Media Capture Depth Stream Extensions API: focal length and depth range.

media/capture/video/video_capture_device_descriptor.h

 // Copyright 2016 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.
 
 #ifndef MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_DEVICE_DESCRIPTOR_H_
 #define MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_DEVICE_DESCRIPTOR_H_
 
 #include <string>
 #include <vector>
 
+#include "base/memory/ref_counted.h"
 #include "media/capture/capture_export.h"
 
 namespace media {
 
 // A Java counterpart will be generated for this enum.
 // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.media
 enum class VideoCaptureApi {
   LINUX_V4L2_SINGLE_PLANE,
   WIN_MEDIA_FOUNDATION,
   WIN_DIRECT_SHOW,
@@ skipping 54 matching lines @@
 
   std::string display_name;  // Name that is intended for display in the UI
   std::string device_id;
   // A unique hardware identifier of the capture device.
   // It is of the form "[vid]:[pid]" when a USB device is detected, and empty
   // otherwise.
   std::string model_id;
 
   VideoCaptureApi capture_api;
   VideoCaptureTransportType transport_type;
+
+  // Contains camera calibration parameters.
+  // These parameters apply to both RGB and depth video devices.  See also
+  // https://w3c.github.io/mediacapture-depth/#mediatracksettings-dictionary
+  // TODO(aleksandar.stojiljkovic): Add principal point and camera distortion
+  // model and coefficients.  See also https://crbug.com/616098
+  struct CameraCalibration
+      : public base::RefCountedThreadSafe<CameraCalibration> {
+    double focal_length_x = 0.0;
+    double focal_length_y = 0.0;
+    // depth near and far are used only for depth cameras.
+    double depth_near = 0.0;
+    double depth_far = 0.0;
+
+   private:
+    friend class base::RefCountedThreadSafe<CameraCalibration>;

[mcasas, 2017/01/05 01:09:32]

I fail to see why should CameraCalibration be ref counted, 
since it's just a POD.

[aleksandar.stojiljkovic, 2017/01/09 18:47:01]

Done.
Didn't know better. As I learned about it here; base::Optional looks like a
proper way.

+    ~CameraCalibration() {}
+  };
+
+  scoped_refptr<CameraCalibration> camera_calibration = nullptr;
 };
 
 using VideoCaptureDeviceDescriptors = std::vector<VideoCaptureDeviceDescriptor>;
 
 }  // namespace media
 
 #endif  // MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_DEVICE_DESCRIPTOR_H_