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Apache License
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/* * Copyright (C) 2008 The Android Open Source Project */* ww w. j av a2 s . c om*/ * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.media; import java.io.FileDescriptor; import java.io.FileNotFoundException; import java.io.IOException; import android.content.ContentResolver; import android.content.Context; import android.content.res.AssetFileDescriptor; import android.graphics.Bitmap; import android.net.Uri; /** * MediaMetadataRetriever class provides a unified interface for retrieving * frame and meta data from an input media file. {@hide} */ public class MediaMetadataRetriever { static { System.loadLibrary("media_jni"); native_init(); } // The field below is accessed by native methods @SuppressWarnings("unused") private int mNativeContext; public MediaMetadataRetriever() { native_setup(); } /** * Call this method before setDataSource() so that the mode becomes * effective for subsequent operations. This method can be called only once * at the beginning if the intended mode of operation for a * MediaMetadataRetriever object remains the same for its whole lifetime, * and thus it is unnecessary to call this method each time setDataSource() * is called. If this is not never called (which is allowed), by default the * intended mode of operation is to both capture frame and retrieve meta * data (i.e., MODE_GET_METADATA_ONLY | MODE_CAPTURE_FRAME_ONLY). Often, * this may not be what one wants, since doing this has negative performance * impact on execution time of a call to setDataSource(), since both types * of operations may be time consuming. * * @param mode * The intended mode of operation. Can be any combination of * MODE_GET_METADATA_ONLY and MODE_CAPTURE_FRAME_ONLY: 1. * MODE_GET_METADATA_ONLY & MODE_CAPTURE_FRAME_ONLY: For neither * frame capture nor meta data retrieval 2. * MODE_GET_METADATA_ONLY: For meta data retrieval only 3. * MODE_CAPTURE_FRAME_ONLY: For frame capture only 4. * MODE_GET_METADATA_ONLY | MODE_CAPTURE_FRAME_ONLY: For both * frame capture and meta data retrieval */ public native void setMode(int mode); /** * @return the current mode of operation. A negative return value indicates * some runtime error has occurred. */ public native int getMode(); /** * Sets the data source (file pathname) to use. Call this method before the * rest of the methods in this class. This method may be time-consuming. * * @param path * The path of the input media file. * @throws IllegalArgumentException * If the path is invalid. */ public native void setDataSource(String path) throws IllegalArgumentException; /** * Sets the data source (FileDescriptor) to use. It is the caller's * responsibility to close the file descriptor. It is safe to do so as soon * as this call returns. Call this method before the rest of the methods in * this class. This method may be time-consuming. * * @param fd * the FileDescriptor for the file you want to play * @param offset * the offset into the file where the data to be played starts, * in bytes. It must be non-negative * @param length * the length in bytes of the data to be played. It must be * non-negative. * @throws IllegalArgumentException * if the arguments are invalid */ public native void setDataSource(FileDescriptor fd, long offset, long length) throws IllegalArgumentException; /** * Sets the data source (FileDescriptor) to use. It is the caller's * responsibility to close the file descriptor. It is safe to do so as soon * as this call returns. Call this method before the rest of the methods in * this class. This method may be time-consuming. * * @param fd * the FileDescriptor for the file you want to play * @throws IllegalArgumentException * if the FileDescriptor is invalid */ public void setDataSource(FileDescriptor fd) throws IllegalArgumentException { // intentionally less than LONG_MAX setDataSource(fd, 0, 0x7ffffffffffffffL); } /** * Sets the data source as a content Uri. Call this method before the rest * of the methods in this class. This method may be time-consuming. * * @param context * the Context to use when resolving the Uri * @param uri * the Content URI of the data you want to play * @throws IllegalArgumentException * if the Uri is invalid * @throws SecurityException * if the Uri cannot be used due to lack of permission. */ public void setDataSource(Context context, Uri uri) throws IllegalArgumentException, SecurityException { if (uri == null) { throw new IllegalArgumentException(); } String scheme = uri.getScheme(); if (scheme == null || scheme.equals("file")) { setDataSource(uri.getPath()); return; } AssetFileDescriptor fd = null; try { ContentResolver resolver = context.getContentResolver(); try { fd = resolver.openAssetFileDescriptor(uri, "r"); } catch (FileNotFoundException e) { throw new IllegalArgumentException(); } if (fd == null) { throw new IllegalArgumentException(); } FileDescriptor descriptor = fd.getFileDescriptor(); if (!descriptor.valid()) { throw new IllegalArgumentException(); } // Note: using getDeclaredLength so that our behavior is the same // as previous versions when the content provider is returning // a full file. if (fd.getDeclaredLength() < 0) { setDataSource(descriptor); } else { setDataSource(descriptor, fd.getStartOffset(), fd.getDeclaredLength()); } return; } catch (SecurityException ex) { } finally { try { if (fd != null) { fd.close(); } } catch (IOException ioEx) { } } setDataSource(uri.toString()); } /** * Call this method after setDataSource(). This method retrieves the meta * data value associated with the keyCode. * * The keyCode currently supported is listed below as METADATA_XXX * constants. With any other value, it returns a null pointer. * * @param keyCode * One of the constants listed below at the end of the class. * @return The meta data value associate with the given keyCode on success; * null on failure. */ public native String extractMetadata(int keyCode); /** * Call this method after setDataSource(). This method finds a * representative frame if successful and returns it as a bitmap. This is * useful for generating a thumbnail for an input media source. * * @return A Bitmap containing a representative video frame, which can be * null, if such a frame cannot be retrieved. */ public native Bitmap captureFrame(); /** * Call this method after setDataSource(). This method finds the optional * graphic or album art associated (embedded or external url linked) the * related data source. * * @return null if no such graphic is found. */ public native byte[] extractAlbumArt(); /** * Call it when one is done with the object. This method releases the memory * allocated internally. */ public native void release(); private native void native_setup(); private static native void native_init(); private native final void native_finalize(); @Override protected void finalize() throws Throwable { try { native_finalize(); } finally { super.finalize(); } } public static final int MODE_GET_METADATA_ONLY = 0x01; public static final int MODE_CAPTURE_FRAME_ONLY = 0x02; /* * Do not change these values without updating their counterparts in * include/media/mediametadataretriever.h! */ public static final int METADATA_KEY_CD_TRACK_NUMBER = 0; public static final int METADATA_KEY_ALBUM = 1; public static final int METADATA_KEY_ARTIST = 2; public static final int METADATA_KEY_AUTHOR = 3; public static final int METADATA_KEY_COMPOSER = 4; public static final int METADATA_KEY_DATE = 5; public static final int METADATA_KEY_GENRE = 6; public static final int METADATA_KEY_TITLE = 7; public static final int METADATA_KEY_YEAR = 8; public static final int METADATA_KEY_DURATION = 9; public static final int METADATA_KEY_NUM_TRACKS = 10; public static final int METADATA_KEY_IS_DRM_CRIPPLED = 11; public static final int METADATA_KEY_CODEC = 12; public static final int METADATA_KEY_RATING = 13; public static final int METADATA_KEY_COMMENT = 14; public static final int METADATA_KEY_COPYRIGHT = 15; public static final int METADATA_KEY_BIT_RATE = 16; public static final int METADATA_KEY_FRAME_RATE = 17; public static final int METADATA_KEY_VIDEO_FORMAT = 18; public static final int METADATA_KEY_VIDEO_HEIGHT = 19; public static final int METADATA_KEY_VIDEO_WIDTH = 20; public static final int METADATA_KEY_WRITER = 21; public static final int METADATA_KEY_MIMETYPE = 22; public static final int METADATA_KEY_DISCNUMBER = 23; public static final int METADATA_KEY_ALBUMARTIST = 24; // Add more here... }