD: [CSaveData::Initialize]
MSVAD: [CMiniportWaveCyclicStreamMSVAD::AllocateBuffer]
MSVAD: [CMiniportWaveCyclicStreamMSVAD::SetFormat]
MSVAD: [CSaveData::SetDataFormat]
MSVAD: New Format: 44100
MSVAD: [CMiniportWaveCyclicStreamMSVAD::SetNotificationFreq]
MSVAD: [CMiniportWaveCyclicStreamMSVAD::SetState]
MSVAD: [CMiniportWaveCyclicStreamMSVAD::SetState]
MSVAD: KSSTATE_PAUSE
MSVAD: [CMiniportWaveCyclicStreamMSVAD::SetState]
MSVAD: KSSTATE_RUN
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=480]
MSVAD: [CSaveData::WriteData ulByteCount=1284]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=628]
MSVAD: [CSaveData::WriteData ulByteCount=1136]
//Truncated for convenience
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=776]
MSVAD: [CSaveData::WriteData ulByteCount=988]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CSaveData::WriteData ulByteCount=1764]
MSVAD: [CMiniportWaveCyclicStreamMSVAD::SetState]
MSVAD: KSSTATE_PAUSE
MSVAD: [CMiniportWaveCyclicStreamMSVAD::SetState]
MSVAD: KSSTATE_STOP
MSVAD: [CSaveData::WaitAllWorkItems]
MSVAD: [CSaveData::SaveFrame]
MSVAD: [CMiniportWaveCyclicStreamMSVAD::SetState]
MSVAD: [CMiniportWaveCyclicStream::~CMiniportWaveCyclicStream]
MSVAD: [CMiniportWaveCyclicStreamMS::~CMiniportWaveCyclicStreamMS]
MSVAD: [CMiniportWaveCyclicStreamMSVAD::FreeBuffer]
MSVAD: [CSaveData::~CSaveData]

这对我来说看起来很直接，例如所有必要的功能都被调用了。我想知道此示例中是否存在已知错误，或者我必须考虑的任何注意事项？

操作系统是虚拟机中的 Windows 7 32 位，正常的音频播放效果很好。 Simple 驱动程序设置为默认播放设备。

最佳答案

问题在于，由于 DDK 8 在方法 CSaveData::InitializeWorkItems (savedata.cpp) 中添加了以下行:

if (m_pWorkItems)
{
    return ntStatus;
}

但是 CSaveData::~CSaveData 只释放“工作项”，而不是 m_pWorkItems 数组。这会导致将来使用释放的“工作项”。

解决这个问题需要替换savedata.cpp, CSaveData::InitializeWorkItems中的代码:

if (m_pWorkItems)
{
    return ntStatus;
}

m_pWorkItems = (PSAVEWORKER_PARAM)
    ExAllocatePoolWithTag
    (
        NonPagedPool,
        sizeof(SAVEWORKER_PARAM) * MAX_WORKER_ITEM_COUNT,
        MSVAD_POOLTAG
    );

通过这段代码:

if (!m_pWorkItems)
{
    m_pWorkItems = (PSAVEWORKER_PARAM)
        ExAllocatePoolWithTag
        (
            NonPagedPool,
            sizeof(SAVEWORKER_PARAM) * MAX_WORKER_ITEM_COUNT,
            MSVAD_POOLTAG
        );
}

关于c++ - Microsoft Virtual Audio Device Driver Sample (MSVAD) 仅创建 44 字节文件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25484981/