ImageCapture: Implement takePhoto() for Windows

media/capture/video/win/video_capture_device_win.cc

 // Copyright (c) 2012 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/win/video_capture_device_win.h"
 
 #include <ks.h>
 #include <ksmedia.h>
 
 #include <algorithm>
 #include <list>
 #include <utility>
 
 #include "base/macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/win/scoped_co_mem.h"
 #include "base/win/scoped_variant.h"
 #include "media/base/timestamp_constants.h"
+#include "media/capture/video/blob_utils.h"
 
 using base::win::ScopedCoMem;
 using base::win::ScopedComPtr;
 using base::win::ScopedVariant;
 
 namespace media {
 
 // Check if a Pin matches a category.
 bool PinMatchesCategory(IPin* pin, REFGUID category) {
   DCHECK(pin);
@@ skipping 414 matching lines @@
     return;
   }
 
   graph_builder_->Disconnect(output_capture_pin_.get());
   graph_builder_->Disconnect(input_sink_pin_.get());
 
   client_.reset();
   state_ = kIdle;
 }
 
+void VideoCaptureDeviceWin::TakePhoto(TakePhotoCallback callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // DirectShow has other means of capturing still pictures, e.g. connecting a
+  // SampleGrabber filter to a PIN_CATEGORY_STILL of |capture_filter_|. This
+  // way, however, is not widespread and proves too cumbersome, so we just grab
+  // the next captured frame instead.
+  take_photo_callbacks_.push(std::move(callback));
+}
+
 // Implements SinkFilterObserver::SinkFilterObserver.
 void VideoCaptureDeviceWin::FrameReceived(const uint8_t* buffer,
                                           int length,
                                           base::TimeDelta timestamp) {
   if (first_ref_time_.is_null())
     first_ref_time_ = base::TimeTicks::Now();
 
   // There is a chance that the platform does not provide us with the timestamp,
   // in which case, we use reference time to calculate a timestamp.
   if (timestamp == media::kNoTimestamp)
     timestamp = base::TimeTicks::Now() - first_ref_time_;
 
   client_->OnIncomingCapturedData(buffer, length, capture_format_, 0,
                                   base::TimeTicks::Now(), timestamp);
+
+  while (!take_photo_callbacks_.empty()) {
+    TakePhotoCallback cb = std::move(take_photo_callbacks_.front());
+    take_photo_callbacks_.pop();
+
+    mojom::BlobPtr blob = Blobify(buffer, length, capture_format_);
+    if (blob)
+      cb.Run(std::move(blob));
+  }
 }
 
 bool VideoCaptureDeviceWin::CreateCapabilityMap() {
   DCHECK(thread_checker_.CalledOnValidThread());
   ScopedComPtr<IAMStreamConfig> stream_config;
   HRESULT hr = output_capture_pin_.QueryInterface(stream_config.Receive());
   if (FAILED(hr)) {
     DPLOG(ERROR) << "Failed to get IAMStreamConfig interface from "
                     "capture device: " << logging::SystemErrorCodeToString(hr);
     return false;
@@ skipping 108 matching lines @@
 }
 
 void VideoCaptureDeviceWin::SetErrorState(
     const tracked_objects::Location& from_here,
     const std::string& reason) {
   DCHECK(thread_checker_.CalledOnValidThread());
   state_ = kError;
   client_->OnError(from_here, reason);
 }
 }  // namespace media