chromium/media/capture/video_capture_types.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_CAPTURE_VIDEO_CAPTURE_TYPES_H_
#define MEDIA_CAPTURE_VIDEO_CAPTURE_TYPES_H_

#include <stddef.h>

#include <vector>

#include "base/unguessable_token.h"
#include "build/build_config.h"
#include "media/base/video_types.h"
#include "media/capture/capture_export.h"
#include "ui/gfx/geometry/size.h"

namespace media {

// TODO(wjia): this type should be defined in a common place and
// shared with device manager.
VideoCaptureSessionId;

// 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 class ResolutionChangePolicy { … };

// Potential values of the googPowerLineFrequency optional constraint passed to
// getUserMedia. Note that the numeric values are currently significant, and are
// used to map enum values to corresponding frequency values.
enum class PowerLineFrequency { … };

enum class VideoCaptureBufferType { … };

// These values are persisted to logs. Entries should not be renumbered and
// numeric values should never be reused.
enum class VideoCaptureError { … };

// WARNING: Do not change the values assigned to the entries. They are used for
// UMA logging.
enum class VideoCaptureFrameDropReason { … };

// Assert that the int:frequency mapping is correct.
static_assert …;
static_assert …;
static_assert …;

// 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 = …;

// Video capture format specification.
// This class is used by the video capture device to specify the format of every
// frame captured and returned to a client. It is also used to specify a
// supported capture format by a device.
struct CAPTURE_EXPORT 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.
struct CAPTURE_EXPORT VideoCaptureParams { … };

CAPTURE_EXPORT std::ostream& operator<<(
    std::ostream& os,
    const VideoCaptureParams::SuggestedConstraints& constraints);

}  // namespace media

#endif  // MEDIA_CAPTURE_VIDEO_CAPTURE_TYPES_H_