Use the encoded video mode for capture setup of decklink devices.

media/capture/video/mac/video_capture_device_decklink_mac.mm

Index: media/capture/video/mac/video_capture_device_decklink_mac.mm
diff --git a/media/capture/video/mac/video_capture_device_decklink_mac.mm b/media/capture/video/mac/video_capture_device_decklink_mac.mm
index 3841be64f27cc6d4efcb1079082264ad1b4cfe4f..b31e0b4887e0a5100296a039dffdea66af639924 100644
--- a/media/capture/video/mac/video_capture_device_decklink_mac.mm
+++ b/media/capture/video/mac/video_capture_device_decklink_mac.mm
@@ -13,6 +13,11 @@
 #include "base/synchronization/lock.h"
 #include "third_party/decklink/mac/include/DeckLinkAPI.h"
 
+namespace media {
+static std::string JoinDeviceNameAndFormat(CFStringRef name,

[mcasas, 2016/04/12 17:54:42]

If this function is only used in this file, we can
stuff it in the anonymous namespace, right?

[jensf, 2016/04/21 07:29:47]

Done.

+                                           CFStringRef format);
+};
+
 namespace {
 
 // DeckLink SDK uses ScopedComPtr-style APIs. Chrome ScopedComPtr is only
@@ -135,52 +140,66 @@ void DeckLinkCaptureDelegate::AllocateAndStart(
   scoped_refptr<IDeckLinkIterator> decklink_iter(
       CreateDeckLinkIteratorInstance());
   DLOG_IF(ERROR, !decklink_iter.get()) << "Error creating DeckLink iterator";
-  if (!decklink_iter.get())
+  if (!decklink_iter.get()) {

[mcasas, 2016/04/12 17:54:42]

No {} for one-line bodies.

[jensf, 2016/04/21 07:29:47]

Done.

     return;
+  }
+
+  ScopedDeckLinkPtr<IDeckLink> chosen_device;
+  ScopedDeckLinkPtr<IDeckLinkInput> chosen_input;
+  ScopedDeckLinkPtr<IDeckLinkDisplayMode> chosen_display_mode;
+  ScopedDeckLinkPtr<IDeckLink> decklink;
+  while (decklink_iter->Next(decklink.Receive()) == S_OK) {
+    ScopedDeckLinkPtr<IDeckLink> decklink_local;
+    decklink_local.swap(decklink);
 
-  ScopedDeckLinkPtr<IDeckLink> decklink_local;
-  while (decklink_iter->Next(decklink_local.Receive()) == S_OK) {
     CFStringRef device_model_name = NULL;

[mcasas, 2016/04/12 17:54:42]

nullptr? nil?

[jensf, 2016/04/21 07:29:47]

Done.

-    if ((decklink_local->GetModelName(&device_model_name) == S_OK) ||
-        (device_name_.id() == base::SysCFStringRefToUTF8(device_model_name))) {
-      break;
+    HRESULT hr = decklink_local->GetModelName(&device_model_name);
+    DVLOG_IF(1, hr != S_OK) << "Error reading Blackmagic device model name";

[mcasas, 2016/04/12 17:54:42]

Consider DLOG_IF(ERROR,...

[jensf, 2016/04/21 07:29:46]

Done.

+    CFStringRef device_display_name = NULL;
+    hr = decklink_local->GetDisplayName(&device_display_name);
+    DVLOG_IF(1, hr != S_OK) << "Error reading Blackmagic device display name";
+    DVLOG_IF(1, hr == S_OK) << "Blackmagic device found with name: "
+                            << base::SysCFStringRefToUTF8(device_display_name);
+
+    if (!device_model_name && !device_display_name)
+      continue;
+
+    ScopedDeckLinkPtr<IDeckLinkInput> decklink_input;
+    if (decklink_local->QueryInterface(IID_IDeckLinkInput,
+                                       decklink_input.ReceiveVoid()) != S_OK) {
+      DLOG(ERROR) << "Error Blackmagic querying input interface.";
+      return;
     }
-  }
-  if (!decklink_local.get()) {
-    SendErrorString(FROM_HERE, "Device id not found in the system");
-    return;
-  }
 
