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

media/capture/video/mac/video_capture_device_decklink_mac.mm

 // 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/capture/video/mac/video_capture_device_decklink_mac.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/synchronization/lock.h"
 #include "third_party/decklink/mac/include/DeckLinkAPI.h"
 
+
 namespace {
 
+static std::string JoinDeviceNameAndFormat(CFStringRef name,
+                                           CFStringRef format);
+
 // DeckLink SDK uses ScopedComPtr-style APIs. Chrome ScopedComPtr is only
 // available for Windows builds. This is a verbatim knock-off of the needed
 // parts of base::win::ScopedComPtr<> for ref counting.
 template <class T>
 class ScopedDeckLinkPtr : public scoped_refptr<T> {
  private:
   using scoped_refptr<T>::ptr_;
 
  public:
   T** Receive() {
@@ skipping 103 matching lines @@
 
 void DeckLinkCaptureDelegate::AllocateAndStart(
     const media::VideoCaptureParams& params) {
   DCHECK(thread_checker_.CalledOnValidThread());
   scoped_refptr<IDeckLinkIterator> decklink_iter(
       CreateDeckLinkIteratorInstance());
   DLOG_IF(ERROR, !decklink_iter.get()) << "Error creating DeckLink iterator";
   if (!decklink_iter.get())
     return;
 
-  ScopedDeckLinkPtr<IDeckLink> decklink_local;
-  while (decklink_iter->Next(decklink_local.Receive()) == S_OK) {
-    CFStringRef device_model_name = NULL;
-    if ((decklink_local->GetModelName(&device_model_name) == S_OK) ||
-        (device_name_.id() == base::SysCFStringRefToUTF8(device_model_name))) {
-      break;
+  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);
+
+    CFStringRef device_model_name = nil;
+    HRESULT hr = decklink_local->GetModelName(&device_model_name);
+    DVLOG_IF(1, hr != S_OK) << "Error reading Blackmagic device model name";

[mcasas, 2016/04/19 21:53:32]

DLOG_IF(ERROR, condition) here and
elsewhere.

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

Done.

+    CFStringRef device_display_name = NULL;

[mcasas, 2016/04/19 21:53:32]

Actually CFStringRef is a C++ construct, so
it should be nullptr, here and in l.153 etc.

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

Done.

+    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;
+    }
+
+    ScopedDeckLinkPtr<IDeckLinkDisplayModeIterator> display_mode_iter;
+    if (decklink_input->GetDisplayModeIterator(display_mode_iter.Receive()) !=
+        S_OK) {
+      continue;
+    }
+
+    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(
+            JoinDeviceNameAndFormat(device_display_name, format_name),
+            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;
+        }
+
+        DVLOG(1) << "Blackmagic camera enumerated: " << name.name();
+      }
+      display_mode.Release();
     }
   }
-  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_local->GetDisplayModeIterator(
-          display_mode_iter.Receive()) != S_OK) {
-    SendErrorString(FROM_HERE, "Error creating Display Mode Iterator");
-    return;
-  }
-
-  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;
-    }
-    display_mode.Release();
-  }
   if (!chosen_display_mode.get()) {
     SendErrorString(FROM_HERE, "Could not find a display mode");
     return;
   }
 #if !defined(NDEBUG)
   DVLOG(1) << "Requested format: "
            << media::VideoCaptureFormat::ToString(params.requested_format);
   CFStringRef format_name = NULL;
   if (chosen_display_mode->GetName(&format_name) == S_OK)
     DVLOG(1) << "Chosen format: " << base::SysCFStringRefToUTF8(format_name);
 #endif
 
   // 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() {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (!decklink_input_.get())
     return;
   if (decklink_input_->StopStreams() != S_OK)
     SendLogString("Problem stopping capture.");
   decklink_input_->SetCallback(NULL);
   decklink_input_->DisableVideoInput();
@@ skipping 84 matching lines @@
   if (frame_receiver_)
     frame_receiver_->SendLogString(message);
 }
 
 void DeckLinkCaptureDelegate::ResetVideoCaptureDeviceReference() {
   DCHECK(thread_checker_.CalledOnValidThread());
   base::AutoLock lock(lock_);
   frame_receiver_ = NULL;
 }
 
-}  // namespace
-
-namespace media {
 
 static std::string JoinDeviceNameAndFormat(CFStringRef name,
                                            CFStringRef format) {
   return base::SysCFStringRefToUTF8(name) + " - " +
          base::SysCFStringRefToUTF8(format);
 }
 
+
+}  // namespace
+
+namespace media {
+
 // static
 void VideoCaptureDeviceDeckLinkMac::EnumerateDevices(
     VideoCaptureDevice::Names* device_names) {
   scoped_refptr<IDeckLinkIterator> decklink_iter(
       CreateDeckLinkIteratorInstance());
   // At this point, not being able to create a DeckLink iterator means that
   // there are no Blackmagic DeckLink devices in the system, don't print error.
   DVLOG_IF(1, !decklink_iter.get()) << "Could not create DeckLink iterator";
   if (!decklink_iter.get())
     return;
@@ skipping 148 matching lines @@
   if (decklink_capture_delegate_.get())
     decklink_capture_delegate_->AllocateAndStart(params);
 }
 
 void VideoCaptureDeviceDeckLinkMac::StopAndDeAllocate() {
   if (decklink_capture_delegate_.get())
     decklink_capture_delegate_->StopAndDeAllocate();
 }
 
 }  // namespace media