Restructure the video_capture code a bit to make room for a Media Foundation class implementation.

This change includes the following:

* Skeleton classes for a couple of base MediaFoundation classes (no code yet).  See *_mf.*.
* Renaming the DirectShow based implementation from "_windows" to "_ds".
* Move the VideoCaptureImpl::CreateDeviceInfo() method into video_capture_factory_windows.cc
  The reason for this is that that's where the other VideoCaptureImpl factory function is
  and the factory function won't be implementation specific.
* Removed use of <initguid.h> from a header file to avoid defining the same guids in multiple object files.
  (more info here: http://msdn.microsoft.com/en-us/library/windows/desktop/dd375463(v=vs.85).aspx)
* Moved a couple of global variables from the capture_delay_values_windows.h header and into
  device_info_ds.cc since that's the only file that uses those variables.
* Delete capture_delay_values_windows.h.
* Added a factory function: DeviceInfoDS::Create() that'll create the DirectShow specific implementation.

TEST=This is mostly moving code around.  The code that is added, is currently "dead". No manual testing needed.
BUG=chromium:140545
Review URL: https://webrtc-codereview.appspot.com/967008

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3135 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/video_capture/windows/help_functions_ds.cc

@@ -0,0 +1,120 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <initguid.h>  // Must come before the help_functions_ds.h include so
+                       // that DEFINE_GUID() entries will be defined in this
+                       // object file.
+
+#include "help_functions_ds.h"
+
+#include <cguid.h>
+
+namespace webrtc
+{
+namespace videocapturemodule
+{
+// This returns minimum :), which will give max frame rate...
+LONGLONG GetMaxOfFrameArray(LONGLONG *maxFps, long size)
+{
+    LONGLONG maxFPS = maxFps[0];
+    for (int i = 0; i < size; i++)
+    {
+        if (maxFPS > maxFps[i])
+            maxFPS = maxFps[i];
+    }
+    return maxFPS;
+}
+
+IPin* GetInputPin(IBaseFilter* filter)
+{
+    HRESULT hr;
+    IPin* pin = NULL;
+    IEnumPins* pPinEnum = NULL;
+    filter->EnumPins(&pPinEnum);
+    if (pPinEnum == NULL)
+    {
+        return NULL;
+    }
+
+    // get first unconnected pin
+    hr = pPinEnum->Reset(); // set to first pin
+
+    while (S_OK == pPinEnum->Next(1, &pin, NULL))
+    {
+        PIN_DIRECTION pPinDir;
+        pin->QueryDirection(&pPinDir);
+        if (PINDIR_INPUT == pPinDir) // This is an input pin
+        {
+            IPin* tempPin = NULL;
+            if (S_OK != pin->ConnectedTo(&tempPin)) // The pint is not connected
+            {
+                pPinEnum->Release();
+                return pin;
+            }
+        }
+        pin->Release();
+    }
+    pPinEnum->Release();
+    return NULL;
+}
+
+IPin* GetOutputPin(IBaseFilter* filter, REFGUID Category)
+{
+    HRESULT hr;
+    IPin* pin = NULL;
+    IEnumPins* pPinEnum = NULL;
+    filter->EnumPins(&pPinEnum);
+    if (pPinEnum == NULL)
+    {
+        return NULL;
+    }
+    // get first unconnected pin
+    hr = pPinEnum->Reset(); // set to first pin
+    while (S_OK == pPinEnum->Next(1, &pin, NULL))
+    {
+        PIN_DIRECTION pPinDir;
+        pin->QueryDirection(&pPinDir);
+        if (PINDIR_OUTPUT == pPinDir) // This is an output pin
+        {
+            if (Category == GUID_NULL || PinMatchesCategory(pin, Category))
+            {
+                pPinEnum->Release();
+                return pin;
+            }
+        }
+        pin->Release();
+        pin = NULL;
+    }
+    pPinEnum->Release();
+    return NULL;
+}
+
+BOOL PinMatchesCategory(IPin *pPin, REFGUID Category)
+{
+    BOOL bFound = FALSE;
+    IKsPropertySet *pKs = NULL;
+    HRESULT hr = pPin->QueryInterface(IID_PPV_ARGS(&pKs));
+    if (SUCCEEDED(hr))
+    {
+        GUID PinCategory;
+        DWORD cbReturned;
+        hr = pKs->Get(AMPROPSETID_Pin, AMPROPERTY_PIN_CATEGORY, NULL, 0, &PinCategory,
+                      sizeof(GUID), &cbReturned);
+        if (SUCCEEDED(hr) && (cbReturned == sizeof(GUID)))
+        {
+            bFound = (PinCategory == Category);
+        }
+        pKs->Release();
+    }
+    return bFound;
+}
+} // namespace videocapturemodule
+} // namespace webrtc
+