linux视频之media媒体框架

Posted 2020-10-10 小谢的编程成长记

　　linux视频媒体(kernel层分析)主要包括三个文件：

　　(/drivers/media/media-device.c ,  /drivers/media/media-devnode.c , /drivers/media/media-entity.c)

一.主要分析/drivers/media/media-device.c文件,此文件中主要的结构是：

　　

struct media_device {
    struct device *dev; //dev->driver_data points to this struct
    struct media_devnode devnode;
    char model[32];
    char driver_name[32];
    char serial[40];
    char bus_info[32];
    u32 hw_revision;
    u32 driver_version;
    u32 topology_version;
    u32 id;
    struct ida entity_internal_idx;
    int entity_internal_idx_max;
    struct list_head entities;
    struct list_head interfaces;
    struct list_head pads;
    struct list_head links;
    struct list_head entity_notify; //notify callback list invoked when a new entity is registered
    spinlock_t lock; //Protects the graph objects creation/removal 
    struct mutex graph_mutex; //Serializes graph operations.
    struct media_entity_graph pm_count_walk;
    void *source_priv;
    int (*enable_source)(struct media_entity *entity, struct media_pipeline *pipe);
    void (*disable_source)(struct media_entity *entity);
    int (*link_notify)(struct media_link *link, u32 flags,
               unsigned int notification);
};