services/camera/libcameraservice/device3/Camera3DummyStream.h

/*
 * Copyright (C) 2014 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 ANDROID_SERVERS_CAMERA3_DUMMY_STREAM_H
#define ANDROID_SERVERS_CAMERA3_DUMMY_STREAM_H

#include <utils/RefBase.h>
#include <gui/Surface.h>

#include "Camera3Stream.h"
#include "Camera3IOStreamBase.h"
#include "Camera3OutputStreamInterface.h"

namespace android {
namespace camera3 {

/**
 * A dummy output stream class, to be used as a placeholder when no valid
 * streams are configured by the client.
 * This is necessary because camera HAL v3.2 or older disallow configuring
 * 0 output streams, while the public camera2 API allows for it.
 */
class Camera3DummyStream :
        public Camera3IOStreamBase,
        public Camera3OutputStreamInterface {

  public:
    /**
     * Set up a dummy stream; doesn't actually connect to anything, and uses
     * a default dummy format and size.
     */
    Camera3DummyStream(int id);

    virtual ~Camera3DummyStream();

    /**
     * Camera3Stream interface
     */

    virtual void     dump(int fd, const Vector<String16> &args) const;

    status_t         setTransform(int transform);

  protected:

    /**
     * Note that we release the lock briefly in this function
     */
    virtual status_t returnBufferCheckedLocked(
            const camera3_stream_buffer &buffer,
            nsecs_t timestamp,
            bool output,
            /*out*/
            sp<Fence> *releaseFenceOut);

    virtual status_t disconnectLocked();

  private:

    // Default dummy parameters; 320x240 is a required size for all devices,
    // otherwise act like a SurfaceView would.
    static const int DUMMY_WIDTH = 320;
    static const int DUMMY_HEIGHT = 240;
    static const int DUMMY_FORMAT = HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED;
    static const android_dataspace DUMMY_DATASPACE = HAL_DATASPACE_UNKNOWN;
    static const uint32_t DUMMY_USAGE = GRALLOC_USAGE_HW_COMPOSER;

    /**
     * Internal Camera3Stream interface
     */
    virtual status_t getBufferLocked(camera3_stream_buffer *buffer);
    virtual status_t returnBufferLocked(
            const camera3_stream_buffer &buffer,
            nsecs_t timestamp);

    virtual status_t configureQueueLocked();

    virtual status_t getEndpointUsage(uint32_t *usage);

}; // class Camera3DummyStream

} // namespace camera3

} // namespace android

#endif