camera/ndk/impl/ACameraMetadata.h

/*
 * Copyright (C) 2015 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.
 */
#ifndef _ACAMERA_METADATA_H
#define _ACAMERA_METADATA_H

#include <sys/types.h>
#include <camera/CameraMetadata.h>

#include "NdkCameraMetadata.h"

using namespace android;

/**
 * ACameraMetadata opaque struct definition
 * Leave outside of android namespace because it's NDK struct
 */
struct ACameraMetadata {
  public:
    typedef enum {
        ACM_CHARACTERISTICS, // Read only
        ACM_REQUEST,         // Read/Write
        ACM_RESULT,          // Read only
    } ACAMERA_METADATA_TYPE;

    // Takes ownership of pass-in buffer
    ACameraMetadata(camera_metadata_t *buffer, ACAMERA_METADATA_TYPE type);
    // Clone
    ACameraMetadata(const ACameraMetadata& other) :
            mData(other.mData), mType(other.mType) {};

    camera_status_t getConstEntry(uint32_t tag, ACameraMetadata_const_entry* entry) const;

    camera_status_t update(uint32_t tag, uint32_t count, const uint8_t* data);
    camera_status_t update(uint32_t tag, uint32_t count, const int32_t* data);
    camera_status_t update(uint32_t tag, uint32_t count, const float* data);
    camera_status_t update(uint32_t tag, uint32_t count, const double* data);
    camera_status_t update(uint32_t tag, uint32_t count, const int64_t* data);
    camera_status_t update(uint32_t tag, uint32_t count, const ACameraMetadata_rational* data);

  private:
    bool isNdkSupportedCapability(const int32_t capability);
    inline bool isVendorTag(const uint32_t tag);
    bool isCaptureRequestTag(const uint32_t tag);
    void filterUnsupportedFeatures(); // Hide features not yet supported by NDK

    template<typename INTERNAL_T, typename NDK_T>
    camera_status_t updateImpl(uint32_t tag, uint32_t count, const NDK_T* data) {
        if (mType != ACM_REQUEST) {
            ALOGE("Error: Write to metadata is only allowed for capture request!");
            return ACAMERA_ERROR_INVALID_PARAMETER;
        }
        if (!isCaptureRequestTag(tag)) {
            ALOGE("Error: tag %d is not writable!", tag);
            return ACAMERA_ERROR_INVALID_PARAMETER;
        }

        // Here we have to use reinterpret_cast because the NDK data type is
        // exact copy of internal data type but they do not inherit from each other
        status_t ret = mData.update(tag, reinterpret_cast<const INTERNAL_T*>(data), count);
        if (ret == OK) {
            return ACAMERA_OK;
        } else {
            return ACAMERA_ERROR_INVALID_PARAMETER;
        }
    }

    CameraMetadata mData;
    const ACAMERA_METADATA_TYPE mType;
};

#endif // _ACAMERA_METADATA_H