New resolution change policies for desktop and tab capture.

media/base/video_capture_types.h

 // 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.
 
 #ifndef MEDIA_BASE_VIDEO_CAPTURE_TYPES_H_
 #define MEDIA_BASE_VIDEO_CAPTURE_TYPES_H_
 
 #include <vector>
 
 #include "media/base/media_export.h"
@@ skipping 16 matching lines @@
   PIXEL_FORMAT_RGB24,
   PIXEL_FORMAT_RGB32,
   PIXEL_FORMAT_ARGB,
   PIXEL_FORMAT_MJPEG,
   PIXEL_FORMAT_TEXTURE,  // Capture format as a GL texture.
   PIXEL_FORMAT_GPUMEMORYBUFFER,
   PIXEL_FORMAT_UNKNOWN,  // Color format not set.
   PIXEL_FORMAT_MAX,
 };
 
-// Policies for capture devices that has source content with dynamic resolution.
+// Policies for capture devices that have source content that varies in size.
+// It is up to the implementation how the captured content will be transformed
+// (e.g., scaling and/or letterboxing) in order to produce video frames that
+// strictly adheree to one of these policies.
 enum ResolutionChangePolicy {
   // Capture device outputs a fixed resolution all the time. The resolution of
   // the first frame is the resolution for all frames.
-  // It is implementation specific for the capture device to scale, letter-box
-  // and pillar-box. The only guarantee is that resolution will never change.
-  RESOLUTION_POLICY_FIXED,
+  RESOLUTION_POLICY_FIXED_RESOLUTION,
 
-  // Capture device outputs frames with dynamic resolution. The width and height
-  // will not exceed the maximum dimensions specified. The typical scenario is
-  // the frames will have the same aspect ratio as the original content and
-  // scaled down to fit inside the limit.
-  RESOLUTION_POLICY_DYNAMIC_WITHIN_LIMIT,
+  // Capture device is allowed to output frames of varying resolutions. The
+  // width and height will not exceed the maximum dimensions specified. The
+  // aspect ratio of the frames will match the aspect ratio of the maximum
+  // dimensions as closely as possible.
+  RESOLUTION_POLICY_FIXED_ASPECT_RATIO,
+
+  // Capture device is allowed to output frames of varying resolutions not
+  // exceeding the maximum dimensions specified.
+  RESOLUTION_POLICY_ANY_WITHIN_LIMIT,
 
   RESOLUTION_POLICY_LAST,
 };
 
 // Some drivers use rational time per frame instead of float frame rate, this
 // constant k is used to convert between both: A fps -> [k/k*A] seconds/frame.
 const int kFrameRatePrecision = 10000;
 
 // Video capture format specification.
 // This class is used by the video capture device to specify the format of every
@@ skipping 10 matching lines @@
   static std::string PixelFormatToString(VideoPixelFormat format);
 
   // Returns the required buffer size to hold an image of a given
   // VideoCaptureFormat with no padding and tightly packed.
   size_t ImageAllocationSize() const;
 
   // Checks that all values are in the expected range. All limits are specified
   // in media::Limits.
   bool IsValid() const;
 
+  bool operator==(const VideoCaptureFormat& other) const {
+    return frame_size == other.frame_size &&
+        frame_rate == other.frame_rate &&
+        pixel_format == other.pixel_format;
+  }
+
   gfx::Size frame_size;
   float frame_rate;
   VideoPixelFormat pixel_format;
 };
 
 typedef std::vector<VideoCaptureFormat> VideoCaptureFormats;
 
 // Parameters for starting video capture.
 // This class is used by the client of a video capture device to specify the
 // format of frames in which the client would like to have captured frames
 // returned.
 class MEDIA_EXPORT VideoCaptureParams {
  public:
   VideoCaptureParams();
 
+  bool operator==(const VideoCaptureParams& other) const {
+    return requested_format == other.requested_format &&
+        resolution_change_policy == other.resolution_change_policy;
+  }
+
   // Requests a resolution and format at which the capture will occur.
   VideoCaptureFormat requested_format;
 
   // Policy for resolution change.
   ResolutionChangePolicy resolution_change_policy;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_CAPTURE_TYPES_H_