VideoCaptureDevice Win: Enumerate devices' supported formats when they don't have a DevicePath prop…

media/video/capture/win/video_capture_device_factory_win.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/video/capture/win/video_capture_device_factory_win.h"
 
 #include <mfapi.h>
 #include <mferror.h>
 
 #include "base/command_line.h"
@@ skipping 105 matching lines @@
   ScopedComPtr<IMoniker> moniker;
   int index = 0;
   while (enum_moniker->Next(1, moniker.Receive(), NULL) == S_OK) {
     ScopedComPtr<IPropertyBag> prop_bag;
     hr = moniker->BindToStorage(0, 0, IID_IPropertyBag, prop_bag.ReceiveVoid());
     if (FAILED(hr)) {
       moniker.Release();
       continue;
     }
 
-    // Find the description or friendly name.
+    // Find the description or friendly name. TODO(mcasas): Investigate using
+    // FriendlyName before Description, http://crbug.com/383395.
     ScopedVariant name;
     hr = prop_bag->Read(L"Description", name.Receive(), 0);
     if (FAILED(hr))
       hr = prop_bag->Read(L"FriendlyName", name.Receive(), 0);
 
     if (SUCCEEDED(hr) && name.type() == VT_BSTR) {
       // Ignore all VFW drivers and the special Google Camera Adapter.
       // Google Camera Adapter is not a real DirectShow camera device.
       // VFW are very old Video for Windows drivers that can not be used.
       const wchar_t* str_ptr = V_BSTR(&name);
@@ skipping 79 matching lines @@
     hr = moniker->BindToStorage(0, 0, IID_IPropertyBag, prop_bag.ReceiveVoid());
     if (FAILED(hr)) {
       moniker.Release();
       continue;
     }
 
     std::string id;
     device_id.Reset();
     hr = prop_bag->Read(L"DevicePath", device_id.Receive(), 0);
     if (FAILED(hr) || device_id.type() != VT_BSTR) {
-      // If there is no clear DevicePath, try with Description and FriendlyName.
+      // If there is no clear DevicePath, try with Description and FriendlyName,
+      // this might happen with non-USB cameras such as DeckLinks. TODO(mcasas):
+      // use FriendlyName before Description, http://crbug.com/383395.
       ScopedVariant name;
       if (SUCCEEDED(prop_bag->Read(L"Description", name.Receive(), 0)) ||
           SUCCEEDED(prop_bag->Read(L"FriendlyName", name.Receive(), 0))) {
         id = base::SysWideToUTF8(V_BSTR(&name));
       }
     } else {
       DCHECK_EQ(device_id.type(), VT_BSTR);
       id = base::SysWideToUTF8(V_BSTR(&device_id));
     }
 
@@ skipping 53 matching lines @@
             VideoCaptureDeviceWin::TranslateMediaSubtypeToPixelFormat(
                 media_type->subtype);
         if (format.pixel_format == PIXEL_FORMAT_UNKNOWN)
           continue;
         VIDEOINFOHEADER* h =
             reinterpret_cast<VIDEOINFOHEADER*>(media_type->pbFormat);
         format.frame_size.SetSize(h->bmiHeader.biWidth,
                                   h->bmiHeader.biHeight);
         // Trust the frame rate from the VIDEOINFOHEADER.
         format.frame_rate = (h->AvgTimePerFrame > 0) ?
-            static_cast<int>(kSecondsToReferenceTime / h->AvgTimePerFrame) :
-            0;
+            kSecondsToReferenceTime / static_cast<float>(h->AvgTimePerFrame) :
+            0.0;
+
         formats->push_back(format);
         DVLOG(1) << device.name() << " resolution: "
              << format.frame_size.ToString() << ", fps: " << format.frame_rate
              << ", pixel format: " << format.pixel_format;
       }
     }
   }
 }
 
 static void GetDeviceSupportedFormatsMediaFoundation(
@@ skipping 26 matching lines @@
     }
     VideoCaptureFormat capture_format;
     capture_format.frame_size.SetSize(width, height);
 
     UINT32 numerator, denominator;
     hr = MFGetAttributeRatio(type, MF_MT_FRAME_RATE, &numerator, &denominator);
     if (FAILED(hr)) {
       DLOG(ERROR) << "MFGetAttributeSize: " << std::hex << hr;
       return;
     }
-    capture_format.frame_rate = denominator ? numerator / denominator : 0;
+    capture_format.frame_rate = denominator ?
+        numerator / static_cast<float>(denominator) : 0.0f;
 
     GUID type_guid;
     hr = type->GetGUID(MF_MT_SUBTYPE, &type_guid);
     if (FAILED(hr)) {
       DLOG(ERROR) << "GetGUID: " << std::hex << hr;
       return;
     }
     VideoCaptureDeviceMFWin::FormatFromGuid(type_guid,
                                             &capture_format.pixel_format);
     type.Release();
@@ skipping 77 matching lines @@
     const VideoCaptureDevice::Name& device,
     VideoCaptureFormats* formats) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (use_media_foundation_)
     GetDeviceSupportedFormatsMediaFoundation(device, formats);
   else
     GetDeviceSupportedFormatsDirectShow(device, formats);
 }
 
 }  // namespace media