-  ScopedDeckLinkPtr<IDeckLinkInput> decklink_input_local;
-  if (decklink_local->QueryInterface(
-          IID_IDeckLinkInput, decklink_input_local.ReceiveVoid()) != S_OK) {
-    SendErrorString(FROM_HERE, "Error querying input interface.");
-    return;
-  }
+    ScopedDeckLinkPtr<IDeckLinkDisplayModeIterator> display_mode_iter;
+    if (decklink_input->GetDisplayModeIterator(display_mode_iter.Receive()) !=
+        S_OK) {
+      continue;
+    }
 
-  ScopedDeckLinkPtr<IDeckLinkDisplayModeIterator> display_mode_iter;
-  if (decklink_input_local->GetDisplayModeIterator(
-          display_mode_iter.Receive()) != S_OK) {
-    SendErrorString(FROM_HERE, "Error creating Display Mode Iterator");
-    return;
-  }
+    ScopedDeckLinkPtr<IDeckLinkDisplayMode> display_mode;
+    while (display_mode_iter->Next(display_mode.Receive()) == S_OK) {
+      CFStringRef format_name = NULL;
+      if (display_mode->GetName(&format_name) == S_OK) {
+        media::VideoCaptureDevice::Name name(
+            media::JoinDeviceNameAndFormat(device_display_name, format_name),
+            media::JoinDeviceNameAndFormat(device_model_name, format_name),
+            media::VideoCaptureDevice::Name::DECKLINK,
+            media::VideoCaptureDevice::Name::OTHER_TRANSPORT);
+
+        if (device_name_.id() == name.id()) {
+          chosen_device.swap(decklink_local);
+          chosen_input.swap(decklink_input);
+          chosen_display_mode.swap(display_mode);
+          break;
+        }
 
-  ScopedDeckLinkPtr<IDeckLinkDisplayMode> chosen_display_mode;
-  ScopedDeckLinkPtr<IDeckLinkDisplayMode> display_mode;
-  float min_diff = FLT_MAX;
-  while (display_mode_iter->Next(display_mode.Receive()) == S_OK) {
-    const float diff = labs(display_mode->GetWidth() -
-                            params.requested_format.frame_size.width()) +
-                       labs(params.requested_format.frame_size.height() -
-                            display_mode->GetHeight()) +
-                       fabs(params.requested_format.frame_rate -
-                            GetDisplayModeFrameRate(display_mode));
-    if (diff < min_diff) {
-      chosen_display_mode = display_mode;
-      min_diff = diff;
+        DVLOG(1) << "Blackmagic camera enumerated: " << name.name();
+      }
+      display_mode.Release();
     }
-    display_mode.Release();
   }
+
   if (!chosen_display_mode.get()) {
     SendErrorString(FROM_HERE, "Could not find a display mode");
     return;
@@ -195,19 +214,19 @@ void DeckLinkCaptureDelegate::AllocateAndStart(
 
   // Enable video input. Configure for no input video format change detection,
   // this in turn will disable calls to VideoInputFormatChanged().
-  if (decklink_input_local->EnableVideoInput(
-          chosen_display_mode->GetDisplayMode(), bmdFormat8BitYUV,
-          bmdVideoInputFlagDefault) != S_OK) {
+  if (chosen_input->EnableVideoInput(chosen_display_mode->GetDisplayMode(),
+                                     bmdFormat8BitYUV,
+                                     bmdVideoInputFlagDefault) != S_OK) {
     SendErrorString(FROM_HERE, "Could not select the video format we like.");
     return;
   }
 
-  decklink_input_local->SetCallback(this);
-  if (decklink_input_local->StartStreams() != S_OK)
+  chosen_input->SetCallback(this);
+  if (chosen_input->StartStreams() != S_OK) {
     SendErrorString(FROM_HERE, "Could not start capturing");
-
-  decklink_.swap(decklink_local);
-  decklink_input_.swap(decklink_input_local);
+  }
+  decklink_.swap(chosen_device);
+  decklink_input_.swap(chosen_input);
 }
 
 void DeckLinkCaptureDelegate::StopAndDeAllocate() {