Question

情况：

使用directshow创建解密过滤器。图是 DecryptFileSource - ＆gt; GDCL Mpeg-4 Demux - ＆gt; FFDShow视频解码器 - ＆gt;增强的视频渲染器

问题：

GraphEdit：显示视频正常。
GraphStudioNext：显示视频，工作很好。
GraphEditPlus：不显示视频，不显示工作。
通过代码：无效。但是，如果我更换带“视频渲染器”或“VMR9”的EVR

另一位用户遇到此问题here但他的答案含糊不清。根据Roman（在上一个链接的评论中），它需要特定的初始化。但是我不确定如何专门初始化它。

当我尝试通过代码创建图形时，不会引发错误。我有一个寻求启用，我可以看到IMediaPosition正在工作。只是没有视频显示，但音频播放

Answer 1

我找到了答案。

编译在＆＃34; Program Files \ Microsoft SDKs \ Windows \ v6.1 \ Samples \ Multimedia \ MediaFoundation \ EVRPresenter＆＃34;
安装DLL＆＃34; regsvr32 EVRPresenter.dll＆＃34;
编译并将MediaFoundation.dll包含到我的产品中。 Link here
而不是像我通常那样创建对象

像这样：

IBaseFilter pEnhancedVideoRenderer = (IBaseFilter)Activator.CreateInstance(Type.GetTypeFromCLSID(CLSID_EnhancedVideoRenderer));

而不是

        IBaseFilter pEVR = (IBaseFilter)new MediaFoundation.EVR.EnhancedVideoRenderer();
        hr = pGraph.AddFilter(pEVR, "Enhanced Video Renderer");

        MediaFoundation.EVR.IMFVideoDisplayControl m_pDisplay;

        InitializeEVR(pEVR, 1, out m_pDisplay);

InitializeEVR：

private void InitializeEVR(IBaseFilter pEVR, int dwStreams, out MediaFoundation.EVR.IMFVideoDisplayControl ppDisplay)
        {
            MediaFoundation.EVR.IMFVideoRenderer pRenderer;
            MediaFoundation.EVR.IMFVideoDisplayControl pDisplay;
            MediaFoundation.EVR.IEVRFilterConfig pConfig;
            MediaFoundation.EVR.IMFVideoPresenter pPresenter;

            // Before doing anything else, set any custom presenter or mixer.

            // Presenter?
            if (m_PresenterCLSID != Guid.Empty)
            {
                Type type = Type.GetTypeFromCLSID(m_PresenterCLSID);

                // An error here means that the custom presenter sample from
                // http://mfnet.sourceforge.net hasn't been installed or
                // registered.
                pPresenter = (MediaFoundation.EVR.IMFVideoPresenter)Activator.CreateInstance(type);

                try
                {
                    pRenderer = (MediaFoundation.EVR.IMFVideoRenderer)pEVR;

                    pRenderer.InitializeRenderer(null, pPresenter);
                }
                finally
                {
                    //Marshal.ReleaseComObject(pPresenter);
                }
            }

            // Continue with the rest of the set-up.

            // Set the video window.
            object o;
            MediaFoundation.IMFGetService pGetService = null;
            pGetService = (MediaFoundation.IMFGetService)pEVR;
            pGetService.GetService(MediaFoundation.MFServices.MR_VIDEO_RENDER_SERVICE, typeof(MediaFoundation.EVR.IMFVideoDisplayControl).GUID, out o);

            try
            {
                pDisplay = (MediaFoundation.EVR.IMFVideoDisplayControl)o;
            }
            catch
            {
                Marshal.ReleaseComObject(o);
                throw;
            }

            try
            {
                // Set the number of streams.
                pDisplay.SetVideoWindow(this.Handle);

                if (dwStreams > 1)
                {
                    pConfig = (MediaFoundation.EVR.IEVRFilterConfig)pEVR;
                    pConfig.SetNumberOfStreams(dwStreams);
                }

                // Set the display position to the entire window.
                Rectangle r = this.ClientRectangle;
                MediaFoundation.Misc.MFRect rc = new MediaFoundation.Misc.MFRect(r.Left, r.Top, r.Right, r.Bottom);

                pDisplay.SetVideoPosition(null, rc);

                // Return the IMFVideoDisplayControl pointer to the caller.
                ppDisplay = pDisplay;
            }
            finally
            {
                //Marshal.ReleaseComObject(pDisplay);
            }
            m_pMixer = null;
        }

使用增强型视频渲染器

1 个答案: