1. 程式人生 > >[android] 如何獲取media檔案的meta data資訊

[android] 如何獲取media檔案的meta data資訊

在app開發過程中,經常需要顯示media檔案的meta data資訊,我們如何獲取這些資訊呢?

MediaStore

首先想到的就是MediaStore類了,它為我們提供的豐富的屬性,我們只要通過sqlite操作,就能獲取這些屬性提供的值啦。

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
	};

不知道如何查詢系統資料庫資料?查查ContentResolver怎麼使用吧微笑
不過有時候,這些屬性還不能滿足我們的需求,這時候就需要一些其他類來幫助了。那麼,來看看其他類吧

MediaMetadataRetriever 類

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

簡單來說,我們可以重MediaMetadataRetriever類中獲取meta data資訊,關鍵是這些meta data資訊是MediaStore類提供不了的,看看這個類能為我們提供哪些屬性,寫一個小demon測試下

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); // 從api level 14才有,即從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();  
        }  
	}

然後,分別拿一個video和audio檔案測試一下,結果如下:

video:找了一個mp4檔案

04-16 11:00:04.997: D/MediaMetadataRetreiverDemon(15813): str:/storage/emulated/0/DCIM/100MEDIA/VIDEO0001.mp4
04-16 11:00:05.027: D/MediaMetadataRetreiverDemon(15813): album:null
04-16 11:00:05.027: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_ALBUMARTIST:null
04-16 11:00:05.027: D/MediaMetadataRetreiverDemon(15813): artist:null
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_AUTHOR:null
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): bitrate:21230041
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_CD_TRACK_NUMBER:null
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_COMPILATION:null
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_COMPOSER:null
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_DATE:20150416T021157.000Z
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_DISC_NUMBER:null
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_DURATION:11869
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_GENRE:null
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_HAS_AUDIO:yes
04-16 11:00:05.037: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_HAS_VIDEO:yes
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_LOCATION:null
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_MIMETYPE:video/mp4
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_NUM_TRACKS:2
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_TITLE:null
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_VIDEO_HEIGHT:1080
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_VIDEO_ROTATION:270
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_VIDEO_WIDTH:1920
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_WRITER:null
04-16 11:00:05.047: D/MediaMetadataRetreiverDemon(15813): METADATA_KEY_YEAR:null

audio:找了一個mp3檔案

04-16 11:09:10.119: D/MediaMetadataRetreiverDemon(17550): str:/storage/emulated/0/Music/Nero MediaHome/Maid with the Flaxen Hair.mp3
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): album:Fine Music, Vol. 1
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_ALBUMARTIST:Richard Stoltzman
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): artist:Richard Stoltzman/Slovak Radio Symphony Orchestra
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_AUTHOR:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): bitrate:192000
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_CD_TRACK_NUMBER:2
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_COMPILATION:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_COMPOSER:Claude Debussy
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_DATE:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_DISC_NUMBER:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_DURATION:169697
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_GENRE:(32)
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_HAS_AUDIO:yes
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_HAS_VIDEO:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_LOCATION:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_MIMETYPE:audio/mpeg
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_NUM_TRACKS:1
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_TITLE:Maid with the Flaxen Hair
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_VIDEO_HEIGHT:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_VIDEO_ROTATION:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_VIDEO_WIDTH:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_WRITER:null
04-16 11:09:10.139: D/MediaMetadataRetreiverDemon(17550): METADATA_KEY_YEAR:2008

有這麼多屬性可以查到,應該夠我們用了吧大笑

知道了video和audio,還有image型別的檔案呢,看看這個類ExifInterface

ExifInterface

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

如何使用這個類,很簡單:

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

然後再來看看exifInterface為我們提供了哪些屬性查詢吧

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

包括camera、gps資訊,以及其他一些專業資料

通過這些工具,我們就基本能解決獲取meta data資訊的問題啦~