media_object.h

Go to the documentation of this file.

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2018, Google Inc.
 *
 * Media Device objects: entities, pads and links.
 */

#pragma once

#include <string>
#include <vector>

#include <linux/media.h>

#include <libcamera/base/class.h>

namespace libcamera {

class MediaDevice;
class MediaEntity;
class MediaPad;

class MediaObject
{
public:
    MediaDevice *device() { return dev_; }
    const MediaDevice *device() const { return dev_; }
    unsigned int id() const { return id_; }

protected:
    friend class MediaDevice;

    MediaObject(MediaDevice *dev, unsigned int id)
        : dev_(dev), id_(id)
    {
    }
    virtual ~MediaObject() = default;

    MediaDevice *dev_;
    unsigned int id_;
};

class MediaLink : public MediaObject
{
public:
    MediaPad *source() const { return source_; }
    MediaPad *sink() const { return sink_; }
    unsigned int flags() const { return flags_; }
    int setEnabled(bool enable);

    std::string toString() const;

private:
    LIBCAMERA_DISABLE_COPY_AND_MOVE(MediaLink)

    friend class MediaDevice;

    MediaLink(const struct media_v2_link *link,
          MediaPad *source, MediaPad *sink);

    MediaPad *source_;
    MediaPad *sink_;
    unsigned int flags_;
};

std::ostream &operator<<(std::ostream &out, const MediaLink &link);

class MediaPad : public MediaObject
{
public:
    unsigned int index() const { return index_; }
    MediaEntity *entity() const { return entity_; }
    unsigned int flags() const { return flags_; }
    const std::vector<MediaLink *> &links() const { return links_; }

    void addLink(MediaLink *link);

    std::string toString() const;

private:
    LIBCAMERA_DISABLE_COPY_AND_MOVE(MediaPad)

    friend class MediaDevice;

    MediaPad(const struct media_v2_pad *pad, MediaEntity *entity);

    unsigned int index_;
    MediaEntity *entity_;
    unsigned int flags_;

    std::vector<MediaLink *> links_;
};

std::ostream &operator<<(std::ostream &out, const MediaPad &pad);

class MediaEntity : public MediaObject
{
public:
    enum class Type {
        Invalid,
        MediaEntity,
        V4L2Subdevice,
        V4L2VideoDevice,
    };

    const std::string &name() const { return name_; }
    unsigned int function() const { return function_; }
    unsigned int flags() const { return flags_; }
    Type type() const { return type_; }
    const std::string &deviceNode() const { return deviceNode_; }
    unsigned int deviceMajor() const { return major_; }
    unsigned int deviceMinor() const { return minor_; }

    const std::vector<MediaPad *> &pads() const { return pads_; }
    const std::vector<MediaEntity *> ancillaryEntities() const { return ancillaryEntities_; }

    const MediaPad *getPadByIndex(unsigned int index) const;
    const MediaPad *getPadById(unsigned int id) const;

    int setDeviceNode(const std::string &deviceNode);

private:
    LIBCAMERA_DISABLE_COPY_AND_MOVE(MediaEntity)

    friend class MediaDevice;

    MediaEntity(MediaDevice *dev, const struct media_v2_entity *entity,
            const struct media_v2_interface *iface);

    void addPad(MediaPad *pad);

    void addAncillaryEntity(MediaEntity *ancillaryEntity);

    std::string name_;
    unsigned int function_;
    unsigned int flags_;
    Type type_;
    std::string deviceNode_;
    unsigned int major_;
    unsigned int minor_;

    std::vector<MediaPad *> pads_;
    std::vector<MediaEntity *> ancillaryEntities_;
};

} /* namespace libcamera */