/*
* Copyright (C) 2016 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@3.2;
import android.hardware.camera.common@1.0::types;
/**
*
* Callback methods for the HAL to call into the framework.
*
* These methods are used to return metadata and image buffers for a completed
* or failed captures, and to notify the framework of asynchronous events such
* as errors.
*
* The framework must not call back into the HAL from within these callbacks,
* and these calls must not block for extended periods.
*
*/
interface ICameraDeviceCallback {
/**
* processCaptureResult:
*
* Send results from one or more completed or partially completed captures
* to the framework.
* processCaptureResult() may be invoked multiple times by the HAL in
* response to a single capture request. This allows, for example, the
* metadata and low-resolution buffers to be returned in one call, and
* post-processed JPEG buffers in a later call, once it is available. Each
* call must include the frame number of the request it is returning
* metadata or buffers for. Only one call to processCaptureResult
* may be made at a time by the HAL although the calls may come from
* different threads in the HAL.
*
* A component (buffer or metadata) of the complete result may only be
* included in one process_capture_result call. A buffer for each stream,
* and the result metadata, must be returned by the HAL for each request in
* one of the processCaptureResult calls, even in case of errors producing
* some of the output. A call to processCaptureResult() with neither
* output buffers or result metadata is not allowed.
*
* The order of returning metadata and buffers for a single result does not
* matter, but buffers for a given stream must be returned in FIFO order. So
* the buffer for request 5 for stream A must always be returned before the
* buffer for request 6 for stream A. This also applies to the result
* metadata; the metadata for request 5 must be returned before the metadata
* for request 6.
*
* However, different streams are independent of each other, so it is
* acceptable and expected that the buffer for request 5 for stream A may be
* returned after the buffer for request 6 for stream B is. And it is
* acceptable that the result metadata for request 6 for stream B is
* returned before the buffer for request 5 for stream A is. If multiple
* capture results are included in a single call, camera framework must
* process results sequentially from lower index to higher index, as if
* these results were sent to camera framework one by one, from lower index
* to higher index.
*
* The HAL retains ownership of result structure, which only needs to be
* valid to access during this call.
*
* The output buffers do not need to be filled yet; the framework must wait
* on the stream buffer release sync fence before reading the buffer
* data. Therefore, this method should be called by the HAL as soon as
* possible, even if some or all of the output buffers are still in
* being filled. The HAL must include valid release sync fences into each
* output_buffers stream buffer entry, or -1 if that stream buffer is
* already filled.
*
* If the result buffer cannot be constructed for a request, the HAL must
* return an empty metadata buffer, but still provide the output buffers and
* their sync fences. In addition, notify() must be called with an
* ERROR_RESULT message.
*
* If an output buffer cannot be filled, its status field must be set to
* STATUS_ERROR. In addition, notify() must be called with a ERROR_BUFFER
* message.
*
* If the entire capture has failed, then this method still needs to be
* called to return the output buffers to the framework. All the buffer
* statuses must be STATUS_ERROR, and the result metadata must be an
* empty buffer. In addition, notify() must be called with a ERROR_REQUEST
* message. In this case, individual ERROR_RESULT/ERROR_BUFFER messages
* must not be sent.
*
* Performance requirements:
*
* This is a non-blocking call. The framework must handle each CaptureResult
* within 5ms.
*
* The pipeline latency (see S7 for definition) should be less than or equal to
* 4 frame intervals, and must be less than or equal to 8 frame intervals.
*
*/
processCaptureResult(vec<CaptureResult> results);
/**
* notify:
*
* Asynchronous notification callback from the HAL, fired for various
* reasons. Only for information independent of frame capture, or that
* require specific timing. Multiple messages may be sent in one call; a
* message with a higher index must be considered to have occurred after a
* message with a lower index.
*
* Multiple threads may call notify() simultaneously.
*
* Buffers delivered to the framework must not be dispatched to the
* application layer until a start of exposure timestamp (or input image's
* start of exposure timestamp for a reprocess request) has been received
* via a SHUTTER notify() call. It is highly recommended to dispatch this
* call as early as possible.
*
* ------------------------------------------------------------------------
* Performance requirements:
*
* This is a non-blocking call. The framework must handle each message in 5ms.
*/
notify(vec<NotifyMsg> msgs);
};