[android] 怎么获取media文件的meta data信息_Android

[android] 如何获取media文件的meta data信息

在app开发过程中，经常需要显示media文件的meta data信息，我们如何获取这些信息呢？

MediaStore

首先想到的就是MediaStore类了，它为我们提供的丰富的属性，我们只要通过sqlite操作，就能获取这些属性提供的值啦。

public static final String[] ItemImageProjection = new String[] {		MediaStore.Images.ImageColumns.DISPLAY_NAME,		MediaStore.Images.ImageColumns.DATA,		MediaStore.Images.ImageColumns.SIZE,		MediaStore.Images.ImageColumns._ID,		MediaStore.Images.ImageColumns.MIME_TYPE	};		public static final String[] ItemVideoProjection = new String[] {		MediaStore.Video.VideoColumns.DISPLAY_NAME,		MediaStore.Video.VideoColumns.DATA,		MediaStore.Video.VideoColumns.SIZE,		MediaStore.Video.VideoColumns._ID,		MediaStore.Video.VideoColumns.MIME_TYPE	};		public static final String[] ItemAudioProjection = new String[] {		MediaStore.Audio.AudioColumns.DISPLAY_NAME,		MediaStore.Audio.AudioColumns.DATA,		MediaStore.Audio.AudioColumns.SIZE,		MediaStore.Audio.AudioColumns._ID,		MediaStore.Audio.AudioColumns.MIME_TYPE	};

不知道如何查询系统数据库数据？查查ContentResolver怎么使用吧
不过有时候，这些属性还不能满足我们的需求，这时候就需要一些其他类来帮助了。那么，来看看其他类吧

MediaMetadataRetriever 类

SDK官方说明：MediaMetadataRetriever class provides a unified interface for retrieving frame and meta data from an input media file.

简单来说，我们可以重MediaMetadataRetriever类中获取meta data信息，关键是这些meta data信息是MediaStore类提供不了的，看看这个类能为我们提供哪些属性，写一个小demon测试下

public void getMetadata(String path){		MediaMetadataRetriever mmr = new MediaMetadataRetriever();  		        Log.d(TAG, "str:" + path);          try {              mmr.setDataSource(path);                     String album = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_ALBUM);              Log.d(TAG, "album:" + album);              Log.d(TAG, "METADATA_KEY_ALBUMARTIST:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_ALBUMARTIST));            String artist = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_ARTIST);              Log.d(TAG, "artist:" + artist);             Log.d(TAG, "METADATA_KEY_AUTHOR:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_AUTHOR));            String bitrate = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_BITRATE); // 从api level 14才有，即从ICS4.0才有此功能              Log.d(TAG, "bitrate:" +bitrate);              Log.d(TAG, "METADATA_KEY_CD_TRACK_NUMBER:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_CD_TRACK_NUMBER));            Log.d(TAG, "METADATA_KEY_COMPILATION:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_COMPILATION));            Log.d(TAG, "METADATA_KEY_COMPOSER:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_COMPOSER));            Log.d(TAG, "METADATA_KEY_DATE:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DATE));            Log.d(TAG, "METADATA_KEY_DISC_NUMBER:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DISC_NUMBER));            Log.d(TAG, "METADATA_KEY_DURATION:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION));            Log.d(TAG, "METADATA_KEY_GENRE:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_GENRE));            Log.d(TAG, "METADATA_KEY_HAS_AUDIO:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_HAS_AUDIO));            Log.d(TAG, "METADATA_KEY_HAS_VIDEO:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_HAS_VIDEO));            Log.d(TAG, "METADATA_KEY_LOCATION:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_LOCATION));            Log.d(TAG, "METADATA_KEY_MIMETYPE:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_MIMETYPE));                    Log.d(TAG, "METADATA_KEY_NUM_TRACKS:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_NUM_TRACKS));            Log.d(TAG, "METADATA_KEY_TITLE:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_TITLE));            Log.d(TAG, "METADATA_KEY_VIDEO_HEIGHT:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT));            Log.d(TAG, "METADATA_KEY_VIDEO_ROTATION:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_ROTATION));            Log.d(TAG, "METADATA_KEY_VIDEO_WIDTH:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH));            Log.d(TAG, "METADATA_KEY_WRITER:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_WRITER));            Log.d(TAG, "METADATA_KEY_YEAR:" + mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_YEAR));        } catch (IllegalArgumentException e) {              // TODO Auto-generated catch block              e.printStackTrace();          } catch (IllegalStateException e) {              // TODO Auto-generated catch block              e.printStackTrace();          }  	}

然后，分别拿一个video和audio文件测试一下，结果如下：

video：找了一个mp4文件

04-16 11:00:04.997: D/MediaMetadataRetreiverDemon(15813): str:/storage/emulated/0/DCIM/100MEDIA/VIDEO0001.mp404-16 11:00:05.027: D/MediaMetadataRetreiverDemon(15813): album:null04-16 11:00:05.027: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_ALBUMARTIST:null04-16 11:00:05.027: D/MediaMetadataRetreiverDemon(15813): artist:null04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_AUTHOR:null04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): bitrate:2123004104-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_CD_TRACK_NUMBER:null04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_COMPILATION:null04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_COMPOSER:null04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_DATE:20150416T021157.000Z04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_DISC_NUMBER:null04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_DURATION:1186904-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_GENRE:null04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_HAS_AUDIO:yes04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_HAS_VIDEO:yes04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_LOCATION:null04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_MIMETYPE:video/mp404-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_NUM_TRACKS:204-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_TITLE:null04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_VIDEO_HEIGHT:108004-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_VIDEO_ROTATION:27004-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_VIDEO_WIDTH:192004-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_WRITER:null04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_YEAR:null

audio：找了一个mp3文件

04-16 11:09:10.119: D/MediaMetadataRetreiverDemon(17550): str:/storage/emulated/0/Music/Nero MediaHome/Maid with the Flaxen Hair.mp304-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): album:Fine Music, Vol. 104-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_ALBUMARTIST:Richard Stoltzman04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): artist:Richard Stoltzman/Slovak Radio Symphony Orchestra04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_AUTHOR:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): bitrate:19200004-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_CD_TRACK_NUMBER:204-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_COMPILATION:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_COMPOSER:Claude Debussy04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_DATE:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_DISC_NUMBER:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_DURATION:16969704-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_GENRE:(32)04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_HAS_AUDIO:yes04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_HAS_VIDEO:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_LOCATION:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_MIMETYPE:audio/mpeg04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_NUM_TRACKS:104-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_TITLE:Maid with the Flaxen Hair04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_VIDEO_HEIGHT:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_VIDEO_ROTATION:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_VIDEO_WIDTH:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_WRITER:null04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_YEAR:2008

有这么多属性可以查到，应该够我们用了吧

知道了video和audio，还有image类型的文件呢，看看这个类ExifInterface

ExifInterface

sdk官方解释：This is a class for reading and writing Exif tags in a JPEG file.

如何使用这个类，很简单：

ExifInterface exifInterface;		try {			exifInterface = new ExifInterface(path);		} catch (IOException e) {			return;		}		exifInterface.getAttribute(ExifInterface.TAG_MODEL);

然后再来看看exifInterface为我们提供了哪些属性查询吧

http://developer.android.com/reference/android/media/ExifInterface.html

包括camera、gps信息，以及其他一些专业数据

通过这些工具，我们就基本能解决获取meta data信息的问题啦~