camera/device/3.5/ICameraDeviceSession.hal

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.hardware.camera.device@3.5;

import android.hardware.camera.common@1.0::Status;
import @3.2::CameraMetadata;
import @3.4::ICameraDeviceSession;
import @3.4::HalStreamConfiguration;

/**
 * Camera device active session interface.
 *
 * Obtained via ICameraDevice::open(), this interface contains the methods to
 * configure and request captures from an active camera device.
 */
interface ICameraDeviceSession extends @3.4::ICameraDeviceSession {

    /**
     * configureStreams_3_5:
     *
     * Identical to @3.4::ICameraDeviceSession.configureStreams, except that:
     *
     * - a streamConfigCounter counter is provided to check for race condition
     *   between configureStreams_3_5 and signalStreamFlush call.
     *
     * @return status Status code for the operation, one of:
     *     OK:
     *         On successful stream configuration.
     *     INTERNAL_ERROR:
     *         If there has been a fatal error and the device is no longer
     *         operational. Only close() can be called successfully by the
     *         framework after this error is returned.
     *     ILLEGAL_ARGUMENT:
     *         If the requested stream configuration is invalid. Some examples
     *         of invalid stream configurations include:
     *           - Including more than 1 INPUT stream
     *           - Not including any OUTPUT streams
     *           - Including streams with unsupported formats, or an unsupported
     *             size for that format.
     *           - Including too many output streams of a certain format.
     *           - Unsupported rotation configuration
     *           - Stream sizes/formats don't satisfy the
     *             StreamConfigurationMode requirements
     *             for non-NORMAL mode, or the requested operation_mode is not
     *             supported by the HAL.
     *           - Unsupported usage flag
     *         The camera service cannot filter out all possible illegal stream
     *         configurations, since some devices may support more simultaneous
     *         streams or larger stream resolutions than the minimum required
     *         for a given camera device hardware level. The HAL must return an
     *         ILLEGAL_ARGUMENT for any unsupported stream set, and then be
     *         ready to accept a future valid stream configuration in a later
     *         configureStreams call.
     * @return halConfiguration The stream parameters desired by the HAL for
     *     each stream, including maximum buffers, the usage flags, and the
     *     override format.
     */
    configureStreams_3_5(@3.5::StreamConfiguration requestedConfiguration)
            generates (Status status,
                       @3.4::HalStreamConfiguration halConfiguration);


    /**
     * signalStreamFlush:
     *
     * Signaling HAL camera service is about to perform configureStreams_3_5 and
     * HAL must return all buffers of designated streams. HAL must finish
     * inflight requests normally and return all buffers that belongs to the
     * designated streams through processCaptureResult or returnStreamBuffer
     * API in a timely manner, or camera service will run into a fatal error.
     *
     * Note that this call serves as an optional hint and camera service may
     * skip sending this call if all buffers are already returned.
     *
     * @param streamIds The ID of streams camera service need all of its
     *     buffers returned.
     *
     * @param streamConfigCounter Note that due to concurrency nature, it is
     *     possible the signalStreamFlush call arrives later than the
     *     corresponding configureStreams_3_5 call, HAL must check
     *     streamConfigCounter for such race condition. If the counter is less
     *     than the counter in the last configureStreams_3_5 call HAL last
     *     received, the call is stale and HAL should just return this call.
     */
    oneway signalStreamFlush(
        vec<int32_t> streamIds,
        uint32_t streamConfigCounter
    );

    /**
     * isReconfigurationRequired:
     *
     * Check whether complete stream reconfiguration is required for possible new session
     * parameter values.
     *
     * This method must be called by the camera framework in case the client changes
     * the value of any advertised session parameters. Depending on the specific values
     * the HAL can decide whether a complete stream reconfiguration is required. In case
     * the HAL returns false, the camera framework must skip the internal reconfiguration.
     * In case Hal returns true, the framework must reconfigure the streams and pass the
     * new session parameter values accordingly.
     * This call may be done by the framework some time before the request with new parameters
     * is submitted to the HAL, and the request may be cancelled before it ever gets submitted.
     * Therefore, the HAL must not use this query as an indication to change its behavior in any
     * way.
     * ------------------------------------------------------------------------
     *
     * Preconditions:
     *
     * The framework can call this method at any time after active
     * session configuration. There must be no impact on the performance of
     * pending camera requests in any way. In particular there must not be
     * any glitches or delays during normal camera streaming.
     *
     * Performance requirements:
     * HW and SW camera settings must not be changed and there must not be
     * a user-visible impact on camera performance.
     *
     * @param oldSessionParams Before session parameters, usually the current session parameters.
     * @param newSessionParams The new session parameters which may be set by client.
     *
     * @return Status Status code for the operation, one of:
     *     OK:
     *          On successful reconfiguration required query.
     *     METHOD_NOT_SUPPORTED:
     *          The camera device does not support the reconfiguration query.
     *     INTERNAL_ERROR:
     *          The reconfiguration query cannot complete due to internal
     *          error.
     * @return true in case the stream reconfiguration is required, false otherwise.
     */
    isReconfigurationRequired(CameraMetadata oldSessionParams, CameraMetadata newSessionParams)
            generates(Status status, bool reconfigurationNeeded);
};