public/fidl/fuchsia.camera/manager.fidl

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.camera;

using fuchsia.sysmem;

// For the bitfield of CameraControlType:
// These are different modes in which an application can request a stream.
// Default value: no stream.
const uint32 CAMERA_CTRL_NONE          = 0x0;
// Normal video or image stream:
const uint32 CAMERA_CTRL_OUTPUT_STREAM = 0x1;
// Attach to another running stream, using whatever settings that stream
// is configure with.
const uint32 CAMERA_CTRL_SNOOP_STREAM  = 0x2;
// Just enable the ability to set configuration parameters for the camera.
const uint32 CAMERA_CTRL_CONFIGURATION = 0x4;
// Some devices accept data back.  Configure a Stream going back to the camera.
const uint32 CAMERA_CTRL_INPUT_STREAM  = 0x8;

//  Indicates what 'permissions' you are requesting for the Stream.
struct CameraAccessRequest {
  // The camera_id corresponds to the camera_id that is given in the DeviceInfo
  // received from GetDevices.
  uint64 camera_id;
  uint32 control; // CameraControlType
  // The requested video format.  Note that this is field is necessary to
  // set The frame rate, even when calling CreateStream.
  // When calling CreateStream, format.format should match buffer_info.format.
  VideoFormat format;
};

// The Camera Manager grants access to individual or sets of cameras
// 1) You request the list of cameras, which gives you camera descriptions
// 2) You request the list of formats available for the camera to which you
//    wish to connect.
// 3) You request a Stream interface using CreateStream.
[Discoverable]
interface Manager {
  // Returns a list of all the video devices that are currently plugged in
  // and enumerated.  The camera_id field of the DeviceInfo is used to specify
  // a device in GetFormats, GetStream and GetStreamAndBufferCollection.
  1: GetDevices() -> (vector<DeviceInfo> descriptions);

  // Get all the available formats for a camera.
  // TODO(CAM-17): Add pagination to support cameras with over 16 formats.
  // |camera_id| is obtained from a DeviceInfo returned by GetDevices.
  2: GetFormats(uint64 camera_id) -> (vector<VideoFormat> formats);

  // Create a Stream with the specified access rights.  This may not succeed.
  // If it does succeed, the Stream will have the rights indicated.
  // |buffer_info| contains a set of buffers to be used with the Stream.
  3: CreateStream(CameraAccessRequest request,
               fuchsia.sysmem.BufferCollectionInfo buffer_info,
               request<Stream> stream);

  // Get a camera stream, and have the camera manager allocate the buffers,
  // assuming no special memory requirements.
  4: GetStreamAndBufferCollection(CameraAccessRequest request,
               request<Stream> stream) ->
               (fuchsia.sysmem.BufferCollectionInfo buffer_info);
};