DirectShow USB攝像頭改變視頻源

Question

嘿所有我想找到設置來改變我的視頻源到我的攝像頭「複合」。似乎如果我拔掉USB，然後插回來，並啓動代碼，它只是一個空白的屏幕。但是，一旦我改變視頻源（在另一個程序中），然後返回並再次運行我的代碼，它就會顯示出來。

所以我需要的東西，讓我改變，爲了讓發生同樣的事情，但我自己的應用程序中，而無需啓動具有功能設置攝像頭另一個程序。

當我拉出USB電纜，然後把它放回來，我運行源代碼，應用程序的圖片框是黑色的。

的「其他程序」我用它來改變視頻源（這似乎工作，彈出圖像）：在我使用的是「其他節目」我回去

源代碼並運行它，這就是我得到那麼：

我使用從這裏稱爲點網絡攝像頭庫的C＃代碼：enter link description here

似乎使用的DirectShow從enter link description here

我已經在源注意到了，它列出了不同類型的視頻設置（在AXExtend.cs下面找到）：

public enum PhysicalConnectorType 
{ 
    Video_Tuner = 1, 
    Video_Composite, 
    Video_SVideo, 
    Video_RGB, 
    Video_YRYBY, 
    Video_SerialDigital, 
    Video_ParallelDigital, 
    Video_SCSI, 
    Video_AUX, 
    Video_1394, 
    Video_USB, 
    Video_VideoDecoder, 
    Video_VideoEncoder, 
    Video_SCART, 
    Video_Black, 

    Audio_Tuner = 0x1000, 
    Audio_Line, 
    Audio_Mic, 
    Audio_AESDigital, 
    Audio_SPDIFDigital, 
    Audio_SCSI, 
    Audio_AUX, 
    Audio_1394, 
    Audio_USB, 
    Audio_AudioDecoder, 
} 

但我不確定如何調用了在這裏碼：

Device selectedDevice = device as Device; 
imageCapture.Device = selectedDevice as Device; 
imageCapture.PerformAutoScale(); 
imageCapture.Refresh(); 
imageCapture.Start(); 

所以我猜測的「Video_Composite」是什麼，我可能需要在爲了做到這一點？

任何幫助將是偉大的！謝謝！

大衛

代碼更新

foreach (Device device in Device.FindDevices()) 
{ 
    if (device.ToString() == "BackupCamera") 
    { 
     Device selectedDevice = device as Device; 
     IGraphBuilder graphBuilder = new FilterGraph() as IGraphBuilder; 
     DsDevice device1 = DsDevice.GetDevicesOfCat(FilterCategory.VideoInputDevice)[1]; // <<--- Your Device 
     Guid baseFilterIdentifier = typeof(IBaseFilter).GUID; 
     object videoSourceObject; 
     device1.Mon.BindToObject(null, null, ref baseFilterIdentifier, out videoSourceObject); 
     IBaseFilter videoSourceBaseFilter = videoSourceObject as IBaseFilter; 
     graphBuilder.AddFilter(videoSourceBaseFilter, "Source"); 
     ICaptureGraphBuilder2 captureGraphBuilder = new CaptureGraphBuilder2() as ICaptureGraphBuilder2; 
     captureGraphBuilder.SetFiltergraph(graphBuilder); 
     object crossbarObject; 
     captureGraphBuilder.FindInterface(FindDirection.UpstreamOnly, null, videoSourceBaseFilter, typeof(IAMCrossbar).GUID, out crossbarObject); 
     IAMCrossbar crossbar = crossbarObject as IAMCrossbar; 
     int inputPinCount, outputPinCount; 
     crossbar.get_PinCounts(out inputPinCount, out outputPinCount); // <<-- In/Out Pins 
     // Pin Selection: Physical Input 2 (e.g. Composite) to Capture Pin 0 
     crossbar.Route(0, 2); 

     imageCapture.Device = selectedDevice as Device; 
     imageCapture.PerformAutoScale(); 
     imageCapture.Refresh(); 
     imageCapture.Start(); 
    } 
} 

Answer 1

運行文件管理器圖形之前，你需要獲得交叉開關接口。您通常爲此使用ICaptureGraphBuilder2::FindInterface。這需要額外的過濾器，並且FindInterface方法特別有用於這個原因：

支持過濾器。如果捕獲設備使用Windows驅動程序型號（WDM）驅動程序，則圖形可能需要WDM視頻捕獲過濾器上游的某些過濾器，例如電視調諧器過濾器或模擬視頻交叉開關過濾器。如果pCategory參數不等於NULL，則此方法自動將插入圖中的所有必需WDM過濾器。

完成此操作後，您將有IAMCrossbar接口，並且IAMCrossbar::Route方法就是如何切換輸入。

參見：Crossbar filter change current input to Composite

代碼片段：

IGraphBuilder graphBuilder = new FilterGraph() as IGraphBuilder; 
DsDevice device = DsDevice.GetDevicesOfCat(FilterCategory.VideoInputDevice)[1]; // <<--- Your Device 
Guid baseFilterIdentifier = typeof(IBaseFilter).GUID; 
object videoSourceObject; 
device.Mon.BindToObject(null, null, ref baseFilterIdentifier, out videoSourceObject); 
IBaseFilter videoSourceBaseFilter = videoSourceObject as IBaseFilter; 
graphBuilder.AddFilter(videoSourceBaseFilter, "Source"); 
ICaptureGraphBuilder2 captureGraphBuilder = new CaptureGraphBuilder2() as ICaptureGraphBuilder2; 
captureGraphBuilder.SetFiltergraph(graphBuilder); 
object crossbarObject; 
captureGraphBuilder.FindInterface(FindDirection.UpstreamOnly, null, videoSourceBaseFilter, typeof(IAMCrossbar).GUID, out crossbarObject); 
IAMCrossbar crossbar = crossbarObject as IAMCrossbar; 
int inputPinCount, outputPinCount; 
crossbar.get_PinCounts(out inputPinCount, out outputPinCount); // <<-- In/Out Pins 
// Pin Selection: Physical Input 2 (e.g. Composite) to Capture Pin 0 
crossbar.Route(0, 2);