android 图片、音频、视频获取以及多媒体数据库学习

android 多媒体数据库，存储于/data/data/com.android.providers.media/databases目录下，有两个db，一个是内部存储数据，一个手机存储卡数据。

 

一）基本表

图片存储有两张表：

1）Images ：字段可以看出主要存储图片信息

2）Thumbnails： 和Images表对应，存储图片缩略图信息。

视频两张表，同图片类似

1）Video表，存储视频基本信息

2）Thumbnails：存储音频的缩略图等信息。

音频存储表：

1）Audio表，音频基本信息

2）另外有专辑，歌手信息的表格

 

二）系统提供的接口

可以读下package android.provider.MediaStore类，class Images、class Audio以及class Video

MediaStore.Audio.AlbumColumnsColumns representing an album  MediaStore.Audio.ArtistColumnsColumns representing an artist  MediaStore.Audio.AudioColumnsColumns for audio file that show up in multiple tables. MediaStore.Audio.GenresColumnsColumns representing an audio genre  MediaStore.Audio.PlaylistsColumnsColumns representing a playlist  MediaStore.Files.FileColumnsFields for master table for all media files. MediaStore.Images.ImageColumns MediaStore.MediaColumnsCommon fields for most MediaProvider tables  MediaStore.Video.VideoColumns 

 

class:

MediaStoreThe Media provider contains meta data for all available media on both internal and external storage devices. MediaStore.AudioContainer for all audio content. MediaStore.Audio.AlbumsContains artists for audio files  MediaStore.Audio.ArtistsContains artists for audio files  MediaStore.Audio.Artists.AlbumsSub-directory of each artist containing all albums on which a song by the artist appears. MediaStore.Audio.GenresContains all genres for audio files  MediaStore.Audio.Genres.MembersSub-directory of each genre containing all members. MediaStore.Audio.Media MediaStore.Audio.PlaylistsContains playlists for audio files  MediaStore.Audio.Playlists.MembersSub-directory of each playlist containing all members. MediaStore.FilesMedia provider table containing an index of all files in the media storage, including non-media files. MediaStore.ImagesContains meta data for all available images. MediaStore.Images.Media MediaStore.Images.ThumbnailsThis class allows developers to query and get two kinds of thumbnails: MINI_KIND: 512 x 384 thumbnail MICRO_KIND: 96 x 96 thumbnail  MediaStore.Video MediaStore.Video.Media MediaStore.Video.ThumbnailsThis class allows developers to query and get two kinds of thumbnails: MINI_KIND: 512 x 384 thumbnail MICRO_KIND: 96 x 96 thumbnail  

 

图片的uri为：

MediaStore.Images.Media

public static final UriEXTERNAL_CONTENT_URIThe content:// style URI for the "primary" external storage volume.public static final UriINTERNAL_CONTENT_URIThe content:// style URI for the internal storage.

分别为内部存储和存储卡存储的图片信息。

音频，视频类似。

 

暂时了解这么多……