如何使用 IGraphBuilder 播放 ogg Vorbis 文件

Question

我需要编写一个可以在 IGraphBuilder 或任何其他 windows API 的帮助下直接播放 .ogg Vorbis 文件的程序（在 C++/win32 API 中）？

我尝试使用 IGraphBuilder，但这对我不起作用。示例代码：

IMediaControl *pControl = NULL;
IGraphBuilder *pGraph= NULL;
IMediaEventEx *pEvent= NULL;
IMediaPosition *pMediaPosition= NULL;

hr = ::CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER,
                        IID_IGraphBuilder, (void **)&pGraph);
if (FAILED(hr)) {
    return false;
}

hr = pGraph->AddFilter(pFilter, L"Out");
hr = pGraph->QueryInterface(IID_IMediaControl, (void **)&pControl);
hr = pGraph->QueryInterface(IID_IMediaEvent, (void **)&pEvent);
hr = pGraph->QueryInterface(IID_IMediaPosition, (void**)&pMediaPosition);

// Build the graph.
hr = pGraph->RenderFile(mFilePath.c_str()/*"C:\sample.ogg file"*/, NULL);

/* here hr = 0x80040265 so SUCCEEDED(hr) didnt allow it to enter in if condition*/
if (SUCCEEDED(hr)) {
    // Run the graph.
    hr = pControl->Run();
    if (SUCCEEDED(hr)) {
        // Wait for completion.
        long evCode;
        pEvent->WaitForCompletion(INFINITE, &evCode);
    }
}

// Clean up in reverse order.
SAFE_RELEASE(pEvent);
SAFE_RELEASE(pControl);
SAFE_RELEASE(pGraph);
pGraph = NULL;

::CoUninitialize();

注意：上面的语句 hr = pGraph->RenderFile() returned the hr = 0x80040265 and condition if (SUCCEEDED(hr)) doesn't allow to play it.

如果我不使用此条件，则 pControl->Run() 将以 return ID_OK 执行。但是没有播放扬声器。请建议 solution/method.

Answer 1

注意HRESULT个错误代码；他们意味着什么。 MSDN 通常对特定于功能的错误代码很有帮助，例如您得到的错误代码。（通过足够的 COM 编程，您将能够通过视觉识别像 E_INVALIDARG 这样的常见代码。）如果没有，您可以使用头文件来查明潜在的错误代码。 HRESULTs 有特定的格式；学习吧！

在IGraphBuilder::RenderFile(), that HRESULT maps to VFW_E_UNSUPPORTED_STREAM, which basically means your setup does not support playing Ogg Vorbis files. You will need to install a filter that allows DirectShow to play Ogg Vorbis files, such as the official one from Xiph.Org的情况下。

如何使用 IGraphBuilder 播放 ogg Vorbis 文件

How to play ogg Vorbis files using IGraphBuilder

c++

winapi

oggvorbis

windows-7