1/*
2 * Copyright (C) 2018 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 [email protected];
18
19import [email protected]::Status;
20import @3.2::CameraMetadata;
21import @3.4::ICameraDeviceSession;
22import @3.4::HalStreamConfiguration;
23
24/**
25 * Camera device active session interface.
26 *
27 * Obtained via ICameraDevice::open(), this interface contains the methods to
28 * configure and request captures from an active camera device.
29 */
30interface ICameraDeviceSession extends @3.4::ICameraDeviceSession {
31
32    /**
33     * configureStreams_3_5:
34     *
35     * Identical to @3.4::ICameraDeviceSession.configureStreams, except that:
36     *
37     * - a streamConfigCounter counter is provided to check for race condition
38     *   between configureStreams_3_5 and signalStreamFlush call.
39     * - In case the HAL overrides dataspace or format for
40     *   IMPLEMENTATION_DEFINED pixel format, camera framework must use original
41     *   dataspace and format in subsequent configureStreams_3_5 calls for the same
42     *   stream. HAL is allowed to change the overriding behavior of format or
43     *   dataspace for reconfiguration of the same stream depending on the stream
44     *   combination.
45     *
46     * @return status Status code for the operation, one of:
47     *     OK:
48     *         On successful stream configuration.
49     *     INTERNAL_ERROR:
50     *         If there has been a fatal error and the device is no longer
51     *         operational. Only close() can be called successfully by the
52     *         framework after this error is returned.
53     *     ILLEGAL_ARGUMENT:
54     *         If the requested stream configuration is invalid. Some examples
55     *         of invalid stream configurations include:
56     *           - Including more than 1 INPUT stream
57     *           - Not including any OUTPUT streams
58     *           - Including streams with unsupported formats, or an unsupported
59     *             size for that format.
60     *           - Including too many output streams of a certain format.
61     *           - Unsupported rotation configuration
62     *           - Stream sizes/formats don't satisfy the
63     *             StreamConfigurationMode requirements
64     *             for non-NORMAL mode, or the requested operation_mode is not
65     *             supported by the HAL.
66     *           - Unsupported usage flag
67     *         The camera service cannot filter out all possible illegal stream
68     *         configurations, since some devices may support more simultaneous
69     *         streams or larger stream resolutions than the minimum required
70     *         for a given camera device hardware level. The HAL must return an
71     *         ILLEGAL_ARGUMENT for any unsupported stream set, and then be
72     *         ready to accept a future valid stream configuration in a later
73     *         configureStreams call.
74     * @return halConfiguration The stream parameters desired by the HAL for
75     *     each stream, including maximum buffers, the usage flags, and the
76     *     override format.
77     */
78    configureStreams_3_5(@3.5::StreamConfiguration requestedConfiguration)
79            generates (Status status,
80                       @3.4::HalStreamConfiguration halConfiguration);
81
82
83    /**
84     * signalStreamFlush:
85     *
86     * Signaling HAL camera service is about to perform configureStreams_3_5 and
87     * HAL must return all buffers of designated streams. HAL must finish
88     * inflight requests normally and return all buffers that belongs to the
89     * designated streams through processCaptureResult or returnStreamBuffer
90     * API in a timely manner, or camera service will run into a fatal error.
91     *
92     * Note that this call serves as an optional hint and camera service may
93     * skip sending this call if all buffers are already returned.
94     *
95     * @param streamIds The ID of streams camera service need all of its
96     *     buffers returned.
97     *
98     * @param streamConfigCounter Note that due to concurrency nature, it is
99     *     possible the signalStreamFlush call arrives later than the
100     *     corresponding configureStreams_3_5 call, HAL must check
101     *     streamConfigCounter for such race condition. If the counter is less
102     *     than the counter in the last configureStreams_3_5 call HAL last
103     *     received, the call is stale and HAL should just return this call.
104     */
105    oneway signalStreamFlush(
106        vec<int32_t> streamIds,
107        uint32_t streamConfigCounter
108    );
109
110    /**
111     * isReconfigurationRequired:
112     *
113     * Check whether complete stream reconfiguration is required for possible new session
114     * parameter values.
115     *
116     * This method must be called by the camera framework in case the client changes
117     * the value of any advertised session parameters. Depending on the specific values
118     * the HAL can decide whether a complete stream reconfiguration is required. In case
119     * the HAL returns false, the camera framework must skip the internal reconfiguration.
120     * In case Hal returns true, the framework must reconfigure the streams and pass the
121     * new session parameter values accordingly.
122     * This call may be done by the framework some time before the request with new parameters
123     * is submitted to the HAL, and the request may be cancelled before it ever gets submitted.
124     * Therefore, the HAL must not use this query as an indication to change its behavior in any
125     * way.
126     * ------------------------------------------------------------------------
127     *
128     * Preconditions:
129     *
130     * The framework can call this method at any time after active
131     * session configuration. There must be no impact on the performance of
132     * pending camera requests in any way. In particular there must not be
133     * any glitches or delays during normal camera streaming.
134     *
135     * Performance requirements:
136     * HW and SW camera settings must not be changed and there must not be
137     * a user-visible impact on camera performance.
138     *
139     * @param oldSessionParams Before session parameters, usually the current session parameters.
140     * @param newSessionParams The new session parameters which may be set by client.
141     *
142     * @return Status Status code for the operation, one of:
143     *     OK:
144     *          On successful reconfiguration required query.
145     *     METHOD_NOT_SUPPORTED:
146     *          The camera device does not support the reconfiguration query.
147     *     INTERNAL_ERROR:
148     *          The reconfiguration query cannot complete due to internal
149     *          error.
150     * @return true in case the stream reconfiguration is required, false otherwise.
151     */
152    isReconfigurationRequired(CameraMetadata oldSessionParams, CameraMetadata newSessionParams)
153            generates(Status status, bool reconfigurationNeeded);
154};
155