1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.hardware.automotive.evs@1.0;
18
19import IEvsCameraStream;
20
21
22/**
23 * Represents a single camera and is the primary interface for capturing images.
24 */
25interface IEvsCamera {
26
27    /**
28     * Returns the ID of this camera.
29     *
30     * @return info The description of this camera.  This must be the same value as
31     *              reported by EvsEnumerator::getCameraList().
32     */
33    getCameraInfo() generates (CameraDesc info);
34
35    /**
36     * Specifies the depth of the buffer chain the camera is asked to support.
37     *
38     * Up to this many frames may be held concurrently by the client of IEvsCamera.
39     * If this many frames have been delivered to the receiver without being returned
40     * by doneWithFrame, the stream must skip frames until a buffer is returned for reuse.
41     * It is legal for this call to come at any time, even while streams are already running,
42     * in which case buffers should be added or removed from the chain as appropriate.
43     * If no call is made to this entry point, the IEvsCamera must support at least one
44     * frame by default. More is acceptable.
45     *
46     * @param  bufferCount Number of buffers the client of IEvsCamera may hold concurrently.
47     * @return result EvsResult::OK is returned if this call is successful.
48     */
49    setMaxFramesInFlight(uint32_t bufferCount) generates (EvsResult result);
50
51    /**
52     * Request to start EVS camera stream from this camera.
53     *
54     * The IEvsCameraStream must begin receiving calls with various events
55     * including new image frame ready until stopVideoStream() is called.
56     *
57     * @param  receiver IEvsCameraStream implementation.
58     * @return result EvsResult::OK is returned if this call is successful.
59     */
60    startVideoStream(IEvsCameraStream receiver) generates (EvsResult result);
61
62    /**
63     * Return a frame that was delivered by to the IEvsCameraStream.
64     *
65     * When done consuming a frame delivered to the IEvsCameraStream
66     * interface, it must be returned to the IEvsCamera for reuse.
67     * A small, finite number of buffers are available (possibly as small
68     * as one), and if the supply is exhausted, no further frames may be
69     * delivered until a buffer is returned.
70     *
71     * @param  buffer A buffer to be returned.
72     */
73    oneway doneWithFrame(BufferDesc buffer);
74
75    /**
76     * Stop the delivery of EVS camera frames.
77     *
78     * Because delivery is asynchronous, frames may continue to arrive for
79     * some time after this call returns. Each must be returned until the
80     * closure of the stream is signaled to the IEvsCameraStream.
81     * This function cannot fail and is simply ignored if the stream isn't running.
82     */
83    stopVideoStream();
84
85    /**
86     * Request driver specific information from the HAL implementation.
87     *
88     * The values allowed for opaqueIdentifier are driver specific,
89     * but no value passed in may crash the driver. The driver should
90     * return 0 for any unrecognized opaqueIdentifier.
91     *
92     * @param  opaqueIdentifier An unique identifier of the information to
93     *                          request.
94     * @return value            Requested information.  Zero is returned if the
95     *                          driver does not recognize a given identifier.
96     */
97    getExtendedInfo(uint32_t opaqueIdentifier) generates (int32_t value);
98
99    /**
100     * Send a driver specific value to the HAL implementation.
101     *
102     * This extension is provided to facilitate car specific
103     * extensions, but no HAL implementation may require this call
104     * in order to function in a default state.
105     * INVALID_ARG is returned if the opaqueValue is not meaningful to
106     * the driver implementation.
107     *
108     * @param  opaqueIdentifier An unique identifier of the information to
109     *                          program.
110     *         opaqueValue      A value to program.
111     * @return result           EvsResult::OK is returned if this call is successful.
112     */
113    setExtendedInfo(uint32_t opaqueIdentifier, int32_t opaqueValue) generates (EvsResult result);
114};
115