从字节数组创建 IMFByteStream

我正在尝试采用一种方法，该方法最初从 Microsoft 的 MediaFoundation 音频播放示例中获取 URL，改为从 const char* 数组中获取源。问题是，CreateObjectFromByteStream 需要 IMFByteStream，而不是 const char*。我怎样才能得到我需要的东西？

// Create a media source from a byte stream
HRESULT CreateMediaSource(const byte *data, IMFMediaSource **ppSource)
{
    MF_OBJECT_TYPE ObjectType = MF_OBJECT_INVALID;

    IMFSourceResolver* pSourceResolver = NULL;
    IUnknown* pSource = NULL;

    // Create the source resolver.
    HRESULT hr = MFCreateSourceResolver(&pSourceResolver);
    if (FAILED(hr))
    {
        goto done;
    }

    // Use the source resolver to create the media source.

    // Note: For simplicity this sample uses the synchronous method to create 
    // the media source. However, creating a media source can take a noticeable
    // amount of time, especially for a network source. For a more responsive 
    // UI, use the asynchronous BeginCreateObjectFromURL method.
    hr = pSourceResolver->CreateObjectFromByteStream(data,
        NULL,                       // URL of the source.
        MF_RESOLUTION_MEDIASOURCE | MF_BYTESTREAM_CONTENT_TYPE,  // Create a source object.
        NULL,                       // Optional property store.
        &ObjectType,        // Receives the created object type. 
        &pSource            // Receives a pointer to the media source.
        );
    if (FAILED(hr))
    {
        goto done;
    }

    // Get the IMFMediaSource interface from the media source.
    hr = pSource->QueryInterface(IID_PPV_ARGS(ppSource));

done:
    SafeRelease(&pSourceResolver);
    SafeRelease(&pSource);
    return hr;
}

您可以使用MFCreateMFByteStreamOnStream()创建一个IMFByteStream从一个IStream你可以创建并IStream使用字节数组SHCreateMemStream()。撰写本文时的文档位于https://learn.microsoft.com/en-us/windows/win32/api/mfidl/nf-mfidl-mfcreatemfbytestreamonstream https://learn.microsoft.com/en-us/windows/win32/api/mfidl/nf-mfidl-mfcreatemfbytestreamonstream and https://learn.microsoft.com/en-us/windows/win32/api/shlwapi/nf-shlwapi-shcreatememstream https://learn.microsoft.com/en-us/windows/win32/api/shlwapi/nf-shlwapi-shcreatememstream

这是一个简单的例子：

// Generate a byte array
int sample_size = 0x100;
BYTE* sample_bytes = (BYTE*)malloc(sample_size)

// Create the IStream from the byte array
IStream* pstm = SHCreateMemStream(sample_bytes, sample_size);

// Create the IMFByteStream from the IStream
IMFByteStream* pibs = NULL;
MFCreateMFByteStreamOnStream(pstm, &pibs);

// Clean up time
if (pibs)
    pibs->Close();
if (pstm)
    pstm->Release();
if (sample_bytes)
    free(sample_bytes)

在 Microsoft API 中，具有 IStream 接口但没有字节数组接口的情况似乎很常见。值得庆幸的是，创建 IStream 很容易。