media/base/video_capture_types.h

   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 #ifndef MEDIA_BASE_VIDEO_CAPTURE_TYPES_H_
   6 #define MEDIA_BASE_VIDEO_CAPTURE_TYPES_H_
   7
   8 #include <vector>
   9
  10 #include "build/build_config.h"
  11 #include "media/base/media_export.h"
  12 #include "ui/gfx/geometry/size.h"
  13
  14 namespace media {
  15
  16 // TODO(wjia): this type should be defined in a common place and
  17 // shared with device manager.
  18 typedef int VideoCaptureSessionId;
  19
  20 // TODO(dshwang): replace it with media::VideoPixelFormat. crbug.com/489744
  21 // Color formats from camera. This list is sorted in order of preference.
  22 // TODO(emircan): http://crbug.com/521068 Consider if this list can be merged
  23 // with media::Format.
  24 // TODO(mcasas): http://crbug.com/504160 Consider making this an enum class.
  25 enum VideoCapturePixelFormat {
  26   VIDEO_CAPTURE_PIXEL_FORMAT_I420,
  27   VIDEO_CAPTURE_PIXEL_FORMAT_YV12,
  28   VIDEO_CAPTURE_PIXEL_FORMAT_NV12,
  29   VIDEO_CAPTURE_PIXEL_FORMAT_NV21,
  30   VIDEO_CAPTURE_PIXEL_FORMAT_UYVY,
  31   VIDEO_CAPTURE_PIXEL_FORMAT_YUY2,
  32   VIDEO_CAPTURE_PIXEL_FORMAT_RGB24,
  33   VIDEO_CAPTURE_PIXEL_FORMAT_RGB32,
  34   VIDEO_CAPTURE_PIXEL_FORMAT_ARGB,
  35   VIDEO_CAPTURE_PIXEL_FORMAT_MJPEG,
  36   VIDEO_CAPTURE_PIXEL_FORMAT_UNKNOWN,  // Color format not set.
  37   VIDEO_CAPTURE_PIXEL_FORMAT_MAX = VIDEO_CAPTURE_PIXEL_FORMAT_UNKNOWN,
  38 };
  39
  40 // Storage type for the pixels. In principle, all combinations of Storage and
  41 // Format are possible, though some are very typical, such as texture + ARGB,
  42 // and others are only available if the platform allows it e.g. GpuMemoryBuffer.
  43 // TODO(mcasas): http://crbug.com/504160 Consider making this an enum class.
  44 enum VideoPixelStorage {
  45   PIXEL_STORAGE_CPU,
  46   PIXEL_STORAGE_TEXTURE,
  47   PIXEL_STORAGE_GPUMEMORYBUFFER,
  48   PIXEL_STORAGE_MAX = PIXEL_STORAGE_GPUMEMORYBUFFER,
  49 };
  50
  51 // Policies for capture devices that have source content that varies in size.
  52 // It is up to the implementation how the captured content will be transformed
  53 // (e.g., scaling and/or letterboxing) in order to produce video frames that
  54 // strictly adheree to one of these policies.
  55 enum ResolutionChangePolicy {
  56   // Capture device outputs a fixed resolution all the time. The resolution of
  57   // the first frame is the resolution for all frames.
  58   RESOLUTION_POLICY_FIXED_RESOLUTION,
  59
  60   // Capture device is allowed to output frames of varying resolutions. The
  61   // width and height will not exceed the maximum dimensions specified. The
  62   // aspect ratio of the frames will match the aspect ratio of the maximum
  63   // dimensions as closely as possible.
  64   RESOLUTION_POLICY_FIXED_ASPECT_RATIO,
  65
  66   // Capture device is allowed to output frames of varying resolutions not
  67   // exceeding the maximum dimensions specified.
  68   RESOLUTION_POLICY_ANY_WITHIN_LIMIT,
  69
  70   // Must always be equal to largest entry in the enum.
  71   RESOLUTION_POLICY_LAST = RESOLUTION_POLICY_ANY_WITHIN_LIMIT,
  72 };
  73
  74 // Some drivers use rational time per frame instead of float frame rate, this
  75 // constant k is used to convert between both: A fps -> [k/k*A] seconds/frame.
  76 const int kFrameRatePrecision = 10000;
  77
  78 // Video capture format specification.
  79 // This class is used by the video capture device to specify the format of every
  80 // frame captured and returned to a client. It is also used to specify a
  81 // supported capture format by a device.
  82 struct MEDIA_EXPORT VideoCaptureFormat {
  83   VideoCaptureFormat();
  84   VideoCaptureFormat(const gfx::Size& frame_size,
  85                      float frame_rate,
  86                      VideoCapturePixelFormat pixel_format);
  87   VideoCaptureFormat(const gfx::Size& frame_size,
  88                      float frame_rate,
  89                      VideoCapturePixelFormat pixel_format,
  90                      VideoPixelStorage pixel_storage);
  91
  92   static std::string ToString(const VideoCaptureFormat& format);
  93   static std::string PixelFormatToString(VideoCapturePixelFormat format);
  94   static std::string PixelStorageToString(VideoPixelStorage storage);
  95
  96   // Returns the required buffer size to hold an image of a given
  97   // VideoCaptureFormat with no padding and tightly packed.
  98   size_t ImageAllocationSize() const;
  99
 100   // Checks that all values are in the expected range. All limits are specified
 101   // in media::Limits.
 102   bool IsValid() const;
 103
 104   bool operator==(const VideoCaptureFormat& other) const {
 105     return frame_size == other.frame_size &&
 106         frame_rate == other.frame_rate &&
 107         pixel_format == other.pixel_format;
 108   }
 109
 110   gfx::Size frame_size;
 111   float frame_rate;
 112   VideoCapturePixelFormat pixel_format;
 113   VideoPixelStorage pixel_storage;
 114 };
 115
 116 typedef std::vector<VideoCaptureFormat> VideoCaptureFormats;
 117
 118 // Parameters for starting video capture.
 119 // This class is used by the client of a video capture device to specify the
 120 // format of frames in which the client would like to have captured frames
 121 // returned.
 122 struct MEDIA_EXPORT VideoCaptureParams {
 123   VideoCaptureParams();
 124
 125   bool operator==(const VideoCaptureParams& other) const {
 126     return requested_format == other.requested_format &&
 127            resolution_change_policy == other.resolution_change_policy;
 128   }
 129
 130   // Requests a resolution and format at which the capture will occur.
 131   VideoCaptureFormat requested_format;
 132
 133   // Policy for resolution change.
 134   ResolutionChangePolicy resolution_change_policy;
 135 };
 136
 137 }  // namespace media
 138
 139 #endif  // MEDIA_BASE_VIDEO_CAPTURE_TYPES_H_