media/capture/video/win/capability_list_win.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/capture/video/win/capability_list_win.h"
   6
   7 #include <algorithm>
   8 #include <functional>
   9
  10 #include "base/logging.h"
  11
  12 namespace media {
  13
  14 static bool CompareCapability(const VideoCaptureFormat& requested,
  15                               const CapabilityWin& capability_lhs,
  16                               const CapabilityWin& capability_rhs) {
  17   const VideoCaptureFormat& lhs = capability_lhs.supported_format;
  18   const VideoCaptureFormat& rhs = capability_rhs.supported_format;
  19
  20   const int diff_height_lhs =
  21       std::abs(lhs.frame_size.height() - requested.frame_size.height());
  22   const int diff_height_rhs =
  23       std::abs(rhs.frame_size.height() - requested.frame_size.height());
  24   if (diff_height_lhs != diff_height_rhs)
  25     return diff_height_lhs < diff_height_rhs;
  26
  27   const int diff_width_lhs =
  28       std::abs(lhs.frame_size.width() - requested.frame_size.width());
  29   const int diff_width_rhs =
  30       std::abs(rhs.frame_size.width() - requested.frame_size.width());
  31   if (diff_width_lhs != diff_width_rhs)
  32     return diff_width_lhs < diff_width_rhs;
  33
  34   const float diff_fps_lhs = std::fabs(lhs.frame_rate - requested.frame_rate);
  35   const float diff_fps_rhs = std::fabs(rhs.frame_rate - requested.frame_rate);
  36   if (diff_fps_lhs != diff_fps_rhs)
  37     return diff_fps_lhs < diff_fps_rhs;
  38
  39   return lhs.pixel_format < rhs.pixel_format;
  40 }
  41
  42 const CapabilityWin& GetBestMatchedCapability(
  43     const VideoCaptureFormat& requested,
  44     const CapabilityList& capabilities) {
  45   DCHECK(!capabilities.empty());
  46   const CapabilityWin* best_match = &(*capabilities.begin());
  47   for (const CapabilityWin& capability : capabilities) {
  48     if (CompareCapability(requested, capability, *best_match))
  49       best_match = &capability;
  50   }
  51   return *best_match;
  52 }
  53
  54 }  // namespace media